What's the top speed of a C43 AMG?

[Mercedes Guy]

I know that the AMG cars are limited to 155mph, but I can't help but wonder how fast it would go without the restriction. I would imagine it would be pretty fast.

[blackmercedes]

When I had the C36, AMG had a "kit" you cold buy that elminated the speed limiter. It came from Europe and was tres expensive. The specs indicated that a bone-stock C36 with the four speed auto and stock gearing would see a top speed increase from 250km/h to 275km/h. They also had a kit for a W203 C32 that had a taller final drive gear-set and non-speed-limited ECU that they said would increase the top speed from a limited 250 to 315km/h.

I suspect that a C43 would be in the 280-285 range, maybe a bit higher.

Due to the significant cost of the "uncorker" I did not buy. ($2K+) Not sure if they're still offering any products like that since I understand you can delete the speed limiter on certain AMG cars when factory ordering in some European markets only, and the fee is hefty.

[el presidente]

John, your estimated range seems reasonable for the C43. Now, RENNtech, Kleemann, Powerchip and others offer ECU updates that raise or in some cases, eliminate the limiter.

315kph for a de-limited C32 seems high.

[el presidente]

Originally Posted by w126

Nitrous on the other hand...

Tell me more...

[el presidente]

[Kuan]

It has 302hp, and at 155mph you're probably using 250hp, 160 of which is just to push the air out of the way. You got 50 to spare, not much more really.

It takes somewhere around 550hp to go 200mph, 350hp just to move the air.

[DslBnz]

Did someone want to see a bit of the C32?

Here's a launch from a stop.

http://www.nyclighting.com/images/car/myc32/1.mpg

[blackmercedes]

Originally Posted by el presidente

315kph for a de-limited C32 seems high.

I read about a C32 with taller gearing a different ECU that clocked at 190mph. The article (UK) was brief and didn't give any details on additional mods. I would have to be suspect that additional boost is allowed by the new ECU, perhaps? I am supposing that some of the old AMG sales pitch had a bit of "bench racing" in it. I know that the speed of the C32 with factory gearing is rpm limited and that the car won't reach it's drag limited speed.

Judging myself by how hard the C36 was pulling when it hit 250, I think it might have had another 15-20km/h in 'er, but it's hard to tell. At speed it compared in "pull" to my 911, which ran out to 270-ish, but that's just seat-of-the-pants stuff and has no scientific value at all!

I know that the W124 500E runs out of breath at about 270km/h with the "snipping" of the speed limiter and it's got 322hp, but it's an aerodynamic brick compared to the W202 and the W203 has a lower Cd yet. It would seem that the 349hp C32 with it's lower Cd would be faster than the W124 500E, but by how much is difficult to estimate without some physics math. Maybe 290? Close to 300?

The C43 is easier on the wind than the 500E, comes close power-wise and has the five speed box. I would imagine that it would also match the 500E's 270, and might post higher. Again, guess work based on some known quantities, but pretty loose.

Anyone with a C32 interested in sinking a whack of $$ into some gears and ECU work and verifying?

[Gilly]

Officially listed as "Lickety Split".

Actually the disc says 250 kph/controlled.

If anyone has that program to figure it out, here are the pertinent data:
Axle ratio 3.07:1
306hp @ 5850 rpm
rear tire 245/40 17
weight empty 1570kg
5th gear ratio 0.83:1
I think that's all that's needed for the max speed programs, except the drag coefficient.
Gilly

[gerryvz]

Originally Posted by w126

I think Gerry VZ runs it (?) Thought I read that at the hot-rod forum. Scary fast, fun!

Yes, I run the BergWerks N2O system. It was around $2,000 for the system and I spent another $1,500 on installation, including $700 for a custom bracket to mount the bottle on the driver's side in the trunk (the battery is on the other side).

If you're interested, you can see dyno results (my car stock, my car with N2O (on a DynoJet dyno), Carl of BergWerks' former car with N2O, and my car with a Mustang dyno) here:







I also have a speed limitation removal device (a small black box) that I was able to obtain, used, off of German eBay for not too much money. It was made by a very small engineering shop called "Ingenieurbuero Wilhelm" near Saarbrucken, near the French border. I visited Herr Wilhelm at his shop last year on my annual jaunt to Europe. He was surprised to meet me and sort of gave me the German version of the Star Wars line, by Ben Kenobi, upon Luke asking him if he'd ever heard of an "Obi-Wan Kenobi": "Now that's a name I've not heard for a long time..." Herr Wilhelm said basically the same thing, in that he hadn't manufactured these speed limitation removal boxes for around 10 years. Currently he is making various electronic enhancement boxes for Carlsson, custom engineered specifically for them. Carlsson galactic HQ is around 10-12 km from his house (I visited them too, the same day).

If you're interested to see what this little speed limitation removal box looks like, you can see it at:



It wires directly into the LH computer and provides around a 175-180 MPH top speed. Top speed with N2O, never tried it...probably never will. N2O is really more practical for drag racing (short bursts). My best time, in very cold weather at the very end of last drag-race season (exactly a year ago) was 12.89 seconds, with 13.1 times repeatable. 13.2-13.3 can be achieved in warmer (summer) weather with little difficulty. Trap speeds are in the 107-108 MPH range.

Cheers,
Gerry

[el presidente]

Gerry,

Have you encountered any issues/problems with using NOS?

[gerryvz]

Originally Posted by el presidente

Gerry,

Have you encountered any issues/problems with using NOS?

No, because the system was custom-engineered by BergWerks for the E500E. It is set up by BW to add 100 HP, though jetting can be changed (depending on if you have enough fuel pressure to handle it; my car does) to perhaps 125 or 150 HP.

Many people believe that N2O is a recipe for disaster. It's only disastrous for an engine if the proper safeguards aren't used to prevent a lean condition, the system is poorly engineered or installed, or if it is used constantly. In my case, none of these conditions are the case and I continue to enjoy stellar reliability and power generation on demand some 1.5 years after installing it. Having ~350HP at the rear wheels is quite a rush, yes. The N2O kicks in like a turbo -- you really feel and hear it.

Don't buy into the negative hype around N2O. As long as it is set up properly, not too aggressive, and used appropriately, it is a fine power generator for those times when you "need it most".

Cheers,
Gerry