I am gathering parts for a head/cam swap on a 96 M6 car. The car has 1" Eibach lowering springs and not rubbing or leaving parts in a parking lot is a must. I need to pass emissions insp with some sort of dual cat installed. I have a Spohn non-long tube torque arm installed. I already have a set of coated SLP shorties in a box. It seems that reading several post's the following items are repeated:
#1 - If there's a question of motor mounts change and go with new poly mounts to avoid headers rubbing. Still might rub steering shaft.
#2 - RK's & AS&M have both good and mixed reviews on install plug access and leaking/non-leaking #1 primary slip fit tube.
#3 - Go with 3/4 primaries for a head/cam car vs 5/8 primaries Mac's
#4 - 96-97 shorties are junk unless an aftermarket hi-flow y/cat pipe is installed with SLP shorties
#5 - Long tubes are best but are going to rub and much more difficult to get the dual cats in place.
So Now here's the questions:
1) Are there any long tubes that will not rub and might work with the Spohn non-LT (w/ drive shaft saftey)? Ie: Pacesetter, TPIS, Kooks?
2) If going with mids Are TPIS or another brand a big step over AS&M or RK's?
3) If going with mids what brand cats are recommended to have a custom y pipe fabricated verses buying high dollar Random and be just as good?
4) On a 96-97 w/ mids, are there any recommendations to avoid rubbing other than poly mounts?
5) How much will I lose if the SLP shorties w/ random or similar hi-flow Y is installed verses mids?
6) what items will I need or run into if using 94-95 mid type headers as far a hooking up the AIR tubes?
7) Does anyone have a header-dual cat set up for sale? RK's for sale now $450 and I'd have to fab included y with new cats, I understand Jet-hot has mac's for $650, AS&M bolt in setup w/ everything for $1400+
I reall don't want the headers rubbing due to there are some Huge speed bumps where I drive the car. I need to pass emissions w/o hassle. I want to help the planned head cam swap with out spending a fortune on headers only. I'm Looking for 96-97 car owners with similar setups and exprience on the setup and install. Thanks!

 

If you are considering LT's but they won't work with your TA, then just get a set of single cat headers. You can have a custom dual cat y pipe made. Its just the single cat headers have better plug access and make more hp than the 96-97 style headers.

 

I just put in the SLP shorties and a magnaflow on my 96 M6 car a little over a week ago. I am very pleased with the setup, definite difference in performance. I have to deal with emissions also so that was a major concern. I also have a short torque arm that i put in at the same time along with new lower control arms. It was a pain to get them in but I didnt have to do anything with motor mounts and there is no problem with the steering shaft. I did have to take the drivers side motor mount bolt out to give me that little extra room but no big deal. I wouldnt bother with long tubes unless you are really trying to squeak every bit of power out you can. I am sure the head/cam package will work well with the slp's. That is where i am headed. I have another set of heads on the bench ready to be ported. Only concern i have is there is a primary that runs close to one of the heater hoses. Just got some insulation and wrapped it around the hose. Problem solved.

Steve

 

So what's the problem: you have coated SLPs in the box. Put'em on.JMHO

 

That's what I thought but it seems several opinions are that the SLP 96-97 shorties are too short for good flow/torque?

I'm not sure because I haven't had experience w/ SLP shorties compaired to mid-type headers. It would be nice to hear from a few that have tried both on a dual cat car.

I am trying to do it the best possible way without spending major bucks and not wanting to have to re-do the header setup later. I may just do that and go with better cats to help access and exhaust flow. I wonder what would be better, modifying my current y-pipe or just shelling out for a random
dual-y if the shortie SLP's is the route chosen?

 

I did call Spohn today and one salesperson recommended AS&M's and another saleperson said that kook's LT's will fit non-LT type torque arm. (10 different answers' from 10 different sales people?) It'd be nice to hear from anyone on this board who has phycially used/installed kook's LT's on a 96-97 car & even better w/ a non-LT Spohn torque arm.

If kook's LT's will fit current torque arm and fit tight to under the car that may be the best way to go?

 

Thanks for the input. Sounds like it went well with the shorties. Common sense says just install the shorties and go with it. I am just looking into other people who have tried mid's or some LT's (other than hooker's - I know they'll drag on 1" lower) on a 96-97. I have $400 in the shorties including new coating so I could sell them fairly easily now if another header setup is alot better. I am going to do some more checking...on kooks and TPIS.

 

I had a thought....... It would be great if there were some
DYNO COMPARISONS on one type header to another. Preferably on the same car/setup before after?
That would be great to see the REAL HP gains on SHORTIES vs MID's vs LONGTUBES. I fairly sure LT tubes would win....but by how much and same for mid's vs shorties. Does anyone have a dyno #'s before/after header swaps? Thanks..

 

Well, I like many others, had to make a decision about what headers to get.

I have 97SS with the dual cats. I didn't want to have to take a chance with the federales with regard to the regs prohibiting the removal or relocation of factory cats, and I preferred a 1 3/4 primary in Stainless, so I went with the SLPs. Toyed with the idea of going with Clear Image mids. They are 1 5/8s, but really look like they would do a great job. Main problem is that they require the random cat Y pipe and the whole thing costs around $1200.00.

So I bought the SLPs (uncoated) and had finishline coatings put a nice finish on them. I did reroute the one heater hose behind the other hose to keep it away from the primary, but other than that I believe I made the right choice given the alternatives.JMHO