O.... M.... G....

[Jagdpanzer]

Bob,
Welcome to the Corsa fan club. Any pics of the install?
I share your comments about the sound qualities of the system, relatively quiet drone free when just cruising down the road then full LT5 thunder when you put your foot in it.
In my case I went with 3" to 2.5" stainless reducers from SW to transition from the 3" cat outlet to the 2.5" Corsa tube diameter. Added 4" flexes just after the reducers to help eliminate bending forces in the system. Also used some exhaust pipe sealant in the joints to eliminate any small leaks.

[Aurora40]

Originally Posted by HIZNHRZ

Next to the Corsa, my favorite was the Callaway Twin Double-D system that I had on my Red/Gry ZR1. There is nothing I didn't like about the Callaway system.

I have always found that system intriguing. But so few people have had one it's hard to know if resonance is an issue. Also the $1800 price tag is offputting.

I've since learned that the mufflers Callaway used are super turbos, and so I wonder if the "mixing chamber" is just an off-the-shelf part too? I think I might be a little upset if I'd paid $1800 to find out a) the system is not stainless, and b) that a local guy could have thrown the parts together for much less. I realize you are paying for their research into which parts to put together, and for the fit/finish and tips, but still...

Anyway, I'll let you know if the system changes. I sort of seem to recall with the Aurora that it got quieter after a few days/weeks of use. Though that car had some issues with where the Corsa system met the stock system in that it didn't clamp tight. They fixed it in person and it's been fine for the 5 years since.

[QB93Z]

Nice write-up Bob. I am planning on getting a Corsa for my 90 as soon as I get the radiator replaced.

Jim

[tomtom72]

Thanks Bob for the response! Much appreciated!

Sorry for this Hi-jack. I was wondering exactly what SSworks modified / changed on the new headers vs the older headers. Does any one know, as I've forgotten the relationship, what the relationship equation was with respect to collector lenght and bottom end or top end results? I remember that a few mfg's had adjustable lenght collectors, back in the stone age circa the 70's, for tuning the power band. I just can't remember the relationship long collectors = bottom end(?), shorter collectors = top end(?).

Again, thanks for your input and sorry for the hi-jack Bob.


Tom

[Paul Workman]

Originally Posted by tomtom72

Thanks Bob for the response! Much appreciated!

Sorry for this Hi-jack. I was wondering exactly what SSworks modified / changed on the new headers vs the older headers. Does any one know, as I've forgotten the relationship, what the relationship equation was with respect to collector lenght and bottom end or top end results? I remember that a few mfg's had adjustable lenght collectors, back in the stone age circa the 70's, for tuning the power band. I just can't remember the relationship long collectors = bottom end(?), shorter collectors = top end(?).

Again, thanks for your input and sorry for the hi-jack Bob.


Tom

Tom,

No easy answer. The collector length is like one instrument in an orchestra - it's effect on the overall symphony (engine tuning) has to be considered as part of the effect all the other "instruments" have on the outcome. The collector is but part of the exhaust system, and the entire length - not only the collector - plays a role.

You can "Google" exhaust tuning, but this is one author that I thought had a pretty clear description of the considerations that go into the design of intake and exhaust systems and how they interact.

Bottom line: Even with considerable computer modeling, the proof is in the experimentation: Axiom: "Truth is where you find it"! Some experimentation is required, regardless (it seems).

I know... But, all that said I'm intrigued by the "gold" Pete seems to have struck with his exhaust system...It seems to be doing pretty well. (More research and empirical "serendipity" is in order (for me) before I hack my exhaust this winter, "fer sher".) It would be nice if "Z boyz fm Illinoiz" could be talked into buying or building a workable dyno so as to do some experimenting w/o having to cough up $100+ "per try"...(Our secret...I'll "spring" it on em after I do some research! ) Given enough pipe and cheap dyno access, I suspect much could be done to optimize the LT5 for whatever kind of driving we each have in mind.

Anywayz...check this out. Keep in mind that tho the model linked in the article is for single, two and four cylinder applications, a V8 with dual exhausts is (afer all) just two "separate" 4-cylinders that happen to share a crank shaft, i.e. their exhausts are separated to their respective group of 4.

W/o entering a single value, the number of considerations in the calculator provides a lot of insight to what it takes to properly tune an exhaust. Check it out!

http://bmwmotorcycletech.info/InExTuning.htm


P.

[XfireZ51]

All,

If you are using the Corsa, speak to Ccmano about his latest mod. He took the Magnaflow Xpipe and resonator and put that in place of the
Corsa pipes. He kept the corsa mufflers however. He pretty much loves it.
No resonance according to Hans and WOT doesn't sound like shredding metal. Basically he has the same system I do but I have tthe MF mufflers to go with it.

[GOLDCYLON]

Well a response to your OMG and gag me with a fork era comments leads me to a modern day response to your Corsa conclusion. Well Duh.....

Actually Tom I chased this one as well and I 100% concur with your statement on the tips. My idea of the best looking and non resonance system would be the corsa system with the Billy Boat oval tips. Fills out the exhaust cut out nicely. Mine came with a gen1 B&B and the resonance was painful. Gen3 is not much better

For a track car the best sounding and best performing system is the B&B without a doubt and damn the resonance. But the best cruiser is Corsa and it sounds mean enough when you need it. Glad your happy

[DMark]

Originally Posted by Aurora40

...... the sound comes from behind you, not from underneath the car...... the interior doesn't rattle and buzz....

I had the same results when I extended my tips pass the exhaust cutout in the bumper. I have SW headers into a Flowmaster system. The resonance would run my wife out of the car on highway trips. Adding the Magnaflow tips fixed that problem.

Amazing that just extending a 1/2 inch pass the edge would move the sound to where it needs to be.

[Paul Workman]

Originally Posted by XfireZ51

All,

If you are using the Corsa, speak to Ccmano about his latest mod. He took the Magnaflow Xpipe and resonator and put that in place of the
Corsa pipes. He kept the corsa mufflers however. He pretty much loves it.
No resonance according to Hans and WOT doesn't sound like shredding metal. Basically he has the same system I do but I have tthe MF mufflers to go with it.

Dom,
I reeeeeaaalllly like the look (from the rear) and the sound of your MF system. Wanting best possible performance for type of diving (I do) w/o interior droning, it would be fun to be able to tweak lengths, diameters, mufflers, etc, and then dyno the results and tweak again...[sigh]. For sure, Pete's onto something, methinks, at least from a drag race perspective (that I've seen). It may be possible to have one's cake and eat it too - at least according to some engineers. But, to your point, I'd like to hear Han's system sometime too.

Interesting thread.

P.

[jonszr1]

so what is petes setup ? i have a 21/2 in set up done by spin tec with a dr gas xpipe i picked up from the flowmaster set up i had , it went from 117.50 best mph to 119.85 best of each system . cars on u tube @ famoso. i wonder if using the factory 23/4 in tubing with 3 in turbo muffler with a 3 in x pipe might be the perfect size. just thought to share