572ysc

So I have a 1999 Mustang GT with a manual and 3.27 gears.

It has a SLP catback LM1 and stock cats, no mods.
NGK V-powers spark plugs with 12.000 miles (i know their due to change)


It pulled 220 rwhp and 263rwtrq with no fan in front of the car is that a decent number?


Vehicle has 158000 miles if that matters much.

TRUEBLUE3934

Do you know if it was measured on a Dynojet or Mustang dyno? I was just having a discussion on the Bullitt Mustang forum and I was told a Mustang dyno would read 12% lower than a Dynojet dyno.

This 12% figure sounds to big to be true, so I am looking for other input before I 100% believe it myself.

For the record, the stock 2001 Bullitts pull about 235rwhp on a Dynojet dyno.

572ysc

Oh ok thanks for the info. I dont know whats the difference? It was a ground installed one. Also would 44psi rear tire pressure have effect on the readings? Thanks for the info.

945LSTANG

those numbers are about right. theyre actually not bad at all considering the age of the car and the amount of miles on it. i would be happy with the results.

cliffyk

Those are typical numbers for a mostly stock '99--'04 GT, running the OEM tune. I have seen 5 or 6 of these dynoed (including mine*), with peak rwHP numbers ranging from 209 to 225 HP (a Bullitt).

A mail-order or canned 93 octane tune would get you up to 235 or so, with noticeable improvement in the mid-range as well. Add a 70mm TB and aftermarket upper plenum, and tweak the tune to add timing at WOT and get the AFR dialed in, and you'll be into 245 to 250 peak HP--and be able to pull strongly right up to redline.

Also, and unless you just like changing spark plugs, get a set of platinum plugs. The NGK V-Power plugs offer nothing but more frequent changes for most any n/a application--very high-compression engines being the only exception.

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* - The first time I dynoed mine, a couple week after I got it, it did 220/243 with a really crappy eBay special CAI, an o/r H-pipe, and Flowmaster 40's welded in to the stock pipes.

massred98gt

ya those are exactely right. you don't have any power mods. i mean thats right around stock give or take a few hp. i would be happy with those numbers. your stang's running stong in its old age

0949er

ok... so i have a quick questions... so WTF is a mustang dyno?

I mean, I know that "dyno" is when you calculate wrHP with how fast you rotate the drum that the wheels spin on (in simplified terms)

but wtf is a "mustang" dyno? and all this conspiracy that some dynos are "incorrect" and "not accurate"?

I have never seen/heard of a mustang dyno/dyno jet... all I have heard of is a shop, that has a dyno in their floor, which is just a steel drum that spins and based on rotation speed and drum weight, etc, it calculates how strong the motor is.

I'm assuming mustang dyno and dyno jet are independent companies that sell the "dyno" setup for shops?

can somebody explain this to me.

cliffyk

That's it, you just answered your own question--read the wikipedia article on dynamometers so that you might understand there are different types that produce different results. Then Google "Mustang dyno" and "DynoJet"...

mrtstang

Those numbers sound about right. Maybe a tad low, but definantly in the normal range.