cal1

What makes you think 557 at the crank is going to out perform 500 at the wheels? the Bi-turbo still has some spool time even though it is greatly minimized. The SC is nearly instant on torque. I haven't done exhaustive searches but, the the Sl63 bi-turbo is purported to run about 12 flat in the 1/4. If that is the best it can do in its stock form, I win.

One thing for certain, whatever the outcome, it would be a blast.

COBRA63

Well, if you have done your research properly, you would know that a stock M157 biturbo engine with a PP package makes 511-520 at th wheels with a huge amount of torque to go with it. 55K making 500rwhp has no chance against it. It's heavier, has less power, and less torque

cal1

Yeah, crumby research on my part and even worse reading of your posts because I obviously completely missed were you mentioned the performance package option.

COBRA63

You mentioned 557hp at the crank. That comes only in the PP package. Which makes 511-520 at the wheel. There are stock dynosheets from Renntech, insidline, and OE tuning. All making That power to the wheels.

A non-pp makes around 460-480 to the wheels, which should also outperform a modded 55k making 500 to the wheels.

Now you mentioned that your SL55 has mods. What mods do you have that make you hit 500rwhp? Can you show us a dynosheet? Or perhaps a video of your car at the dyno run?

cal1

^
I have to tell you, I am growing a bit tired of this. I really hope you aren't some new guy with 50 posts that just creates arguments for the fun of it. I am going to assume you are not. I can assure you that is not my intention. I think the 5.5 BiTurbo is awesome and there is no argument that a stock 5.5 biturbo will walk an SL63 with a 6.3 na.


Now to your questions. The HP numbers I mentioned were based on what I called a non-exhaustive research. That means I made a quick search saw a few numbers and ran with them. You state that I did not do my research properly. Fine, I relinquish that point to you if that is your intent, YOU WIN.

You state "now I mention mods". Not sure what you mean. I mentioned mods in post #24.

the last dyno tune done on my car by Jake and Jerry at EC showed nearly 500 WHP and 539 WTQ. I do not have a copy of the chart. On to my mod list.

RT Package plus which consists of 178 counter pulley, HE, pump and ECU/TCU tune. 80mm TB, EvoSport shorty headers ceramic coated. Phenolic spacers and secondary cat delete. Oh, and EC dyno tune to bring all of the mods together.

I know you are super big on dyno numbers. I see them only as comparison from mod to mod and not something to use to figure out which car walks which. I have run a number of high dyno Mustang Cobras and beat them. To me, the numbers show best at the track. In my non-exhaustive research, I saw the new SL63 running 12 flat. My PB on streets is 11.86.

Here is my time slip

Let me know if you question the authenticity of my time slip. i will be happy to give you any number of members who will vouch for me.

COBRA63

I think you are taking this personally. Not my intent partner. Just wanted to get some facts down. Thank you for posting your slip. You mentioned that you saw the new SL63 make a 12 flat. Well, this must have been just so recent, since it just came out. Your time slip is from October, which is in a much better runing condition than this time of year. Therefore, Ina better whether condition, the SL could easily equate your time or beat it. (this was most likely the non pp sl63). Therefore, down low you cannot beat it. That's all I am saying

cal1

I learned something from you today about the M157 which is totally cool. learned about 1,000 posts ago not to take stuff personal. Keep in mind, there are people that jump on here with the sole intent of creating havoc. The vast majority of people are super helpful to everyone. You only have 50 some posts, but clearly fall in the later group, I think.

Hopefully one day i will get the chance to line up with an R231 AMG at the track. If he is modded, I am toast. If not, I'm not as certain of the outcome as you.

By the way, if memory serves, we had record heat that day in October.

COBRA63

I checked that, and it looks like on October 21st 2009 @ 8:50pm the temperature was 57F and DA was around 1100. Much. Better condition than nowadays this time of year @ Muncie Dragway

Check it out ion dragtimes.

http://www.dragtimes.com/da-density-...time=8:53%20PM

My number of posts isn't relevant here

AndrewJM

Now, I think that we can all agree that both the R230 and R231 are very nice cars.

COBRA63

Cali1 and I never disagreed on that point

cal1

This just shows the limitations of trying to communicate accurately and fully through posts. I remember that night very well. It was cool and dry and even better, it had been hot during the day and the track still had some heat in it. I used this little guy "" to try and convey sarcasm.

Thanks for the link, I have been there many times to check DAs. Did you notice the list of fastest SL55s while you were there?

As far as this, "My number of posts isn't relevant here" I think so too.

By the way, the tranny on the R231 AMG must do a great job of getting power to the wheels with minimum loss. What would you say is a good rule of thumb on percentage loss?

COBRA63

Still doesnt change the fact that you were running @ better conditions!

Your welcome. As a matter of fact I did. looks like the best was a 10.89 running with these mods:
http://www.dragtimes.com/Mercedes-Be...lip-19936.html
This was done on the 18th of December at Famaso, where the DA was 915. You can clearly see a dynosheet posted of the SL making about 597 to the wheels. Still not good enough to run this M157 baby with a tune + exhust only @ worse conditions in a florida summer wheather, it ran a 10.7

Actually, No. The R231 is equipped with the MCT 7 speed AMG speedshift, which is known to lose more power to the wheels. As we have seen in the 2009 SL63, which equips an MCT, it doesnt use a torque converter, but a wet startup clutch, which in turn suck more horsepower for faster shifting. I would say the loss would be around 18-20%.

Sorry to dissapoint, but fact is the newer engines burry the previous 55K

Let me know if you have anymore question!

cal1

I do have one more question and need your expertise. We have established the MCT7 losses 18 to 20%. So how do you reconcile this statement:

You mentioned 557hp at the crank. That comes only in the PP package. Which makes 511-520 at the wheel. There are stock dynosheets from Renntech, insidline, and OE tuning. All making That power to the wheels.

According to your loss ratios, at 18% loss and 557 at the crank, you get roughly 400 at the wheels. 100 HP less than my car.

COBRA63

Thats because it is underrated from the factory. It is actually making more than 557hp. Here are some stock dynosheets:
http://news.renntechmercedes.com/page/4/

and this qoute:

" The Performance Package isn’t anything intense, it just raises boost from 14.5psi to 18.8. On the dyno, they put down 483WHP/478tq and 516WHP/544tq, respectively. So that means A, they’re both really fast and powerful and B, both are a little under-rated from the factory"


Morever, the MCT that was first introduced on the SL63 proved to be a powerful tansmission,but with the expense of a little loss of power to the wheels for better shifting. 63 Na motors with a rating of above 500HP are known to dyno above 400rwp with the normal 7g tronic tranny. Look at how this SL63 that Evosport worked on dynoed:

https://mbworld.org/forums/sl55-amg-...er-thread.html

BTW,the SL63 has a rating of 518HP and you can clearly see here that it dynoed 384 RWHP Stock, which is a loss of about %20


again, numbers are good for comparisons, what matters is what happens on the street and at the track. Go find yourself a stock M157 SL63 and race him from standpoint, roll on,and high speeds, and you will know what I am talking about when he is ahead of you on all runs

let me know if you have any other questions