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Large turbo problem!

nizmokid

By nizmokid,
in Engines & Forced Induction

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nizmokid Mentor

nizmokid

Posted
Posted

I have just placed a larger turbo into my car and was going to tune with a SAFC2 but the larger turbo (GCG ball bearing 450hp turbo) makes the car die at idel!!! the car runs awsome, fuel mixtures are perfect on cruise and on boost, but when the car pulls up to a stop the car won't hold idel and stall.

I have tried everything in the safc2 but it won't fix the problem, my mechanic said it is caused when the throtal is closed shut after the turbo has spooled up. The turbo keeps spinning (ball bearing) and the airflow meter keeps thinking the car needs air and alacates fuel to the car when it doesn't need it, which stalls (flouds) the motor.

The Car will Idel fine then started, just does this when the the car has just come off boost and pulls up to a stop?

Has anyone had this problem??? and know how to fix it with the safc2?

I was told I need to get a computer which uses a Map sensor and lose the airflow meter to fix this problem!!!

I can get a Greddy Emanage with all the goodies which includes the E-01 boost controler (big screentype) , greddy stearing wheel boost switch, wiring harnesses, software for $1350 brand new.

so might tread this path if I can't fix it with the SAFC2! anyone used one of these Greddy emanages on their Skyline r33?????

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nizmokid Mentor

nizmokid

Posted
  • Author
Posted

we tryed eveything in the Safc2 and I had the same problem with the blitz BOV (before I put the Big turbo on) and that did fix the problem but the car is getting too much fuel when it pulls up after boosting....turbo still sucking air when stopped and tricks the airflow meter into giving the car more fuel at idel.....stall!

could it be ur aftermarket bov>?

i had a similiar problem, used the safc2 to fix it.....DECEL AIR....its in the SETTINGS menu(or the ETC menu)...a function in the safc2...read the instructions to adjust it..

Sydneykid Grand Master

Sydneykid

Posted
Posted
I was told I need to get a computer which uses a Map sensor and lose the airflow meter to fix this problem!!!

Let's get this one out of the way first, that's :bs!: Get whoever told you that and :kick:

I have 2 cars with GCG ball bearing hi flows, both of them had the standard ECU for some time after the turbo was fitted. And neither of them stalled because of the turbo. Open to atmosphere BOV's were the big problem. If you close the throttle, then no airlfow can get from the turbo into the engine, it is bypassed by the BOV. If the BOV recirculates to the inlet after the AFM, then there is no excess airflow through the AFM, and therefore no rich running.

If the BOV is already plumb back, then there is another problem.

SAFC2's have 2 sets of tuning corrretion, one is for 100% throttle and the other for less than 70% (usually, but you can adjust it). This is so you can have leaner settings for cruise fuel economy and still have suitable A/F ratios for high power (full throttle). Have a look at what corrections have been applied in the SAFC for less than 70% throttle, particularly the lower rpm settings. You can lean it out there and see if that helps.

But I seriously doubt that is the problem, I would be looking for something else like an air leak, or a dirty AFM, too high fuel pressure etc

Hope that was of some help:cheers:

ghostflame Explorer

ghostflame

Posted
Posted

ive recently put a t04 on my car running stock computer and ive got the same problem as you just dies on ide after i give it some throttle and it runs rich at that time. Checked for all leaks as best i could but nothing i had an exuast manifold leak at start but I fixed that problem and still had the stalling. Im going to see what happens after new computer is put in.

RS500 Experienced

RS500

Posted
Posted

as there is a different vacuum reading with the larger turbos, the bov's behave differently which will cause this stalling on idle after acceleration.

try plumbing them back or removing them as to confirm this as being the problem.

ghostflame Explorer

ghostflame

Posted
Posted

ok i dont have any blow off valve on the car. ive made a custom pipe that crosses over the engine as my turbo is high mount. but seeing how the car is modified the stock computer would be getting totally different readings,only fix i think is getting an aftermarket computer to adjust your air and fuel ratios.

nizmokid Mentor

nizmokid

Posted
  • Author
Posted

cheers Sydneykid I will try these before I end up shelling out for an full aftermarket computer?

I was looking at a emanage but wasn't sure if I could get rid of the afm all together and just run a map sensor? any info on the emanage reguarding this question would be great.

cheers

Let's get this one out of the way first, that's :bs!: Get whoever told you that and :kick:

I have 2 cars with GCG ball bearing hi flows, both of them had the standard ECU for some time after the turbo was fitted. And neither of them stalled because of the turbo. Open to atmosphere BOV's were the big problem. If you close the throttle, then no airlfow can get from the turbo into the engine, it is bypassed by the BOV. If the BOV recirculates to the inlet after the AFM, then there is no excess airflow through the AFM, and therefore no rich running.

If the BOV is already plumb back, then there is another problem.

SAFC2's have 2 sets of tuning corrretion, one is for 100% throttle and the other for less than 70% (usually, but you can adjust it). This is so you can have leaner settings for cruise fuel economy and still have suitable A/F ratios for high power (full throttle). Have a look at what corrections have been applied in the SAFC for less than 70% throttle, particularly the lower rpm settings. You can lean it out there and see if that helps.

But I seriously doubt that is the problem, I would be looking for something else like an air leak, or a dirty AFM, too high fuel pressure etc

Hope that was of some help:cheers:

FATGTS-R Experienced

FATGTS-R

Posted
Posted

Ghostflame, try fitting up a plumback bov as that I think is your problem.

As SK mentioned, when you close your throttle the air has to go somewhere and in your case it would be coming out your air filter.

My car, HR31, had no bov fitted from factory and it suffered in the same way. Stock turbo (T3/4) and 6psi boost saw it stall a few times everyday.

I would hate to see somebody spend a packet on an ecu when the fix could of come in the form of a $40 bosch bov.

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