As most of you probably know, I have the Renntech stage 4 package which consists of ECU, Pulley, Headers, and Airbox. I am thinking of swapping my Renntech headers for the Evosport headers.

2 Questions
1) Will I need to get my ECU retuned?

2) What are the risks in mixing tuners?
I know that people often say that you shouldn't mix tuners, but what risks do I have in doing so?

Thanks!!

 

Do you have a pic of the Renntech headers?

 

They are both shorty headers.. The Renntech has a slightly different design in it's pipe arrangement.

The ECU will be fine with either header. They both bolt up to stock manifold which means the tube diameters are the same and in essence the flow characteristics are the same.

I dont know the performance figures of the Renntech, so I can't give an opinion on whether the swap would be worthwhile.

I am very happy with the Evosport headers.. I gained 31rwhp from stock to headers only. Good low end torque and seems to pull hard through the whole rev range. No complaints so far...

 

Even if you picked up a few horsepower by switching, it would hardly be worth it. That money would be better spent on a 80mm TB.

 

The headers you have currently are good headers, however i believe there would be a slight power gain from switching to our headers, but i think you could definitely place youre money better- I'm not sure if you already have an LSD, but that'd be a nice upgrade. just something for you to think about

 

My Renntech headers are not coated (to keep the heat inside) and I want coated headers. Thus, I am faced with a decision. Send them out to jet-hot to get coated and drive around with my exhaust manifold in the interim or buy Evosport headers which are heat coated and sell mine..

Decisions....Decisions..

 

Chris:

What exactly is an LSD?

 

Limited Slip Differential.
http://en.wikipedia.org/wiki/Limited_slip_differential

 

i've used jet-hot coatings for a few projects and if that's all you're looking for i think you're expecting too much. while it may slightly reduce ambient temps, you won't notice enough to warrant the work imho. performance gains (coated vs. non-coated) is minimal at best and again, it won't warrant the effort to change them out.

as already suggested, spend the time an $$$ in areas that you'll notice the benefits.

 

I am on the same fence as you are, except i haven't done stage II yet. I have done research on RENNtech and they are a straight bolt on. It has an "odd" 4 into 3 into 1, but once I was taught why I actually like it better.

I can't speak for EVO, so maybe Chris can let us both know the deal with their headers. As far as coatings, minimal at best, especially if you aren't doing it to everything (i.e. full exhaust coat) and regulating engine bay temps.

Also, maybe Evo could clarify the status on the pulleys? Is there an issue with the belt? That really was what scared me away from jumping on the stage 2 a month or so ago and that is when i ran into the RENNtech.

 

What about heat soak? I was planning on getting my air intake tubes thermo wrapped and thought for a second and realized that I might as well coat the source of my potential heat problem. The headers!!! These things transmit a lot more heat than the exhaust manifold. Hot air rises... and heats up the intake tubes. Doesn't it make more sense to jet-hot the headers before even considering thermo wrapping the intake tubes?

 

lol. I cannot even conceive an iota of gain from wrapping your intake tubes. you have way too much free time on your hands if you think about this ****. keep your headers, buy LSD.

 

Check this out!
https://mbworld.org/forums/showthrea...ghlight=intake

 

Would you elaborate on this? Thanks.

 

https://mbworld.org/forums/showthrea...ght=Amg+header
This thread has pictures of Renntech, Kleemann, Supersprint, and Evosport headers..

 

heat soak is something to worry about, but i don't think you're going to show a significant advantage at preventing it with thermal coatings or wraps.

thermal wrap does a much better job at insulating than ceramic coatings so save the time and money and use the wrap on your air tubes if you're really concerned with ambient heat. but remember...thermal wrap not only keeps heat out, it keeps heat in as well so that's something to consider. i just don't believe the (claimed) performance benefits are enough to overcome the price of swapping headers or even the time and work to have your existing headers coated. if the exhaust was already off the car, sure why not...besides, it looks cool too.

what ever you do, don't use thermal wrap on your exhaust. i learned the hard way on a set of custom headers and again with a custom turbo set-up. the wrap will cause the metal to retain far too much heat and cause a process that's called hydrogen embrittlement. this basically causes the metal to become brittle, fatigue, crumble, and fail...all rather quickly. the metal can turn a brownish color and many people mistake this for rust thinking "it must have gotten wet or the humidity was too high". it's not rust and can happen regardless of moisture!!! the process is more likely to happen with lesser quality metals. does it happen to everyone...definitely not. can it happen to anyone...DEFINITELY! don't risk destroying a several thousand dollar exhaust system trying to reduce heat for a possible but unlikely gain of a couple of hp.

the dyno testing i've seen regarding thermal insulators (ceramic/thermal wrap) on exhaust has not yeilded a gain or loss that was significant enough to be outside the range of error that could be contributed to the dyno, operator, or ambient differences between runs so my advice would be to spend your time and money elsewhere.

