Building boost on line??
Will stall to about 4000 rpm on the brake so leaving there.
I stage, engage the brake and put it on the floor.
Stock rear brakes
Turbo is a GT-91 with a 91mm turbine and the housing that was on it was a 1.08, am being told that was too small which was causing the backpressure to be high.
lots of bad info in here...
two step/three step for an auto car only control rpm/total boost...not the ability to build boost
if you can't build on the brake against the converter, you aren't building any on a 2-step either
potential problems:
wrong cam
exhaust leak
boost leak
wrong converter
wrong turbo size
too much fuel
not enough timing
not enough compression
etc
two step/three step for an auto car only control rpm/total boost...not the ability to build boost
if you can't build on the brake against the converter, you aren't building any on a 2-step either
potential problems:
wrong cam
exhaust leak
boost leak
wrong converter
wrong turbo size
too much fuel
not enough timing
not enough compression
etc
Have an AMS-500 however it was not being used because we couldn't get it to hold the gate closed using boost because of the backpressure.
Will stall to about 4000 rpm on the brake so leaving there.
I stage, engage the brake and put it on the floor.
Stock rear brakes
Turbo is a GT-91 with a 91mm turbine and the housing that was on it was a 1.08, am being told that was too small which was causing the backpressure to be high.
Will stall to about 4000 rpm on the brake so leaving there.
I stage, engage the brake and put it on the floor.
Stock rear brakes
Turbo is a GT-91 with a 91mm turbine and the housing that was on it was a 1.08, am being told that was too small which was causing the backpressure to be high.
My tuner put one on the car and they said it had 15 psi of back pressure. It was a gauge that looked like it went where the wastegate goes so that it measures the backpressure where the wastegate sees it. Would this be considered a lot?
It needs to measure the pressure in the crossover between the headers and turbo. It had 15psi of backpressure when? idle, staging, down track? What was the boost pressure it measured 15psi?
Well that is in the crossover tube but its after the Y. I believe that 15 psi was at idle but I could be wrong on that as I didn't ask that exact question. The highest boost we can get it to boost to is 8 psi before the wastegate opens, and thats with a big wastegate spring, like a 15 psi spring.
If it had 15psi of backpressure at 8psi of boost, the turbine housing is probably too small. 2:1 back pressure at that low of boost will kill any motor. Its a problem I'm seeing more and more of with the cheap ebay turbos. Seems like the turbine housing/wheels are not efficient.
Well that is in the crossover tube but its after the Y. I believe that 15 psi was at idle but I could be wrong on that as I didn't ask that exact question. The highest boost we can get it to boost to is 8 psi before the wastegate opens, and thats with a big wastegate spring, like a 15 psi spring.
Well thats what they are saying too so thats why we are puting a bigger housing on it. This isn't a cheap ebay turbo though, its a Garrett, it is considered to be one of their "budget" turbos but its not some chinese garbage company that nobody has ever heard of. We got it here. http://www.forcedinductions.com/productsgarrett.htm
No I do not, I am sure the tuning shop does though, I will once its back together as I do have HPtuners but only drove the car enough to make a couple of shakedown runs.
So whats a good ratio of boost to backpressure thats acceptable?
So whats a good ratio of boost to backpressure thats acceptable?
Is your turbo a T4 or T6 turbine housing?



