After Market Exhaust Who has the Power?

[Fugitive]

My locale Corvette club met in the Bay Area last month and they had the clubs highly regarded mechanic super tuner and he made a claim that frustrated me. "Flowmasters don't make power!" I really could not argue with him because I never dynoed my LT4 after I got the Flowmasters. I can clearly feel a difference especially since I removed the resonator. But my question is who went out and tested all the major brands Corsa. Borla, Power Effects, and Flowmaster? I mean same car same dyno? That's the only way to know the difference. I find it hard to beleive I wasted my money four years ago. Scott

 

[froggy47]

I was reading on one of the "exhaust" web sites (maybe corsa) that they tested all the majors and give or take 5hp they were all about the same for gains, just find the sound you like.

 

[Fugitive]

Yo fellaz that's exactly what I thought! Thanks for the input damn ZR1 you went the distance on both of yours! Yeah froggy that's wy I went with the Flows they sounded best I figure there all pretty close! Thanks! Scott

 

[CKA_Racing]

One of the corvette mags did testing on an LT4, the smae day and dyno with Flowmaster, Borla, Power Effects, Triflow B&B but not the Corsa since it was not made at that time. I have a write up on this. I'll post the results if I can find the file. Power Effects came out on top not by much, then B&B.

 

[Stealdads67]

I was reading on one of the "exhaust" web sites (maybe corsa) that they tested all the majors and give or take 5hp they were all about the same for gains, just find the sound you like.

Yea, but with saying that... If one gives up 5, and the other adds 5... thats a 10hp difference.... I want that 10hp... haha

 

[CKA_Racing]

Yea, but with saying that... If one gives up 5, and the other adds 5... thats a 10hp difference.... I want that 10hp... haha

Yes, that's fine but you are paying up the ying yang for 5-10hp. May not be worth it to some especially if your vette is stock.

 

[CKA_Racing]

One of the corvette mags did testing on an LT4, the smae day and dyno with Flowmaster, Borla, Power Effects, Triflow B&B but not the Corsa since it was not made at that time. I have a write up on this. I'll post the results if I can find the file. Power Effects came out on top not by much, then B&B.

Before I go on, I'd like to give you some advice. Go to as many vette shows/events and listen to the different exhaust sound first hand. Also take a ride in these vettes if you can to check for resonance. Make sure you ask if any other exhaust mods were done such as headers, cats removed, etc. These mods affect how much resonance there is. From there decide on which look you prefer and also how much you are willing to spend. Also ask yourself what benefits are important to you from the exhaust mods. What's more important? More power? Just a nice sound?
Least costly?

I will make comments on sound and looks. Keep in mind this is based on personal choice. The other comments are base on my five years of reading forum comments, magazine article and personal experience.

Since you mention Borla, I'll start there. This system has been very well known for bad resonance. Wimpy tailpipes for an after market system. Nice finish. Fair price. Sound is ok. Fit is not always the greatest.

Corsa - Practically no resonance at all. Fair price. Good quality. Decent tailpipes. Ugly welds show too much. Sound is ok but not deep enough. Too quite at idle. Excellent fit.

Power Effects - Excellent quality. Nice deep big block sound. Excellent finish. Excellent fit. Have adjustable flaps in the mufflers that can be used to adjust the backpressure and loudness. It also helps in dealing with the resonance. With closed flaps there is a tiny bit of resonance at around 2,000rpm. This cat back is 2 3/4 inch which ideal for torq and horsepower for a streetcar. You can install the L98 part# on a LT4 using the factory LT4 resonator. Cut about ten inches from the stock resonator and the L98 Y-pipes slips right on snuggly.
This saves you from spending the $400+ they want for the PE resonator section. So this system cost me $835 four years ago.

B&B Triflow - The best-looking tailpipes around. Excellent quality. There have been issues with fit. Mufflers spinning, not the easiest to install. Comes in 3-inch pipe. The system has resonance.

Flowmaster - Not one of the best-looking mufflers out there for a vette. For some it's just fine and serves there needs just fine. Finish is not as good as the others. Has resonance.

MagnaFlow - Nice tailpipes. Has resonance.

Dynomax - Sound is ok but not loud enough for most. Cheap in price. Lousy tailpipes.

The following info was taken from an article in Corvette Fever June 1998 issue.
Exhaust shoot out! By Jim Van Dorn
Dyno results on stock Grand Sport LT4.

HP/TORQ
Stock:
299/307

BB Triflow catback 3-inch:
310/310

Dynomax mufflers only:
304/310

Borla Corvette Challenge cat back 2 3/4 inch:
304/309

Flowmaster cat back 2 1/2 inch:
306/309

Power Effects cat back 2 3/4 inch:
299/308 - flaps in closed position
311/313 - flaps in open position

As you can see the is very little difference between them all especially when you consider cost.

