Pistons for NA

[twilightprotege]

hey guys

for those of you that have noticed at the bottom of my signature "Operation 175whp NA has begun...Stay tuned", this may give you a few insights

anyway, appart from the j-spec 10.4:1 and mazdaspeed 10.7:1 pistons, are they any other readily available high compression (above 10:1) pistons available?

if not, where's the cheapest to get them? the best i have found for the 10.7's is http://www.ecommerceorders.com/MazdaParts/ - $134.95 (i certainly hope that's for 4 of them), but if not corksport has 4 10.4:1 pistons for $185

or can maybe one of the AV's do better???

[akhilleus]

mitch @ protege5online might be able to help. He can get stuff through mazdamotorsports... and it will be cheaper than corksport. There are pistons in existence that are higher than 10.7 .. I believe that tripoint used pistons with 11.1 static comp. ratio. However i dont know if they are for sale. Also i dont think i need to mention this but i am assuming u will have a standalone of some kind.

[twilightprotege]

yeah i did think of mitch, but his website doesnt have any information and i couldnt be bothered emailing at the moment.

i'm not planning a standalone at this stage, but the australian ecu can support piggy back's (i'm going to get a unichip piggy back). that'll help timing and fuel maps etc.

i didnt want to go too high with the comp ratio, hell i dont even know what will be a safe level. any ideas?

[akhilleus]

i think 10.7 tuned will be very effective :D

[twilightprotege]

yeah the $134.95 from mazdaparts for the 10.7's sounds pretty good to me :D

then add coating on to them and thinner head gasket and arp head studs....strong engine :D

[twilightprotege]

oh and probably close to 11:1 comp ratio

[akhilleus]

U will definately be good. I got the exhaust cam from perf. Will send it to crower soon. Next is header. I dont think i will do HC pistons though... too expensive plus i would need an ems. I have some cam questions too though i will pm u.

[twilightprotege]

does anyone know what a safe level for a compression ratio will be NA?

[Mr. Win]

i talked to perf and he told me for n/a11:1. What type of ecu work should i do im going to have them machined in two weeks. He said thier goign to come out with custom ground cams soon so i sold my jspec and im waiting for these.

[Mr. Win]

Are you looking to go Naturally aspirated or Forced induction?
If you are planning on staying NA then 11- 11.5 :1 would be optimal for good power on pump gas. We fabricate NA pistons thru JE
If I can help in any way let me know.
Regards Nick

also savin up to buy a port and polished intake mani and throttle body.

[CitizenPro]

I may be interested in the high comp pistons SenorCorwin. Im not familiar with what works good for our car. 11:1 pistons seems kinda high, but i guess for us N/A peeps it will work.....let me know.

Thanx, Charles

[twilightprotege]

that's good to know nick says it can handle 11:1, so at the moment it looks like i'll be going for the 10.7:1 + coating + thin as possible head gasket. that'll give it around 11:1 compression ratio i'm sure.

senor you'll definately need some sort of aftermarket ecu to get best power. i'm quite lucky that the aussie ecu can support piggy backs. i'm getting a unichip (supports fuel and ignition tuning). also a p&p intake mani will help a lot with power!

[Mr. Win]

yea i know but what to go with for the ecu for us in the USA.

you'll need like 93 octane,can you get that in tehas?

[hi-perf]

yes 93 octane is available in texas

[twilightprotege]

i wonder how the australian fuel compairs to yours. we have 98ron octane, but i've heard the ron here stands for something different to yours ???

[hi-perf]

yeah i remember reading about that.

god i hate freakin america and their standards. now we have to have two sets of tools, SAE (fractions) and metric tools...

hp/tq and that other unit they use...

its just the american way...but the SAE tools really piss me off

[twilightprotege]

well you yankies always have to be different ;) LOL

[akhilleus]

apparently RON is poorer quality gas than US gas. Also you will need an ems that can control timing well. Even the mp3 with advanced timing doesnt run the 10.7HC pistons well. They work but little in gains... ask mp3moose. anyhting more than 9.7:1 is worthless without an ems... and the only one i know of that would work really well would be perfs. creation which i ecstatically recommmend... trust me.

[twilightprotege]

^ i'm so lucky piggy backs that control fuel and timing work with my ecu :D

[Mr. Win]

rub it in our faces you know what you could do is send out ecu from wrecked sport20s and rewire them from riht handdrive you could bank! haha

[hi-perf]

would you have to go forged rods when you bump up compression that high?

[twilightprotege]

senor - tee hee :D

fy the unichip has 17 RPM sites between 500 RPM and 8000 RPM and 12 load sites between zero throttle position and wide-open throttle position. This equates to 204 possible adjustments for fuel and a further 204 adjustments for ignition timing.

hi-perf - it shouldnt no.

