i have a 2010 R56 JCW, about 3,000 miles on a new engine from mini, turbo also replaced at same time(also from mini), i installed a high flow cat down pipe from PLM. when the car is fully warmed up and i go WOT it hits some sort of limiter at 5000 rpm, almost sounds like anti lag, boost doesnt drop and a/f also stays around 13. it doesnt matter what gear its in. im stumped! it does the same thing with a catless downpipe as well, but not with the stock one. Any ideas? my only guess is MAYBE the Spark is being blown out? Thanks!

 

Sounds like a diverter valve problem. That or the waste gate is cycling too much. Take it back to the dealer that replaced things for you, and have them check it out.

 

+1 if they have a new warranty on that , have them check it out.

 

thanks for the reply @oldbrokenwind i actually checked that i have a forge bov thought maybe it had a leak replaced it with a brand new diverter same issue, so when they did the engine and turbo they only had a 1 year warranty. the engine and turbo were put in the summer of 2018. i did probably 5 hours of searching the forum and manage to find 1 other person that had the same exact problem, turns out his battery was dead, so at 2am when i found this i checked my battery voltage and it was reading 11.1v, he stated that he replaced the battery and the issue went away. so fingers crossed that, that will fix the issue.

Also mods to note:
PLM high flow cat
invidia q300 exhaust
cold air intake
turbo muffler delete
Upgraded intercooler
forge BOV

 

So i replaced the battery didn't fix the issue, (i knew it was a long shot but the battery needed to be replaced anyway) how would i go about checking the waste gate to see if it cycling too much?

 

There's an OBD II signal called "WGDC" --- waste gate duty cycle. Easy enough to access but need special equipment and knowledge of what to look for. Basic WG operation can be checked by applying a vacuum, 10 - 15 in Hg, and watch the WG close. PITA to access and view.

WG and DV are two different devices. Since you have a Forge BOV, that's the 1st item I'd check. Workmanship by a novice is always suspect. Since I have a big aftermarket turbo with an external DV I have no experience checking the OEM DV, that's why I suggested the dealer. Maybe someone else can help you diagnose it.

 

Ive been running the forge bov for 4 years no issue with stock JCW cat. put the high flow cat on and this issue pops up. i like to think i know this car pretty well but there is always more to learn it seems. i do all my own work, the issue is if i take it to a dealer they automatically blame the after market parts. When i was having am issue with the turbo not making boost they blamed the aftermarket intake tube saying they can not diagnose it until the stock one is on even though it passed the smoke test for leaks, so i had to buy a new stock pipe it obviously wasnt the issue. it was a bad turbo im just confused as to why its only doing it with the high flow and catless DP. i do appreciate your in put greatly @oldbrokenwind also i did do the vaccum test on the waste gate and no issue there, held just fine. could it be a park issue? i did replace the coils and plugs about 1000 miles ago when a coil went bad, plugs are gapped to .20. replaced hpfp at same time could a colder plug help do you thinnk since it is running 18-19psi. @MarioKart i would love to get your opinion on this.

Also worth a mention it did this with the old engine and turbo as well.

 

When most people get tuned they switch to NGK 1422 ILKR8E6 and gap them to .022.

 

Okay thanks @NeonLed
I’ll have to see what plugs I actually have I think they are just stock JCW plugs from what I read the 1422 are one step colder than that? The car isn’t tuned yet Going for a manic tune really soon. But I have all supporting mods for a stage II or III. Just want to get this figured out first. Do you know if the plugs on way motor are the correct ones? They don’t have a part number. I’m seriously doubting it’s a waste gate or bov issue

 

This sounds like a misfire to me. Maybe a HPFP starting to go out? I had a near identical issue after getting a stage 2 tune years ago. At like 4-5k RPM the engine would misfire under load, would be fine otherwise. No codes or CEL. After about a week I started getting the low fuel rail pressure codes and rough cold starts. Replaced the HPFP and it was fine. I would wait for any codes to pop up before throwing $1k at that fix though.

Are you tuned for the new downpipe? Generally you shouldn't have any issues beyond a CEL popping up for the O2 sensor but who knows.

My other thought is maybe you have a bad tank of gas and the engine is sensing knock and pulls timing.

 

I’m going to rule out the HPFP, I replaced that about 8 months ago when. Trouble shooting another issue. Also going to rule out bad gas because it has done this every time I only get gas at shell and Sunoco.

 

Way just says they are 1 heat range colder than the stock plugs. So idk. I just bought mine from here https://www.maperformance.com/produc...-x-ilkr8e6-set

Also if you're not tuned you shouldn't be seeing that much boost untuned. In this thread people were seeing 15-16psi when it overboosted https://www.northamericanmotoring.co...r56-boost.html. You might want to check and see what the dealership put the wastegate length to. They might have it tighten to much causing it make more than it should be.

