trying to get some turbo surge fixed... have an 05, still has the stock water to air cooling + an fmic on a 3071r internal wg on a .64 ar. looks like when i'm up in the boost pretty good the maf is reading surges although i can't hear them. has hallman pro mbc

the turbo is definitely not too big for the car, so what kind of options am i looking at? i'm not sure if the oem intake manifold is capable of causing this issue or not since it's so restrictive.

any ideas?

 

whats your BOV set up like? make sure it's opening immediately

 

running a turbo xs rfl.. it is instant, also loosened the bov tension form all the way tight to almost all the way open and it does the same thing both ways. i was questioning the way this is hooked up though. the bov has a boost access port about 6" on the charge line away from the turbo, then about 6 inches closer to the intercooler is the bov. the bov boost port is tee'd into the boost port in the middle of the manifold on top (where the stuff hooks up).

do you think that maybe it has to do with the bov getting boost activation from between the engine and air to water cooler and the bov being way down the line near the compressor?

i was thinking of changing the boost source for the bov to the same point that the boost controller gets it from

 

I'd have to see a picture to visualize exactly where its hooked up. but if the line is off of the intake mani it should be fine, shouldn't matter where your actual bov is.

My bov is about 10 -12" away from the turbo and I run a line from the intake mani to the bov.

A good way to check is rev it up in neutral and watch your bov it should open as soon as you let off. if not possibly your line is pinching or the spring is too stiff.


Asides from a bov issue I can't see anything else causing this surge

I would try and run a line straight from the intake mani to the bov

 

ok will try that. will unhook the boost controller and hook it into that one

reason i mentioned where it hooks up is because there is a pressure difference form where the bov is to where the actuator is plugged in. when on the dyno they picked up peak of 22.6 psi (wired into the first charge pipe), and on the computer it only picked up about 20.4 psi iirc

guess the intercooler and the water to air cooler together drop the pressure a decent amount

nix that^^^ wasn't even thinking it needed vacuum not boost lol

 

fix?

 

just to specify this is WOT/under load surge, not when i release the throttle

 

oh **** I didnt see that in the first place. I have no clue on that one, possibly related to recirc wg dump

 

What wastegate setup do you have? How big is your exhaust? I had issues for year because of a bad exhaust setup with a recirced gate.

 

it's a full 3" with a zzp catless downpipe and hahn exhaust

wastegate is internal

 

are you sure its not the placement of your MAF sensor? I had an issue with my maf freq was choppy at high rpm's and it wasn'tbecause of surge, it was because of my MAF location. If the MAF is too close to a bend, either before, or after it, it can cause a choppy MAF frequency reading.

 

i'm not sure on the maf reading wrong or not, it's dead in the center of the length of the pipe that goes from the intercooler to the throttle body on a straight section.

if i post the hpt logs would that help see what i'm talking about?

 

yes...please post log

 

this is the config file used to log:

http://rapidshare.com/files/39223915...nfo_4.cfg.html

dyno run 1

http://rapidshare.com/files/392239153/run1.hpl.html

dyno run 2

http://rapidshare.com/files/392239154/run2.hpl.html

i have the dyno sheet scanned somewhere that shows the hp/tq/boost/afr on it, not sure if that would help but i cna find it and upload it too

 

you get spikes of knock right when it occurs too

 

yeah that was just a splurge on the dyno, think from being under heavy load in 4th. we didn't see it in any more of the runs after the first two

here's a couple more from the street:

http://rapidshare.com/files/392280676/run3.hpl.html

http://rapidshare.com/files/392280677/run4.hpl.html

and have plenty more that stay on zero kr, so we weren't too concerned with those hiccups

do you think there may be something to do with having the stock cooling system and the fmic choking it down?

 

your IAT2s never exceeded 160ish from the log i looked at

the DeltaP accross the FMIC shouldnt be an issue for the laminova manifold, not the ideal setup but at least it is cooled

 

yeah the temps are definitely not a concern. i was looking at it from the perspective of the laminovas themselves causing a good amount of backpressure, especially when already going through a intercooler.

already in the process of ordering an rdfabs intake, so this will be taken out of the equation as soon as i can get that

 

rd fabs mani is awesome but FYI, FMIC wont cause back pressure, it causes pressure loss due to expansion