Adding to my long list of crap I'm ordering for my car I'm down to the exhaust. For the time being I'm not going to run headers on the stock
L-98 but I am going to do the rest of the exhaust. This is what I'm wanting to do.... 3" duals with an X-pipe, dual XR1 Borla race mufflers with slash tips in the stock location at the rear. I think this would sound wicked, even more so when I build my new motor. So... with that being said, the Borla's are 5" in diameter and I'm lowered with Sportline springs. I don't think they'll work, anyone else run this setup?

 

Or another option... Build a 3" Y-pipe then install one 3" Borla XR1 in the same location SLP uses with their Loudmouth catbacks with dual tips exiting the rear. But.. this muffler is 5" in diameter. Think I'd have enough clearance running it this way?

 

Where are you putting the borlas? Tuck them up under the rear bumper on either side of the gas tank and run tips off them out back. 5" case should fit in there. If you plan to put them in the I-pipe region before the axle, you'll have to get creative on mounting. I ran a single 6" case down there on a single 4" exhaust and it cleared fine but did sit very low.

I have this type of setup on my turbo car but use bullets instead of xr1's. It sounds good but the turbos and low compression quiet this car down alot.
I had a single XR1 type muffler on a single 4" exhaust on my 383 for a few weeks and it was stupid loud but sounded great.

 

A 3" x-pipe will be a tight squeeze - those are 2.5" pipes in the above pics.

The exhaust setup I had before the true duals consisted of shorty headers and an XR-1 muffler where the stock cat was - that fit nicely.

 

I believe I've decided to run a single 3" set-up since theres no real power difference between duals and single. I looked up under the car and measured, seems to me I could fit the XR1 where the SLP Loudmouth bullet goes on the 4th gens... I had this on my 01 SS so I'm using it as reference. So with that being said, I'm going to build a custom 3" Y-pipe, yeah it'll be tight but I had one on my 4th gen with no issues, same thing basically, using a Magnaflow 3" transition Y onto a 3" intermediate pipe to the Borla XR1 and out the rear with duals like stock with Magnaflow polished tips. I'll post pics of before and after once I get it all fabbed up and installed.

I kinda wanted duals but this is a corner carver and not a drag car so I need ground clearance, as much as I can get anyway. I think it'll sound really mean even with the stock L-98.. We'll see though..

 

Thats a real nice set-up you have, wow. Yeah it'll be tight but if done right I believe it'll be fine. I had a 3" Y on my 01 SS with Long tubes and had no major issues rubbing. Occasionally I'd hit something hard enough to scrape a little but I can live with that. If it doesn't turn out then I'll go with a 2.5" pipe. Really want the most I can get since I'm not going with duals.

 

Well there can be significant gains with the right exhaust depending on the motor but a stockish L98 is ok with single 3" exhaust. Dual 3" is overkill and is what I run on my 700whp turbo car.

What you plan to do is how I ran my ultraflow 6" round. Much like the SLP systems. 3" ypipe into single 4 then into muffler then over axle , splitting into dual 3" exits, one on each side like factory but with big tips out the bumper.

I ran the SAME type setup but with 3" pipe on my bolt on L98 and with a powerstick tube muffler.

 

had 3" single w borla xr1 in stock location sounded great sounds even better with cam
Ill look for sound clip and post it when found

 

Nice! Did you like that setup? I think it'll be perfect on my car. I just don't see the point in spending $400.00 on just a regular catback when I can custom build something much better for the same price.

 

Sweet man, I'll post pictures and a sound clip once mine gets done as well. Kinda funny actually, my L-98 has less than 10,000 miles on the rebuild. It was re-ringed, installed a new crank and new bearings and gaskets.

I ordered myself a 4 bolt main roller block from Summit and will be building a heads, cam 355ci for the car over the winter. Can't wait to hear it with a cam... cause you know, stock is never good enough.