Missig Bhp Power

[Brabus SL]

Hi all

, I have a 2003 SL55 AMG Based BRABUS SK55 K8, I would like to find out if anyone knows what the "Charge Air Temperature" for a standard SL55 AMG should be, I recently had my car put through the STAR diagnostics and my "CHARGE AIR TEMPERATURE SENSOR" and "INTAKE AIR TEMPERATURE SENSOR" values are 50 C, is this normal, I had my car put on the Dyno and I should have 550 hp, instead I have 510 hp, where has all those horses gone???

I was told that my temperature may be to high causing the ECU to reduce the engine power!!!

 

[obi_waynne]

This could be the difference between power at the flywheel (usually quoted by manufacturers IIRC) and power at the wheels which is subject to transmission losses.

What is the mileage of the car? Perhaps it just needs a thorough service. Injectors can foul up a bit with age.

 

[pgarner]

Air intake temp does seem rather high
remember that the charge air temp has been through the supercharger and intercooler so could still be quite high

 

[Brabus SL]

My car has 31.000 miles, it last had a main dealer service 3,000 miles ago.
this issue only came to light when my friends CLS55 AMG was creeping up besides me from 90 mph - 140 mph and I could not shake him off until his limiter kicked in.

BRABUS SL K8 PERFORMANCE
0-60mph 4.1
550bhp @ 6200rpm
Torque 578lb ft at 3000rpm.
Weight 1955Kg

AMG CLS55 PERFORMANCE
0-60mph 4.7
476bhp @ 6100rpm
Torque 516lb ft at 4500rpm
Weight 1730kg

 

[Brabus SL]

Air intake temp does seem rather high
remember that the charge air temp has been through the supercharger and intercooler so could still be quite high

Thanks for your reply

I was told that if the tempreture is to high the ECU will pill back the power in order to prevent "Detonation" I am told by DMS that the idle temperature should be around 43C and under load around 55C, from my research I have found out that these 55 Kompresor engines have a inherent problem "the charge cooler pump" they tend to fail very often and in order to protect the engine the ECU disengages the Supercharger via the electromagnetic clutch resulting im massive power loss, now I don't have massive power loss but I am not sure what happens if the charge cooler pump starts to fail and stops pumping the water fast enough, does the ecu only disengage the Supercharger when the temperature only reaches a certainhigh level or can the ecu reduce the engine power slightly (constantly varying) without interupting the Supercharger seeing the Supercharger is controlled via a electomagnetic clutch and I understand it would therefore be either on or off.

confused I am!

 

[Brabus SL]

Just came of the phone from speaking to BRABUS in Germany, the technical person I spoke to was very helpful, among the things he suggested was to send the ECU to them and they will remap it for free as during the cars life Mercedes Benz may have upgraded the software during a service, clearing the original BRABUS ECU remap!

The other recomendation was to remove the Charge Coolers (Mercedes & BRABUS) and clean them out and/or replace the BRABUS Chargecooler Pump and the Mercedes Benz Charge Cooler Pump.

Or Bring the car the BRABUS in Germany and they will check it :bigsmile:!
seven hours drive away!!!

 

[obi_waynne]

But the drive back on the Autobhan will be a lot of fun!

 

[T9 man]

Well the chaps in Brabus Germany have proven to be very help to you, which is a rare commodity in specialist engineering companies these days!
and the offer of the free remap? my kind of dealer! good luck with the work and keep us updated with how everything works out as I am thinking about buying a Brabus monster myself to keep my Saab company in the garage!

 

[Brabus SL]

Re: Charge Cooler Pumps

Just came of the phone from speaking to BRABUS in Germany, the technical person I spoke to was very helpful, among the things he suggested was to send the ECU to them and they will remap it for free as during the cars life Mercedes Benz may have upgraded the software during a service, clearing the original BRABUS ECU remap!

The other recomendation was to remove the Charge Coolers (Mercedes & BRABUS) and clean them out and/or replace the BRABUS Chargecooler Pump and the Mercedes Benz Charge Cooler Pump.

Or Bring the car the BRABUS in Germany and they will check it :bigsmile:!
seven hours drive away!!!

 

[Brabus SL]

Re: Missig Bhp Back (maybe)

Hi All I think I am back!! (Maybe)
MotorAid checked both pumps on my car and found the AMG (Bosch) pump not working at all! so only the smaller BRABUS pump was operating and its job is to only pumping the water around the smaller additional charge cooler, the water was not flowing through the larger AMG charge cooler causing the Supercharger temp to rise to high also causing the air intake temp to also rise. The faulty AMG pump did not show up in Star as the BRABUS pump was wired in parallel to the AMG pump therefore there was still a resistive load telling star all was working. my "BRABUS" power seems to be back now albeit my charge temp at idle still remains at 50C but at driving on the proving ground the air intake temp sensor measurement was recorded as follows.
40 MPH -38C
50 MPH -40C
70 MPH -42C
80 MPH -57C
90 MPH -60C
100 MPH - 61C
120 MPH - 58C
130 MPH - 77C
140 MPH - 73C
150 MPH - 75C
I was told that the Air intake temperature readings are to high causing power loss but the car feels more punchy! Its very difficult to find ot what would be considered to be normal as BRABUS say 50C at idle is OK but two independent Mercedes Tuning specialist say its to high and it should be between 30's and early 40's and not 50C, apparently Mercedes state 50C is the Max, but with all my additional BRABUS cooling the temp should be considerably less! not quite sure what to do next if the air intake temp is to high, I have now changed my air filters to BMC Air Filters which contain no oil like the K & N filters which I have read the oil from the K&N Air filters can damage the MAF sensor, not sure if the is true so I did not want to take the chance.
I will have to compare with my friends CLS55 AMG, yesterday he has it remapped by Evolve, prior to his remap he told me he had his exhaust mid-boxes removed which may have given him additional BHP when we first compared the performance of our cars, he now has 535 BHP from his Dyno Run, i will be seeing him soon!

 

[Brabus SL]

This could be the difference between power at the flywheel (usually quoted by manufacturers IIRC) and power at the wheels which is subject to transmission losses.

What is the mileage of the car? Perhaps it just needs a thorough service. Injectors can foul up a bit with age.

Hi Waynne,
my car service was carried out around 2 years ago, since then it has only covered 5,000 miles, the cars service indicator indicates 5,000 more miles before next "B" Service (Plugs ect) the previous service "A" was a Lubrication service carried out by MB @ £300 (theives)