By the way, where did you buy your headers and sound pipe from? I noticed there's been a lot of fake RENNtech headers selling on e-bay lately?

They are original renntech products

 

I'm just curious.... how do you know that? Did you buy them from RENNtech in Florida? I've seen so many people buy products thinking it's a certain brand name only to discover later that they were replicas.

 

Without stirring the pot just yet; that will come in due time. These old tunes were made by Jeff Katz. He is no longer with Renntech, along with a bunch of other people. Some have moved on to well respected shops like RENN HAUS Euro.Spec, Speedriven, Evotech, and Switzer.

 

This would still mean that with the right software, those headers will indeed produce some decent amount of power and a good amount of torque. The OP stated he had Evosport/Powerchip software; so unless their software is not as good as Jeff's software or something is wrong with those headers or maybe his car, there should be no reason his car would lose power or even feel sluggish

In any case, I think RENNtech offers 2 or 3 year warranty on their products, you should contact them and try to find out what's going on.

 

Headers should make more power as a stand alone mod. If you see a loss after installing headers. You can tune that back in. With headers you can add a certain amount of ignition to the tune and make power over stock. From what a RENNtech employee told me, its a hardware issue.

 

Are you saying there is a problem with ALL of RENNtech's shorty headers for the 63s ?. Are there any details of what exactly is wrong with the headers? I don't understand why this stuff stays hidden We need details on what exactly is wrong with them?

RENNtech themselves don't even claim a ton of power with their shorty headers alone. I think they claim only 10 to 15 hp gain (at the crank). However, when combined with software and sound pipe, the gains are decent as shown in the dyno above.

Honestly, I've seen their shorty headers + software make power on Rick's & Craig's CLS63s along with 2 different CLK63 BS along with at least one E63. There were at least 3 different dynos posted on this site alone about them. And since all those different cars gained power, I am inclined to think that the headers do make power. Are there any dynos of the headers actually losing power on an otherwise healthy/problem-free car? And were there any explanation as to why that happened?

clkblk... either way RENNtech offers warranty on their products. So the best thing for you is to contact RENNtech and have them solve the problem. I'm sure they'll be more than willing to work with you since you just bought the stuff a couple of days ago. However, I would really suggest you dyno your car before and after the headers so that you have proof that your car lost power with their headers and sound pipe. This should give you a lot more leverage.

 

I'm sorry but something is not right with the idea that you have to have an ECU tune to go a long with bolt on headers in order to make any gains Is it a good idea? Probably. Is it a necessity though

 

Not sure how to comment on your comment...who in their right mind would spend the money on a set of headers and not get an ECU tune??? That's about on par with buying a swiming pool but not wanting to and/or being able to afford to fill it with water



As for the "necessity" comment, is any 500hp car a "necessity" to begin with? If you're gonna tune a car at least tune it properly, pissing away money by half a$$ing a project is worse than spending 3 times the amount to get it done right IMO.

 

the fueling on these cars is very complex as is are the adaptations the ECU can control. This isn't like bolting a set of Throley headers to carburated OHV big block. As previously mentioned, just adding headers to a 63 motor will cause a lean condition which could burn up a piston in no time. Anyway, I hear what you're saying, but these modern engines are becoming harder and harder to tweak since they are so highly engineered to run within such exact specs.

 

+1000 I agree and believe in that statement strongly.

 

Im going to wait until I make anymore comments on RENNtech. Mo i think you know why. I happen to be very good friends with a former RENNtech employee as you know. This statement was made to me before he left RENNtech.

As for headers and no tune... I'm running that way. granted my car is a 55. 55k's come boggishly rich from the factory. So running long headers isn't an issue without tuning at all.

 

I guess I was thinking of the SLK55, CLK55 and C55 AMG realm, where there have been owners running headers only without a tune for some time (for whatever reason). For example: https://mbworld.org/forums/slk55-r17...ll-review.html
This, of course, is with the 5.5 V8 and I have more experience with it than the 63 engines. The 63 motor may in fact be more sensitive and have a tendency to run lean with the application of headers only and no tune....

 

Basic physics with any NA motor....be it FI or Carb...
The more and faster you take out from the cylinder, the more you have to put in...

It's all about balance....

Surprised that most dyno operators don't concurrently read AFR with a wide band O2 sensor on the pull....