[akhilleus]

maybe ... but if u want to run that high comp. u need a serious ecu upgrade. tripoint ran 11.1:1 static and they used motec. So u would need to use something like what perfworks is making. To truly take advantage of those kind of upgrades u need comprehensive management. otherwise even minimal tuning with other ecus wont yeild much. With the mpi tuner u cant even control fuel w/o extra injectors. And timing isnt as precise. u need something that is totally OBDII compatible. at least in the US.

[hi-perf]

with n20 i guess thats a given :D

[twilightprotege]

oh forgot to add - you dont want a 2nd hand aus-spec ecu....they are like $1000aud (rip off)...and i have looked around for ones to buy and sell to you guys and that's what they are all asking :(

[akhilleus]

Twilight, I can say that perfworks ecu easily surpasses the unichip in variability and adjustment... i mean it would blow the unichip away. I have seen it.

[twilightprotege]

it definately will yep (knew about what nick was doing before he made it public)...but for $350aud + tuning for the unichip...i'm happy with that

[Mr. Win]

^^^ excatly its all bout cost where as perfworks will be ooh 3gs i duno i stopped reading the thread go to long with the same questions.

[twilightprotege]

quick question (never actually looked into this), but are piston rings re-useable?

[mp3moose]

They should be as long as you don't have too many miles on them. I reused mine as I couldn't find any new ones in stock at the time of install. BTW, I had about 11K miles on my car when I did the swap.
moose

[twilightprotege]

new mazda ones arent cheap. i was quoted almost twice the price of the pistons (reason for my question). i have 55000k's on my engine (almost 35000miles), so i'll try to reuse them, but i wont be touching the pistons for a bit anyway.

[mp3moose]

That should be fine, just make sure there is no obvious damage on them when you do pull them out.
moose

[SpicyMchaggis]

my advice, get a ton of power out of the n/a..then tell me how you did it, and a price..and i will copy you..haha..

[twilightprotege]

hahahaha....good plan spicy.

but at the moment it's looking like a 210-220hp engine at the crank for what i have planned

[hi-perf]

with what mods?

[mp3moose]

More importantly what engine management?

[SpicyMchaggis]

MORE importantly, help me stuff a KL-ZE in my 3rd gen.

[mp3moose]

Thats a tall order sir. I almost pulled mine out of my mx6 but after some measurements and research that became next to impossible.

[SpicyMchaggis]

its not impossible..just needs custom made mounts and cut wheel wells.

[mp3moose]

Its impossible for my wallet.

[twilightprotege]

let's just say the biggest change to come (which will shock a few people) is a re-working of my custom cams

engine management - unichip (aussies get the obdi ecu like the j-spec)

[mp3moose]

Sweet! but damn you for getting OBD I =)

[perfworks]

Yup 11:1 is max on pump gas (93 octane US) The Aussie standard is about as good as Cali gas. But as long as you will control peak timing lead you will be ok. Depending on the type of EMS used and any further induction mods you should be ok with a 20% decrease in timing lead across the board to start. I mentioned to you Andy that if you plan on staying with the stock rods then YOU NEED TWO THINGS: A very very good timing tune & a rev limit of 6000 rpm.

[SpicyMchaggis]

6000!! So no vtec?!

[perfworks]

6000!! So no vtec?!The protege stock FS 9 head falls of at 5000 RPM. Depending on any further mods you wont make any more power that is worth the tensile destruction to the rods. The stock rods can handle torque but excess rpms will kill the rod bolts and piston wrist pin bore.

[twilightprotege]

nick in what way to mean the head falls off at 5k? not forgetting i've had my head ported

also, you say a lower rev limit, i assume you mean with 11:1 comp? what if i stay with my 9.7?

[hi-perf]

does the rpm thing apply to the fp-de also?

[perfworks]

nick in what way to mean the head falls off at 5k? not forgetting i've had my head ported

also, you say a lower rev limit, i assume you mean with 11:1 comp? what if i stay with my 9.7?Peak velocity passed the valve seems to occur right after 5000 rpm STOCK. Peak VE seems to also take place around 5000 rpm STOCK. The porting will have little to do with what the RODS can handle. The stock Rods' tensile strength is not up to par for revs above 6000 rpm for prolonged periods of time associated with NA vehicles. You will also need a more radical cam profile than stock for the port work you have done to maintain and/or increase velocity thru the runners. We are waiting for confirmation on the stock valve train tolerances to come back so that we may maket our race/street cams. That may help your situation a bit. BUT unless you upgrade the rods the power you MAY make above the rev limit posed, will not be worth the expense of a blown motor.

[perfworks]

does the rpm thing apply to the fp-de also? I would need to see specs for the bore and stroke on the stock engine along with flow numbers for the head and some dyno sheets to give you an answer.

