Handling wise there's no comparison. Speed wise the 65 will still beat it handily. The only thing faster than an SL65 is an SLR or SL65 Black.

How about a modified SL55? Supercharger!

Well, a heavily modified SL55 can run 1/4 mile faster than a stock SL65 but any SL65 can be easily modified to be faster than any SL55. 6.0L V12 + twin turbos > 5.5L V8 + supercharger.

Bad example. Torque multiplication only comes into play on a comparative basis when horsepower of the lower torque car is equal to or greater than that of the higher torque car because...that higher horsepower can be converted into higher torque with gear multiplication.

Unfortunately for your example, the lower torque car, 63, also has lower horsepower, so it cannot convert nonexistent higher horsepower into higher torque.

A lose-lose situation

An SL 65 would have to be heavily modified to beat your SL 55 since you have the fastest 55 in the world, jfm003. And I'm not sure the 65 would beat you in the quarter mile even then with the issues of hooking it up. That said I agree that stock the 65 is certainly faster than the 55. I have heard of one 65 in the high 10's, but you are getting close at 11.4, and no nitrous to boot! As you know I had a SL 600 for a short time and didn't like the turbo lag. I decided the SL 55 modified was more to my liking.

Just read about an SL55 in southern Cal that ran an 11.38 with the same set up as yours. It's posted on the E55 site. I'm sure you've seen it posted from their day at the dragstrip. Still prefer the 55 engine over the 63, but the torque in the 65 is something else.

Hey there, Mike!

No, I had missed the 11.3 run. Thanks for pointing it out. I left him a congratulatory message over on that forum.

His setup is a bit stronger than mine, with long tube headers and primary cats removed while I'm running shorty headers through the OEM cats. He also has supplemental cooling.

I've decided to add the VRP heat exchanger but haven't decided whether to do any power-related mods beyond that.

How about you? Anything else in your future other than the VRP engine tune?

I just saw your reply. I am slow- what can I say

You are wrong. Less crank tq, hp but shorter gearing can more than offset a higher tq/ hp longer gearing car. I will give you an example- the 65 at 150 has just gone into 5th which is 0.83:1. Rear end is 2.65. At 4500 rpms it is making say 550 tq at the crank which is 550 x 0.83x 2.65 = 1209 to the asphalt (ideal case, no losses, etc.)

The 63 motor at 150 is in 5th which is 1:1 and the rear end is 3.06. At 6000 rpms it is making say 400 tq at the crank which is 400 x 1.0 x 3.06 = 1224

add the fact that the 63 car is lighter and the 7g mct tranny has less losses (no tq converter) and things can go either way as the speeds climb

This is also precisely the reason why an sl65 cannot pull away from an e60 m5 at speeds... And the m5 has 100 less horses and 1/2 of it 65 tq (but has 7 short gears and 8250 redline).

you have to understand that all that matters is tq to the ground at any moment and the crank tq /hp numbers are good start, but are not representative of what happens during a long race

Missed his post by almost 3 years

+1