StephenK

(IGNORE Run #1 NOT MY CAR - Used for a COMPARISON)

vraa

So your top numbers are 496hp & 596lb-ft torque?

StephenK

That is as of today. On my second run with was the third run on the report, I expected a decrease in horsepower, but was puzzled why the torque went up from 595 to 622.

Also, since Mercedes advertises 493 hp and 590 lb-ft of torque, how do I convert my numbers to compare to these.

vraa

Mercedes numbers are at the crank, that means they dont' take in account the 20% parasitic loss from the transmission.

So...

493 * .8 = 395
590 * .8 = 472

So your numbers are showing a (using the third run, which is the second run for you) 101hp increase and a 123lb-ft torque increase.

On the RENNtech PDF, you should be getting a 132hp increase and a 155lb-ft torque increase.

What were the temp at the dyno, and do you have a A/F ratio graph as well?

But then again, if you multiply the theoretical increases by .8, they call almost perfectly with your gains. I need to do either a little more math, or a little less thinking

StephenK

Temps are below the dyno graph.

vraa

90F.
I guess that's good, but still, I'd assume most track runs are going to be in the high 70's.

Did you go to the track yet?

StephenK

Ricky any idea why HP would go down and Torque up in RUN #3

vraa

Your guess is as good as mine, I have no earthly idea.

The first thought that came into my head was the turbos spooling, but that's dead because it's referring to peak torque. Your third run seems to have a lot more under the curve. Almost.. too much of a variance.

StephenK

What does that mean Ricky, under the curve????

vraa

I'm really not sure how to best explain it, it's kinda like, peak numbers aren't the end all be all way of saying how much power a car has.

The way the curve is shaped and the area under a curve also plays a big role.

RennTechV12

I'll make this simple for you. Your high numbers (at the flywheel) the way the car manufacturers rate them (factoring in a 20% drivetrain loss)

HP: 590
TQ: 747

These numbers are what you should expect and are very respectable!

Your TQ # is very strong, higher than any production car in the world, including the AMG 65's.

Each car reacts differently to the computer flash. If you put 100/101 octane gas in your car you would probably gain 30-40hp and 40-50TQ.

vraa

Does the RENNtech ECU account for higher octane gas?
I didn't know that!

RennTechV12

No, but all forced induction motors run better off higher octane gas.

I just got the SL600 flashed with a 100 octane program today, took it to the track 2nite and ran 3-5 10ths faster than usual. It's hot here, 90f at 10pm so I only was able to run a 12.01@118, faster than the normal 12.3-12.5 summertime runs. The only downside to the 100 octane flash is that I've got to run 100 octane all the time now, but it's only $2 more than our 91 ocatne garbage gas.

vraa

Well, if StephenK doesn't have the 100octane map, his current ECU won't advance the timing enough to compensate. It'll be a waste of money for him.

Have you dynoed with 100+ octane? I'm interested in seeing the dynos on that.

RennTechV12

Not yet, getting it done tuesday, will post. Car is DEFINETLY faster.

Before the 100 octane flash, I would always run 4-8 mph faster in the 1/4 with 100 octane, instead of pump gas; in the Benz and the Porsche.

absent

Did you dyno your car before the mods?
I was disappointed with my results on my old S600:
485hp before the mods(Renntech Stage 3)
525hp after (both measures RWHP)

StephenK

Who did you do the flash thru?????

RennTechV12

My local tuner Dynocomp