[hi-perf]

fpde

stroke 85mm

bore 83mm (going to be 85 or 86 after a while)

it uses the same head as the fs motor, so id say that the flow numbers would be the same.

the fp-de also utilizes beefier rods.

[Boston5761]

whats the best piston set-up for the p5, compression ration, was the highest you can go on stock motor, what has to be done when adding pistons, im assuming rods,fuel upgrade,what else, i dont want to spend a ton just want a higher compression motor that is strong and reliable

[Boston5761]

i called corksport an talked to them about the j-spec 10:4 2.0l pistons, they said no modifications or adjustments would be needed, will i see any gains from these, and should i get new rings?

[AZDriftR]

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[melicha8]

i dont want to spend a ton just want a higher compression motor that is strong and reliable

you don't want to spend a ton? well then why did you even post. High comp. pistons don't do diddily shit unless you have the mods to make it work. It sounds cliche because it is, but this is not going to happen unless you do spend a ton

[mp3moose]

i called corksport an talked to them about the j-spec 10:4 2.0l pistons, they said no modifications or adjustments would be needed, will i see any gains from these, and should i get new rings?

nope, rings yes, if your car has any miles on it at all.

[mp3moose]

high compression = not for noobs.

[twilightprotege]

gains from the 10.4:1 pistons - very very little...until you get custom cams and an ecu

[Boston5761]

high compression = not for noobs.

if these give no gains then why do you have the 10.7's, im guessing the mazdaspeed ones, just asking

[mp3moose]

^ I was first to have them. No one knew for sure. I've never been on a dyno, but I felt nothing.

[Gen1GT]

Theoretically and increase in compression from 9:1 to 10.5:1 should give you a 4% gain in horsepower and torque. Most of the time this will be instant and immediate once you put the pistons in. The engine isn't bringing in any more air, or asking anything differently of the fuel system, it's just compressing the same amount of air into a smaller space. The problem with installing them on a North American FS-DE is the OBDII computer, and poor fuel. You'll definitely need 93 or 94 octane, and even still the computer could be pulling timing if it's sensing knock. But 10.5:1 IS NOT crazy compression. If someone DOESN'T see gains from raising compression, something is seriously wrong.

[Installshield 2]

With raising compression, you do change the timing needs though...which is why if you can't control the spark, you will not see much of anything in terms of gains...and once the compression is raised significantly...you will just start to create problems altogether...

OBD-I cars usually had very little trouble when a person would mess with the timing...they didn't care...our ECU will throw a fit...and it will not do it on its own, depending on load and other parameters...it is sometimes beneficial to slightly increase timing when compression is increased (not by much, and only at certain rpm points)...that on its own will give excellent gains, but hopefully you can already tell that our ECU will have nothing to do with that...

[Maz2001MP]

wouldn't lighter internals be better for revs compared to forged ? that's what i figured. seeing that rsx's, etc. use cast pieces.. i dunno lol

[Installshield 2]

Yeah, kind of...

A recipricating assembly has a certain level of strength that all parts must have in order for it to work properly and reliably...and after factoring in cost, most companies for high production engines, use cast steel as the internal material (production as in quantity made, not in terms of power)...Steel is easy to tool for, so setting up the equipment to make the rods, pistons etc is relatively quick and cheap...and its also readily available and easily recyclable (sp?)...and steel also meets the requirements of nearly every production engine on the small displacement market...minus a few...Meaning cast pieces tolerate the stock ouput of small engines for the most part, and usually last a long time...

but then we come in...

yes you are correct...the lighter the pistons, crank, rods...the less of a parasitic loss...the more vibration, sometimes...and above all, the faster and higher the engine can rev...redlines in general are usually set by an engines ability to breathe at high rpm...such as with the FS...a lot of guys claim that the engine is set at 6500 rpm because of its stroke...not true... an E-46 M3's engine has a stroke of 91mm, just one mm under ours, and redlines at 8700rpm...albeit it has hellishly exotic internals compared to our FS...but physically raising a redline that high with just better internals is pretty much impossible...The FS-ZE has a redline of 7000rpm, and has the same internals as us, with a little higher compression...But anyway, the FS we have cannot breathe at all at high rpm, and everyone knows how it feels in stock form at 6500rpm...nothing going on..the cams, namely, are truely milled for torque at lowend, not power at highend...

