Exhaust Ponderings - CEG Archives

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I know exhaust topics have been beat to death but I would really appreciate some feedback on this idea. Upon looking at the SVT exhaust, after the resonator, the exhaust makes a couple of 90 degree bends around the tank and goes to the split for quasi dual. Are there any gains at the rear split to be had. Secondly, wouldn't it make more sense to run a single 2.25 all the way back to a single exhaust coming out the right side and running under the tank and between where the rear suspension arms attach to the frame. Less bends means more consistent flow right???

Originally posted by 2112:
1. Are there any gains at the rear split to be had.
2a. Secondly, wouldn't it make more sense to run a single 2.25 all the way back
2b. to a single exhaust coming out the right side
2c. and running under the tank and between where the rear suspension arms attach to the frame.
3. Less bends means more consistent flow right???

1. Looks. The SVT will not look like crap because one exhaust cutout is empty! To answer the performance part. A properly setup quasi-dual and single exhaust will give the same performance when taking into account mandrel bends & aftermarket mufflers.

2a. No. 2.5" single pipe is the proper diameter.
2b. No, see #1 about looking like an ignorant ricer.
2c. The piping never "really" goes under the tank. It goes around it. Hence why 4 90 bends are needed!

3. Not exactly. Less bends = less energy lost = better exhaust velocity = better performance. So yes less bends are better.

Looking like crap, though, would not be the case for non-SVT rear bumpers.

The rear Y is just another source of turbulence, but if done well, not much of one.

If I (in my limited knowledge) were designing a system for best performance, looks be damned, (or for a non-SVT body), I would go with a single pipe with outlet on the right, or a true dual.

Originally posted by RogerB:
1. Looking like crap, though, would not be the case for non-SVT rear bumpers.

2. The rear Y is just another source of turbulence, but if done well, not much of one.

3. If I (in my limited knowledge) were designing a system for best performance, looks be damned, (or for a non-SVT body), I would go with a single pipe with outlet on the right, or a true dual.

1. He has an SVT.

2. Right. If well done, not enough to notice any performance difference.

3. Right. True duals are your best option. "Technically" single exhaust would be a little more efficient than quasi dual since it does not have the Y split. However any performance difference would be very hard to measure.

Originally posted by DemonSVT:

Originally posted by RogerB:
1. Looking like crap, though, would not be the case for non-SVT rear bumpers.

2. The rear Y is just another source of turbulence, but if done well, not much of one.

3. If I (in my limited knowledge) were designing a system for best performance, looks be damned, (or for a non-SVT body), I would go with a single pipe with outlet on the right, or a true dual.

1. He has an SVT.

2. Right. If well done, not enough to notice any performance difference.

3. Right. True duals are your best option. "Technically" single exhaust would be a little more efficient than quasi dual since it does not have the Y split. However any performance difference would be very hard to measure.

1. I know. But I don't.

2. ...

3. Is the weight penalty of a true dual significant? What about cost?

Originally posted by RogerB:
1. I know. But I don't.

3. Is the weight penalty of a true dual significant? What about cost?

1. Well I was responding to his post.

3. Depends on how the setup is done & what materials and mufflers are used.

A straight back dual exhaust using 2" piping & small mufflers/bullets combo would not weigh much more than a 2.5" single with a normal muffler/resonator combo that wrapped around the tank. Folks forget (or just don't know) how heavy 2.5" piping is compared to 2" 3" piping more so!

Also it depends if one setup used a converter and the other didn't.

Also it depends if one setup used the stock Y-pipe unit (31lbs by itself!!!) Even just the stock Y weighs 13lbs. Over twice what the equivalent mandrel bent piping for duals weighs. Now an aftermarket Y is only a couple pounds heavier.

So to answer your question... There is no set answer.

However I do think certain dual setups can be lighter than a quasi-dual setup and that's what applies to me (SVT)

Originally posted by DemonSVT:

Originally posted by RogerB:
1. I know. But I don't.

