cookiee55amg

Hi folks just asking for some advise, I am currently about to buy some kleeman headers and down pipes as any one had any fitting problems removing the primary cats, Or would you settle for the evo headers and remove the centre silencers. does anyone know of the horsepower gains of these 2 headers. CHEERS

boohoo

There is a guy on here called scorcher from the uk he has some kleeman headers fitted i think...drop him an email i'm sure he will help....think he had some issues with left and right hand drive.
cheers jon

komp55

"Settle" for the Evosport headers? LOL.

It really depends on what you're looking for from the header. The Evos are a direct bolt-in header replacement for the factory exhaust manifolds. On the other hand, the Kleemans are of the hack and weld variety, where you end up having to weld the downpipes to the factory exhaust after doing some cutting. Both will get you approximately equivalent power gains, but the Evosports are a more righteous design given them being a true bolt-in.

Scorcher

Yep, that's right - I've got a RHD car in the UK, and no manufacturer would guarantee a fit for my car except Kleemann, and I had them fitted by the UK dealership. There is more work involved, and yep, the front cats have to be cut off and sensors switched off, but DAMN it's worth the effort

jcjmw

I have the K2. No problems with fitting, everything went fine. They only thing that I think you need to do is to have the ECU programed to ignore the 2 O2 sensors that are removed when you use Kleeman's down pipe - if I remember right.

Exotic-metal55

Would you be able to shorten the down tubes and then still flange up the primary stock cats?

jangy

I was becoming more of an EVO fan of late, until the objective posts; but you just aren't being fair with the OP. The EVO shortys are indeed nice, but not anywhere near equivalent gains, when one has almost DOUBLE the gains of the other.....each serves a different purpose and client base.

jangy

Serge did....

komp55

Double the gains all else being equal? I'd like to see some comparison dyno graphs that support your claim.

I would submit that if the Kleemanns produce any more power, it's not because of the header design, but because you hacked out the primary cats to install them. I'm sure the Kleemanns are a fine product and do have their own client base, but in the facist emissions area where I live, my car would NEVER pass inspection with Kleemanns installed and catalysts removed. And not to mention potential warranty issues with MB . . . .

Never thought I would defend the Evos after the attitude those guys exhibited about their "secret" thermal coating, but there you have it.

C32madness

EVO uses mild steel for their headers. The tight radius of the EVO headers are a result of trying to squeeze them into the factory space.

Kleeman uses stainless 304. They lose the pre cats in order to have a smooth path to the collectors.

The win goes to the kleemans. Much better design and build material. The fact you have to cut the pre cat and weld on a short section is trival.

Zod

show gains my friend
header vs header, if cat is removed that is a + so does not count
Also i recall reading a few cases of kleeman cracked headers..& check engine lights

bottem line once you install the kleeman you can not go back to stock, as you have choped the primaries and done welding work on the AMG exhust. Unless you want to re-weld... But alot of people are happy with Kleemann so that also speaks for its self. Evo sport is also very good & great customer service

rflow306

I can't believe I'm saying this but I agree with Jangy.

Exotic-metal55

You hit most the points but the main power difference is the stock DOWN pipes.. They are so small,, it is PURE waste to bolt any shorty up to those stock 1.7 down pipes on 500 HP plus motors. A WASTE!! .. If Evo opened up their collector and supplied large ID down tubes, then they would free up a lot of power.. Stock down tubes could be saved and re-welded back to primary cat to go back stock.. Kleeman will easilly make more power on our S/C engine, even using stock cats..

komp55

Much better design? Sure, if you want to hack-up a few thousand dollars worth of factory exhaust components. Even the Renntech headers, the VRP big manifolds, and the Floored Fabrication big manifolds don't demand a purchaser destroy the most expensive portion of his factory exhaust to do the install. Personally, I think it's a much poorer design. If you want real headers, get long tubes from VRP or Supersprint. Otherwise, any of the direct bolt-in options are a much better option for most owners. I view the Kleemans as sort of a half-baked compromise that couldn't decide whether it wanted to be a sort of shorty header or a real header - and ended up being neither.