But first of all say you get new cams and headwork...that allow our hellishly fast pistons to still breath at 7300rpm and higher...then you have an issue...the stock internals, particulary the upper end of the rods and the wrist pins, will start to give in at that speed...So next order is for forged internals...I used forged aluminum...aluminum on its own is nowhere near strong enough to be inside an engine, but after a process of forging...it is...lb for lb forged aluminum is stronger than cast steel...so with that in mind, you can reduce considerable mass from the aluminum rod and pistons, and still be stronger than cast steel...overall your assembly will be lighter than stock, yet still stronger...both good for high rpm...and being that there is less overall mass, you are also helping the crank out considerably (there is much less mass for it to be pushing and pulling all the time)...just aluminum rods and pistons, with some measurements on making the rods a little longer than stock (not getting into that here, but that helps reduce piston acceleration) can allow you to raise the redline up to around 8k...after that we get into an oiling mess that gets expensive...

and you don't have to use just forged aluminum...there are other options...FI guys tend to use forged steels, because they are much stronger than both cast steel and forged aluminum (they are dealing with cylinder pressures an NA engine will never see...NA guys need light stuff, that is just a little stronger than stock) and lots of options are available in that area...and titanium is another option...but that is so expensive I can't see its worth on a small four cylinder...

[twilightprotege]

as always, nice and informative jamie

[Installshield 2]

ha, thanks man...

[Gen1GT]

wouldn't lighter internals be better for revs compared to forged ? that's what i figured. seeing that rsx's, etc. use cast pieces.. i dunno lol

Yes, lighter internals are better for NA, and I thought the FS had forged rods too. I'd be suprised if the RSX rods are cast. Every car has aluminum pistons, obviously most being cast. Forged aluminum pistons have better physical and thermodynamic properties than cast, and can be made with less material and still be stronger. Check out this reference:

http://www.importbuilders.com/pistoncomparo.html

Stock BP pistons are 425g! Wiseco pistons are 303g(for larger 84mm bore compared to stock 83mm). Just go to show you how much an advantage forged is........

[Installshield 2]

Yes, lighter internals are better for NA, and I thought the FS had forged rods too. I'd be suprised if the RSX rods are cast. Every car has aluminum pistons, obviously most being cast. Forged aluminum pistons have better physical and thermodynamic properties than cast, and can be made with less material and still be stronger. Check out this reference:

http://www.importbuilders.com/pistoncomparo.html

Stock BP pistons are 425g! Wiseco pistons are 303g(for larger 84mm bore compared to stock 83mm). Just go to show you how much an advantage forged is........

Good point...I didn't mention much about stock pistons, the stock rods are what are normally cast steel...

and just to keep it as clear as possible...Stock pistons are generally a cast aluminum alloy...which consists of Aluminum and Silicon, the silicon allowing the alloy to overall be tensionally stronger...and far less malable/ductile..

[protito]

I have read this and I am a little confused by what all of you are saying. I am considering going with 10.4:1 comp pistons myself. What I don't understand is why raising the compression will change my timing and fuel??? To my knowledge the ecu send the fuel based on what the o2 sensor says. Raising the compression is making a smaller area for the air and fuel to combust. Which in terms is the same A/F ratio as the factory compression. Somebody please explain this to me.

[Installshield 2]

This is the complicated part...

you need changes indirectly of the higher compression...theoretically a change in compression only takes what you have...and squeezes it harder...making more heat, and more power...which is true...but with that on its own, you get very little gains unless you substantially change the timing and fuel parameters...

the main reason you need to control some things is how the new pistons are oriented in the cylinders...the pistons are shaped differently, and after the mixture is squeezed, the environment is different than before...it will not be extremely significant with the pistons you mentioned...but with 12:1 or something higher, the pistons are noticably different...the entire quench area is changed...so your timing needs to be changed...

the fuel thing is also dependant on the increase in compression...more compression means more heat...more heat means more residual heat...and more residual heat means you are closer to detonation...which makes the need for more fuel needed...more compression, more fuel...its nothing like more fuel for tubo guys...but just slightly longer injector firing is all it takes...

but not all of this really applies to what you are looking to run...10.4 is not a huge jump...and honestly the only thing you need tuning for is to make up for how bad the stock ecu sucks...You won't see much of anything with the stock ecu...but just because everything is so conservative already...the higher compression will work for an hp or two, but if you get a standalone...you could turn that into 15 with some ignition advance...probably more...and then add the 10-15 hp that you free up everywhere else with the ECU on its own...

so with a standalone and your pistons, you could easily see 25-30whp depending on how aggressive the timing and a/f's are...but without the ECU, you won't see anything really...the timing is completely wrong for power to begin with...let alone with a quench area that is demanding more aggressive timing for substantially better power output...

[Gen1GT]

If I may add....with higher compression you're prone to spontaneous detonation. When you compress air, it heats up. Because of this, you need higher quality fuel ie higher octane. Octane rating is the rating in which fuel resists detonation.

