P5 NA Build - Target 175whp

awesome stuff...

the difference between 175 and 200 is pretty huge... longer rods, insane redline, intake and exhaust system tuned to a very fine peaky power band, loads and loads of head work.

having said that, 175 is going to be alot of work still. It'll probably be vastly easier to live with than a 200hp monster though.

Suggest you still look at a custom exhaust manifold (tuned 4-1 headers with a merge collector.....), some sort of work on the intake manifold and look at some nice strong forged rods

Forged rods? Would these absolutely be needed if your NA and around 175-200whp? Would forged rods help create more HP or would it be more of a precautionary measure?
 
If your shooting for the goal of 200, RPMs are gonna be needed to achieve it and something thats gonna be able to take the additional stress.
 
Forged rods? Would these absolutely be needed if your NA and around 175-200whp? Would forged rods help create more HP or would it be more of a precautionary measure?

rods are most definantly something worth considering.

The crank is fine, you wont break that in a hurry, but the rods are very weak. With the additional side loading brought on by increased RPM, plus additional compression, i wouldn't even flinch at putting rods in any built NA motor.
 
rods are most definantly something worth considering.

The crank is fine, you wont break that in a hurry, but the rods are very weak. With the additional side loading brought on by increased RPM, plus additional compression, i wouldn't even flinch at putting rods in any built NA motor.

Good to know. Yet another pricey item to add to the shopping list (braindead(wow)
 
Am I crazy for not getting forged rods with the setup I have planned and a redline limit of 7000??? The reason I chose to limit myself at 7000 rpm is because I figured I wouldnt need new rods & valve springs. I also remember reading in istallshields build thread that building our motors for high hp causes more parasitic loss at daily driving conditions - which is something I was trying to avoid. I still have time to addto the parts list I already have since the head is being shipped to Ken at PG tomorrow and the lead time is three weeks. let me know what you guys think. Forged rods are lighter as well, right? If I head for 7500rpm would new valve springs be needed? I guess in the grand scheme of things they aren't that pricey either.... I just dont know id I want to upgrade the whole exhaust then either. All the stuff I just listed is probably another 1500-2000 bucks. Things to think about... could be the difference between 160hp and 175hp...
 
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Am I crazy for not getting forged rods with the setup I have planned and a redline limit of 7000??? The reason I chose to limit myself at 7000 rpm is because I figured I wouldnt need new rods & valve springs. I also remember reading in istallshields build thread that building our motors for high hp causes more parasitic loss at daily driving conditions - which is something I was trying to avoid. I still have time to addto the parts list I already have since the head is being shipped to Ken at PG tomorrow and the lead time is three weeks. let me know what you guys think. Forged rods are lighter as well, right? If I head for 7500rpm would new valve springs be needed? I guess in the grand scheme of things they aren't that pricey either.... I just dont know id I want to upgrade the whole exhaust then either. All the stuff I just listed is probably another 1500-2000 bucks. Things to think about... could be the difference between 160hp and 175hp...

Well, exhaust system can be re-done later, when funds permit. Building the motor is something you don't want to have to redo.
In my opinion, while the thing is a part, new rods would be a smart thing to do - its relatively cheap insurance against failure, and it will allow you to push harder if you decide 175 isn't enough. It also has the potential to support more engine speed, but it doesn't necessarily mean you have to use that potential..... if 7000rpm is fast enough to get your goal, then leave it at 7000rpm....but i'd still get rods either way (make sure if you order from PG or another AV, that you tell them the rods you need are being used with FS-ZE pistons... if they give you the slightly longer rods you could have/will have problems)


Weight would depend on the rod I'd think. Different rod manufacturers are going to make rods out of different materials, at different thicknesses with different weights. If you do go to after market rods though, you'll need to add balancing to the cost of building the engine, if you haven't already.

beefier springs at 7500 - depends on a few things.. but seeing as you've got the twiggy sticks, i'd think it couldn't hurt. Bare in mind however that 7500rpm isn't that silly though, the FS-ZE pushes that far if memory serves....and i'd be more than a little surprised if it had outrageous valve springs. They are more than likely identical to ours.

