Turbo Lag

[Street Toyz]

:wtf: Anyone else that has an MSP notice how it falls on its face under medium acceleration at about 3K rpm ? Is this the infamous turbo lag ? If so, has anyone had the problem corrected ? I'm afraid to take the car back to the dealer yet and have the monkey's there, try and tell me it needed new mufler bearings .. lol. It also seems that sometimes the turbo wont even kick in through 1st gear. Lemme know please. :confused:

[JonnyMiata]

If anything I feel the car pull strong at that 3K point. I feel the power come on at about 2500 just after the turbo lag. The car is very similar in feel to my Audi TT that I used to have. You may want to have them look at it if what you are saying is happening.

I am finding that I need to easy the clutch out a bit slower or I will get some serious wheel spin from the turbo kicking in.

Jonny

[Grimace]

You don't really feel the effect of the turbo until around 3000 RPM. But that is normal of any turbocharged car. Turbo boost builds with revs, and the impellor(s) won't spin until a lot of air is being blasted by them. (Drive a WRX while short shifting before 3500 RPM all the time and you'll be sorely disappointed.) Turbo lag can't be "corrected", its a fact of life and there is nothing that can be done to eliminate it. Maybe you are confusing supercharging and turbocharging?
The Mazdaspeed Protege even has the advantage of a high compression ratio for a turbocharged engine, so until the turbo kicks in, it drives like a nice regular Protege 2.0L. After it kicks in, away you go. Its one of the best turbocharged-engined cars I've driven - extremely tractable and easy to drive in traffic. Definately the most linear turbo engine I've ever come across.
But while you are breaking in the car, you shouldn't be in the rev range where the turbo kicks in. Keep it under the 3000-3500 RPM for the first while. Then after the first 600 miles go by, slowly increase the revs at which you shift, until (at your discretion) you can rev all the way to redline if your heart so desires.

Edit - Johnny beat me to it. ;)

[slug420]

well jonny says he has no lag and it picks up at 2500

street toys says it falls flat at 2500

maztech i think it was, who posted from texas where he test drove and redlined a msp said it fell flat at 3000

u think there might be somethin to this?

[jroof]

Ask our friends to the north. Digi, Devil, Limited...you boys having any problem with the engine wimping out at 3K?

[Newf]

I drove the car today. Turbo kicked in at 3000 rpms in every gear. Very Noticable and addictive.

[JonnyMiata]

slug,

I said that I had turbo lag......reread what I wrote.

"I feel the power come on at about 2500 just after the turbo lag."

I have not driven a turbo car without it. It is the nature of the beast. It is just that now car manufacturers are getting the hang of it and using smaller turbo that don't take so long to spool up.

Jonny

[Street Toyz]

The problem I'm experiencing may not be lag. It may be an ignition issue. Once the turbo kicks in, at the very begining the car stumbles like I lifted my foot off the gas and put it back down. A very scientific explanation I know, but thats what the car does.
I saw another post similar to this earlier but cant find it now, go figure.

[Limited Edition]

Originally posted by jroof
Ask our friends to the north. Digi, Devil, Limited...you boys having any problem with the engine wimping out at 3K?

Well, since my car hasn't been broken into yet I haven't really put the throttle foot more than 50%. So it's very hard for me to give my input on this one. But i have occasionally hit 4000rpm in 1st and 2nd gear. When i took it up to 4K rpm i never had the throttle at more than 50% so, in terms of lag i didn't feel it.

However, someone did mention that all turbo needs higher revs for the turbo to create a high boost. So if you're at 1200rpm and at 100% throttle, you'll feel that lag, because the turbine is spinning to full potential. But it won't take long at all until it's at full boost. :D Once above 3000rpm and still at full throttle, you'll be flying!:D

If you want a better answer to this topic, ask dpmmsp. His car is fully broken into and has likely brought his car up to redline a few times.

[maztechnhtown]

I said that the car fell flat on its face at 1500 with the clutch let out too fast, but took it a minute for the turbo to kick in then it was balls to the wall :D It kinda felt like your going 20 in 4th gear just no power and the rpms rise slowly then speeds up.

