worf928

That's what I use too. But, I didn't want get into a discussion about the "right" percentage and that's why I quote a range.

The actual peaks are 294 rwhp and 292 ft-lbs. I'll take the extra 4 rwhp and 7 ft-lbs if you don't mind

My '91 had, at the time of the dyno, just been equipped with freshly-cleaned and balanced injectors. My butt-o-meter noticed a difference and I'll bet the dyno will notice a difference with yours when you do it again with some fresh components.

worf928

Any thoughts on the seeming discrepancy between Porsche's published GT vs. GTS numbers and the dyno results? GT's conservative and GTS agressive? Or characteristics of GTSs that make them "fall off" more-quickly than S4s/GTs?

Oil ingestion in GTSs? Average mileage lower than GTs and consequent lack of "Italian Tune-ups" (e.g. varnished injectors, carbon buildup, etc.)

Our GTS will go on a dyno at some point once I'm sure it is running right. (Belt and WP time for it.)

This is a very good point. Running the same car on the dyno in 3rd, or 4th or 5th will result in differences across the board. So, when comparing numbers from car-to-car or from time-to-time with the same car the gear used must also be noted.

EDIT: My chart represents 4th gear runs.

Tom. M

And don't forget the ultimate...need to compare like dyno's. there are differences between dyno brands and even within the same dyno ...different shop. I know there shouldn't be (and that corrections can be used ) but they aren't apples to apples...

For a while there we were using dynojets primarily and most had the Devek dyno protocol down..but for some reason ..folks are straying...and there are mustang/dynocom etc dynos out there now... and some folks even post raw numbers..not SAE..

worf928

Yup. I was operating on the assumption that we all know that only SAE-corrected numbers from an interial-type DynoJet can be compared run-to-run and car-to-car.