ssalib428

I posted a thread several weeks ago about my friends CLS 55 having an engine problem when driving at a high speed. The car did have a stage 1 kit on it. After several runs at around 140 mph we actually blew up one of the pistons causing the engine to pressurize and oil explosed everywhere. We did not feel comfortable having an amg engine rebuild. So are in the process getting a used engine installed in the car which is in good condition with under 45k miles. Our concern is with the Stage 1 pulley being reinstalled on the engine. I'm not sure what size the pulley is but we obviously don't want to have this problem again. Can you guys please give me some input and information on this? I know the ecu has to be retuned and to work properly with the pulley and i'm sure the size of the pulley makes a difference on power gains and tuning? I'm just looking for more information on this so we don't run into any more problems.

maxwerks

In order for people to help you , you need to state , stage 1 by who ? who did the ECU on the car originally , pulley by who and what size ..etc

ssalib428

We don't have any prior history on the Stage 1 kit. If may have been tuned wrong. We bought the car used back December and Stage 1 kit was already done. How can we find out this information, is it stamped on the pulley itself? How do we measure the pulley size?

If I take it to Merecedes can they tell what what tune the ecu has and can they just flash it back to stock if needed? Are there any other qualified mechanic's in NJ that can do this besides Merecedes since its an aftermarket part. If so, who do you guys recommend.

I really just want to know if it is a true stage 1 kit. I'm not sure if it was tuned properly in the first place and that's what caused the piston to explode. I really need some help to find out what can be done to determine this.

keith954

Put bigger fuel injectors or a new fuel rail and injectors in the new engine. You probably ran lean and caused the engine to blow. You guys aren't the first to blow the engine on a high speed run. The tune could be good and you can still blow the engine because the #1 or 8 cylinder is starved for fuel. For one the fuel pressure in the stock rail sucks, and you could be at 100% duty cycle for your stock injectors..

ssalib428

I appreciate your input. We are still looking into all options. We also researched the pulley size and its a 180mm which I believe is the biggest size.

Has anyone ever removed there ecu and sent it out to be tuned? If so, who do you recommend for tuning?

maxwerks

I am sorry but if you dont know anything about the history or the previous work on the car , then how do you know it is stage 1 ? Stage 1 or stage 7 only means anything when you know who did the work and what does that stage include .. normally if it is the very first of minor modification I would ' guess " that it is the only the ECU ..unless there is a stamp anywhere on the car by someone other than MB , then the only way is to have the car at MB have it hooked up to their system and read out everything for you . I personally wouldnt tamper with ANYTHING on that car until you know what EXACTLY has been modified on it ...

ssalib428

I appreciate all response. I think we are just going to put stock pulley on the car and leave it alone. I honestly don't want anymore headaches. Thanks again for the advance.

boost420

Too many variables to comment. A 180mm on an untuned car could be a huge issue.

CharlyE500

180mm pulley
- ECU tune very very important. Without tune engine will blown for sure.
- It will generate huge heat and lack of fuel in cylinder #8 so you will need to upgrade Fuel injectors and fuel rail. Not sure if you need both but injector upgrade is a must. The best size of pulley in my opinion is 168 kleemann and Renntech.

From my understanding here are the stages:
1 - Pulley + ECU
2- Header
3- TB
4- camshaft
5- Supercharge pulley