I have the radix with a 3.25 pulley and mods in the sig. I think I have horrible exhaust flow for a couple of reasons. I have TOG headers, with factory y-pipe, going into the factory 2.75 or 3 inch exhaust into a single in/single out 3" 18" Magnaflow muffler routed to the back of the truck by the roll pan.

Potential Problem(s):
I see about 10 pounds on a 3.25 pulley from 5000-6000 rpm. I should only see about 8.5 to 9 max.

When I dynoed the truck, it spit the bung to the wideband out of the exhaust at 5200 rpm. There was a huge spike in the hp reading at this rpm range.

I have really high IAT's and Im thinking because I have a restriction in the exhaust that is hding boost in the engine. And if I remember right, boost is a measurement of restriction.

Potential Solution(s):

I was thinking about doing dual electric cut outs.

Making a new exhaust system with no cats, an x or h pipe, and 2 magnaflows. This definately going to be expensive as it will cost around $650.00. It will also be the most work as I have to build an entire new system. I would use the original system for smog purposes and the other one for performance.

What are some other options? Electric cut outs worth it? Do they leak? Worth having 2 exhaust systems?

 

do long tubes and make the a set of cats that bolt in and out with race pipes. Thats your best way. Do an x-pipe and true duals. That will fix your back pressure problem.

Rick

 

I've read the electric cutouts will leak eventually.

Most who go true duals do install an x or h pipe.

 

I have AS&M L/T Headers dual 2 1/2 into a dual in dual out magnaflow built in X pipe strait out the back with 18'' x 31/2'' tips.

 

My buddy that has a radix on his truck has dual 2.5" no cats x pipe dynomax racing bullets dumped and it sounds awesome and he says he got 3 tenths over just an aftermarket muffler spliced in.

 

Take a look .. this is exactly that system
https://ls1tech.com/forums/showthread.php?t=310454