wrd1972

Please post your 1LE numbers as soon as possible, I am very anxious to see them. I am wanting to travel the same road.

wrd1972

Sporty-X

hum sorry if people don't seems to beleive it. But that the number i got. I made the car dynoed before starting bigger mods.

What i had exactly was : a moroso CAI, TB by-pass, no cats, no EGR, no AIR .. and that was all. My car is an A4.

I have now Pacesetter LT + Ypipe and hooker catback + mad z28 tune and OBD1 coversion. The hot cam kit is waiting on the desk close to me ..

I haven't dynoed the car after LT install and PCM tune. I will wait after the cam install.

I don't know what to say on my numbers. We put it 2 times on the dyno the same day (it was evening) and i got 2 times a little over 290 (265 at the wheels). That hasn't chocked me.

Anyway, if theses numbers seems unrealistic, tell me it instead of blaming me. We have just ONE dyno in the whole country so i would also love to know if the numbers i pay a very lot to get are realistic or not.

Javier97Z28

There's your problem, you were quoting flywheel #'s. Nobody on here that mentions CHASSIS dyno #'s ever mentions anything about flywheel #'s, they are all talking about rwhp number. The person in this thread is quoting rear wheel numbers, not flywheel.

That is all! That being said, your #'s sound correct now for an A4 with minor boltons.

95z28man

Don't LT1's come from the factory with like 275hp? How can all the mods only bring it up to that... or is because the factory numbers are just hp and not rwhp? About how much rwhp do they come with if thats the case?

FeelTheSpeed

the 275 raiting is fwhp, the rwhp rating depends on the dyno and the car. Some put down more than others. My car with Mac mids, borla catback, TB, LT4 KM, Pulley and with cats made 292 rwhp 326 rwtq. And that was an M6 not Auto.

Javier97Z28

ALL factory HP ratings are flywheel #'s that do not account for drivetrain loss.

mattybz28

M6's have less drivetrain loss than an auto and will dyno higher with similar mods.

Ray86IROC

Rear wheel HP numbers are around 13-18% (depending on tranny) lower than flywheel numbers as a general rough rule. It's important to note that GM is pretty consistant in underrating the factory HP in the later Fbodies though. Even the LT1s rated at 275-285 flywheel hp are making more like 300ish hp, the same kinda power the Vette LT1s were rated at. Take a look at some of the stock LT1 dyno threads around and you'll see 240-260 rwhp numbers on average for stock LT1s in good tune, autos closer to the lower end of that range, manuals nearer the high end of course. That's a pretty solid ~300hp at the flywheel...

wrd1972

Your HP claim is much closer for flywheel HP. Nobody on the forum uses flywheel numbers because the engine must be removed from the car. FWHP numbers should not be posted unless you have specified "FWHP" or similar.

What kind of dyno are you using that provides FWHP numbers, or did you calculate those numbers factoring in parasitic loss?

Sporty-X

i have never said it was rear wheel hp Javier. Just read it again

The dyno calculate itself fwhp (and that is the graph you have with it. You can also have rwhp with it but if you don't ask for, the shop don't give it to you.

Anyway .... there is much important in life than arguing on such things

Sporty-X

and ok ok ) i would NEVER talk again abour FWHP

yotaman96

I have never heard of not getting rwhp from a dyno shop.

Javier97Z28

You're missing my point. Everyone jumped on you because noone here talks about flywheel numbers, everyone automatically assumes RWHP. That's all. So when you posted those numbers everyone looked at 'em crosseyed.

Not an argument, just clearing it up.

stereomandan

Good numbers, looks about right.

I made 285/320 with similar mods, through a single high flow cat. I also have the hooker catback.

Goes to show what I've been saying all along. Any headers that are mids or long tubes perform relatively the same. Actually, the MAC mids, with the 1 5/8" primaries look better at low RPM due to scavenging.

Dan