Like I said, show me comparison dynos, all else being equal, including primary cats being removed with Evo headers, and then we can have a discussion about which header made more power on a dyno. Otherwise, it's simply a false claim to state generally that the Kleemanns make double the power of the Evos. Without any evidence. Which is par for the course about most claims made around here these days.

komp55

Since all of the shortys make measurable HP gains when bolted up to the stock downpipes, I'm not sure how you get to saying it's "PURE waste" to do so. Since no one has thus far documented the actual measured HP gains of Kleemanns over shortys on an apples-to-apples basis, I think we just take away that all headers are better than the factory manifolds, and some headers may be better than others, but no one really knows with certainty what the exact difference in gains are between different header designs.

Exotic-metal55

Kompressed, I hear what you are saying. It is hard to get any side by side or even single proof HP gains on most Benz products.. Yes, they are there but it takes numerous to test to even be close to being un-biased.

Bottom line, there is not enough people going to the track and the dyno`s can be all over the place.. I look at track gains and then try and sort through the D/A`s and times.. I see to many people using naturally aspirated motor t knowledge on our supercharged motor exhaust. The S/C exh. is not the same animal as N/A and really takes well to being opened up.

No matter what header you use on a OD pulley/80TB plus moded motor,, those 1.7 down pipes have to go.IMO. You know you had to cringe some as you bolted those tiny little 1.7" down pipes up to your shiney, new, large evos

I need headers bad! I have held off due to the lack of info, the time it has taken to sort through threads, track times, D/A and last some dyno info. Here is my process.

Log style: Ok, in-expensive bolt on that could rival or surpass other shorties but just not the look or power potential there to grow with..

Evo: Nice header for what it is made for but collector Id is to small and uses small down pipes.. If I buy these, I will cut the collector off to open up ID and make new down pipes to primary cats.

Kleeman Seem to meet my needs out of the box but do not know if I have room to keep primary cats.. That is a must for me..

Long tubes. To much noise, vibration and other pure hot rod features for my needs.

komp55

Yeah, I was pretty surprised to see how small the diameter of the downpipes was after I unbolted the cats during my Evo header install. But when you're doing it yourself, and you're that far into the install, there's no turning back - small downpipes or not.

jangy

As a note, i have the VRP HEMs ande have been researching headers (long and short) for some time. Hope to make a choice on the final one soon.

jangy

Agreed 100%. EVOSport and Kleeman are class acts for their clients.

jangy

I have seen a kleeman long header cut off with the connection to the primarys welded on. I never saw it on a car nor heard about any data. Obviously, you lose some equal length and long tube advantages as you shorten the headers, but the outlet to the primaries was huge.

Rocketman

My experience with the Kleemann headers - they fit fine but you must remove the primary cats and then the issue begins. No amount of conversation with Cory or the reprogramming of the ECU would allow my car to pass VA emissions readiness without primary cats installed. This in spite of initial assurance from Cory to my shop guy that the car would pass with the headers and the ECU upgrade. So back to the shop for new 200 cell primary cats - at a cost of almost $800 installed so that my car would be legal in the eyes of the State of VA. Now the car runs great, has a nice sound, and will pass the emissions readiness requirement. Not my most pleasant experience.

jangy

In california our inspections include visuals that you can't pass without a carb legal replacement. NOTHING can be replaced if it is not carb legal, regardless of the actual gasses being passed. Given that and experiences like yours, I would NEVER assume that ANY aftermarket exhaust work will be legal or hassle free. But, in this case, keeping the primary cats / O2 sensors is a big issue for smog. The shorty headers will basically hide.

As far as tune, what was off on your car? You should have been running leaner than stock and I don't see why a proper tune would make you fail emmissions. Was some parameter off? that should be addressed by the tune, no?

komp55

So now Kleemanns are "long headers"? I really don't think so, but I would agree that true long tube headers (i.e., Supersprint or VRPs) have the potential to show significant power gains over both shorties and Kleemanns (a shorty with a larger downpipe and primary cat removal).

rarfinancial

Damn, Now that's funny.
What's the deal ? you want the most power? cut and weld... you spend your $$ and drive faster than the speed limit anyways thats not legal, is it? LONGTUBES MAN J&R Performance will soon have a set out that will kick AZZ, like no other

jangy

They are long tubes compared to shorties. I get your point, but don't agree. we can leave it at that. i know of waaaaay too many SS setups that lost power. Given the price, are they longer than the Kleemans? yes, sure. But how can you justify paying such a tax for simple exhaust parts? Especially when they have all of the same downside as the Kleemans? Either way, I get your point and as long as the parts are on the table, I don't have much more to add.