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the whole problem story - car won't go over 5100rpm


wilkorangerover

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Even if you'd fubar'd your turbo's from what ever arrangements you have or from driving around with pipe blown off, would have thought you'd still have all rpm available to you, albeit reaching high rpm slowly.

 

I did wonder whether your Ebay intercooler was blocked with summink but then you said the cars fine for 1st 10-15mins till it warms up so that rules out that idea.

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To assist with the explanations - iirc Adam had the Apexi DV on a stainless pipe,a nd not in stock location, so i guess its all been blanked off now.

 

Not sure it's a very good idea having no pressure relief on throttle release, don't see it limiting rpm but get a stock item on there at least.

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Not sure it's a very good idea having no pressure relief on throttle release, don't see it limiting rpm but get a stock item on there at least.

 

It shouldn't or couldn't really cause an issue apart from compressor surging which on boost shouldn't be an issue as surging occurs when there is more pressure on the downwind side of the compressor than torque on the shaft from the exhaust side ie when you lift you close the throttle valve and stop the air continuing through the engine hence causing pressure in your inlet with nothing coming from your exhaust to turn your compressor. Sounds on a single like a loud chattering swooosh swoosh swoosh swooosh swoooooooosh (I get this every time my pipe to my BOV pops off.

The stock system is however very complicated so I wouldn't rule out the lack of BOV being the problem.

 

 

One side note. Are you auto or manual? Does the car go through 5100 rpm if you take it easy on the throttle advancing the revs slowly? I ask as my car used to do exactly this at WOT.

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OK that rules that out then. My moneys on excessive boost causing boost cut in and around 5100 rpm in all gears (although from memory 120 isn't quite 5100 rpm in O/D on)

 

But he's not actually getting boost cut "exclamation warning, engine check light, etc" is that correct? Which he would do if he was hitting the overboost cut?

 

The rpm is limited to 5100rpm after 10-15mins of driving as far as i could understand from whats been said.

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Wilko you say you had a atmospheric dump valve on the car right? And you took it off? The question is did you put a stock recirculating dump valve back on in it's place? Or is it just blanked off?

 

Sorry if this is already answered lol

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Could it be anything to do with the second turbo not coming online? Rather than a rev limit as such?

When my second turbo stopped coming online (Auto) it was the VSV's or Actuator getting stuck. This used to happen once the car got warm. Failing that a pipe on wrong?

 

Disclaimer: I dont do tech :innocent:

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Maybe the bulbs out on the warning light.

 

Both of them?? And you'd probably notice at start up if they were missing. Hmm very strange one. Quick check of fault codes would probably be the first place to look before doing anything else as its the easiest thing to do.

 

Reading back through it then the facts are

 

Car will boost and act perfectly normally with WOT and boost, the car will sail past 5100 RPM no bothers at all, It will also go past 112 mph if you manage that in 10 minutes of setting off cold? Am I right in that?

 

Then after 10-15 minutes the car changes characteristics completely and will not go beyond 5100 RPM in any gear?

 

How does it get stopped at 5100? Does it feel like fuel cut ie sharp loss of power and a couple of seconds before the power comes back online again?

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Wilko you say you had a atmospheric dump valve on the car right? And you took it off? The question is did you put a stock recirculating dump valve back on in it's place? Or is it just blanked off?

 

Sorry if this is already answered lol

 

hi guru, no i didnt put anything in its place just the new stainless pipe which came with the intercooler

, how do i check the actuator ????? for the second turbo??

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If its doing it at a set speed which the revs seem to be suggesting then there is some sort of speed limit going on here. What device do you use for delimiting the vehicle? I ask as the apexi RSM I used to use could be selected to any speed you desired the car to be limited to.

Its a bit odd because for sure 5800 rpm in second is nowhere near to 100 mph (mines getting to just over 120 KMpH at that revs in second). Looking at my dyno sheet 3rd gear 5727 rpm is 107 mph (ok diffs etc are going to vary slightly from an aristo to a supra but not that much).

If you have a mate with a video camera maybes its time to get onto a private test track and get some of the driving on tape so you can review it and post your findings. But for now first things first perform an ecu diagnostic. http://www.mkivsupra.net/vbb/showthread.php?t=35920 see what that throws up.

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