PCA0891

1988 S4 75K.
I am about to undertake several wintertime upgrades. I currently have a RMB from Mark on the car and that's it on the exhaust end. My plan is to add an X-Pipe but sadly in Tn " Al Gore Country" we are required to have cats.
That said. I am looking for the least restrictive cats I can find. I would be very grateful for any leads or links you all may have to offer. So far, I have looked at 928 Motorsports and there's appear to be the front runner with 150 CPI. I have seen several sites offering cats but with no real technical data.
Thanks in advance!!!

Robert
88 S4 75k
76 930 38K
78 Targa 17K
E55 DD

SMTCapeCod

Motorsport L SLC tested a number of units while developing their x-pipe, including different strata and CPI. 928sRus sells the winners.

ROG100

Just buy the high flow cats that are an option with the X pipe.
X pipe is built by Motorsport SLC not to be confused with 928 Motorsport - two different companies.
928sRus and 928 MS sell the same X pipe system - I may be cheaper though 8>)

Tony

What Rog said...i have those cats on the Xpipe...sounds good, flows well...and passes smog.

PCA0891

Thanks Roger and Tony. I will be ordering the pipe and cats this coming weekend. Along with the refresh bits to send up to Austin.
I remain grateful for the feedback from my fellow 928er's

Happy and Safe Holidays
Robert

88 S4 75k
76 930T 38K
78 Targa 17K
E55 Daily Driver

PC-85-928S

does anyone sell an x-pipe with dual high flow cats welded in place, as opposed to using clamps?

ROG100

Not that I have seen but easy to weld them in place on the X instead of using clamps.

RKD in OKC

Cost me a whole $20 to have a local discount muffler shop weld my cats to my x-pipe.

elgreco

Hey patrick let me know when ever you are ready i got a mig welder.

Strat_928

I have Roger's HiFlow Cat and 3 inch Y-pipe.....it worked wonders on the 16v. awesome!.....but no numbers....sorry

Kiln_Red

Hey, Robert. Looking forward to doing the work. While it is fresh on my mind, do you have any preference on clamps vs. MIG? Makes no difference to me. I am happy to do it either way.

jayc67

Weld vs clamp:

I have heard that folks running oil with high levels of ZDDP will clog their cats faster than normal, so clamps would seem like a good idea if that is true, so you can swap them out easily if they get restricted. Does anyone know if that's actually the case?

SeanR

Typically the cats that run afoul are due to other fueling issues. MAF/TempII etc.

Owners tend to get gungho about the performance mods and forget that they might want to get the car running properly first.

Kiln_Red

I agree with both of the above statements. Robert is taking a good approach with his car IMO. We'll be doing an intake refresh and the exhaust work among other things. I'll be painting his intake & valve covers while they are out as well as his brake calipers, replacing ODO gear, and removing his dash & door panels to have them sent off for refurb. Other recent work includes new wheels & tires, new TB/WP, new cooling hoses, etc. I'm not sure of anymore performance mods that are being considered but, clearly, this car is receiving great car.

Speedtoys

Vclamps are the only way to go, if not welded.

However, labor intensive..gotta be really straight to be done right.

They make cat/test pipe work pretty fast..faster than getting the car in the -air- even.