how much back pressure do you guys have?
i thought mine was a little high, iam only boosting 14psi

my setup is
b16a1
Garrett 57trim stage 3 turbine 63 A/R
UGR manifold 3"downpipe and exhaust with no cat
itr cams
the light blue line is rpm
the pink is boost
yellow is back pressure
max backpressure was 1,4 bar
[IMG][/IMG]

 

you probably shoud have went with a .80 or better A/R. anyways are you sure you arent building a crap load of crankcase pressure

 

i have a catchcan with 2, 12an from the block and the headcover has a filter on it.
why do you ask that?

 

ok just checking have you tried setting the catch can up from the back side of the block ?
also whats the turbo specs and how much you reving it too

 

yes its from the back of the block and i am reving 8800 but i shift gear when i reach 8500.
the turbo is a garret t04e/t3 57 trim
stage 3 turbine wheel 63A/R on the turbine and 60 on the compressor

 

Where are you monitoring backpressure?

 

i took it one Inch from the collektor

 

what kind of power is the car making? where does it peak? and where does it fall off?

these answers would determine if backpressure would even be of concern.

 

we had one guy running 29psi of boost and had 75psi backpressure LOL

he was wondering why the wastegates were opening on their own.

 

haven't dynoed yet but i have checked my hp with a gtech and a AP22 and it sas that the peak hp is around 8200-8500. the car pulls hard all the way to readline

 

That would be a 1.55:1 ratio - thats not high at all. Most oem setups go well past 2:1, while VERY few 4-cyl turbo setups go below 1:1. You will tell when your exhaust/turbine becomes a big restriction - torque will drop like it was a V8 at redline.

 

but the b16 with itr cam should be very sensitive to backpressure because of the high value cams. a friend of mine drive a s40 t4 with 442 hk and 30psi and the backpressure don't pass the intake pressure
he has one of these turbos, made in Sweden but the price is 2100$
http://www.turboservice.se/KX500.html
its a kkk27 but with some other pieces