SL55/63/65/R230 AMG: Video of V12 BiTurbo Dyno - 624 rwhp
http://www.youtube.com/user/roadtest.../0/x8H5rUyV3E4
Ahhhhh, so 1.5 after tune. Marcin posted that is was 0.9bar for a 600 stock, and 1.5 for a 65 stock.
Any ways. Stock boost for 600 cars is 0.9 bar. Stock boost for 65 cars is 1.5 bar. These numbers are straight out of MB repair/tech manuals. From personal exp. most cars stock are right at that number or slightly lower.
Last edited by Benz-O-Rama; Feb 10, 2010 at 12:10 AM.
But what do I know.
The Best of Mercedes & AMG
stock boost is 1.5 bar. TMC M5 said that you said it was around 22 psi. It doesn't matter how much you tweek an ecu it's boost that gives you the big extra gain. Either the manual is wrong or your dyno reading is wrong.
It's just logic.
I can post stock tune dyno graphs with a boost pickup and they usually read about 12-13.5 psi. Which is just under 1 bar. 1 bar = 14.7 psi in case anyone is wondering.
Tom
If 1.5 is stock then is that peak, usually peak boost drops to a sustainable figure, 21 psi dropping to maybe 19/18 psi. I presume the re map takes out the limit or raises it along with fuelling etc. I still can't see a 100 rwhp extra with only 1 or 2 extra psi. I don't pretend to know a lot about modern turbo cars, all of my knowledge was gained on turbo cars over 20 years ago, however I can't see that the big figures have altered that much.
max. That's from a UK MB manual. So that's around 18 psi, so SGC has got
around 22 that's a gain of 4 psi. Working on a figure of around just over 20 bhp per 1 lb boost would give you 80 + bhp gain which seems about right.
Sorry to be vague but no one is sure down to the last dot. So 4 gets you a lot more!!

Enmjoy your ride.
max. That's from a UK MB manual. So that's around 18 psi, so SGC has got
around 22 that's a gain of 4 psi. Working on a figure of around just over 20 bhp per 1 lb boost would give you 80 + bhp gain which seems about right.
Sorry to be vague but no one is sure down to the last dot. So 4 gets you a lot more!!

Enmjoy your ride.
TIMING AND AIR FUEL RATIO HAVE A PROFOUND EFFECT ON POWER OUTPUT. YOU CAN GAIN OVER 100 HP WITH THESE CARS (V12TT AND MOST FORCED INDUCTION CARS) KEEPING THEM AT STOCK BOOST BY RUNNING LOTS OF TIMING.
The reason I'm against running 93 octane in a V12 car that puts down over 600 RWHP is this. There is only one way (assuming the turbos and engine are stock) to get more horsepower out of this platform once the turbos are maxed out. That is with ignition advance, or advanced timing (AFR plays a role, but I'm assuming nobody in their right mind wants to gain power by running leaner than stock). To put down over 600 RWHP the timing map is aggressive and NOT 93 octane friendly. What happens? Timing and boost are being reduced and throttle body closes (ECU protecting the engine) limiting overall power. The car can actually run slower on 93 octane gas than it does with a stock tune. I also don't like to leave the integrity of my motor in the hands of a sensor or two. They sometimes go bad.
Last edited by MarkoCL65; Feb 10, 2010 at 07:06 PM.
The reason I'm against running 93 octane in a V12 car that puts down over 600 RWHP is this. There is only one way (assuming the turbos and engine are stock) to get more horsepower out of this platform once the turbos are maxed out. That is with ignition advance, or advanced timing (AFR plays a role, but I'm assuming nobody in their right mind wants to gain power by running leaner than stock). To put down over 600 RWHP the timing map is aggressive and NOT 93 octane friendly. What happens? Timing is being reduced and throttle body closes (ECU protecting the engine) limiting overall power. The car can actually run slower on 93 octane gas than it does with a stock tune. I also don't like to leave the integrity of my motor in the hands of a sensor or two. They sometimes go bad.
Focusing on your second paragraph, are you stating that it's not safe to run 93 octane on a tuned V12TT if it's approaching 600WHP? I'm just a hair under 500whp on a historically low reading Dyno Dynamics, so who knows (and who cares, really) what the dynojet number is. But, I only run 93 octane. Do you only run race gas in yours? I know my AFR is still pretty close to stock, although I don't have my chart in front of me. I remember the AFR being close to the fat stock number.
1. The turbos are way out of their efficiency range and the compressed air is exremely hot. This creates ideal conditions for detonation, especially with stock intercoolers.
2. The timing map is aggressive which in turn creates more cylinder pressure and heat, further contributing to the ideal conditions for detonation.
3. Stock intercoolers are restrictive. Any restriction causes more heat. Hot charged air and an aggressive timing map are not what you'd consider a recipe for longevity.
A higher octane fuel does lower combustion chamber temperatures. That's my fuel of choice (100 oct unl) Normally a 5.5 or 6.0L engine can make up to 750 RWHP safely on pump gas, but not these cars, not with these restrictive intercoolers, small turbos and manifolds.
I don't think you have anything to worry about.
Last edited by MarkoCL65; Feb 10, 2010 at 07:22 PM.
1. The turbos are way out of their efficiency range and the compressed air is exremely hot. This creates ideal conditions for detonation, especially with stock intercoolers.
2. The timing map is aggressive which in turn creates more cylinder pressure and heat, further contributing to the ideal conditions for detonation.
3. Stock intercoolers are restrictive. Any restriction causes more heat. Hot charged air and an aggressive timing map are not what you'd consider a recipe for longevity.
A higher octane fuel does lower combustion chamber temperatures. That's my fuel of choice (100 oct unl) Normally a 5.5 or 6.0L engine can make up to 750 RWHP safely on pump gas, but not these cars, not with these restrictive intercoolers, small turbos and manifolds.
I don't think you have anything to worry about.
The reason I'm against running 93 octane in a V12 car that puts down over 600 RWHP is this. There is only one way (assuming the turbos and engine are stock) to get more horsepower out of this platform once the turbos are maxed out. That is with ignition advance, or advanced timing (AFR plays a role, but I'm assuming nobody in their right mind wants to gain power by running leaner than stock). To put down over 600 RWHP the timing map is aggressive and NOT 93 octane friendly. What happens? Timing and boost are being reduced and throttle body closes (ECU protecting the engine) limiting overall power. The car can actually run slower on 93 octane gas than it does with a stock tune. I also don't like to leave the integrity of my motor in the hands of a sensor or two. They sometimes go bad.
I agree 100%. The ECU will pulls quite a bit of timing on my car with 93 octane.
The reason I'm against running 93 octane in a V12 car that puts down over 600 RWHP is this. There is only one way (assuming the turbos and engine are stock) to get more horsepower out of this platform once the turbos are maxed out. That is with ignition advance, or advanced timing (AFR plays a role, but I'm assuming nobody in their right mind wants to gain power by running leaner than stock). To put down over 600 RWHP the timing map is aggressive and NOT 93 octane friendly. What happens? Timing and boost are being reduced and throttle body closes (ECU protecting the engine) limiting overall power. The car can actually run slower on 93 octane gas than it does with a stock tune. I also don't like to leave the integrity of my motor in the hands of a sensor or two. They sometimes go bad.
18-19 psi. However running a engine with lots of ignition and lean is likely to cause detonation. I think most tuners simply up the boost with the necessary ecu adjustments, it's quick,safe and makes them a load of bucks.




