IcemanG17

Okay lets see who has the post powerful 5.0L 32V engine out there (or earlier euro S motors). Three catagories:
1. Normally aspirated and smog (with cats) legal
2. Normally aspirated (no cats)
3. Blown (super or turbo or nitrous)

Ideally lets use dyno runs (please post graph) but G-techs or similar will work.

The best catagory #1 I have heard of is around 340rwhp, with blowers going over 500rwhp...this should be good so I'll start

1. Using a Gtech averages about 265 rwhp for a 88 auto with RMB and K&N.

mspiegle

you probably shouldn't accept the gtech measurment

IcemanG17

I understand that Gtechs are not as accurate as a real dyno, but are better than the "seat of pants" measurements. Since many of us have Gtechs it allows for a wider sample of horsepower for people that haven't used a dyno.

Imo000

Is there a formula to calculate HP from 1/4 mile times?

mspiegle

a search on google should yield alot of results. I like this site: http://www.smokemup.com/

Well, if you're going to supply a gtech number, mentioning the weight used would be good since that's the major factor that varies.

Z

Tim Murphy's supercharged 5.0 liter S4:



There are a lot of things that can affect the G-Tech horsepower numbers. Depending on what weight you enter, you can make their horsepower results say anything you want. Even if the weight is correct, and all other coinditions are perfect, they don't take into account aerodynamic drag, so the numbers will not reflect the actual rear wheel horsepower anyway.

Nicole

The question is how long will it do this with the K&N filter until the MAF fails (too much filter oil) or the engine seizes (not enough filter oil)...

drnick

louis otts GT makes 335 rwhp i think?? no cats.

Kevin Michael

Actually, The G-TECH does take aero drag into account therefore reflecting a more "usable" (steetable) measurement. Say a dyno run yields 280 hp. A g-tech run, if properly set up (very important!) , will most likely yield a measurment of 265hp. This is because it takes into consideration aero drag , and hp. loss through the natural characteristics of the car being on a real road, with real drag in different climates etc. I find it to be fairly accurate if used correctly within maybe 5-10 hp.

Chris Lockhart

Well, I still have some fuel issues to fix eventually, that are hindering things a little, but FWIW my best numbers are in my sig line. This is with MSDS headers, and no cats, on a DynoJet 248C.

IcemanG17

Z
Murphys car is a 5 speed correct? How much boost is he running to get those numbers? Has to be alot!

Nicole
The PO put on the K&N, I checked it the other day and the filter is not leaking oil on the MAF, but still looks good

Z

Yes, Tim's car is a 5-speed. That dyno chart was with 12psi-12.5psi of boost. Unfortunately the season ended before he could get to the dyno again. The fuel mixture is a little better now than it was then, and he's also running more boost now.

IcemanG17

Z
Thats alot of power for a stock compression 5.0L car. Tim must have a complete exhaust with upgraded injectors & more to make that kind of power. So I estimate that his car was about 300whp before the SC....which is quite good. So what is the boost limit for a stock compression car? Generally as boost goes up engine life goes down, how long does will his engine last at those HP numbers?
Thanks

Z

Stock exhaust manifolds, "X" pipe, stock pipes behind that, with two resonators in place of the rear muffler because the RMB was too loud for him with the "X" pipe. Injectors are the same 30lb ones that he supplies in the kits.

As with any engine, it would depend on how it was driven and maintained, but that couldn't be answered until it wears out, breaks, or whatever ends up happening to it eventually. The engine's coming out and being replaced with a higher power one that's being built now, so this engine will probably just be stored until it finds it's way back into a car again.

Imo000

This is the result of one calculation:


Your Results
Your 1985 Porsche 928S weighs about 3625 pounds and can complete a 1/4 mile in about 13.541 seconds. That means that you've got about 288.56 HP at the wheels, and about 375.13 HP at the flywheel.

I've also used the following fromula to double check: HP = (Weight / ((ET/5.825)^3))
and it resulted with the identical value as the other calculator yield as RWHP (288.56rwhp).

I used the following values in both cases: Wehicle weight (from 928 registry) 3351lb, drive weight 274lb, ET 13.541 sec. The track is almost at sea level therefore, no alterations were needed to the original time.

I'm a bit baffled as to the accuracy of these results. Is the formula above accurate for rwhp calculation?