Also, because of higher peak cylinder pressures, you sometimes have to reduce ignition timing. You want ignition to occur when it can have maximum effect on pushing down on the piston. This is why ignition normally happens before the piston is at Top Dead Centre(anywhere from 5-40° + depending on engine, RPM and conditions). Since the flame front takes time to burn itself and create pressure, peak cylinder pressures are ideally around 20° ATDC. Since the air/fuel mixture is squeezed into a smaller space with higher compression, peak cylinder pressures happen sooner, so you pull back some ignition timing. And because the same amount of fuel is burning in a smaller space, it exerts more force and you get more power. If ignition happens at the same time it normally would, peak cylinder pressure happens too soon and all the forces want to push straight down on the rods and crankshaft.

This is why it's so important to have control over ignition timing for optimum performance.

[Installshield 2]

right...depending on rpm, sometimes you need to advance ignition, and sometimes you need to pull it back...depends on load too...but its obvious you need control of it to avoid detonation, maximize power and drivability...

[protito]

Thanks for clearing that up. It all makes since. Do you two have any recomendations on a standalone I should use???

[Maz2001MP]

i was seriously thinking about a haltech or something similar for myself. I am hoping to squeeze 10 - 15 whp more out of a stock set up with a full exhaust and intake.

[twilightprotege]

full exhaust, intake and ecu, there should be no reasons you wouldnt get to atleast 140whp, more than likely 150whp

[Maz2001MP]

I know this is a slight thread jack.. Install mentioned that for streetability sake (my car is a daily driver) a haltech is not good enough for daily driving because it is not a "learning ECU".. are there any suggestions for a standalone that offers the full tunability with the ability to learn and adapt to different conditions?

[Maz2001MP]

full exhaust, intake and ecu, there should be no reasons you wouldnt get to atleast 140whp, more than likely 150whp

will this be with a near stock redline?? Im guessing so.. atleast no more than 7 grand which is found on the JDM FSZE..

i would be extremely happy with 140whp.. my goal is to have full bolt-ons excluding cams and an ECU to see what numbers I can get out of the car without modifying internals.. im a little concerned about reliability also. i shouldnt be though because my car breaks down every 4 thousand miles lol... (cheers2)

[Maz2001MP]

dude u know its sad when you gain HP back from fixing something on your car that causes a check engine light and a decrease in performance hahaha..

[Installshield 2]

will this be with a near stock redline?? Im guessing so.. atleast no more than 7 grand which is found on the JDM FSZE..

i would be extremely happy with 140whp.. my goal is to have full bolt-ons excluding cams and an ECU to see what numbers I can get out of the car without modifying internals.. im a little concerned about reliability also. i shouldnt be though because my car breaks down every 4 thousand miles lol... (cheers2)

that would probably be right on or a little above 6500rpm...at least for 150whp...not sure...I don't think we could pull 150whp out of the stock cams...even with a standalone and fulle exhaust...but even the J-spec cam upgrade would be more than up for the breathing needed to make 140whp or so...the J-spec intake cam will breathe enough for 130whp with good bolt-ons (I/H/E), and that is without a standalone...a standalone could more than make up for 10whp...

[Maz2001MP]

I'm sure there has been much debate over this.. but back to cam suggestions..

- I'm guessing we have three options: wagner, regrinds (jdm or usdm), customs..

if i picked up some jdm cams and had regrinds done what numbers could i expect? i would be happy with 160+ whp for a general goal btw..

still no wagner cam specs? i guess we'll just assume that they are "mild" cams.. good enough for the stock internals in the head..

and now down to custom cams.. what prices are we looking at for something like this?

it has to be taken into account though i'm not sure what type of max redline the first two options might support or the pro's and con's of those options..

[Installshield 2]

well first of all...the stock bottom end will not support the revs you are going to need to get to over 160whp...with some extremely well done porting/polishing...perfect cams...full standalone...and a perfect diameter'd exhaust, you may see just on 160 at about 7200 rpm...but thats it...you could hold that reliably, but anything over that is simply going to take more revs...which the stock internals can't take...not to mention higher compression will make the effort much more worthwhile...

and what do mean by regrind the JDM cams...don't buy them if you want regrinds...just find some stock ones from a used car...most places will hardweld stock cams for pretty cheap...and then you can regrind them...the numbers you will see at the end will be directly correlated to how much research you do, and how well you do it...if you start making mods that don't sit well with each other, you won't see much...

[twilightprotege]

custom cams are a must for any big numbers.

and like install said, you'll need to go to 7000rpm to get real good numbers.

but still, i'm hoping to prove a p5 can get into the 14's over a 1/4 mile with the stock ecu. i know it's not real quick, but faster than a real lotta cars on the road...faster than a mazdaspeed protege too! (stock that is)

[Nightmare]

is the N/A MPI really worth it then?
i gotta know what EMS im saving for LoL

[MPNick]

Even with a bone stock setup the MPI Tuner will get you more power. Doing any engine mods without being able to control timing and fuel will be a waste of time and money.

