new exhaust

[dragon8504]

i am thinking of putting on a completely new exhaust. since my muffler already needs to be replaced. i am not sure if i should go high performence or what. i would also like to know what class the high performence exhaust system would put me in in relation to scca solo2 rules. what pipe size, cats, and mufflers do you people suggest???

[Chiketkd]

According to SCCA Solo II class rules, you can add any exhaust you wish aft of the catalytic convertor(s) and remain in G Stock.

A high performance muffler from Magnaflow or Flowmaster will be less restrictive than the stock unit and cost much less. If you don't want a loud and raspy sound, get a high flow resonator from Dayle (MotorSport SVX). A 2.5" system using the stock layout will return the best results - anything larger will cause a loss of low end torque.

-Chike

Originally posted by dragon8504
i am thinking of putting on a completely new exhaust. since my muffler already needs to be replaced. i am not sure if i should go high performence or what. i would also like to know what class the high performence exhaust system would put me in in relation to scca solo2 rules. what pipe size, cats, and mufflers do you people suggest???

[mbtoloczko]

If you want some info on sound levels and flow rates of some aftermarket mufflers, have a look here:

http://www.ls1sounds.com/faq.htm

The OEM tubing size after the secondary catalytic converter is about 2.36" ID. 2.5" OD tubing (OD is the standard for measuring exhaust tubing in the USA) has an ID of about 2.4", so its a good size to use for a cat-back system.

If you are making your own exhaust and are anticipating some bends in the tubing that more than 10 deg, you may want to consider using mandrel bends. Helps flow rate.

anyone know if its possible to remove the catalitic converters on the y pipe and just put a turbo catalitic converter on? mine arn't too good and i heard theres a way to have just one major catalitic converter and pass inspection. please get back to me

[SVXRide]

Originally posted by Dober
anyone know if its possible to remove the catalitic converters on the y pipe and just put a turbo catalitic converter on? mine arn't too good and i heard theres a way to have just one major catalitic converter and pass inspection. please get back to me

You're going to have a problem getting any muffler shop to remove the existing cats without replacing them -- your best bet it to replace them all with high flow versions (Magnaflow makes them and I think Flowmaster does also). I've also read that the cats from Mustangs work. I just had the secondary cat replaced with a Magnaflow 2.5 inch high flow cat along with a 2.5 high flow resonator. Sound might be a tiny bit louder/deeper than stock.

-Bill

[Chiketkd]

Agreed. The high flow cats from Maganflow work very well with our cars. Bill is also right in saying that no shop will just remove your cats w/o some replacement going on in it's place.

-Chike

Originally posted by SVXRide
You're going to have a problem getting any muffler shop to remove the existing cats without replacing them -- your best bet it to replace them all with high flow versions (Magnaflow makes them and I think Flowmaster does also).

[dragon8504]

exactly which seriers and sizes am i looking at from magnaflow and flowmaster? what do you people like or have in your SVX's?

[Merz]

Would replacing the cats with straight pipe have the same performance improvements as replacing them with high-flow cats? It would be a lot cheaper to buy straight pipe than high-flow cats. I would be doing the welding myself, so I wont have to worry about whether the shop would remove the cats.

Thanks

[SVXRide]

It really gets down to whether your car is still "emissions legal" after whatever mods you do. If your state doesn't have annual emissions tests, then you could legally remove the cats - you just have to rationalize in your own mind what you're doing to the air you breath. A high flow cat is going to be more restrictive than a piece of straight pipe, but by how much more I'd have to sit down and do some flow calculations first..
-Bill
p.s. you also should be aware that more and more autoX governing bodies are imposing noise limits on all cars running in order to keep their course sites (i.e. neighbors start complaining if things get too loud) I think the upper limit tends to be around 95 dBs.

[SVXObsessed]

If that gets enforced (or is it already enforced?) in WA im screwed!

[dragon8504]

what are the dimensions of the stock mufflers?

and what other setups are out there?

[mbtoloczko]

The only ready-made exhaust system for the SVX is the Stebro exhaust. Everything else must be hand-built.