I would take it to your dealer, tell the advisor to let you ride with a tech there, let me hook up the wds and watch the fuel trim pids and the spark adv make sure that the pcm is noticing with the turbo spools up and make sure that the fuel is being adjusted by the pcm. I think that is where i would start but not sure can't diagnoise over the internet :)

[dpmmsp]

I'm at 2,000kms now and have put the car through a few paces lately .... %*/#$%:mad: weather permitting.
The turbo coming on is very noticeable between 2,500 and 3,000 rpms, as Newf will tell you. It is usually vvvveeerrryyyy smooth, but it does "hiccup" every now and then where it just ..... hesitates ... then jumps forward. The trick is trying to get it to happen with any predictability. It seems to be when you are accelerating and short-shift a little, changing gears just after the turbo comes on, and suddenly the engine has dropped to just where the turbo should again be kicking in, but there is no pressure. It hesitates. People are probablying noticing more than they should because everyone is breaking in their cars so they are changing gears early. I'm no expert, but that's my guess.

[spooling]

The hiccup has happened to me on a couple of occasions but nothing to worry about maybe until later if problems occur. I'm around 600 miles in a week and have redlined it once, too tempting to go there all the time.

[dafababa]

Yes, I have noticed this with mine as well. It kind of hesitats a little but only when I am around 2600 to 2900 rpm and then shift. I have 1200 miles on her now so I been starting to really drive her like she is meant to be, if you stay on the gas till about 4500 to 5000 and then shift there is no hesitation at all.

[APEXistud]

Originally posted by Grimace
.....Turbo lag can't be "corrected", its a fact of life and there is nothing that can be done to eliminate it. Maybe you are confusing supercharging and turbocharging?....

Correctamundo. Corky put it best..."No lag means no Turbo" But, there is one thing you can do aside from be patient. Have some custom t25 made for you. You could have a custom trim made to have your boost at a different point. Keep in mind that you will never have a top end monster with a little t25. For top end (freeway running) you will need a larger turbo, T3 or hybrid T3/T4.

[redmption]

Dude I have been trippin thinking this was a phantom problem but the turbo does fall flat in 2nd gear, but its only some times. I doint recall having problems in any other gear but sometimes it hiccups in 2nd between 3500 and 4000 and sometimes it feels like the turbo isnt kicking in at all. I know its not turbo lag it has to be something else. Crappy thing is it only happens sometimes, so I know when I take it to Mazda it will be the time it choses not to. Oh what to do....

[AGR]

I think I know what were talking about here. I notice it sometimes, also. It seems, especially when the engine has only been running the first 20-30 minutes or so, when you really give it gas, it almost seems like it is starving for fuel perhaps (for lack of better words). Not much of a hesitation, but it's there. After driving for a while, it seems to go away. I notice this mostly only under hard acceleration.

Cheers!

(drinks)

[Dexter]

as long as my car goes im happy. :D

[122 Vega]

My MSP does this too, I referred to it as a hiccup as well. It is right about 3000-3500 rpm and just lifting throttle to prepare to shift, you can make it do it if you want. I thought it was going to be a problem, but I have accepted it as a "trait"or "characteristic" that I will gladly accept. I have redlined my car several times while trying to make a boost chart, and it won't do it at WOT, only partial throttle, just cruising. It will only happen if you lift throttle just at the right time, I haven't been able to see the boost gauge when it happens, maybe I'll put the video camera on it this week.

Britt
www.geocities.com/kiva75

[gotdlife]

I have noticed the exact same issue. Not sure what it is. If it doesn't go away after 3k miles will ask the dealer about it.

[turboge]

At 5000+ miles now, and I notice the stumble every time. It occurs between 3000-4500rpm. This turbo is very hesitant below 3000rpm, and doesn't completely spool tilll approximately 5000.

From my mazda turbo engine tuning experience I believe that it is all related to the ECU. Either the car is poorly programmed to handle boost in those RPM ranges, or the knock sensor (if even equipped) is wigging out. Other things lead me to believe that the boost solenoid may be incorrectly programmed as well, and that it may be "cycling" its signal and creating some kind of boost spike. A boost gauge is not on the car yet so I can't tell on that one.

Either way, this is not normal of a "stock" turbo'd car. Also, this is a rather small ball bearing turbo, I would expect full boost to be delivered by 3000rpm and held smoothly from then on. I've tuned on larger ball bearing turbo's and have had no problems with lag like this.

Also, there is a way to cure some lag. Free up the intake, and the exhaust. The free'r the turbo can flow the quicker it will spin for you. I've seen drops of nearly 1000rpm for complete spoolup on GT-R turbo's with intake and exhaust mods. We'll be modding soon to find out.

[AGR]

Originally posted by turboge
At 5000+ miles now, and I notice the stumble every time. It occurs between 3000-4500rpm. This turbo is very hesitant below 3000rpm, and doesn't completely spool tilll approximately 5000.

