2004 GT Horsepower????

I am pretty sure it's the HP at the crank. For manual trannys you take away

15% of the HP.. so 260 / 1.15 = roughly 226.1 rwhp.

-Mike

ah that is a question I was also wanting answered. Thanks! So... here is a similar question: My 96 GT I believe is rated at 215 hp so I guess that means 215 at the "crank" and my rear wheel hp is 215 minus 15% and I'm too lazy to pull up calculator or excel right now so yeah it's 215 minus 15%. My question is this. If I get new heads for my stock 96 GT engine... I hear that not 99 heads but even better are 2003 heads... what will hp at the crank be then? Oh and torque numbers would be great if you have those! Like I THINK right now a stock 96 GT has around 300 torque at crank but not sure. Does the 15% rule apply to torque as well?

Thanks! Scott

96 GT Convertible 3.73 gears

You will probably gain roughly 60~70 hp (hp, not rwhp)... as in at the flywheel. Other factors come into play when transferring that HP to the rear wheels.. for example your clutch. A cheap O'Reilly clutch compared with a King Cobra clutch... big difference when you get some power. I am currently using a cheapo O'Reilly clutch kit & it's spinning when I drop the clutch in

2nd & 3rd. Next I'll try something a bit more "performance-oriented". Also.. I really should get a stinkin aluminum clutch quadrant *sigH*. If only I had money to spend on car stuff. Also... since you seem to be fairly unexperienced (and dem ain't fightin words) you should learn how to drive your car as it is now.. especially with those gears. Experiment a whoooole lot. If you can afford it... get it on a dyno & see what your actual HP/Torque is and at what RPM. It'll help you be a lot better driver. Good luck with everything ;D.

-Mike

98 Mustang GT - Dark Green CAI 3.73 gears coming soon

260hp at flywheel subtract 15% maybe more maybe less. this however is the Ford advertised hp numbers. After the Cobra numbers were lesss than advertised in the 90's Ford usually leans a little towards the conservative side. Your best bet is to dyno it.

Thanks, Mike, for the info! I've actually been driving with those 3.73 gears for about 2 years now. I'm definitely ready to add some ooomph to this car. I'll also look into clutches. I have heard some people complaining about the high end clutches being super hard to depress. I have strong legs but I don't want it to be a pain to just push in a clutch... especially on those times in heavy traffic. Ideas? Recommendations? Would I be right in assuming a clutch equal to 96 GT stock Ford clutch would be okay if I had an extra 60-70 hp on this 96 GT?

A stock clutch from Ford *might* be enough... leaning more towards yes.. but I'd still look for a better one (Steeda?) if it's not too much more. Btw... if you're swapping heads.. better watch the compression. You will have a hard time supercharging I hear if you do a headswap to 99+ GT heads.

It's funny that you mention high-end clutches being hard to depress... a guy I met in a 95 GT who has a King Cobra clutch says it's about the same (maybe a tad harder) than stock clutch... but in his old 91 5.0 he had a clutch (bought used, don't know what it was) that was ungodly hard to depress & his wife was constantly griping about it.

-Mike

Putting it on a dyno is always the best way to find your HP/torque numbers... but around here it costs $75/2 runs. If you can spare the cash then go for it! I want my 98 GT on a dyno next week. We only have 1 shop here that has a dyno.

-Mike

conservative

Yeah I don't have any intention of supercharging. Thanks for the advice!

flywheel???

I have the King Cobra clutch in my 90 mustang and my wife says it is easier to depress than the stock clutch. It feels the same to me as the stock did. I did add a UPR clutch quadrant with firewall adjustment for it when I made the change. That perhaps makes it a little easier to depress as well.

I have heard only good things about King Cobra clutch (Stage 2?). Nobody has complained about it being too difficult to depress & they say the clutch never spins. I plan on looking into one very soon. =)

-Mike

"performance-oriented".

'04 is the same as the '03 is the same as the '02. They've been putting down anywhere from 225 to 235 rwhp bone stock. Do the math and you'll find an approximate percentage loss through the drivetrain (~11-14%) at that power level. As power changes, so does loss through any moving part due to things like centrifugal force and changes in friction from applied force.

The '96-'97 cars put down around 180 rwhp bone stock. The '99 heads and the '03 heads will be the same from a power standpoint. Same combustion chamber, same valves, same ports. The changes are in the cam bearing caps and the number of bolts holding the valve covers on. Brake (or flywheel) hp should be a little more than the '02-'04 puts out stock due to the increased compression. Plan on around 265-270 bhp. Torque at the rear wheels should be in the 275-280 ft*lbs range. That 15% isn't a rule so much as it's a rule-of-thumb - i.e. it doesn't mean much any it definitely doesn't always apply. Basically, look at the specs of a new GT and and in a few hp and a few ft*lbs. It's not an exact science anyway, and every dyno will be a little different.