IcemanG17

Its amazing what a touch of boost to a smaller V8 with twice as many valves can do!! "there is no replacement for displacement" Should be "there is not replacement for DOHC"

Glenn M

Kevin,
Very nice, Don T. let me drive his car yesterday I was impressed at how easy it was to drive around town. Then when you step on it , damn, pulls like a freight train!

Kevin Michael

Yes, ol' Don has a mean ride for sure!

hacker-pschorr

I wouldn't go that far:
http://ls1tech.com/forums/showthread.php?t=698480

Jim R.

Kevin,

Nice show and good looking power curves!

One quick thing though; was the A/F ratio measured with a wired in WBO2 sensor or the tailpipe sniffer? If that was a true WBO2 in the exhaust ahead of the cats (if you have them) I think you are running a bit lean, especially down low. If it was the tailpipe sniffer, don't worry about it.

Jim

Cameron

Very impressive. Congrats and thanks for posting the results.

SwayBar

Yes there is, weight. The 928 32v weighs in at 600 lbs, and a a considerable amount of that weight is up high which compromises the coveted low center of gravity.

On the other hand, the Chevy 2v pushrod LS6 and LS7 weigh in at 400 lbs and has a much lower center of gravity vs DOHC.

Let's examine this a little closer.

Chevy 2v pushrod:
LS6 5.7L 2v puts out 405 hp for 71 hp / Liter
LS6 7.0L 2v puts out 505 hp for 72 hp / Liter

928 32v DOHC:
928 S4 4v puts out 317 hp for 63 hp / Liter
928 GT 4v puts out 330 hp for 66 hp / Liter
928 GTS 4v puts out 340 hp for 63 hp / Liter

Now lets do hp/lb which is (engine hp / engine weight), so we're looking at a relative efficiency of the engine:

Chevy 2v pushrod:
LS6 405 hp / 400 lbs = 1.0125 hp/lb
LS7 505 hp / 400 lbs = 1.2625 hp/lb

928 32v DOHC:
928 S4 317 hp / 600 lbs = 0.5283 hp/lb
928 GT 330 hp / 600 lbs = 0.5500 hp/lb
928 GTS 340 hp / 600 lbs = 0.5666 hp/lb

So as you can see, there is no comparison. Not only does the 928 DOHC put out less hp per Liter, it weighs 1.5 times more, which is huge.

Now you know why Chevy is still using 'only' 2v pushrod motors, eschewing the 'sexy', but fat and heavy, 4v DOHC motor.

AO

I agree that it's looking a bit lean. You may want to try adding a bit more fuel. But I think those tail sniffers are pretty accurate. Here;s a comparison of my Run#1 with my WB (below) and their sniffer (above). The WB measure the extremes a bit more than the sniffer, but all-in-all I'd say they're pretty close. YMMV.

F451

Very interesting, and something that I had never considered before. Thanks for posting this thought provoking info.

And Kevin, nice pull!

-Ed

worf928

+1 on running too lean. One easy thing to check: WOT switch. Test at the ECU connector pins and make sure the wide-open switch is getting its signal to the LH.

Abby Normal

How about we start a "Master Dyno Thread" where all of these dyno sheets can be posted?

Post your dyno and list your mods. It would be neat to be able to scroll through all of the different set ups and results in one thread..imo

I suggest someone with a dyno start it. I don't have one now but you can bet your **** I will soon.

It's sure great to look at these threads and see the results of how far the development of HP adders for the 928 has come. Getting 400 HP/TQ to the ground has become relatively easy thanks to some great 928 Companies and owners!

AO

Go for it... Make sure it says "Official" in the thread title...

hacker-pschorr

Abby,
I asked Randy about doing a "Performance Thread" where you were only allowed to post Dyno Charts, 1/4 slips, G-Tech data etc.... Randy loved the idea, I forgot about it until just now (I didn't have a sheet to post at the time).

I'll start one with my latest dyno sheet.

Abby Normal

Cool, go for it! I'd say title it Official Dyno Thread to narrow down the search however the other info will be great to have there also.

hacker-pschorr

Here yea go, how's this?

https://rennlist.com/forums/928-forum/346823-official-928-dyno-and-performance-bragging-thread.html

Maybe it could be a sticky?