TRUEBLUE3934

The tune for the GT will kick in the rev limiter much lower than the 4V should. The 4V is a much happier motor reving higher. The A/F of 11.9 is rich for a NA motor. My NA A/F is around 12.9. A supercharged motor should have a lower A/F ratio than a NA motor.

I'd guess a proper tune and rev limit would get you to around 285-290rwhp. Only way to know is to do it though. I'm sure you will see a noticeable gain once that is corrected.

I don't see gears listed in your sig. If you are stock gears now, swapping to 4.10 will make a huge difference with the 4V (let it rev).

GOOD LUCK and let us know how this turns out for you!!!

jeh4269

I'm gonna pick up an SCT tuner on Monday and get it tuned as soon as I can.TRUEBLUE I have 4.10's here,just need to get them installed.I think the low rev limiter prob hurt me the most.After I get her tuned I'll post the new numbers.Really hoping for over 290.No matter what HP I end up with it's def alot more fun to drive than the 2v was.

lizzyfan

Who did your dyno run

ctgreddy

yeah that's cutting down way too early man. I'd say between a 12.8-13.0 is ideal for an n/a afr. i wonder why it's hitting the rev limiter so early tho? a stock gt's limiter doesn't kick on until around 6000 doesn't it?

uberstang1

I think there is some kind of conflict woth the gt ecu and the cobra crankshaft and or camshaft position sensor

ctgreddy

would it be possible to find a cobra ecu on ebay or corral and just throw it in, or are there harness differences? that seems like the easiest way to go about it.

jeh4269

I had Godspeed Performance dyno it.It was easier to use the GT ECU and get it tuned than to swap in a Cobra ECU.My tach read 5400 and his computer said 5150 when the limiter kicked in.He got his reading straight off the carnkshaft.Hoping to get another 30rwhp after everything is fixed during the tune.He said the dyno is a Landon C.Anyone ever heard of them?

uberstang1

John I have a cobra ECU, its not difficult to install you simply removed the passenger interior kick panel, loosen the bracket and then its plug and play.

ctgreddy

you can expect your stock tach to be off a little bit. i know in my '95 i had an autometer tach with a shift light set to 6400, and when the shift light came on my stock tach was up around 7k.

jeh4269

Hey Keith I was told that the main issue with swapping in a cobra ecu is with pats.I guess my keys wouldn't start the car.IDK.I was told it was easier to let the gt ecu in and tune it.I'll ask Dave and see what he sats.Your ecu is a 97 correct?Would that work with a 96 engine?I think it will.I thought the 96-97 cobra's were pretty much the same but in 98 they were a little diff,or are the ecu's the same all three yrs.