wow, what a dissapointment so far

it put down 280/296 and lost about 5rwhp down low. STOCK it put down 275rwhp.

with 4.10's and a tune it put down 285, so now with a CAI and hooker LT's it LOST about 5rwhp it is running 12:1 A/F so there may be 10rwhp in tuning a/f, but is still way low.

I'm going to buy the SCT pro racer tuning software so I can take some logs and see what the hell is going on. maybe its pulling a bunch of timing for some reason. no ses codes though.

I was expecting ~310rwhp out of it

 

What brand and type of headers?

 

That would be disappointing paying that much money and losing hp. Could be in the tuning though. I think 12:1 is a little on the rich end. Also the timing is very complex on these Mustangs and may have been altered somewhat with headers.

You will like the Pro Racers kit. I have the HP Tuner for my Camaro and the SCT Pro for my Mustang. The Hp is functionally easier to work with but they both do essentially the same thing. SCT has excellent customer support. You can always get a knowledgeable person on the phone.

 

the tuner at the dyno I went to said if it had excessive timing in it from the previous tune it could actually be pulling a lot of timing because when it pulls timing it pulls a LOT.

I'm sure there is 10rwhp in a/f alone.

they are hooker longtubes, 1 5/8 with a 2.5" x-pipe and mac mufflers.

I seriously doubt there is much difference between 1 5/8 brands. I'm betting there is a tuning issue somewhere.

 

Don't know if it's the same w/ ls1's but I know when longtubes are put on a mod motor the a/f goes rich. Your a/f should be around 12.8-13.1 all the way to redline. I'm sure you can pick up a few hp there. As far as timing I'd go 4-6* advanced from stock. I set my at 7* advanced from idle. -Mark

 

My a/f never drops beow 12.7:1.

Are your numebers SAE or STD? If STD, what were the weather conditions?

I am about to install longtubes, I am just looking for gains throughout the entire curve and better performance. I would like to get 300+ rwhp, but if I don't it isn't a big deal.