 

You may just want to log fuel rail pressure when it happens. Anything below 2000psi at WOT would probably give you an issue.

 

@NeonLed okay thanks for the link! I will buy those today! You said gap them to .022 correct?

it could be that they are too hot of a plug and spark could be blowing out maybe due to too big of a gap

@thebombardier i have a scan gauge II, I’ll have to set it up to read fuel pressure. It could be an issue with the fuel pressure regulator, I was thinking that as well.

thanks for the quick replies!

Will update on the plugs as soon as they come in. Should be delivered the 15th.

 

Ya .022. The 1422 are a heat range 8 the stock plugs are 7. But youre not tuned right? Cause if youre running 18-19 psi on the stock tune that could also be the reason why the car is acting up.

 

@NeonLed yes I’m not running a tune I have a boost gauge and it will tell you peak boost and it peaked at 19 psi, thought that was high for a stock tune but it’s a JCW so didn’t think anything of it.

now I’ve read so many things on the gapping of plugs, do you know of hand what they come gapped to? I’ll have to buy a feeler gauge to check them

 

Mine came gapped to .022 when I check all of them with a feeler gauge.

 

NGK 1422 ILKR8E6 --- the "8" translates to heat range, and the "6" is translates to 0.6 mm. NGK sets gap at factory, but it should be checked --- VERY carefully, the electrode is fragile.

 

Got the ngk 1422 plugs (gapped to .022) still does it. I’ve notice itll rev fine to red line when there is no check engine or codes pending. But once I have a cel or cel pending for p0136 or p0141 it seems like it does the weird limiter thing at 5k. Is the computer doing something weird like a safe mode? It doesn’t seem “safe” when it hits that limiter it’s very violent sounding and thoughts?

 

My only other guess at this point is the same as NeonLed, that with the higher flow downpipe the car starts overboosting. The stock map doesn't have the ability to compensate for the extra air with fuel so it starts pulling timing.

 

i agree with you guys. It peaked at 20psi I have a glow shift boost gauge and it’ll tell you peak boost and it is 20psi on the dot.

i guess my only option is to get a tune??

I might throw my stock DP on for now.

thanks for your help! @NeonLed @oldbrokenwind @thebombardier

 

I remember back when I started out on scratch with my 09 MCS, I came to this forum asking for details about what might happen if I were to upgrade my stock turbo into JMTC-42 without a tune. Definitive answer I get is that the stock MCS tune cannot handle the much increased boost from the stock 13 psi limit, with a slight over-boost to 15-16 psi is fine, but the stock tune definitely does not support full boost at high levels beyond 5,000 rpms. Fortunately I did get a RPM stage 2 tune before I upgraded the turbo (I settled for JCW turbo + JCW manifold kit + catless DP), so I didn't experience anything like you're going through. But I can imagine if they were correct, had I gone up with turbo and exhaust upgrade without a tune, 5,000+ rpms is where I would see similar event like yours. Since you already have a JCW, but the fact that when you free up flow and get a boost raise then experience that limitation beyond 5,000 rpms, it's what I would speculate that maybe even the JCW stock tune has the same sort of limitation once you go free up the exhaust flow by much. I suspect that your problem can all go away with a tune which handles the consistently lengthened over-boost.

 

You need to fix your overboosting issue first. Any issues you have with your car will only be amplified with a tune, not fixed by it. I would start with backing the wastegate screw off little by little until you start seeing a change.

On a tune, the car will be able to set fuel and timing for higher boost but it will also try to create even more boost than you're already making. I recall a member on here a while back hitting over 22 psi on a stock turbo with the wastegate overtightened on a Stage 2 tune, which is in the danger zone for the stock engine internals.

 

Like I said in one of my posts earlier, you need to check and see what the length is on the wastegate actuator. All you have to do is take the top heat shield off and measure it.

 

Update! I had the car tuned by @MarioKart ,thanks man! stage 2 tune and his catless downpipe fixed the problem of the breaking up at 5rpm but what I didn’t realize is it was over boosting by 5psi before the tune and now it is over boosting after the tune as well I’ve been working with Mario and we are both stumped now. We’ve been going back and forth but no idea

it boost fine in non sport mode 15psi all day, but when I have it in sport mode it should only boost to about 21psi and it does 25psi, not the tune since it did it before it was tuned

Some of the things I have replaced in trouble shooting is the boost solenoid, checked the vacuum lines, both map senors, bov( tried a new stock one and currently have a brand new forge motor sport on) checked the waste gate with vacuum pump and the waste gate rod to make sure it was correctly adjusted still over boosting. Even tried backing the waste gate nut off all the way to the end and nothing changed

its just an odd thing because you only hear of these cars not making enough boost. Any ideas? THANKS!