I was looking at the fast system and had some questions. This would be on a 91 with batch fire. If I get just the ECU, then I would have to stay with batch fire because of the wiring right? Is it a piggyback or do you throw out the old gm ecu? Will all of the FAST systems contol a 2 bar map for boost? I looked at their site, but I didn't really get much out of it. Is anyone using one of these and are you happy with it?
Mine is also a 1991 and you will absolutely need to keep your existing ECU. Mak at Fast Track Performance will sell you a cut in harness. The stock ECU will control your gauges, auto trans if you have one, selectaride, etc. Basically the only thing that really happens is you share enough info. between the stock ECU and the FAST unit that the stock ECU still kind of thinks its operational, of course the wires to the IAC and spark control are cut from the stock ECU and are now controlled by the FAST unit. I installed my own without any difficulty. Its an awesome unit. I hope this helps..
Its pretty easy with one of Macks piggy back harnesses. If and when you decide to do this I can help you with it. I have done a few of the piggy back conversions. You share the TPS, MAP and what Mac does is add a couple resistors to simulate the coolant and intake air sensors. That way you can dedicate the factory sensors to the FAST system. However if you use a 2 bar map you can leave the stock MAP in there for the GM ECM other wise its one more error code to have to mask in the stock ECM.
The FAST system can support a 2 bar map easily. It can also control nitrous and other devices. Have you thought of using the new ACCEL gen 7 system? I looked at that and found it to be even more advanced and easier to tune than the FAST. You should check it out.
I have been checking it out, probably as you were writing your response. It seems like a pretty neat system. The cost is still hard to justify, but these systems seem like a better deal than the EFI034 or the 7749 ecm. With the 034 you have to have two sets of injectors and with the 7749 edm I will loose some of my dash functions. The only downside to the ACCEL seems to be the cost. If I did it, I suppose I would bite the bullet and get the WB 02 as well.
I am running a FAST system that completely replaces the stock computer, and the only thing I lost was instant the instant fuel economy features. Everything else works fine. I am using a White Racing wiring harness adapter.
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F.A.S.T. ecu and turbos
