Aps St Question
Originally Posted by spracked
are cars are cursed sugar!
Originally Posted by spracked
sugar is your car at gt or do you have it at home?
my car has been down for almost a month now, im going threw withdrawls.
my car has been down for almost a month now, im going threw withdrawls.
Originally Posted by spracked
i have a feeling my car and your car are going to become good friends 
so good news, the car is smoking less and less which is good. I guess something with the unichip wasnt ziptied correctly so it wasnt reading very well. now we are making close to 9lbs! car is about to be dynoed so hopefully i come out with some good numbers and hopefully i get the car tonight.
Originally Posted by spracked
so good news, the car is smoking less and less which is good. I guess something with the unichip wasnt ziptied correctly so it wasnt reading very well. now we are making close to 9lbs! car is about to be dynoed so hopefully i come out with some good numbers and hopefully i get the car tonight.
Originally Posted by spracked
go to the sonic meet tomorrow in anaheim! i should be there with my car if everything goes smoothly
Originally Posted by sugarspunZ
that is good news bro. when you get your car back we should meet up. i would love to check it out and see how an APS ST is when it is running propperly.
OK . just did some tests on the dyno and on the road .
first. on the dyno, i had a friend look underthe car while doing a pull. the car goes to about 9 psi and drops to 7. the wastegate cracks open, and this is without wastgate pressure line connected! usually with the line disconected the car is supposed to keep rising on the boost to a much higher pressure. also, we measured the back pressure and its about 5-6psi , which is very high. so, here is the conclusion: too high a back pressure causing too high a manifold pressure, pushing the wastegate door open at load, which limits the boost as a side effect. and yes, this is after the preload on the wastegate spring is set to near-maximum. so ... this is a consequence of restrictive exhaust, only a 2.5 inch single..and on top of that, the aps adapter, brings it down to even smaller 60mm... we were hoping that it would not be bad enough to cause this problem, but 5-6psi of backpressure is just too much
final numbers: 340 hp, 379 ft-lb torque
first. on the dyno, i had a friend look underthe car while doing a pull. the car goes to about 9 psi and drops to 7. the wastegate cracks open, and this is without wastgate pressure line connected! usually with the line disconected the car is supposed to keep rising on the boost to a much higher pressure. also, we measured the back pressure and its about 5-6psi , which is very high. so, here is the conclusion: too high a back pressure causing too high a manifold pressure, pushing the wastegate door open at load, which limits the boost as a side effect. and yes, this is after the preload on the wastegate spring is set to near-maximum. so ... this is a consequence of restrictive exhaust, only a 2.5 inch single..and on top of that, the aps adapter, brings it down to even smaller 60mm... we were hoping that it would not be bad enough to cause this problem, but 5-6psi of backpressure is just too much
final numbers: 340 hp, 379 ft-lb torque
Originally Posted by JoeDirtPharmD
Sam - any opinion on whether an external wastegate setup (assuming the car is coupled with an APS 2.5" exaust) would resolve the boost loss?
Originally Posted by sugarspunZ
spracked,
sounds like a new exhaust is in order. i sell you my aps st exhaust. or go with the big 3" aps exhaust.
sounds like a new exhaust is in order. i sell you my aps st exhaust. or go with the big 3" aps exhaust.
why are you selling it? is it on your car?
Originally Posted by spracked
why are you selling it? is it on your car?
definatley get the aps st exhaust. i went thru 3 exhausts (stock, fujistubo, JIC)before i finally relented and get the aps st exhaust. might be pricey to some but for this kit, it's worth it. BTW, nice numbers from Sam the tuner out there on the west coast. now get that aps exhaust and i bet you'll see a 20-25hp increase because of the better flow. the thing i like about the exhaust is that it doesnt sound louder than the fujistubo i had when i was n/a. the jic 3inch was too loud, attracting attention wherever i went. some times it was nice, but when the windows were up, i couldn't hear myself think because of the exhaust drone. with the aps exhaust, it has a nice mellow tone and actually burbles a little with the cams installed. once i hit the gas, i hear turbo and BOV for a change, which is nice. i like the stealth mode and i can blend in with all the g35's out there with a shiny exhaust.......till i hit the gas that is.


