silverboy

After a custom tune, following are my numbers (at the wheel) vs stock

Torque
before after
4K rpm 220lb 255lb
5K rpm 255lb 295lb
6K rpm 260lb 280lb

HP

4K 165hp 190hp
6K 295hp 320hp
8K 340hp 380hp

Stock head, GMG exhaust for 4L. Torque is immediately noticeable. Perhaps if I changed my cams I would have gained more. But it's cool, I'm happy. Cost was cheap. Capricorn was the supplier.

AEsco48

Congrats....

But...

When you say cheap...?

997 GT3 RSweden

Hi
Here ar My numbers on My 4.1
430.8 hk at wheels at 8150 rpm
425 nm at wheels at 5300 rpm

In engine ar 513hk at 8150
503 nm at 5350rpm

Regards

Robin

Jamie_GT3

Need dyno's and conditions from the dyno as well to make heads or tails!

RSRanger

PM sent

Serge944

You have a meaningful delta. HP gain is what's expected, all things being equal, considering the % displacement increase.

You'd gain more hp with different cams, at the expense of torque decrease. My 4L produced more torque/power up to 5k than the factory RS 4.0, but at the expense of peak hp. I was happy too, because it made up for the weak point in the factory 3.6's powerband: low end. The power coming out of a low speed corner in 2nd gear was just incredible.

Jamie_GT3

For everyone's benefit. Hk is the Swedish word for German PS and French CV, all of which are 1hp = 1.014PS

So divide PS or hk by 1.014 to get it into HP.

Also silver, you were on a bone crushing dyno for such low numbers. Most 3.6L stock on a dyno jet make 360-380 or so depending on exhaust...

TRAKCAR

Pardon my ignorance but should you guys not get better than a 4.0 = 474HP to the wheels?

Tuned 3.8's get 440's right?
What am I missing?

Serge944

Using stock 996 camshafts yields the following results. If I was to do it again, I would have installed more aggressive intake cams. Numbers are based on dynojet SAE results, and before the dyno ***** jump in, you will notice the results of the factory cars are pretty representative of factory claimed numbers.

RPM Wheel Torque lb/ft
RS 4.0, Serge944 4.0, RS 3.8
3000 268 265 238
3500 270 280 244
4000 277 285 248
4500 293 296 260
5000 307 310 280
5500 314 305 290
6000 319 290 290
6500 309 295 283
7000 314 280 290
7500 304 268 278
8000 284 243 275

Note: my 4.0 #s are baseline, before any tuning. Further gains were achieved with a tune.

Serge944

No.

If you look at the displacement to hp output of the 4.0, its a pretty incredible achievement, as it doesn't follow the typical hp/l ratios of the rest of the GT3 factory lineup. Porche got a 11% hp jump with a 5% displacement increase over the RS 3.8 - and that car was high strung as it is!

Porsche went through great lengths to realize the 500hp result, so one should question similar claimed results from lesser efforts.

If you look at the european efforts from tuners like RS tuning, Manthey, etc, you will notice that they need more than 4 liters to get 500 hp in street configuration.

Jamie_GT3

It does depend on the dyno... Dyno jet is inertia based and yields higher numbers, other dyno's (mustang, dyno dynamics etc) are brake dyno's. what's important as serge said, was the difference when run on the same dyno under similar conditions. When we post dyno figures the dyno, correction and conditions are all important so that one can understand the numbers being presented...

Or we all go out and just get 1/4mile trap speeds and back out the HP from that!

997 GT3 RSweden

My numbers on the engine in the RS Tuning in Germany.
My figures on the wheels come in from Turbo center in Sweden.
Normally it disappears between 14-16% through transmitionen.

Regards

Robin

10 GT3

I see lots of stuff typed here, but not a single dyno sheet. Hmmm...

TRAKCAR

[QUOTE=Jamie_GT3;10557608]It does depend on the dyno... Dyno jet is inertia based and yields higher numbers, other dyno's (mustang, dyno dynamics etc) are brake dyno's. what's important as serge said, was the difference when run on the same dyno under similar conditions. When we post dyno figures the dyno, correction and conditions are all important so that one can understand the numbers being presented...

Or we all go out and just get 1/4mile trap speeds and back out the HP from that![/QUOTE

You guys can school me on this for sure.
ll we have is base numbers of a few 3.8's with side muffler delete, with catless headers VS 4.0
We did it all in one day. Swapping exhausts on the Dyno.

Seems like the 4.0 has about 35 - 50 up more stock / exhaust that

RSRanger

10 GT3 you are absolutely correct. I am breaking my silence in the forum after the GMG bullcrap!!!! Too many blind suck ups around here.
I have PM'ed the OP and no response. I would try to help and add to factors dealing with a build but he has not responded to me. That's just fine.

My 3.6 to 4.154L build has been documented and with Dynojet graph.

Serge, please post dyno graphs of your 4.0 bore build. You seem to be the "gold standard" for a 4.0 builds. My Champion Motorsport build is a POS by your standards.

OMG why do I even bother as an amateur dealing with all these experts? Us starving marvin need to go home and coward under our beds.

Ranger (Sua Sponte)