3. Is the weight penalty of a true dual significant? What about cost?

1. Well I was responding to his post.

3. Depends on how the setup is done & what materials and mufflers are used.

A straight back dual exhaust using 2" piping & small mufflers/bullets combo would not weigh much more than a 2.5" single with a normal muffler/resonator combo that wrapped around the tank. Folks forget (or just don't know) how heavy 2.5" piping is compared to 2" 3" piping more so!

Also it depends if one setup used a converter and the other didn't.

Also it depends if one setup used the stock Y-pipe unit (31lbs by itself!!!) Even just the stock Y weighs 13lbs. Over twice what the equivalent mandrel bent piping for duals weighs. Now an aftermarket Y is only a couple pounds heavier.

So to answer your question... There is no set answer.

However I do think certain dual setups can be lighter than a quasi-dual setup and that's what applies to me (SVT)

1. Well, so was I, but for the benefit of all, great philanthropist that I am.

3. Thanks for the info. Sorry if it's old news.

Ok, so I've got a 1998 SE Sport, and I've been planning in the future a large revamp of the entire car. Probably some honed manifolds and perhaps a 3L with some ported heads in there, and probably the SHOshop Power Package too. But the exhaust i was going to go for the SVT duals, which would mean that I'd need a new bumper/body kit, which would mean a new paint job. Well, [censored], that's a lot for a lil bit of performance. However, it looks like that the SVT exhaust isn't exactly better? Is there a straight exhaust system out there that would be good on a setup such as this? Remember that there would be a hi-flow y-pipe and cat on there. Also, I'm not a big fan of noise. I'm a crazy big audiofile, so interior noise from the exhaust is annoying to me. A little bit of engine roar from up front I like, but if it's making noise behind me, it's a bit frustrating. Is there anything that can appease me in a single pipe? ANYTHING?

Originally posted by WeaselBomb:
Is there a straight exhaust system out there that would be good on a setup such as this? interior noise from the exhaust is annoying to me. Is there anything that can appease me in a single pipe? ANYTHING?

I'm not sure if any single outlet aftermarket performance systems are available. If you're looking for a high flowing, modest sounding single outlet exhasut system maybe your best bet is to have one custom made at a shop. This will also allow you to work with the technician at the shop to pick and choose the components you'll be installing.

If you're willing to spend the money, Borla has an excellent system for the SVT Contour which can easily be fitted to a non-svt. The Borla system performs well and is proven to boost low RPM torque over the stock SVT exhaust. Plus its quiet, barely louder than the stock system, with interior noise no more than it is in a stock SVT.

Hey, thanks alot. The borla, how exactly would that fit to a non SVT? Anyone got pix of dual exhaust on an SE?

Just to show you how stupid the single exhaust on an SVT looks like:

I am going to be going to mandrel bent 3" quasi dual soon. The above is just temporary

Thats why I didn't even bother with a tip.

Originally posted by WeaselBomb:
The borla, how exactly would that fit to a non SVT? Anyone got pix of dual exhaust on an SE?

Its a simple matter of adding an extra hangar to fit a SVT exhaust on a non-svt. The bolt flange on the back of the main catalytic converter should be the same with an SE or SVT, but you should figure that out first before you buy anything to save you the trouble of flanges that don't match up.

Thanks for the opinions and data. I'll let you know what I do if anyone is interested. Thanks again.

Originally posted by WeaselBomb:
Anyone got pix of dual exhaust on an SE?

Lot's of pics here from various angles. OK from some angles. A little awkward from others. Not everyone's cup of tea. I may trim them someday, but not a high priority.

Originally posted by WeaselBomb:
Hey, thanks alot. The borla, how exactly would that fit to a non SVT? Anyone got pix of dual exhaust on an SE?

http://AirKnightsOnline.dyndns.org/ContourPics/ProfileShots

Dom, that Brullen looks sweet. Much better than my Borla. I'm jealous.