Boost Leak?
I have an MBC and a bigger FMIC...
Normal -- It can't be normal...my buddy has a stock evo with no boost controller and his holds 19psi all the way to redline in every gear....and I am constantly reading about guys cars pulling the same boost in all gears. If it is normal than I want to do what all the abnormal guys are doing to get theirs to boost in all gears.
Noize,
So your car does not hit and sustain the same boost in 2nd as it does 4th???
thanks for the help guys... i appreciate it...
If something is wrong I want to fix it, if nothing is wrong I want to fix my head so I can believe nothing is wrong.
-Doug
Normal -- It can't be normal...my buddy has a stock evo with no boost controller and his holds 19psi all the way to redline in every gear....and I am constantly reading about guys cars pulling the same boost in all gears. If it is normal than I want to do what all the abnormal guys are doing to get theirs to boost in all gears.
Noize,
So your car does not hit and sustain the same boost in 2nd as it does 4th???
thanks for the help guys... i appreciate it...
If something is wrong I want to fix it, if nothing is wrong I want to fix my head so I can believe nothing is wrong.
-Doug
A stock EVO will not hold 19 psi to redline. I would call Buscher. I have never owned a bigger FMIC so I don't know how they behave. I do know there is a pressure drop when using them. Which can cause some lower end lag.
I know that a sotck evo will not hold boost...I had one and it would not hold. However I have ridden in his car and it holds.... even if his gauge is messed up it still peaks and holds at the same level in all gears with no taper...and that is all I want to peak and hold that level in all gears...
Buschur told me it is normal... I just want to get other opinions. The car drove like a champ when I got it back from them. Then got a hole in the intercooler (you can see it in my avatar). The car ran extreemily rich as it was not getting any air. I got another FMIC from Buschur put it on and tightened everything up had it pressure tested etc. However the car definately does not pull as hard in 1-3 as it did before...ofcourse this pull is measured by my butt...real sicentific I know...
-Doug
Buschur told me it is normal... I just want to get other opinions. The car drove like a champ when I got it back from them. Then got a hole in the intercooler (you can see it in my avatar). The car ran extreemily rich as it was not getting any air. I got another FMIC from Buschur put it on and tightened everything up had it pressure tested etc. However the car definately does not pull as hard in 1-3 as it did before...ofcourse this pull is measured by my butt...real sicentific I know...
-Doug
Are you running a cat? If your car was running really rich that can cause it become slightly plugged, which might be part of the problem, but I have a feeling you are probably running a test pipe so that won't apply. If Buschur says that's how it is suppose to be, then that's the way it is suppose to be.
Originally Posted by RallyRedEVO
I have a Vishnu Stage 1 XFlash, with a signature turbo back exhaust. I just got my boost gauge installed, and I was watching it. I noticed that at idle, it seems to hold around 14 -16 vac. And that when I get on it, the gauge will jump up to what looks to be around 24 - 25 PSI, then settle back down around 20 - 21 ( hard to watch at that speed ) up until around 6000 RPM. Then at around 6000 RPM, it seems to start backing off, until it goes almost down to 12 - 13 PSI at 7000 RPM. Is that normal, or do I maybe have a boost leak? Thing is that it does this pretty consistently.
I'm just concerned because I don't have much more time to get new parts in, if I need them, before the May dyno day.
Thanks
I'm just concerned because I don't have much more time to get new parts in, if I need them, before the May dyno day.
Thanks
I experience the exact same thing...can't sustain boost in lower gears...boost will spike to about 24psi then settle to about 20 psi on WOT.
on top of that, i get the "misfire" (p0300 error) while cruising in 5th...and it gets worse after the first "shudder".
i've tightened those 3 clamps on my stock BOV...changed to BPR8ES's (.24)...changed all driveline fluids with Mitsubishi "stuff"....
planning on getting a new BOV, a new intake (too bad I threw my stock box)..I dunno.
CAR RUNS LIKE CRAP!
Shiv, when can you start tuning our EVOs....they need attention
you guys are upset about settling to 20 psi in the low gears. Try only getting 18 psi or so...that really sucks...
jj_008,
Yes I have a high flow cat... what do you mean by "plugged"???
thanks for the help...
-Doug
jj_008,
Yes I have a high flow cat... what do you mean by "plugged"???
thanks for the help...
-Doug
I think you guys are too obsessed with holding your peak boost til redline. You are not necessarily making the most power that way. You may be just overspinning and overheating the turbo for no good reason. Of all the Vishnu dyno charts I've seen here w/ accompanying boost chart, they all taper a few psi to redline and still make nice power up there.
chickenbtrest.. What are your mods?
It is important when tapping off the FPR to make sure all joints are zip tied ...While under boost, as we experiment with higher pressures, it is possible for the rubber tube to expand and pop off leaving the motor in a lean and dangerous state
this has happened once on my car on the dyno and because of the type of dyno I was using I was able to abort the run before any damage was done....