[Nightmare]

i ment to ask, is the MPI N/A tuner the one i should be shooting for? by the sounds of it, i could really use a full standalone?

[Installshield 2]

I know very little of that thing...it is not a full standalone...which is why I have never really been interested...but a whole lot of FI guys use it, and really like it...

for me though, its a very expensive piggyback...and I was never found of the extra injector aspect...you can buy a LinkPlus EMS (a big brand with miata guys) for only about 200 dollars more ($1,000 compared to $800 or so)...and you will have no questions about accuracy, resolution, or just running bigger injectors overall (rather than secondary TB injectors)...this isn't something against the MPi...this is something against our stock ECU...I never liked it, and do not want it controlling any of the engine's parameters...even if it is being tricked by a piggy...

[Gen1GT]

I agree with Jamie. Piggybacks and NA don't mix....you need full control of ignition timing, not just some extra fuel thrown in for funsies.....

[MPNick]

I agree with Jamie. Piggybacks and NA don't mix....you need full control of ignition timing, not just some extra fuel thrown in for funsies.....

Not sure what you mean. The MPI will allow you to change your timing as needed. Advance up to 12 degrees and remove upto 44 degrees.

What other timing control do you need?

[Captain KRM P5]

give me the part numbers to the high compression pistons and i will get you a price for four :)

[Nightmare]

Not sure what you mean. The MPI will allow you to change your timing as needed. Advance up to 12 degrees and remove upto 44 degrees.

What other timing control do you need?


i was just wondering this, there is an MPI for N/A.

[flat_black]

Ken: The part number for the HC pistons are as follows:

FSY4-11-SA0 : Normal bore, 10.7:1 compression
FSY4-11-SB0 : .025 over, 10.7:1 compression
FSY4-11-SBX : .050 over, 10.7:1 compression

On a side note, where's my darn header? ;) Hehee. Order number is 301. =)

Nah, I'm not surprised it's not here yet. Just curious. =)

- Eddie

[Gen1GT]

Not sure what you mean. The MPI will allow you to change your timing as needed. Advance up to 12 degrees and remove upto 44 degrees.

What other timing control do you need?

I stand corrected. I thought it was a piggyback fuel computer. Does it have outputs for injectors or coils, or does it modify stock fuel and ignition maps by intercepting inputs?

[twilightprotege]

as far as i was aware the 10.7:1 mazdaspeed pistons are no longer available, only the j-spec 10.4:1's in normal bore, 0.025 and 0.05 over

another problem with the mpi & na - can it increase the rev limit?

[MPNick]

I stand corrected. I thought it was a piggyback fuel computer. Does it have outputs for injectors or coils, or does it modify stock fuel and ignition maps by intercepting inputs?

We drive the coil directly, two coil outputs.

For fuel control on the NA you can modify the MAF or even better is to work the O2. THe MPI has a built in O2 tuner. You can dial in any AFR you want at any point.

[MPNick]

C-P will make me any piston setup I ask. For the NA we can do a very strong lightweight slug with a low drag ring pack.

[Installshield 2]

as far as i was aware the 10.7:1 mazdaspeed pistons are no longer available, only the j-spec 10.4:1's in normal bore, 0.025 and 0.05 over

another problem with the mpi & na - can it increase the rev limit?

Great points on both...The Mazdaspeed pistons and exhaust cam have been discountinued...according to Mazdamotorsports, there were only limited amounts of each made for replacements on the limited production Japanese MPS's (which are what had the high comp and cam)...and they have since sold out for importing...

No big deal though...if you want 10.7:1 compression or so, you can just use the stock ZE pistons and a copper head gasket to make up the .3 extra static CR...the gasket will be about 150 bucks though...

Also, I missed the most important aspect of the MPi...if it can't control the rev limit, there is no way it will be a good choice for a heavy NA build...We have drilled this a million times, hp= (torqueXrpm)/5252...small displacement engines HAVE to rev to get anywhere near 100bhp/liter (at least NA wise)...and even a rev limiter at 7000 rpm (I believe that is around what the limiter is at heavy load stock) will not get you close...its hard to prevent the FS from being fairly peaky...and with that you run into 300 rpm making difference between upwards of 10 hp...you cut it short, you lose out on some significant power...

[steve_protege]

So what would be the best ratio and yield the highest gains safely? I hear 10.1:1 all the time, but can anything else be done to make it higher (or lower)? Im looking for something for my N/A now, but in the far far future, something for F/I.

