My dyno results w/mods

[John in Norcal]

Took my car to Dyno Spot Racing in San Jose during Thanksgiving weekend and put my car to the test on DSR's inhouse Dynojet 248H. My car is a 1987 Carrera Targa 3.2. The engine is stock except for:

1) Steve Wong chip
2) Fabspeed pre-muffler (cat bypass)
3) Borla muffler

Here are results from the dyno run. I'm new to this forum but browse here regularly for useful info. Thought I'd share it here with everyone since there is alot of talk about the actual power increase associated with these popular mods.

[rsr808]

From the looks of your dyno results... are you now running less than stock horsepower/torque? It's the stock HP on your car 208 or something like that?

[Tim Walsh]

Actually with a US carrera that makes 217 at the flywheel the expected output to a chassis dyno would be in the neighborhood of 185. (217 *0.85) So I would expect he's slightly above stock

[John in Norcal]

Originally posted by rsr808
From the looks of your dyno results... are you now running less than stock horsepower/torque? It's the stock HP on your car 208 or something like that?

I should definitely be running more hp/torque than stock. The results from the dyno chart show rwhp. Assuming a conservative 15% loss from flywheel to the rear wheels, I should still be running about 236hp ( 200.8 / .85). I believe stock HP rating for a '87 3.2 is 217.

[rsr808]

Ahhhhhhhh... I see... I just learned how to read a dyno today!!! Thanks Guys!

[Steve W]

John's car shows pretty healthy midrange torque, although 236 hp ain't bad either. Here's TomTurtle's results on his 30k mile 88 Club Sport, also at DSR in San Jose that shows 243 hp (206.8/.085). Also running a Borla muffler, with a Dansk premuffler, a cone air filter, and my 91 octane chip. We think Tom's cone air filter may have something to do with his extended hp curve.

The bottom curve represents the best run with the stock chip with stock cat, the middle curve is with the addition of a the performance chip for a premuffler/sport exhaust, and the top curve is after the addition of the Dansk premuffler. Note how the hp at 6200 has increased about 14.6 rwhp, or an equivalent of 17 engine hp. There are more details posted online if interested.

[stealthn]

I'm confused...isn't the FB premuff suppose to putout @11hp, that would mean the chip and muffler only give you 8hp?
I know the numbers (manufacturers) are usually hiped, but I would expect more HP from the above combo.

No dispersions, just curious questioning....

[Steve W]

Some Pelican members have fitted on premufflers and dynoed about 8 hp at the top end, however it seems that when either a sport muffler or premuffler is installed first, 6-8 hp is gained. Richard Nelson (dickster) performed a test here a while back:

at last dyno figures for 1986 3.2 with dansk premuffler/sport 2 out muffler

Subsequently, when the other is added, only about 2-4 hp extra is attained for a total of about 11-12 hp. So the results are not cumulative to each other. In both these instances, the cars started off with a Borla muffler. In TomTurtle's case, he also had a cone filter intake on his stock run. Without these mods, he would probably have started off with about 186 rwhp instead of 200. It should be noted though that Tom's Club Sport only has 30k miles and comes with a factory blueprinted and balanced motor.

Because the fuel curve of a stock 3.2 chip is so rich past 5000, any leaning out of the fuel curve here increases power on a stock car. In these cases, installing a premuffler or sport muffler leans out the fuel mixture here, so about 2-3 hp comes from the leaning of the mixture, and about 6 comes from the actual increased flow of the sport muffler or premuffler. When both are combined it is about 11-12 hp. It could be said that frequently manufacturers claims are not all they are hyped up to be. Often claims of an x amount of hp gain is not at the peak of the curve, but somewhere else. You can't just add up numbers and simply come up with a final total. Exhaust, intake mods, chips work together as a system to produce a realistic figure. In these instances, 236 hp and 243 hp from some simple mods isn't too bad for U.S. spec 3.2s which originally started stock at 217 hp.

[Wil Ferch]

See my reponse to this related thread....my stock 85 showed 200 rear wheel hp.
3.2 Dyno Run today - graph

---Wil Ferch