alright here is what i dont get. if i want to get a piggyback system which is best since i will try to go 10-12 pounds at the end how to i pre-tune the system without blowing it? how do i know where the turbo starts to boost and how much without actually running the system and running it lean the first time? i think i heard something about calculating it but what are the equations or where can i find a site on this? i have read through maximum boost but found little on this part. it works more with a FMU when installing and that type of stuff. sorry if this is to basic for some of you......

anyone?

Busy as hell right now, I'll post when I get home. Since it will have to be a more detailed post. The question isn't esy, its where most people run into trouble, hence the lack of replies.

WD

What piggy back are you running? That would help us out a little.

Rick

basically im about to put a clutch and flywheel on and then buy a turbo system. im just lost when it comes to tuning. i remember some post talking about some equations or sometion. im going to be using an apex afc-II definitly.....if this is a dumb question do you know where i can read. i thought maximum boost would help and it doesnt!!!!!! i thought it was the god of teaching boost to dumbasses!!!!

If you want a pre-tuned system, you might want to look at JWT ecu instead of piggy back. Just plug and play.

have you looked at the e-manage at all?

i havent really looked at the emanage to much. the apexi one looks good and does what i need it to do with the knock sensor. a lot of people have used it and never heard any complaints and im looking to do the tuning with the piggyback myself. the best way to learn is to do it yourself. thats how ive been doing it so far with the car.

Ok, after many 14 hour shifts at work, I can finally post somthing here.

OK, I'm going to assume your using a decent turbine kit and a FMIC. For 10 psi I'd go with 370cc injectors. So obviously your stock ECU isn't going to be able to trim them down enough by itself. Thats where the piggyback comes in. Its good that you use a knock sensor or dyno during all this tuning. But you should be ok since the SAFCII has a knock sensor built in. However, I'm not sure how well it works.

So lets say your boost is set to 5 psi. To do this you need to know what spring pressure your wastegate is set to open at. The dealer should be able to tell you. You'll have to use a boost controller from here on out to increase the boost.

At 5 psi with 370cc injectors your idle is going to be pig rich and will probably fowl your plugs if you drive it this way. But as boost comes on you will start to lean out a small amount. Nothing even close to detonation though.

So your first tuning will be trimming the injectors enough to get your car to idle without running rich. The best bet is to use a dyno for 1 day of tuning. It might cost 100 bucks, but believe me, using a wideband O2 makes things so much easier. But there's always the seat of the pants tune. You can do this by trimming the the injectors till the motor starts to idle smoother or untill knock starts to indicate on your SAFC. If knock gets detected, immediatly add more fuel. You don't want to be running that lean. You should tune your motor with enough room for error, like a bad tank of gas, or a really hot day, anything that can effect detonation.

Once your motor is idling fine, you'll have to start adjusting the RPM's just prior to boost and under boost. You really should use a dyno to do this part. Its pretty damn easy to blow up a motor. But lets just say you decide to use the old seat of the pants again. There's really only one formula that I know of that has worked for me and most other guys without a A/F meter. Turn up the boost slowly...SLOWLY...watch your knock meter...when knock indicates release throttle and add fuel at that point...add alot of fuel. You can always go back and lean it out if you choose later. The make another full rpm pull. If no knock is indicated, turn up the boost another psi....repeat slowly. Your probably going to have to use another person since getting your car to boost requires you to be driving. I recommend a long straight road with no traffic and if possible, don't use first gear to tune with. 2nd or 3rd would be better.

Sorry it took so long to reply, I've been busy. Just a word of advice, be sure you want to tackle this. If you have second thoughts, any shop with a dyno should be able to help, at a fare price as well. If I missed anything or you have questions just keep this thread going. Hope that helped out some.

WD

WD that was great help, I'm a total newb when it comes to tuning and that helps alot, I think I'll definately go with the AFC/stock ecu/370 cc injectors. One question, are 72 lb injectors the same thing as 370cc?

nope

using this handy dandy formula -> cc/min*10.5=lb/hr

then we have that 72lbs injectors are aproximately 756cc/min

thanks a lot for the help WD

hey WD, when you say after setting it up make it good for bad days like hot days and bad fuel. does that mean add a little extra fuel? keep it rich type thing? how much should you add?