While on the subject of internals, are the ZL-VE cams from Corksport ready to be released yet? I e-mailed a whiles back and was told by Derrick that they were still going through the R-n-D phase and should be released soon. Just wondering if anyone has heard anything.... If these aren't done yet, are we closer to finding any cams for the 1.6 liter ZM-DE?

[Installshield 2]

well you could basically run a turbo, albeit with much lower boost, all the way to about 11:1...after that it gets pretty messy...But as far as I am concerned...something like 10.5:1 and 4psi of boost is the absolute best combo you could ever ask for...not only do you great power out of boost, you are not pushing too much air...so you can use a tiny turbo with fast spool up...and end up making about the same power you would with 8psi and 8.5:1 static CR...

But many high performance production engines are running upwards of 12:1 compression...that is no big deal with good tuning, and could easily last 150,000 miles...now 14:1 and up is reserved for racing situations, and will rapidly destroy reliability...I am at 13:1, and know it will not hold for 200,000 miles...but with nothing but 93octane gasoline and hopefully accurate tuning, it will be perfectly fine...

[steve_protege]

So from what I understand, I could run 10.5:1 - 10.7:1 with Hi-comp pistons, Adjustable cam gears (from SRmotorsports.com and ZL-VE cams (from Corksport.com) safely? Then in the future get the Wagner or HiBoost 1.6 liter turbo kit and run 4-5 PSI without fear of slippage or tranny problems...




well you could basically run a turbo, albeit with much lower boost, all the way to about 11:1...after that it gets pretty messy...But as far as I am concerned...something like 10.5:1 and 4psi of boost is the absolute best combo you could ever ask for...not only do you great power out of boost, you are not pushing too much air...so you can use a tiny turbo with fast spool up...and end up making about the same power you would with 8psi and 8.5:1 static CR...

But many high performance production engines are running upwards of 12:1 compression...that is no big deal with good tuning, and could easily last 150,000 miles...now 14:1 and up is reserved for racing situations, and will rapidly destroy reliability...I am at 13:1, and know it will not hold for 200,000 miles...but with nothing but 93octane gasoline and hopefully accurate tuning, it will be perfectly fine...

[Gen1GT]

So from what I understand, I could run 10.5:1 - 10.7:1 with Hi-comp pistons, Adjustable cam gears (from SRmotorsports.com and ZL-VE cams (from Corksport.com) safely? Then in the future get the Wagner or HiBoost 1.6 liter turbo kit and run 4-5 PSI without fear of slippage or tranny problems...

What do you mean by fear of slippage? Clutch? Any time you increase the torque output of your engine, you're going to lessen the lifespan of your drivetrain ie clutch, transmission etc...

[steve_protege]

What do you mean by fear of slippage? Clutch? Any time you increase the torque output of your engine, you're going to lessen the lifespan of your drivetrain ie clutch, transmission etc...


By slippage I mean the tranny. I don't have a manual so I don't have to worry about the clutch failing or anything, but I just wanted to make sure that if/when I get the turbo kit my tranny and other various parts on the vehicle won't "konk" out on me because of it. Well atleast not right away...

[Installshield 2]

The automatics do not hold nearly as much torque as the manuals...So unless you are planning on getting the transaxle re-worked to handle the power, I would plan on mods that keep you around 6psi worth of power...anything over, and you will just get slipping from the auto (if it is stock of course)...

[steve_protege]

The automatics do not hold nearly as much torque as the manuals...So unless you are planning on getting the transaxle re-worked to handle the power, I would plan on mods that keep you around 6psi worth of power...anything over, and you will just get slipping from the auto (if it is stock of course)...

Oh, I know. I don't plan on going anything higher than 4-5 PSI. Everyone tells me that on semi-stock internals and same ol weak tranny, I should be alright if I don't exceed 5. Im not looking to blow anyone out of the water, but I do want to show off a bit when the time arises. Know what I mean? Im going to have some upgraded parts (better torque converter, beefier axels (if I can find some) ). Would porting/polishing the head, IM and TB plus maybe getting a valve job done increase the PSI any? Maybe an extra 1 or 2?

[Installshield 2]

Increase the psi of your boost?...if so, no...everything else being equal, mods such as that can lower the boost level by increasing the volume of the airs path...makes no difference though, you have a little less pressure, and more power because of easier flow...

But remember...your transaxle will be the weakest link...and you are safe for a certain amount of torque...says its 150lb-ft or something (not sure what exactly it is)....any decent turbo kit shouldn't have too much trouble giving that much torque on 6psi of boost (well not sure about the 1.6L, so maybe you can run a lot more)...

but you limit is torque and overall power output...not turbo pressure...so any mods that you make such as pnp of the head, cams, etc. will just make you have more power with less boost...which isn't what you will need with an auto...you could easily destroy your gearbox just by increasing the boost...and you can easily get what is safe for your gearbox with just a turbo system, and no other mods....