So yeah, add rods, and upgraded valve springs to your shopping list, leave the exhaust for the time being and do that later on if you don't reach your goal, or when you have the funds to do it.
 
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Thanks LW, What you are saying makes complete sense but I dont know If Im sold on dropping that much (more) money. I will, however, talk to Ken at PG and my shop to see what I would be getting myself into with rods, balancing, and valve springs.
 
Thanks LW, What you are saying makes complete sense but I dont know If Im sold on dropping that much (more) money. I will, however, talk to Ken at PG and my shop to see what I would be getting myself into with rods, balancing, and valve springs.

it obviously comes down to what you can and can't afford/are willing to spend. That is and always will be the limiting factor. You could stick your rev limit at 7000rpm, and not upgrade the springs - but still forge and balance the bottom end if you wanted to save money... then rework the head later if you want more, thats always an option...

My way of looking at it, is that while you have the engine in pieces you should do everything you want to do, to save pulling it down again when you run into the limit of the stock parts. Your engine is going to be fairly highly strung - not nearly as much as the guys going after 200whp, but you are still pushing past what you could achieve with bolt ons... purely for piece of mind, if nothing else, i'd be forging. Plus the extra head room you will get will allow you to go further, should you ever wish to do it.

That is not the only way to look at it, of course - just my 2 cents....

I've added you to the race thread in the original post - I think whatever you do, you'll probably move faster than the guys going for the big numbers simply because you are not going to have the expense of insane custom parts etc, so the information you provide in this thread will really help the NA section immensely, and the things you find out along the way will help everyone.

Good luck with it all, i'll be following your progress closely... and remember - pics or ban! :p
;)
 
By going with forged rods, that "should" prevent you from joining the "Zoom Zoom BOOM Club", right? Or what's the main reason for people unwillingly joining that club?
 
By going with forged rods, that "should" prevent you from joining the "Zoom Zoom BOOM Club", right? Or what's the main reason for people unwillingly joining that club?

zoom zoom boom is rod related mostly...or transmission related ;)

However we'll likely break the rods due to sustained high RPM operation and the incredible side loading brought on by short rods....the turbo guys break them because they push them to power that the rods simply cannot sustain.
 
the turbo guys break them because they push them to power that the rods simply cannot sustain.

And I'd assume that increasing the compression on a NA motor could basically do pretty much the same thing, right?
 
Quote Ken from PG

"if you go with the FS-ZE pistons you cannot use aftermarket rods. the pistons would have to be machined to accept a floating wristpin or the rods would require machining. there really is no reason to upgrade to forged rods on most N/A setups. factory rods should suffice honestly."

but..... like LW said Peace of mind especially if you want to go well above 7250 (like to hit 200whp :) ) Remember Ken said MOST NA setups.

I have decided for my application I am going to leave the bottom end alone.

I have also added one more modification which I will announce later. I think LW may already have this in mind. ;)

Looks like from reading around 150whp is a hard mark to pass.
 
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Ken and i will have to agree to disagree on the rods. Power holding is only one part of the puzzle when determining whether rods are a good idea or not. if you look at the sums, at 7000rpm, our piston speeds are getting maxed out, piston velocities are insane and side loading stress is incredible.... how much of that side loading stress the stock rods can put up with is anyones guess....as far as i know noone has dropped a rod on an NA build - but then we've never seen a whole stack of people try and chase down numbers north of 160hp at once... i think we're going to learn a few new things about the FS engine in the coming months.

150whp is a hard mark to pass on stock pistons, remember, your pistons are LOWER compression than the australian pistons, which are lower than JDM.... you've increased your compression and if you do everything else right, you should see a decent gain... that plus the bolt ons should see you crack 150whp without batting an eyelid... 175 however, might be a stretch without going to the extreme...only time will tell!

