komp55

After doing a forum archive search, it appears that these are the two choices available to us if we want a direct, bolt-in header that bolts up without modification to the stock catalysts.

I didn't see any posts that compare actual performance gains of the two header designs, but the consensus seems to be dependable gains of 25-30HP and maybe 30-35 ft. lbs. of torque from either on an otherwise stock engine.

In looking at the available of photos of each, I note the following:

Renntech:
1. About $1,000 more expensive
2. Stainless steel tubing, mandrel bent, non-segmented
3. 4-2-1 design
4. non-coated

Evosport:
1. About $1,000 less costly than Renntech
2. Tubing is aluminized steel, not higher quality stainless
3. Tubing is mandrel bent, but each primary appears to be two or more segments butt-welded together (not seamless)
4. 4 into 1 design
5. high temp thermal coating

So it looks like each has some merit. Renntech uses higher quality materials, but I don't know if their design is superior to the Evosport design or not. They're much more costly per on a HP/$ basis.

Evosports are made with cheaper steel and have butt-welded primaries, which are not optimal for flow. But they do have coating and may have a better design for flow purposes. Plus, they're less expensive on a HP/$ basis (assuming they produce as much HP as the Renntechs).

So for me, it would probably boil down to which set actually FITs the best and installs with the most ease. I don't want to end up having to lift the engine or having to remove a bunch of stuff to install them. Has anyone personally installed them that can speak to this? Any other factors to be considered (ignoring cost)?

ROCKETW19

when i first started moddin my car i was realy drawn to the evo headers due to price. i ended up goin with supersprint whole exhaust system for pure HP gains. cost well we wont talk about that. anyways back to your choices if you live near the cali bay area i would say go with renntech from adam at euroelites his service and qualty of work are worth tons. if you live in so-cal i would say go with evo as they are located there. if you live somewhere else i would take renntech for there customer support if anything goes wrong they dont try and say it was this guys fault they just send another part. if you add stage 1 renn also they will always give you free updates to your ECU. they are always makin them better. i know renn cost the most but i like the service they give and the guarantee from adam cant be beat.

viper04

why can't someone come up with some that don't cost as much. $3000-$4000(shorty headers) seem a little high when you think of what really go's into make a set of header. Just look at the cost for a set of header for a Viper, Corvette, ect, same Idea just cost a lot less. Just my .02.

DFW01E55

That's the tax you pay to play in this league!

There's a Mercedes tax which is higher than a BMW tax, and there's a Porsche tax which is about equal to the MB tax but the Ferrari tax is higher than the Porsche tax, Lambo tax, Bentley tax, the list goes on.

All of these taxes are way higher than the Chevy, Ford or Dodge taxes.

It's your choice.

Jrocket

Doesnt make it justifiable though.

DFW01E55

Sorry to disagree Jrocket, but it's called capitalism and it's proven to be the best system going.

You get price where you can and take short margins when you must.

Jrocket

Oh I agree with you on that,but I still cant get over the price for the MB aftermarket parts.The problem is,it is not that hard too produce headers etc. for these cars at a considerable amount less.The problem is the price that everyone else has already set is so high that the newcomer(builder)wants to make the smae amount on the sale.

Guess what Im saying is I need to get on the ball and have some sets made for our cars at a better price.

JLP

Not to mention there are alot more Vettes being built than E55's, more available sales also helps support a cheaper price.
If Hooker can sell 10,000 headers a year to vette owners and Renntech can only sell 1000 headers then Hooker can sell them much cheaper.

Jrocket

True somewhat.Obviously the initial cost of make the first set and developing a jig is going to take some money.BUt its not that much to warrant the price they still bring in.Most stainless shorty headers go for 400-600,just a ball park guess there.MB stuff is through the roof compared to that.

NagsHD

and vrus is the perfect example. his cf project by anyone else would be 2 to 4 times what hes doing it for. im all over the bs mb tax after having a new z06. a set of long tube headers + race cats for 1700 was a steal. simply dont buy from the thieves and they will have nothing to sell. john a ccw wheels is another good example of quality products at good prices.

BiTurboAmg

I am not sure if they sold but there was a set of kleemann headers for sale on the board on 12/28/06 may be worth looking at. Good luck

viper04

That was my point Vrus, can make a T/B that just as good as any of the other tuner, for far less. So it can be done. I'm sure someone can make a shorty header for half what the other tuner are. I do love capitalism with out it I could not own two business.

komp55

the relative merits of these two header brands? I've already accepted the fact that I will be overpaying with either set I purchase. I am more interested in which makes more power, which fits better, which will last longer, etc. Anyone?

jangy

kompressed55: very nice writeup, and I agree with your summary. I would also like to hear about install ease. Perhaps anyone who hasn't even installed them themselves can speak to the install ocsts as that would give us a clue as to how hard the install is. My guess is that the RENN is going to be the easiest install, since it is the 4-2-1 design that is more compact (although not equal in length for each).

eLTURCOamg

on a lease return would the dealership get pissed?

jangy

I doubt the dealer would even notice the headers. Either way, I'd say keep your oem one and swap it out so you can sell the RENN one used. I'd pay for a used one right now!

Vadim @ FD

I designed the headers that evosport sells.

The reason for aluminized steel is twofold - stainless is more expensive and has a tendency to crack when bent very sharply after a number of heat cycles.

Also to create one piece tubes for each would add to the cost of the headers. Each set is built on individual order basis and is done by a professional fabricator to assure quality and consistency.

komp55

Strange comment about cracking. BMW has used stainless steel headers in some of their M Cars since the mid 1980's (e.g., M635CSI, E34 M5, E30 M3, etc.). The tubular headers the M635CSi look like a real snake's nest - yet were one piece mandrel formed primaries. Some of those cars are running around 20 years later with their original stainless steel headers and - no cracks. Now that I think about it, the Mercedes 190 2.5L 16 also had stainless tubular headers, and no cracking issues that I've ever heard or read about.

I will believe you on the cost saving issue, but not the quality of material issue. Nonetheless, thanks for making a direct fit option to the Renntech offering available.

Apple '55

For what it's worth, I just had the Evosport headers installed and the MB tech commented on their quality design and exact fit. The ceramic coating is supposed to reduce heat too, no?

Vadim @ FD

[QUOTES]Strange comment about cracking. [/QUOTE]

OEMs use softer 4-series stainless steel.

Most fabricators use 3-series stainless steel that is harder and more prone to cracking.

My opinion is based not only on theory, but also on experience of working on and tuning a lot of cars. Many with aftermarket stainless steel headers.

Even Supersprint is not immune from it, just search BMW forums and you will see what I mean.

Thank you! Yes the coating helps with heat and corrosion.

DFW01E55

Vadim, did you design a set for the CL?
I checked Evo's site and didn't find them.
Maybe you've got experience that says they are the same fit as another 55?