Jump to content
The mkiv Supra Owners Club

bpu but getting stock boost


mellonman

Recommended Posts

all

i have a jspec tt been bpu for a while now but have a problem.

it started with getting over boost at gear change 1.3

and when setting my avcr up to compensate have noticed the the duty was high so then thought today i would check what boost i was getting with it set to off and have found that the first turbo is only making 0.6 and at full boost 0.9

 

any hopes for me?

Link to comment
Share on other sites

  • 3 months later...

I imagine it was the HKS filter that killed them, the blades look eroded and it's fairly mangy in there, things should be pretty clean in the intact tract apart from oil from the PCV system.

 

Are you seeing normal boost on the first turbo? Is it only once the second comes online that you don't get past stock boost? How have you gone BPU?

Link to comment
Share on other sites

Also, is this a change, i.e. did it used to work ok and now it only reaches stock boost, or has it always been like this? Your first post reads like it always behaved so, in which case perhaps just tune the boost controller to make 1.2bar instead of 1.3?

Link to comment
Share on other sites

first turbo 0.7 then second 0.9 about 5000rpm maybe due to hybrid!, the first cat is 2.5 and then 3 with cat back

im not sure if it always done it as had he avcr before i went bpu

when i turn up the avcr the car seens good as gold but just had a aem fic with 650 injectors and fuel rail hoping this would help but have had some problems

they say it was gonna det at 1.2 @390 bhp

but the had no o2 fitted and had not wired in the wide band i have

they still had the hks fcd wired in

 

does it look like my engine is shot it sounds sweet

Link to comment
Share on other sites

Are the decats both 3"? I only hit 1.0bar with a 1.2bar restrictor ring in place.

 

When you say hybrids, do they have the UK wastegates? Have you tried using the AVCR to up the boost or are you trying it without any boost control?

 

yeah i am doing this without avcr on, when its on all is normal or so i thought till the mapper said it was gonna det at 1.2 but i had been running that for the last 2 months before it was half mapped by him

and still has jspec waste gates

Edited by mellonman (see edit history)
Link to comment
Share on other sites

Maybe the EGBV is siezed/ the vsv not working? Tried it in TTC mode?

 

tryed in ttc and was the same just some looooonnneeeey lag

i made sure the egcv was free they are had to move anyway right due to spring tension, the egbv vsv is bypass due to avcr

 

The egbv is the no2 waste gate right?

Edited by mellonman (see edit history)
Link to comment
Share on other sites

Your engine isn't shot :)

 

It won't det at 1.2bar as long as everything (fuel system, ignition etc) is working properly - hundreds of people run 1.2bar BPU on a daily basis.

 

Turning off the AVCr causes lag as there is no clever boost control any more - the wastegate creeps open as boost pressure rises. It won't limit maximum boost but it does slow production of it. The stock valve that stops wastegate creep is bypassed in the installation of the AVCr.

 

Your first decat of 2.5" might be the restriction. Different cars behave different ways for some reason, which is why the restrictor ring size is always a bit of a dark art.

Link to comment
Share on other sites

Your engine isn't shot :)

 

It won't det at 1.2bar as long as everything (fuel system, ignition etc) is working properly - hundreds of people run 1.2bar BPU on a daily basis.

 

Turning off the AVCr causes lag as there is no clever boost control any more - the wastegate creeps open as boost pressure rises. It won't limit maximum boost but it does slow production of it. The stock valve that stops wastegate creep is bypassed in the installation of the AVCr.

 

Your first decat of 2.5" might be the restriction. Different cars behave different ways for some reason, which is why the restrictor ring size is always a bit of a dark art.

 

He has a 2.5" decat? I read that he has a CAT pipe in place, as i aksed him specifically.

Link to comment
Share on other sites

Your engine isn't shot :)

 

It won't det at 1.2bar as long as everything (fuel system, ignition etc) is working properly - hundreds of people run 1.2bar BPU on a daily basis.

 

Turning off the AVCr causes lag as there is no clever boost control any more - the wastegate creeps open as boost pressure rises. It won't limit maximum boost but it does slow production of it. The stock valve that stops wastegate creep is bypassed in the installation of the AVCr.

 

Your first decat of 2.5" might be the restriction. Different cars behave different ways for some reason, which is why the restrictor ring size is always a bit of a dark art.

 

great :D

good explaination about turning off the avcr, looks like a file and the restictor ring will be having a chat

Link to comment
Share on other sites

scott i have no cats first de cat is 2.5 and second is 3

 

Ahh, you said the first CAT was 2.5" ;)

 

The smaller diameter decat pipe will lower the pressure a little. I think the restrictor rings are designed for use in a 3" straight through system so anything less than that will require a little modification. I would suggest aiming for 1.0bar in low gears and 1.1bar in higher gears (Without the boost control on). That way you will keep your EGTs down while not having to worry about boost spikes.

Link to comment
Share on other sites

OK I've been reading your other thread and as I've pointed out there, you have a lot of unresolved issues with the car including detonation problems. Stop chasing power, BPU, or even giving the car any sort of abuse until you've fixed them.

 

Let me re-iterate this part of my "your engine isn't shot" comment:

"It won't det at 1.2bar as long as everything (fuel system, ignition etc) is working properly"

 

Sounds like it isn't.

Link to comment
Share on other sites

OK I've been reading your other thread and as I've pointed out there, you have a lot of unresolved issues with the car including detonation problems. Stop chasing power, BPU, or even giving the car any sort of abuse until you've fixed them.

 

Let me re-iterate this part of my "your engine isn't shot" comment:

"It won't det at 1.2bar as long as everything (fuel system, ignition etc) is working properly"

 

Thanks for taking the time to look ian

this thead was started some time back before i had aem fitted just revived it to see if i could get any ideas on if i have a problem or if it was normal to get them figures with avcr off and looks like that is all normal so im happy there :)

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.