Like i said, it comes down to how much money you are willing to spend, and where you are willing to spend it. I have no doubt you'll topple 150hp, i'm just slightly worried about your rods should you need to increase your redline to something outlandish in order to get those last few horsepower out of the engine.....

Tom03es: yes increasing static compression will increase stresses, but nothing like what boosting will do...
 
quick question, how did you paint red lettering on the valve cover without overspray??

im getting mine powdercoated in a week and i do not know what to do for the lettering. either i sand it down (which i want to do) or paint it (which i do not know how to do).

thanks
 
quick question, how did you paint red lettering on the valve cover without overspray??

im getting mine powdercoated in a week and i do not know what to do for the lettering. either i sand it down (which i want to do) or paint it (which i do not know how to do).

thanks

he said he masked it.

My approach would be to paint the whole thing red to start with. a few good coats of a durable enamel gloss engine paint.

Once completely dried and cured, spray the whole thing with black... then let that dry

then using a sanding block, sand back the black on the writing, then reduce your grit slowly but surely. If you do a careful job you should end up with a very smart finish....

once all done, clear coat and done.
 
Ken and i will have to agree to disagree on the rods. Power holding is only one part of the puzzle when determining whether rods are a good idea or not. if you look at the sums, at 7000rpm, our piston speeds are getting maxed out, piston velocities are insane and side loading stress is incredible.... how much of that side loading stress the stock rods can put up with is anyones guess....as far as i know noone has dropped a rod on an NA build - but then we've never seen a whole stack of people try and chase down numbers north of 160hp at once... i think we're going to learn a few new things about the FS engine in the coming months.

150whp is a hard mark to pass on stock pistons, remember, your pistons are LOWER compression than the australian pistons, which are lower than JDM.... you've increased your compression and if you do everything else right, you should see a decent gain... that plus the bolt ons should see you crack 150whp without batting an eyelid... 175 however, might be a stretch without going to the extreme...only time will tell!

Like i said, it comes down to how much money you are willing to spend, and where you are willing to spend it. I have no doubt you'll topple 150hp, i'm just slightly worried about your rods should you need to increase your redline to something outlandish in order to get those last few horsepower out of the engine.....

Tom03es: yes increasing static compression will increase stresses, but nothing like what boosting will do...

Ive read about quite a few ppl on the forums going to 7k rpms on a daily basis on thier cars with no problems. (example Kansei) Which is something I probably wouldnt be doing quite as frequently. If I dont hit my ultimate goal of 175 hp by 7k I can live with that knowing I wont blow my motor. Maybe I will kick myself later for not allowing myself "extra room" to push higher hp but right now my goals are a little milder than your beast :)
 
he said he masked it.

My approach would be to paint the whole thing red to start with. a few good coats of a durable enamel gloss engine paint.

Once completely dried and cured, spray the whole thing with black... then let that dry

then using a sanding block, sand back the black on the writing, then reduce your grit slowly but surely. If you do a careful job you should end up with a very smart finish....

once all done, clear coat and done.

I kind of did what LW said but I started off with black, then sanded & masked, then hit it with red. I didnt put a clear coat on it bc I didnt want it to be too glossy but thats probably a good idea to protect the paint. Ill have to consider that.
 
I kind of did what LW said but I started off with black, then sanded & masked, then hit it with red. I didnt put a clear coat on it bc I didnt want it to be too glossy but thats probably a good idea to protect the paint. Ill have to consider that.

you chose the hard way ;) my way involves no masking (but probably wouldn't give as good a result, because if you sand too much, you go through the black AND through the red under coat....
 
The Parts - continued

Anyways back to the build.....

I have decided to add the oversized valve, spring, and hardware package from supertech and crossover auto through PG. I'm going with the single spring for a little extra closing power and because im not pushing redline too much. There is no reason why my head shouldnt breathe well at high rpms now! The limiting factors will now probably be the intake and exhaust like LW said. PG has agreed to port and polish the head and size for the bigger valves all in one step!
 

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