Jim Morton

I finally got around to doing baseline dyno runs on my GTS. Results look good, as well as reasonable.

Only mods to the engine are GT resonators and RMB. Ambient air temps were in the low 60's.

Enjoy.

RyanPerrella

those are really nice numbers

i wonder what it will do with an x-pipe and some of your sharktuner time

actually, considering the above......wow!

GregBBRD

How much power does the factory claim a stock GTS makes?

Jim Morton

OEM Spec Book says 257kw / 350 HP, 500NM / 369 Torque(SAE)

FWIW, my point in posting here was not to claim a specific number, but to post a baseline for upcoming work as well as a comparison to Dennis K's car. I am using the same dyno with the same calibration on the dyno torque cell and run parameters. No attempts to spike numbers here...

As an interesting note, the parasitic test on my GTS showed less rolling friction than Dennis' car, his with DOT-R tires. I would think this makes sense.

Other note. The PSD faulted during the intial calibration. Just before the fault, the car looked very uncomfortable on the rollers. I am glad it was well strapped down.

ptuomov

A question: Does the completely stock GTS have that valley in the torque curve around where the flappy opens?

Peter F

I assume this is because the computer senses that the front ABS sensors doesn't give a signal since the frint wheels stand still.
Same on my GT when it was tested.

/Peter

Jim Morton

Yup, we tought the same thing. I should have pulled the fuse or ? before getting on the rollers.

IcemanG17

Jim
325ish whp from an otherwise Stock GTS is VERY good........ Did you do any sharktuning?

Jim Morton

No sharktuning, yet. The runs were simply baselines.

The timing of this was VERY impromtu as I was at the dyno on other business. I had my son with me and we thought it would be fun to let him see Dad's car run against the other car (911) I was working on. It was definately fun stuff for him.

GregBBRD

So, it looks like this baseline would indicate a drivetrain loss of almost exactly 10%, from what Porsche claims as a power output?

RyanPerrella

or, isnt it safe to say that the engine is making MORE then the simple round 345 (or 350) HP number that Porsche quoted?

10% driveline loss is nearly unheard of.

GregBBRD

Porsche isn't really know as a company that under estimates their horsepower. Of course, there are going to be examples, from the factory, that have both higher and lower horsepower.

Not sure that I'd bet my life on the accuracy of this dyno, however it certainly doesn't matter, as long as it is just a baseline data point.

928ntslow

My 93 GTS 5 spd made 313rwhp @5990rpm and 332 rwtrq @ 3435rpm baseline

With the X pipe, 330rwhp @ 5755rpm and 353 rwtq @3390rpm.

So your numbers seem about right but in a very weird spot. Whats up with the major dip around 3700 though???

mark kibort

thats pretty wishful thinking that the 928 transmission at 6000rpm is 90% efficient.

either way, great dyno run! those motors are the BOMB!! wish I had one as we could probably tweak it to the same hp im making now and i could still run my races in a "STock" powered 928!

MK

pcar928fan

What kind of dyno was that? I have run both my Automatic GTS's on a dyno here in town and they are both VERY CLOSE (50k miles on the '94 and 130k miles on the '92). The auto is particularly parasitic in my opinion. They were as follows:

'94 286rwhp/306rwtq
'92 283rwhp/304rwtq

Your numbers are WAY better than mine!