Popo928

On whim, I went to the dyno today. Mustang dyno and 86 degrees. For those that don't know Helmut, she was Shane's, then Darien's, and now mine. It's an 86.5, X-pipe, rmb, porken chips with an 89 slate gray interior 5 spd. I was hoping for close to 300 rwhp. Let's just say this.... Ken...you da man!.....I knew this car was strong but damn.....I'm sending a German hooker to your door in 15 mintues...you deserve it!

When I positioned it on the dyno, it had 125,928 miles!

Results: 306, 308, and 311 rwhp!

(I couldn't figure out how to get the videos to attach. See link for pics and vids of dynos).

https://www.dropbox.com/sh/1r8b4f1oy...kaYybtsAa?dl=0

OTR18WHEELER

How's come the repost was timestamped 15 minutes before the first thread?

Shane

Awesome numbers! Congrats, I knew Helmut had something special when he put 281/278 down with the cats still in, just was running some old AA clone chips.

Enjoy!

Popo928

I posted from my phone and I'm not really sure why other posted twice.

ptuomov

Are those rwhps or flywheel hps estimated from the rwhps?



The dyno graph seems to say "engine" so I am trying to interpret that. If it's estimated engine hp, then what was the driveline loss assumption?

It's a good result regardless, given that the stock engine starts at 288 hp at the flywheel. But if it's actually 311 hp at the wheels, then it's really a huge gain over stock.

Am I reading the AFR curve correctly to be in the 11s?

dr bob

I had the pleasure of riding in this car when Darien was on his way from Shane's place in Washngton to it's transit home near Los Angeles. Even at 4000ft altitude here, it pulled really strong. You have a winner!

Imo000

Is this one of those "overly optimistic" dynos that shops like to use to attract customers? Most of them have been cranked up to satisfy customer expectations.

GlenL

So much information!

The 11:1 A/F ratio means its too rich. Best Power is usually in the range of 12.5:1 or a bit higher.

"Engine" or "BHP" vs. "RWHP" on which dyno with what correction is standard is a huge variable. All dynos should be corrected to provide a common basis for comparisons both between cars and for one car over time. That takes air pressure and temperature into account as cooler days and higher pressure create more power. Really hard to do accurately but it's better than not doing it. I suggest using DIN correction as that'd be how Porsche spec's their engines.

As for RWHP vs. crank (aka "Brake Horsepower" or "BHP") it's a crapshoot. The lore is that dynojet could never get the "right" horsepower by just doing the math on their rig (by acceleration of the barrels) so they added a fudge factor that'd give a higher RWHP number. Take that and divide by 0.85 for manuals or 0.8 for autos and you get near the stated power numbers. Those factors put back the estimated 15% loss for manuals and 20% loss for automatics.

Back to the OP! Those are good-looking numbers. I'm no longer surprised that you can get 300 at the wheels from the 5l 32V engine. I've gotten 289RWHP from my Euro S and (I believe because I'm like that) I can get 300+ with some tuning.

NoVector

Just a shower thought... It’d be cool to have a portable dyno at 928 events. Not for ***** envy and all that; but just to see if the dyno is set right and we’re comparing apples to apples. I’ve had mine tested at a couple car shows with portable dynos and have a variance of a 100 hp between them so I really don’t know what I have anymore. It still does 0-60 mph in ~5-6 seconds so I doubt I’m a 100 hp down. But it’d still be nice to know… So as an example, if we were all at an event and the OPs numbers are right and I get on the dyno next and I'm off by 100, I'd definitely know I have a problem.

SMTCapeCod

No one's piled on w/mustang v. dynojet yet...cool..

Darien

Again, an all around strong car Not sure who is kidding on this thread but I can verify that it's one of the strongest "non-boosted" sharks that I have driven.

I actually had to call Ken on the drive down from WA to Palmdale to congratulate him on an awesome job with the S300 chips. The engine pulls hard and ignition timing is spot on.

I'm glad to see those RWHP numbers. With cooler temps and a little leaner, I'm sure they will increase.

Congrats!!

Popo928

It's a mustang dyno which is known to be conservative. It's also the same dyno my 85 US auto put down 265 before it was supercharged but that was 8 years ago. Has the dyno been tampered with? I don't know.

Popo928

Update - I drove with my son up to northern KY today and visited an unnamed fello who's name rhymes with Don June. You know... the guy who does twin turbo 928s? Anyway, we did a few runs with Helmut on his dyno. He said his dyno is 5 to 7 percent stingier than dyno jets. It put down 291 with the temperature in the shop at 97 and 63 percent humidity. He said it would clear 300 if it had been 60 degrees. He also said it was stronger than a stock S4 which the numbers clearly support. Bottom line is dynos vary somewhat and this car is pretty strong which made for smiles across my face as well as my son's.

ptuomov

291 rear axel hp with STD correction is very strong. Good luck with the manifold pressure project that I can see in my crystal ball!

Popo928