 

I remember that discusion. I was wondering what jangy found out that made him like the 4 to 3 design.

 

So, you saying you will put your hands on an EVO header? If so, I'll buy it and watch. If not, then hmmmm.....

 

The wrap is more efficient, but it is not the problem. With wrap, you end up with air between the wrap and the metal that acts as an insulator. The heat is drawn from the exhaust and bounces back infrom the wrap. The equilibrium of heat that sits around the metal is the problem.

What is hydrogen embrittlement? never heard that one. the temps you are getting are nowhere near enough to split H2 atoms up, so I am confused on the term. What does happen is actually very similar to rusting, other than it does not involve Iron. You have to keep in mind that most chemical reactions are accelerated by heat, pressure, and pH. As the environment heats up and cools off, the gases that get trapped between the wrap and pipes can condensate and react. Also, the actual heat cycling of the metal will make it brittle.

I have also seen many cars trashed by just wrapping the pipes without a thought to the "seal". Nowadays, most people use the wrap more like fiberglass and wrap small pieces and coat it with a goo to make a nice seal. No air is no insulation and thus less trapped heat.

 

I think the intake tubes heatup from "radiation" rather than convection or conduction.
And its a waste of time - I think. https://mbworld.org/forums/w211-amg/145853-air-tube-temperature-recordings-results.html

 

I didn't mean to bring a dead horse back to life, but that thread is REALLY funny. Now, I don't feel so bad for my run in with Grumpy. You can talk theory or you can talk reality.
In theory I have no idea and don't really care. In reality, there are 3 headers that I would consider. I will be getting either the Kleeman, RENNTech, or EVO. So, for this discussion, get the rest out of your mind. NONE OF THEM ARE identical length. Psshhh.

It is so funny how you guys just wanna buy and buy and have no clue why. Then others of you want to teach and teach and have no E55 or headers. OK OK, so you USED to own it all and have done it all, but times do change.

Ask yourself what the header will do for you and that will lead you to which is best for you.

The info that I was given may have actually been from EVOtech? I do not know them, but their name was on the documents along with Renntech, EVOSport, and Kleeman. What was measured was the constant flow out, which completely takes FIRING ORDER into account. The RENNTech one was a steady and smoother flow. The Kleeman was also very smooth. The EVOsport was more of a pulse pulse. What does all this mean? I dunno, but I'd bet that more heat can get pulled on the constant flows than the pulsing. Now, between the RENNTech and the Kleeman (both smooth) there was a bit of difference DEPENDING on RPMS. At low revs, the Kleeman has an advantage due to its bigger canister area. But, once the revs get up and the canister is full, the Kleeman is not as smooth as the RENNtech and so it gets more backpressure going.

Conclusions:

Kleeman: Advantage = most extreme, disadvantage = most extreme. The thought of having to deal with cats and O2 sensors is a pain, expecially for minimal gains. MB is already dying to kill your warranty, why help? Also, here in Cali that can become a pain.

RENNTech: Advantage = California Smog legal 100% and only company, period. Understand that. i do not care how "clean" your car runs, if it ain't certified, CA does not believe it and RENN is. Another advantage is a straight bolt on at both ends. Disadvantage = not enough mid range help. the exit tubes are bigger than stock so you get the low end grunt, but there is just not a big enough "pit" to suck heat, even if the exhaust could get it all out.

EVO: Advantage = none, Disadvantage = none. It is a balance between the two. Very simple install, with minimal mods, but NOT certified.

Just the facts maam, and I do mean Grumpy. Watch the lesson in engineering he is about to dump on me. Believe whatever you guys want, but spend your money where your ***** are are don't just do what someone here says without thinking it through. If you do not understand how a mod works in extreme detail, maybe you should wait on it??

p.s. I love ya dragon, but no K car is CARB, not even your old one.

 

jangy - I believe EVOTECH is a partner of RENNtech, so whatever results you were reading or what not may be biased.

 

Well, i already knew it was biased, since it was done by RENNtech, I just didn't know EVOtech's involvement.

 

Thanks for the advice....

 

Oh well I'm an idiot then
http://renntechmercedes.com/
Bottom of the site, EVOTECH logo.