It is important when tapping off the FPR to make sure all joints are zip tied ...While under boost, as we experiment with higher pressures, it is possible for the rubber tube to expand and pop off leaving the motor in a lean and dangerous state
this has happened once on my car on the dyno and because of the type of dyno I was using I was able to abort the run before any damage was done....
Dyno4mance,
I have Buschur Stage 4 - including complete new exhaust and intake piping (both lower and upper), new bigger FMIC, BOV, MBC, 264i/272e cams, buschur flash, SAFCII.
The FPR is untouched. I also had it pressure tested to 30psi + and do not notice taper in higher gears so do not think it is a leak. Also just had it tested with a wideband o2 to check the air/fuel and everything was fine.
The cat was not checked....but would that only effect 1,2 and 3 gear???
weightless,
I am not obsessed with holding peak boost. My problem is that it will not boost in 1,2,3 the same as it does in 4,5. My MBC seems to be holding boost jsut fine. It is getting to the boost level that I have a problem with. Not only does it not boost as high it also appears to take longer to get there. Boost taper is one thing but not boosting to the level in the first place is something else.
-Doug
I have Buschur Stage 4 - including complete new exhaust and intake piping (both lower and upper), new bigger FMIC, BOV, MBC, 264i/272e cams, buschur flash, SAFCII.
The FPR is untouched. I also had it pressure tested to 30psi + and do not notice taper in higher gears so do not think it is a leak. Also just had it tested with a wideband o2 to check the air/fuel and everything was fine.
The cat was not checked....but would that only effect 1,2 and 3 gear???
weightless,
I am not obsessed with holding peak boost. My problem is that it will not boost in 1,2,3 the same as it does in 4,5. My MBC seems to be holding boost jsut fine. It is getting to the boost level that I have a problem with. Not only does it not boost as high it also appears to take longer to get there. Boost taper is one thing but not boosting to the level in the first place is something else.
-Doug
finally found a "fix" for my EVO's problems (surging, shuddering, p0300, boost spikes, popping exhaust on decel, etc......)
timing was off....that was the case with my setup.
adjusted Crank, MAF on my piggy-back - car is smooooooth again.
aaahhhhh.....happy hour....
but wait! gotta find out first what triggered those whacked values on my piggy.....
naaah....that will have to wait. Single malt for now......
looking at all the plugs, driveline fluids, tools, grease, receipts from the past week or two......
timing was off....that was the case with my setup.
adjusted Crank, MAF on my piggy-back - car is smooooooth again.
aaahhhhh.....happy hour....
but wait! gotta find out first what triggered those whacked values on my piggy.....
naaah....that will have to wait. Single malt for now......
looking at all the plugs, driveline fluids, tools, grease, receipts from the past week or two......
Newbie
Joined: Aug 2003
Posts: 99
Likes: 0
From: Canandaigua, NY
Originally Posted by chickenbrest
Ok here is one for you guys...
First off let me say that I do not have a Vishnu tuned car. That being said I seem to be having problems with my boost.
The problem appears to be in 1,2, and 3 gear...4th and 5th seem ok. I am able to get 1.4 (20.58) bar spike and hold in 4th and 5th gear all the way to red line. However in 3rd the best I can get it 1.3 bar and then drop a little around the 6000 mark. 2nd gear is like spike at 1.3 but drop to 1.2 or 1.1 and 1st gear is 1.2 or 1.1 max.
Does anyone have a clue as to what might be causing this. The car seems less torquey. It will still accelerate but not as hard as before, especially in the low gears.
I have had it pressure tested up to 30+psi so I do not believe it is a leak plus the boost does not drop in 5th at all and pretty much hold true in 4th as well. The issue is that I just can't get it to boost up as high in 1,2 and 3rd.
Any ideas???
thanks,
-Doug
First off let me say that I do not have a Vishnu tuned car. That being said I seem to be having problems with my boost.
The problem appears to be in 1,2, and 3 gear...4th and 5th seem ok. I am able to get 1.4 (20.58) bar spike and hold in 4th and 5th gear all the way to red line. However in 3rd the best I can get it 1.3 bar and then drop a little around the 6000 mark. 2nd gear is like spike at 1.3 but drop to 1.2 or 1.1 and 1st gear is 1.2 or 1.1 max.
Does anyone have a clue as to what might be causing this. The car seems less torquey. It will still accelerate but not as hard as before, especially in the low gears.
I have had it pressure tested up to 30+psi so I do not believe it is a leak plus the boost does not drop in 5th at all and pretty much hold true in 4th as well. The issue is that I just can't get it to boost up as high in 1,2 and 3rd.
Any ideas???
thanks,
-Doug