Some interesting comments they had were, "Borla teamed with Doug Rippie Motosports in developing their Corvette Challenge cat-back 2 3/4 inch system. Rippie's original request for the larger-diameter pipe was made when he fitted his mega-horsepower former Lemans engine (600+hp) to a production ZR-1. Rippie later related, "We found the 3-inch system was great for horsepower, but (it) lost torque. The 2 3/4 inch system was the best of both worlds.

I have an issue with the above. If that's true why is it the Triflow 3-inch tested pushed 310 torq and the Borla pushed 309torq. Could it be that they are really referring to how the max torq moves to a lower rpm with the 2 3/4 and moves up higher in the rpm's for the 3-inch? Is this possible?
I can feel a difference in low-end torq if I closed the flaps on my PE system. Feels like it has more but maybe it's just available sooner.


They also tested sound levels at 70mph cruise, at idle, interior sound. Let me know if this interest anyone and I’ll start a new post with the results. What's interesting is that they don't mention resonance at all. I'm thinking the Cruise @70mph sound level test would be as good indication of how loud the resonance is.
Stock 94
Triflow 107
Dynomax 96
Borla 100
Flowmaster 97
Power Effects 100(Closed) 103(Open)<this turns it into a straight pipe, you can see inside the exhaust.

107 DB is loud for most folks.
For me open headers use to be not loud enough.

So bigger is better for horsepower in a modified car I would think. When you have such a high level of power I don't think it makes much difference if you lose let's say 10-20ft pounds of torq for a streetcar.

 

[Hutch]

Excellent synopsis, Steve. I couldn't agree more with your conclusions.

BTW, I have PowerEffects on the GS coupe and Corsas on the wife's GS convertible.

 

[Fugitive]

Would you guys believe I only paid five hundred forty three dollars five years ago for my Flowmaster Cat back system! I cut off the resonator had straight pipes welded into place and put some nice looking stainless steel LT1 tips on it. Looks great sounds better bet I'm getting about 12 to 15 increase. Thats a guess Later! Scott

 

[Hutch]

Flowmasters are indeed a good value. Just have the cheapest looking exhaust tips on the market, but it looks like you corrected that problem.

 

[vetteguy]

Thanks CKA, I'm in the market for a new system and that report is very helpful. Pretty much decided on Corsa, just looking for a good price. Anyone know of any let me know. Thanks, Guy

 

[froggy47]

Me too, Corsa, but I need a good deal on the price. Group purchase?

 

[1996man]

some very very good points being made. excellent article! i have one question. while i agree with everything else i have to say that the way the ips look is completely opinion kinda like if it sounds "good". but that being said i have a question about tips. how hard is it to change tips on a catback/muffler? i love the power effects system but really want the LT style tips, maybe the lt1 SS tips that midamerica sells. is it possible to do this?

 

[Hutch]

i love the power effects system but really want the LT style tips, maybe the lt1 SS tips that midamerica sells. is it possible to do this?

Well, never say never but this comes darn close.

PowerEffects exhaust tips are cast aluminum jobs that bolt directly to the "power capsules" (aka, mufflers). It would be a real trick to fabricate something that looked like LT1 tips yet still mount to the PE mufflers.

You can get chromed or polished PE tips if you want, but they are pricey.

 

[Sharondippity]

My locale Corvette club met in the Bay Area last month and they had the clubs highly regarded mechanic super tuner and he made a claim that frustrated me. "Flowmasters don't make power!" I really could not argue with him because I never dynoed my LT4 after I got the Flowmasters. I can clearly feel a difference especially since I removed the resonator. But my question is who went out and tested all the major brands Corsa. Borla, Power Effects, and Flowmaster? I mean same car same dyno? That's the only way to know the difference. I find it hard to beleive I wasted my money four years ago. Scott

[o/t]Where does your club meet?


Thanks all for responding to this thread; it's most informative.

 

[1996man]

i wonder if you were handy with a spot welder you could cut that part off that comes out of the muffler?hmmmmm
ill have to look into that peice a little closer/ i am sure something could be done

 

[No Go]

I was a believer that Corvette exhaust was pretty good from the factory...never intended to install an aftermarket setup.

Well, I came into ownership of a new Corsa system for the LT4-only restriction is I chassis dyno it before and after install.

I picked up 17 RWHP with that change alone...same dyno/operator/similar conditions-corrected too.

No BS.

That is a significant gain...never heard any other system come close...

 

[Fugitive]

Yo Sharondippity we meet in Santa Clara off of Fair Oaks it runs into Remington just off the El Camino. If you want I can find you the thread and answer any questions you might have. We are a very active club very big on the auto cross stuff! Later Scott

 

[firedawg]

Me too, Corsa, but I need a good deal on the price. Group purchase?

Froggy, Corvette Forum has a group purchase on these now, under C-4 General Discussion off of the home page, here is a link, Corsa Group Purchase

 

[froggy47]

Thanks firedawg,

I ordered one, it's on the way. Whooeeee! Gonna make my Vette roar.