GTJay99

Here's my deal. I gotta 99 Gt and have the following mods: SCT Big air Maf, Cold air, Dragon plenum elbow, Ported/polished Stock PI heads(Stock valves), Comp 270 Cams, Equal length shorty headers, and Mac Exhaust(no cats). I had the car tuned and it made 280hp and 301 tq at the wheels. Not bad for a 2v. Stock was 208hp. I then Installed the Professional Products Intake manifold and their 75mm Throttle Body also 30lb injectors. Took it back to the dyno shop to tune. The car"LOST" 15hp and 20tq at the wheels. Allaround LOST, It never showed any gain at all. Has anyone ever heard or had this problem? I heard a lot of good but I got but results.

racer02GTstang

you probably have to big of injectors for what you have... also... could be in the tuning... have the intake port matched.. may help some... do you think the gaskets have a good seal for the air going in? there are a bunch of factors it could be

oxfordgt

You've got mods that are hurting you like the maf and the injectors. I dont see how you were making 280 rwhp with those mods. Cams and ported heads are your only power adding mods and maybe 10hp from the midpipe.

ZW99GT

Yeah, thats pretty uncommon. I've heard of bone stock cars losing a little power. Nothing like 15 hp or anything. It's either in the tuning, install, or the dyno. Did you have both tunes on the same dyno?

racer02GTstang

let me ask... what did you have to do to fit those cams in your motor??? did you notch the pistons or get cam gears??

cammed99gt

Man no way was my first thought but who knows.Is your car aauto, mine made 310 to the wheels not tring to cut u down but thats a little on the low side.30s arefine because thats what im running in mine.It could be the tune i guess.been thinking of tring it out my self but i dont know now.Keep us postedon this one please.

racer02GTstang

310rwhp is alot on an n/a car... hell.. so do heads and cams really dooo thhhhhaaattt much?

GTJay99

Bottom end is all stock. Vacuum was where it was supposed to be and the air/fuel mixture was on the money. Same dyno and tuner. My only other thought would be more spark (Better plugs and coils) I am lost on this whole ordeal.

cammed99gt

I got stage 2 heads and cams and bolt ons minus under drive pulleys(havent put on yet)and it made 310rwhp and 314rwtq but i got LT headers he doesnt.

cammed99gt

Oh yea and my stock pi inake was port matched to my heads.Thatmight beworth 2-3 horsepower