The Kooks mids are 1 7/8 and the slp are 1 3/4. The cats on the slp's are very restrictive and bottle neck down, so whatever flow the long tube provide quickly bottles up at the cats. There were a couple of pics on the board here. The Kooks provides a more high flow cat than slp.
There is a set of used Kooks mids just posted for sale. Pretty good price.
Livernois ran the Kooks mids on their GXP, so you know it they're running them, they got their stamp of approval.
I have them as well with an x pipe and GXP axle backs. They will be louder than stock for sure. I just reinstalled the stock axle backs and its tamed down a little, quiet at cruising but louder at idle.
If you do headers, I would do x pipe to take full effect of the extra flow gains.
I have a thread of my install as well. When I had the Kooks mids, x pipe, and solo catback, it was loud and there was some slight drone on the highway.
I sold the solo and went to the GXP axlebacks and it sounded perfect!

 

Don't want to start another thread for this question but....... can't you take the slp high flow cats to a muffler shop and get them to "open up" the inlet side so that it wouldn't be so restrictive? Of course I mean get them to do some fabrication to the inlet side of the cats or something?

 

Here is a picture comparing Kooks LT's, Kooks Mids, and SLP LT's. For me the issue with SLP is the collector...it is not as nice as Kooks. We have never dyno tested SLP LT's, but Kooks LT's make about 45 RWHP with their X-pipe. The Kooks mid lengths make like 35 RWHP. SLP is likely in the same range Kooks Mid Lengths.

 

I have GXP axb with Livernois tune. I am set on kooks mids. If you want to meet up and you can hear what is sound like.

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Yeah the kooks mids would definitely pass NC inspection. I had no problem when I had my car. Make sure if you get the mids to get the 1 7/8.

 

I just went through this exact same dilemma but had pacesetter lts on my mind as well. I ended up ordering a Livernois tune, Rotofab, and kooks mids. I haven't installed the headers yet but the tune and intake pair nicely with my solo catback.

Good luck.

 

Between the two, get the Kooks mids bro.


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Thanks guys.


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There is no need to modify the SLP cats, IF, you are running the stock midpipe. The cats are 3" inlet and 2.25 outlet, the same size as the stock piping. The advantage of the Kooks mids is that the ball end will mate to stock piping or up to 3" no problem. Kooks mids you can add now to the stock system and they can handle any cat back mod in the future.

 

kooks mids ftw.

 

I got my Kooks Mids brand new with free shipping from Maryland Speed. I had to call in to get a great price. I would highly recommend this set up over the SLP. Kooks is a superior product by far.

Here is a link to my install thread with more details on the product...

http://www.g8board.com/forums/showthread.php?t=53823&highlight=kooks+mids+score