From my mazda turbo engine tuning experience I believe that it is all related to the ECU. Either the car is poorly programmed to handle boost in those RPM ranges, or the knock sensor (if even equipped) is wigging out. Other things lead me to believe that the boost solenoid may be incorrectly programmed as well, and that it may be "cycling" its signal and creating some kind of boost spike. A boost gauge is not on the car yet so I can't tell on that one.

Either way, this is not normal of a "stock" turbo'd car. Also, this is a rather small ball bearing turbo, I would expect full boost to be delivered by 3000rpm and held smoothly from then on. I've tuned on larger ball bearing turbo's and have had no problems with lag like this.

Also, there is a way to cure some lag. Free up the intake, and the exhaust. The free'r the turbo can flow the quicker it will spin for you. I've seen drops of nearly 1000rpm for complete spoolup on GT-R turbo's with intake and exhaust mods. We'll be modding soon to find out.

Good info! Thanks Braden. It isn't really consistent on mine, but happens once in awhile. I will be interested to see your later posts regarding this. And; I do want a boost gauge. Are they a pain to install? And; which do you recommend? Thanks!

Cheers!
(drinks)

[turboge]

I tend to use Autometer Boost gauges. They are so simple to install even a mouse could do it. Basically you position your gauge, run nylon tubing through the firewall..... then T into a vacuum line that is near the intake manifold or off the intake manifold, secure all connections and you're done.

Placing it closer to the turbo (i.e. off the compressor outlet) will give you a boost number that is higher than that after the intercooler, where a pressure drop will show. I like to measure at the manifold to see what is actually entering the engine.

You can get some new autometers for like $50 from most places. I think the phantom will suit the MSP best.

-Braden

[AGR]

Originally posted by turboge
I tend to use Autometer Boost gauges. They are so simple to install even a mouse could do it. Basically you position your gauge, run nylon tubing through the firewall..... then T into a vacuum line that is near the intake manifold or off the intake manifold, secure all connections and you're done.

Placing it closer to the turbo (i.e. off the compressor outlet) will give you a boost number that is higher than that after the intercooler, where a pressure drop will show. I like to measure at the manifold to see what is actually entering the engine.

You can get some new autometers for like $50 from most places. I think the phantom will suit the MSP best.

-Braden

I know I want a boost gauge that matches the MAZDASPEED 'red' lighted gauges, if possible. It's a not a show stopper, but it looks like the Autometer is black numbered.

Cheers!
(drinks)

[unwrittenLaw]

Thought I'd bring this thread back..Are you guys still noticing these problems with 'hiccuping/hesitation' at certain rpm's, etc..? Has anyone figured out if this is just turbo lag or something else? I notice it usually when I first start driving and I have 3000+ miles on my MSP so I think its pretty well broken in...Should I even bother trying to talk to the dealer about this problem?

Thanks

[psifactor]

Anyone else that has an MSP notice how it falls on its face under medium acceleration at about 3K rpm ? Is this the infamous turbo lag ? If so, has anyone had the problem corrected ? I'm afraid to take the car back to the dealer yet and have the monkey's there, try and tell me it needed new mufler bearings .. lol. It also seems that sometimes the turbo wont even kick in through 1st gear. Lemme know please.

it sounds like something is wrong.. I would take it to the dealer and have them look at it..

Dude I have been trippin thinking this was a phantom problem but the turbo does fall flat in 2nd gear, but its only some times. I doint recall having problems in any other gear but sometimes it hiccups in 2nd between 3500 and 4000 and sometimes it feels like the turbo isnt kicking in at all. I know its not turbo lag it has to be something else. Crappy thing is it only happens sometimes, so I know when I take it to Mazda it will be the time it choses not to. Oh what to do....



Wow..I just made a thread the other day asking what kind of problems that mazdaspeed folks were experiencing.. I sold a car to a customre and now he is really upset about the performance. His car is doing the same thing. The service department has not been able to figure it out. We are having a mazda engineer come down and take a look at his car. I think there may be something wrong with the ecu. maybe it was programed incorrectly.
This problem might become some sorta of recall on the msp.
redmption..how many miles do you have on your car.. And how were then driven?

[Newf]

Are you saying it only happens when you first get in the car? And when she warms up it doesn't

[psifactor]

Are you saying it only happens when you first get in the car? And when she warms up it doesn't


The car I am talking about is completely random.

Its really werid. Something I have never sen before.