[steve_protege]

What if I get some new transaxels from Levelten? Plus do some of the other mods to stregthen the tranny. Like get a valve body recalibration and have a new torque converter put it? I wouldn't be looking to increase the PSI of the kit, but get more out of amount of air I have coming into the engine bay and accompanying pipes, turbo, etc...




Increase the psi of your boost?...if so, no...everything else being equal, mods such as that can lower the boost level by increasing the volume of the airs path...makes no difference though, you have a little less pressure, and more power because of easier flow...

But remember...your transaxle will be the weakest link...and you are safe for a certain amount of torque...says its 150lb-ft or something (not sure what exactly it is)....any decent turbo kit shouldn't have too much trouble giving that much torque on 6psi of boost (well not sure about the 1.6L, so maybe you can run a lot more)...

but you limit is torque and overall power output...not turbo pressure...so any mods that you make such as pnp of the head, cams, etc. will just make you have more power with less boost...which isn't what you will need with an auto...you could easily destroy your gearbox just by increasing the boost...and you can easily get what is safe for your gearbox with just a turbo system, and no other mods....

[steve_protege]

Whats the update Andrew? Would you be able to get some pistons with the 10.5:1 ratio?

[Installshield 2]

What if I get some new transaxels from Levelten? Plus do some of the other mods to stregthen the tranny. Like get a valve body recalibration and have a new torque converter put it? I wouldn't be looking to increase the PSI of the kit, but get more out of amount of air I have coming into the engine bay and accompanying pipes, turbo, etc...

Of course if you strengthen your automatic transaxle, you will be able to run more torque through it...that is up to you, and that stuff isn't very cheap (some shops offer rebuilds with stronger clutches/valves etc. for around a grand, which can be good an addional 50-75 lb/ft)...not bad considering a clutch/flywheel and installation on a manual is nearly that much if you can't the work yourself...

I was referring to the stock automatic...you can always make that auto stronger...It just takes money...so its your call...personally, I would just spend the money on a manual conversion, or trade the car in for a manual with similar miles (I have witnessed people literally make a profit doing that...equal miles, traded an automatic Civic for a manual Civic and $400...)

[Gen1GT]

LOL, strengthening an automatic for the Protege is like putting a Shimano XTR rear derailleur on a tricycle.

[Boston5761]

what will be needed to run the corksport pistons? will i need an ems, should i keep stock rods....91 or higher octane fuel? basically are these pistons pretty much a bolt on type thing since they came out the j-spec motor and will they give me what 4whp maybe from pistons and higher octane fuel....what about thinner head gasket?

[flat_black]

I think we ended up doing the math and finding they were worth MAYBE 2 horsepower. Thinner headgasket would further increase the compression. But with supporting modifications, such as an aftermarket EMS, you'll get better gains. Higher compression pistons are a means to an end, rather than an end itself. It should be done in conjunction with other mods, such as cams, headwork, some valve springs, and maybe balance the crankshaft, rods, and pistons to facilitate high revving, since horsepower is a function of RPM, as well, so long as your engine can breath that high up.

[Gen1GT]

I think we ended up doing the math and finding they were worth MAYBE 2 horsepower. Thinner headgasket would further increase the compression. But with supporting modifications, such as an aftermarket EMS, you'll get better gains. Higher compression pistons are a means to an end, rather than an end itself. It should be done in conjunction with other mods, such as cams, headwork, some valve springs, and maybe balance the crankshaft, rods, and pistons to facilitate high revving, since horsepower is a function of RPM, as well, so long as your engine can breath that high up.

I gotta disagree with you on that one Eddie. Pistons can give both an increase in displancement, as well as an increase in compression. If I throw in some 11:1, 2mm overbore pistons, all else being equal, I should net 10% more power over my stock setup. (5% for increase in displacement from 1839cc to 1929cc: 5% for CR increase of 8.8:1 to 11:1).

Effectively, there would probably be more gains than that, as the larger bore would help to unshroud the valves.

[flat_black]

Oh, assuming you're overboring it, yeah, that's going to result in a reasonable gain... But from the sound of it, he's going to just drop the pistons in, increasing CR from 9.1 to 10.4:1, in the case of the 'drop in' pistons.

I can verify the fact that that doesn't help all that much. =)

[Shift2xlr8]

So the consensus was that the 10.4:1 pistons dropped in on the stock rods without doing cams and EMS, was all of about a 2hp gain? Or is there more power that will be gained from just simply dropping in the 10.4 pistons? I only ask because I have no clue what kind of power you can gain from HC pistons. I personally have looked at this route as apposed to going turbo...I guess me like everyone else is trying to find a cheaper way to go fast(er) with out raping our wallets/bank accounts.

Chris