How much degrees & how much boost?
 

1. I read on this site that the Apexi VAFC advances the ignition timing. How much degree(s) per pound of boost does it advances the timing?

2. When I got my TurboXS boost controller, the instructions said I should turn the adjustment screw until it is fully closed then open it three (3) complete circles. How much PSI does three full circle of adjustment equal?

Thanks in advance for all the help.

Re:How much degrees & how much boost?
 

1) why would you want to advance timing while adding boost? Unless trying to find the detonation point, that is not recommended.

2) Every boost controller is different, someone might be able to tell you specifics on that one if they use it, otherwise it's trial and errors. Get a good reading boost gauge.

Re:How much degrees & how much boost?
 

Not entirely true Spenser....
If you look at a stock rom the timing is retarded when RPM's increase.
The thing the Hack does is...it moves the ignition table so when you are at 2-5 psi roughly the timing is like when it was at closed throttle and the timing there is about 30-40+ degree depends on your stock rom. and acctually the timing should be at about 16-20 degree at that point.
that is a lot of advanced timing there and nothing can cure it exept for a chipped ecu and then you would defeat the purpose in using a AFC hack.

Re:How much degrees & how much boost?
 

I heard before that a MSD BTM would not work with a VAFC/SAFC.....not sure why just something i heard before.

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Re:How much degrees & how much boost?
 

It will work, but it won't retard that much at the area where you need it the most.

Re:How much degrees & how much boost?
 

point for semnos...the btm would retard the timing in boost, which wont solve the afc's problem of vacuum and low-boost timing advance

Re:How much degrees & how much boost?
 

What's up ghettoturbo??
Haven't seen ya in a while...so what you got now?? still the silver EK?

Re:How much degrees & how much boost?
 

im out of school for summer so im on 56k :P :P...the ek is still here for now, but i pulled the motor. I'm in the process of finding something cheap to drive to work.

Re:How much degrees & how much boost?
 

but isn't low boost still boost?

from what i am reading here, you guys are saying the BTM only work at high/full boost.

I am just curious about all this, i will be using uberdata within a week or two.

Re:How much degrees & how much boost?
 

Spenser, thanks a million. I already have a VAFC. I bought it because I read that it was OK if I was not going to boost over 8psi. I guess I am stuck with it for a while. I also have an extra P28 ECU. Who would you recommend to chip it for me?

Thanks to everyone else that responded.

Re:How much degrees & how much boost?
 

think of it this way....you would have to ask someone else for specifics, but at low boost the afc is advancing your timing, and if you had a btm, you could retard it some to maybe compensate. but now, as the boost goes up, youre retarding more, and so is the ecu, meaning your car will run like ass

Re:How much degrees & how much boost?
 

sorry man, I don't know anything about P28, all i know how to chip is obd0 (PM6) make a post in the engine management section, and read some more about chipping, it's actually really easy to do it yourself, you seem like a smart person, i bet you could do it.

Re:How much degrees & how much boost?
 

So if the ECU is retarding the timing at high boost, it would be best if I retard the timing by a modest amount...6 degrees from stock which is 16 degrees BTDC. So, when the ECU advance the timing in low boost, the increase will be cancelled by the amount it is retarded in high boost. Is my assessment a good one?

Re:How much degrees & how much boost?
 

Spencer, thanks again for the feedback. I will do some more reading.

Re:How much degrees & how much boost?
 

i am about to chip my P28, so if you want i can tell you what to get and how to do it, but remember it is my first time. :-\

Re:How much degrees & how much boost?
 

kinda..people do retard at the dizzy to compensate for the afc, but its just not the best setup since you will end up with very retarded (no pun) timing up high from what i understand

Re:How much degrees & how much boost?
 

Thanks man.

Re:How much degrees & how much boost?
 

I just retarded my cam gear 3*.Havent had a problem with detonation yet ;)

Re:How much degrees & how much boost?
 

I don't think retarding the cam gear will affect detonation. Advancing or retarding the cam gear will only affect the power output. Retarding the cam gear will reduce low down power but it ncrease top end speed...advancing the cam gear is the opposite ;).