[Logan]

I've noticed the power seems to hesitate depending on how much throttle I've giving it.
If I have the pedal mashed to the floor, it pulls just fine, but if I have it around 75% down, it's almost like the engine is hiccuping.
It's very frustrating.

[Newf]

interesting. One way to solve it though....FLOOR IT! :)

Honestly, the last time I took one out, she was fine, no hiccup at all unless I punched the throttle, got off it quicky, and puched it again all within 2-3 seconds. There's just no real reason to do this while driving but I thought i'd try it. Most 4 cyls seem to do it anyhow.

[MSP-4-ME]

I have 1200 miles on mine and it does the same exact thing at about 3500rpms at partial thottle. I thought it was just a "turbo" characteristic because I never owner at turbocharged car before. I am used to superchargers. Definitely a hiccup in power at 3500rpm .

[psifactor]

the car I am having problems with this does it at 100% throttle as well.

Maybe it starts out at only 75% and then contiunues to get worse

[yashooa]

Mine runs great. Rev to 2200-2500 RPM and then slip the clutch out while pressing down the gas and it feels like two pit bulls are vying for control of my arms.
In short no lag, no flat face-ness, no problem.

Good luck with your repair.

[psifactor]

rev it up to 4500 to 5000k and drop the clutch...hehehe fun stuff
give it a try...

Trust me..nothing will break


(I'm just mad because some sentra wanted to race so I launched it and lifted the clutch too fast breaking the rear differential:( But I still beat him with 3 wheel drive:) )

[psifactor]

there shouldnt be Much lag on this GT25 if any at all. this thing should spool fast. and Branden is right, there are ways to "correct" the lag of turbos: free up the intake and exhaust tract, port/gasket match the manifold and O2 housing/turbine elbow. the problem is that the American driving public wants a car that will get up and go when you step on the gas; instant torque. thats just one thing that is not a trait of a turbocharger, it will always have some degree of lag. it can be minimized by using a small AR ratio turbine housing and higher compression to placate the driving public. this is bad for us Tuners though. it puts a limit on how much boost we can safely run. And i dont know about you, but i want to run 93 octane all the time, which really will limite the amoutn of boost.

Anyhow, this problem sounds like its related to the o2 sensor feedback in the ECU. The ECU has two modes of operation for the O2 sensor: open loop and closed loop. Closed loop is what causes the blinky light on your AF guage to swing back and forth, the O2 voltages are cycling. This is when the ECU is using the O2 sensor for feedback and tries to gain a fuel mixture as close to Stoich. as possible for best fuel mileage. The other mode is closed loop, when it Stops cycling back and forth, and the O2 voltage is rather steady. This is when the ECU disregards the O2 sensor feedback, and then begins to run off of preprogrammed fuel maps inside the ECU.

Usually, the change over from Open and closed loop is related to 2 things: Throttle postion and RPM. For instance, on our DSM, anything more than like 50% throttle or somethign liek that, it goes open loop. and anything above 4000 rpm, it goes open loop, regardless of throttle position. So there may be a dead spot or a glitch when the ECU transitions from closed loop to open loop. its probably the reason why some MSP tend to run lean at partial throttle; because the Throttle isnt opend enough to cause the ECU to go open loop, and the ECU is still trying to gain a stoich mixture even though the turbo is creating postive manifold pressure. if this is the case, then you will have quite a bit of part throttle knock and get timing pull. Usually a safe A/F ratio in a turbo application is 12.5:1. Stoich is 14.7:1, or too lean for high load conditions. 11:1 is REally rich, and very safe for a turbo application, but its cooling the EGT's too much and doenst create as much cylinder pressure as it possibly could...so leaning it out a little would create a little more power, at the risk of incresing knock.

so, to sum it up: ECU and O2 sensor problems...i think

Branden feel free to step in

[yashooa]

Originally posted by psifactor

Branden feel free to step in

I'll step in...
In to what? Well that is a different story :D
Thanks for the length of your wind sir...
I saalute U....
(nuts)

Heehee good reaD none the-less DOOD.

[turboge]

I'll be working on the ECU problem soon. I am almost certain the programming is thoroughly flawed. There is no need to run 10:1 A/F ratios under such light boost. I've got a portable wideband and still might be able to hop on the dyno soon enough to play around with an S-AFC II and see what kind of numbers we can generate.

The hiccup from what I can tell could be a combination of a leaking Bypass valve or poor programming. If you give the car gas in any gear you can feel it stumbling. The 3500-4500 hiccup is due to air flow, we have solved this with the addition of the Injen intake. A little more playing around and we'll get it working how it should have been.