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Juggy
10-07-2008, 12:53 PM
ok, so ive been having a cutout problem lately!!!
i cannot figure this out.

the car is not pulling any codes, and the car cuts out at various random rpm/boost ranges, and im believing it to possibly compressor surge??

what causes this?? can a small air filter contribute to surge?
im running a kind of small air filter on a 3" CAI setup...was thinking about running it open but i already munched up one turbo doing that and id rather not mess up a GT30R

its a 2.2 G headed car, runnin 3 bar cal. the car runs like poop on a stock cal with the 2.2 and g head :(
contraption22
10-07-2008, 01:09 PM
The 2.2/G head combination is very tricky, especially if you are running TII pistons with the G head. The compression is very low, and if you are using a swirl head cal, the ignition is too lazy.

I don't really have an answer about the compressor surge.
tryingbe
10-07-2008, 01:55 PM
What calibration are you using?
inmyshadow
10-07-2008, 03:04 PM
compressor surge happens when you lift off the throttle and the BOV doesn't work or flow enough.

For compressor surge, what are you running for a BOV?

I'm using a Greddy Type S. It was working fine using two vacuum sources. But my new Super60 didn't have the vacuum fitting on the compressor housing. I would get compressor surge with either one or both vacuum lines hooked up to my BOV. I found a site that shows how to modify the BOV so it works more like a DSM bov. Now I don't have problems.
Juggy
10-07-2008, 03:04 PM
yes im running TII pistons with the G head. its a cal from a local board member, it has 25 degrees additional timing over a stock TII cal and we are running similar setups, and he has already run this calibration without issues

i just cant seem to get to hold it down at WOT without it cutting out, theres no knock light coming on, wideband was reading good i know the cal is rich (but now wideband is reading stoich at almost all times??? wtf??? sensor bad? who knows)
Juggy
10-07-2008, 03:06 PM
ok its def not surge then, its a Tial sport 50mm diapragm on the 11psi spring

its only happening at WOT
Mopar318
10-07-2008, 03:20 PM
A miss match of Turbine/Compressor selection along with the engine can have ALOT to do with compressor surge.

The bov is not the main concern.

What your describing, almost sounds like your blowing out the spark. Your gap may be to large on your plugs. A high ignition coil, and a shorter gap will help prevent this.
Speedeuphoria
10-07-2008, 04:00 PM
compressor surge happens when you lift off the throttle and the BOV doesn't work or flow enough.


A miss match of Turbine/Compressor selection along with the engine can have ALOT to do with compressor surge.

The bov is not the main concern.

Yes 2 different things, that people call surge. One has to do with the BOV and the other is essentially spooling too fast, hence the surge line on the compressor maps.
Juggy
10-07-2008, 05:56 PM
im running an MSD blaster 2 coil, and RN9YC plugs gapped to .030"

I think i might switch back to the 12YC's with this G head

I just swapped out the HEP, hopefully I can hold WOT!!! im stumped otherwise :confused:
t3rse
10-07-2008, 06:26 PM
I would gap the plugs down to .023 and see if it helps...
Frank
10-07-2008, 06:28 PM
Try dropping the gap to 0.024 and see what happens. Also try a different coil
Frank
10-07-2008, 06:28 PM
Blast you beat me too it!
contraption22
10-08-2008, 12:05 AM
I'd agree with dropping the plug gap and swapping the coil out for a stocker.
8valves
10-08-2008, 09:08 AM
Dang, you guys run some small plug gaps!
Juggy
10-08-2008, 10:22 AM
Dang, you guys run some small plug gaps!


YA HOLY CRAPPP!!!! :nod:

so im taking it that, blowing out the spark feels like OB cutout??

ill regap and swap back 2 stock coil 2day, and go for a spin when the weather is looking better :( I had a stocker coil in there b4, and the same thing was going on. that resistor pack that bolts onto the bracket with the 1 wire on it, this goes to the (-) side of coil right??? are they really needed?? I dont even have one one right now.

Another thing I was thinking is that maybe I just have a bad SMEC, theres a couple others with socketed comps in town so im going to try another computer too if this regap and coil thing dont work.


i went for a ride yesterday and was able to get up to 18psi, cars screams....until it cuts out! so i was able to hold it down and wind it out a bit, then when it cuts out, i try to get back in it and it will basically just keep cutting out as soon as I go WOT, even 3/4 pedaling it and she cuts out.
Juggy
10-08-2008, 10:40 AM
I would also like to mention that I disconnected the knock sensor and the problem was still persistant! so I know its not that. im guessing the gas is about 98 octane? 4.5 gallons of 110 with about 6 passes down the strip, then topped off with 91 octane.

timing is good, I have the taft S3 cam advanced 4 degrees and have ran it as high as 8 degrees
Frank
10-08-2008, 11:22 AM
Sounds like spark issue...
8valves
10-08-2008, 02:06 PM
I would also like to mention that I disconnected the knock sensor and the problem was still persistant! so I know its not that. im guessing the gas is about 98 octane? 4.5 gallons of 110 with about 6 passes down the strip, then topped off with 91 octane.

timing is good, I have the taft S3 cam advanced 4 degrees and have ran it as high as 8 degrees

How does that cam act if you try to retard it? <Random un-related curiosity>

Usually when I ran into spark blow-out it's not violent like an OB condition, more like a stuttering, not a shutdown.

Which is yours like?
Mopar318
10-08-2008, 02:24 PM
YA HOLY CRAPPP!!!! :nod:

so im taking it that, blowing out the spark feels like OB cutout??

ill regap and swap back 2 stock coil 2day, and go for a spin when the weather is looking better :( I had a stocker coil in there b4, and the same thing was going on. that resistor pack that bolts onto the bracket with the 1 wire on it, this goes to the (-) side of coil right??? are they really needed?? I dont even have one one right now.

Another thing I was thinking is that maybe I just have a bad SMEC, theres a couple others with socketed comps in town so im going to try another computer too if this regap and coil thing dont work.


i went for a ride yesterday and was able to get up to 18psi, cars screams....until it cuts out! so i was able to hold it down and wind it out a bit, then when it cuts out, i try to get back in it and it will basically just keep cutting out as soon as I go WOT, even 3/4 pedaling it and she cuts out.

No spark blowout feel more like a miss. OB cutout feels like your hitting a brick wall.:lol:
Juggy
10-08-2008, 11:30 PM
this is definately more like OB cutout!!!
thursday is looking good for weather, im going to play around with a few things and hope to figure this prob out!!

on 18 psi im pretty sure i felt the spark blowout aka miss after 6700rpm...i willl regap 2morrow and chnage back 2 stock coil, then if that doesnt solve things, ill go back to 2 bar TII cal even tho the car runs like pooop!!

Aaron the cam is +4 degrees right now.....I wanted to ask what you were running?? same turbo, same cam.....what was your cam timing set at??? also spark plug gap?? im guessin .028-.030 after you comment about the tight gap??
8valves
10-09-2008, 08:17 AM
Cory, just give me a call, that'd be much easier. Thanks.
Pat
10-09-2008, 06:02 PM
I've had what felt like a cut out turn out to be the my intake hose sucking shut because I didn't have a high enough flowing air filter. It wasn't a spark blow out (which feels like a miss to me), but a hard, violent cut of the motor. I was sure it was overboost, but it ended up being restriction on the intake side.