boost probs

[Mase]

I've fitted a couple of different bleed valves and each time it wants to hold close to the right boost in 1st, then every other gear tries to go all the way to 1bar before it hits the fuel cut. Anybody got any ideas as to what this is? Im concerned that if i get an electronic one it may not work also.

Thanks

[bbenny]

fuel cut is a bitch! you should be able to get a bleed valve to spike at about 1bar and drop a little under without hitting fuel cut. if you have a standard turbo i wouldnt run it any higher than that anyway. if you have an aftermarket turbo i would get your ecu retuned or buy a fuel cut defender...

[Vovan]

better reprogram your ECU, as fuel cut defender changes the airflow that the ECU sees and doing this make your mixture leaner, because ECU sees less air and provides less fuel.

[Mase]

The problem isn't the fuel cut. The bleed valve was adjusted accordingly and no matter what it doesn't hold boost. I set both bleed valves to run at 0.7bar and each time no matter which way i turned the valve 1st gear would hold the boost level desired then 2nd gear onwards would try and go all the way to 1bar. Any ideas?

[bbenny]

hmmm have you tried moving the bleed valve all together, i know my turbosmart valve wouldnt run anything less than 1bar, they arent very good.

otherwise look for a split in the actuator hose, ive seen splits that cause overboost a few times.

first try removing the bleeder, if it still runs over 0.7-0.8bar replace the vacume hose and try again

[Mase]

nah as soon as the bleed valve is out it runs stock boost no problems at all. I've run new vacuum lines there too just to be sure. Still no difference. Im just concerned that when i buy an electronic boost controller that it may not work either.

[bbenny]

nah buy an EBC they control the boost level, basically you tell it what you want to run and it holds the wastgate closed till it reaches that level then opens it.

they are far more precise than a bleedvalve. im ditching my bleedvalve for one now.

im looking at either a blitz SBC IDii or an apexi AVCR both of those give you alot of precise adjustments.

not as cheap as a bleed valve unfortunately

[gtstii]

do you have a dump pipe on the car - what sort is it?

[rb25]

you might wanna try disconnecting the standard boost solenoid.......

[Skyrine-Dave]

2nd and 3rd gear would be spiking alot harder due to the extra load = boost and the bleed valve struggling to bleed off the extra boost. 1st gear on my car doesnt come close to full boost i think it goes to about 7psi.

[Skyrine-Dave]

just found a problem.. my boost guage is only reading to 5psi for some reason now!!! its definately boosting harder than that.! time to go trouble shooting.

[rb25]

hijacked!!!

[Mase]

IT may have a 3" dump pipe on there but im not 100% sure, either way it goes straight into a stocko silvia exhaust after that. Where do i remove the stock boost solenoid??? 2nd gear onwards doesn't hold boost at all no matter where the bleed valve is adjusted to. Im just concerned that when i get an ebc it won't work either.

[rb25]

Jay95R33 has described it well in this thread.

http://www.skylinesaustralia.com/forums/sh...&threadid=22301

-rb

[Mr R32 M-Spec]

My friend has a 180sx 2L turbo. he put his on the dyno the other day at CRD and was dissapointed that it wouldn't hold boost either, he has a FMIC, dual stage boost controller, bosch fuel pump, filter exhaust...

CRD put it down the the fact that no matter how high they boosted it, it wouldn't hold the boost because there was a loose spring in the turbo that was soft. so his spikes to 17PSI but drops straight off to 12PSI or so. only makes 153.4KW at the wheels. it should be making more, he is going to change the turbo.

sorry to ramble, just thought if you had a stock turbo that might be the problem

[Mase]

grrr, now i think my turbo is on the way out cuz it was trying to go all the way to 1 bar. Very frustrating.