Exhaust Questions

[Too Ez]

Okay, I'm to the point where I think its about time to do a little exhaust work. Now, my question to you guys is that if I cut the 3rd cat off do I just put in a straight pipe like they did with my Tempo? Is there anything else I have to do besides just cut it out and put something in its place? And will any check engine lights come on or anything when this happens?

For those of you with Gen3's please give me some feedback if you have already done this to your SHO's!! Thanks Everyone!

 

[spragers]

I'm thinking of doing a little upgrading myself with my tax return money (new mufflers at least, either Borla or Flowmaster), I'm wondering what the specific size is for our SHO's?

 

[SHOZ123]

You can replace the third cat with just a straight pipe. I would try to save the cat and just cut it out as they are very expensive.

I like the Silver Bullet mufflers. Had them for 5 years now and still as good as new with no corrosion at all. If I were to buy them again I would get the 2" offset/offset kind. The 2" will fit without any need for reducing and the OEM tips will fit right on them too.

 

[Too Ez]

Mufflers will go on during the summer. I'm doing little by little. So I dont have to put a resonater on or anything if the 3rd cat is cut off? I was either going to go with Borla or Flowmaster. Anyone have any comments or complaints about either or?

 

[SHOMEX]

Hi, I have the borla catback system and I love it. also I removed the third cat and the renonator from the catback and now sounds lovely, pretty deep and no raspy at all.

 

[Mr. SHO]

I haven't heard any convincing arguments for removing the 3rd cat. I was all set to do it... in fact I spent the better part of a day under the car getting the damn thing off. When I asked the email list about tips on getting the thing off the car, I was told by a handful of people that removal/gutting of the 3rd cat actually hurts performance (not just in theory... this was based on track times). I ended up putting the cat back in there intact.

The mufflers are the biggest restriction. Get some turbos on there and you'll free up some ponies.

 

[SHOMEX]

Well I didn't remove the third cat for performance I just did it to gain a little more sound on the exhaust and if I were to do it again I'll just buy to quality mufflers and cut the resonator no more.

 

[SHOZ123]

Mufflers will go on during the summer. I'm doing little by little. So I dont have to put a resonater on or anything if the 3rd cat is cut off? I was either going to go with Borla or Flowmaster. Anyone have any comments or complaints about either or?

There already is a resonator after the cat.

 

[SHOZ123]

Well I didn't remove the third cat for performance I just did it to gain a little more sound on the exhaust and if I were to do it again I'll just buy to quality mufflers and cut the resonator no more.

If you want the sound the V6ers **** for remove the cat, remove the resonator and get some straight through mufflers. Power is not lost it just gets moved around. Hello 144!!!

 

[Ian Macoomb]

I removed my 3rd cat and resonator and put a straight pipe with a y-shaped cutout on it. Left the stock mufflers in place. It's barely any louder than stock and it certainly didn't hurt my performance.

 

[spragers]

So, a Flowmaster 2" offset / 2" offset will fit in with the stock exhaust piping...

What about the muffler length? The 40 series says 13" case length, 19" overall, and the 50 series says 17" case length, 23" overall?

Anybody know what the stock muffler specs are?

 

[Mr. SHO]

I misspoke when I said the 3rd cat removal doesn't help performance. The top-end breathing IS improved by the removal and will result in a higher peak output, but it comes at the expense of some low-end pull. The overall picture I have formed in my mind is that the low-end is more desirable in most situations (like at the strip when the race is over before you can tap too much of that high-end pull), but the 3rd cat removal will help on a dyno if what you are looking for is a higher HP/TQ peak.

Not sure the actual dimensions of the stock mufflers, but they are quite a few inches longer than most aftermarket performance mufflers. You will need to add in some extra pipe.

 

[Too Ez]

Would I get a good V8 rumble if i kept the cat and just put in some flowmasters?

 

[Mr Anonymous]

Would I get a good V8 rumble if i kept the cat and just put in some flowmasters?

Absolutely.

 

[JaySHOguy]

Would I get a good V8 rumble if i kept the cat and just put in some flowmasters?

And, to get just a bit more sound out of it, remove the resonator.

My V8 SHO was plenty loud enough without the res. and the Flowmaster 40's.
I really miss that sound . Sounded almost exotic when you romped on it.

 

[99V8SHO]

If you want the sound the V6ers **** for remove the cat, remove the resonator and get some straight through mufflers. Power is not lost it just gets moved around. Hello 144!!!

That is the exact setup I have. Borla mufflers are straight-through.

 

[SHOtype]

I would recomend only removeing parts of the exhaust at a time, drive it around for a week or two before you remove the next part. I yanked my cat and got so excited over the difference that I put in strait pipes. Loud as all ****. I have to coast past cops because I'm to afraid that they will pull me over.

 

[CT97White]

This is an article about an active exhaust butterfly that could be used to regulate exhaust backpressure as a function of engine rpm or throttle position. This could be used to reduce noise at idle and cruise (& potentially improve low-end torque) while still allowing increased peak output from a modified exhaust. Looks interesting.

http://www.autospeed.com.au/cms/A_2291/article.html

 

[RoadSHO]

This is a site for a sound clip of the Flowmaster 40's on a V-8 SHO.
http://filebox.vt.edu/users/migilles/sounds/sho2.mp3

 

[spragers]

You've got 50's on your SHO, how do you like the sound?