Exhaust question

[mad47]

Corsa .................
I love the sound under acceleration and the quiet at cruse.
But this is a very personal choice and would strongly recommend you hear serveral systems before picking the one that "turns your crank"Corsa...................

 

[wx briefer]

Corsa is truly a "Deaf defying" exhaust! :gap

 

[Wamp]

power effects

Everyone is so excited over Corsa, what made the decision of Corsa over Power Effects? I'd rather have something I can tune myself. I've heard of Corsa sounding alot different between model years also.. I would like to see a picture of the power effects installed on a 90's vette if anyone has one.

 

[tboo]

I didnt like the way Corsas sound. I currently have B & B on my 94 LT-1 & am thinking of getting a flowmaster cat-back for my recently aquired 96 CE LT-4

 

[brooks]

The B & B 3" cat back produces the most HP and the most noise. If racing is your objective then go for it. However, at 1500-1900 RPM in 5th gear you can't carry on a conversation. The resonance is so bad you can’t here the radio or anything else. at 5700 RPM in 5th they sound great. I just sold my B & B and I am going to purchase a power effects. The tunable feature is a great option

 

[wx briefer]

Brooks, how do you hear anything at 5700 RPM in 5TH? :J

 

[tboo]

I have 3 inch triflows on my 94 lt-1 & I dont think they are that loud-in fact i wish they were louder! I dont find resonance to be that bad.

 

[brooks]

wx....its really not that loud in the 170-180- range

 

[bob eshleman]

Power Effects

HI, I have a 96 LT4 stock exhaust with P/E power capslues. Sound is great and tuneable.Some resonance at 1800 -2000 in 6th,wife says too loud at that speed.I am having a 3" "X" pipe made and have TPIS headers to install but waiting to return from Bowling Green. Will keep you posted. 3 mpg differance on T-way with exhaust fully open compared to fully closed.Thanks for your site.Bob p.s. 29.5 mpg@ 75mph

 

[Topless]

Make sure the person making the x knows what they are doing. They should be two pipes that are joined by a whole in the sidewalls. If they run two pipes into one bigger one, and then back out into two pipes, run. That is not an x-pipe.

I will see what I can do about scanning the pictures of my system in this weekend. I have 3" with a custom x made up.

-Mike

 

[bob eshleman]

X- pipe

HI Mike, do you think the 3" x-pipe will cut down the resonance? I am using Power Effects mufflers 2 3/4".Bob

 

[Topless]

Ummm... Some. I have a full 3 inch system from the body of the cats (ie. cats have 3" outlets) to the back. I don't have mufflers, and right now, the system dumps about mid way up the spare tire. I have some resonanace in the 16-1900 rpm range. It is better than what I had with the 3" KBD system though. (by a long shot)

I have be told that 3" systems will have a tendancy towards being loud and some resonance. Part of it might be my dumps though. There is some nice burble to it at the low end, and I like that. I have to put some tips on it though to complete it.

I guess to get to the point, you might benefit from it. If you don't have any other cross over, they you can probably gain from it. Mine is just in front of where the pipes split to go around the spare.

Before I had the system made up, I had a balance tube welded in at almost that same point. I did not gain much from that.

Let me know what you go with, and how it comes out.

-Mike

 

[Michael Malone Smith]

I have Borlas on my GS and love them. Just the right sound for a corvette.When I first bought the car I didn't know what was on it and after asking around I was convinced they were Corsa but this last weekend at a car show , the former owner walked up and after intros said he knew it was his former ride because of the borlas he had installed. Really nice guy and I was thrilled to meet him. Hope you consider Borla for a choice.

 

[Wamp]

Power Effects

I just put the Power Effects system on my car this week, in my garage with two ramps and the system sounds awesome. Little resonanse around 2,000 rpm (5th gear, 60mph). with the system wide open I hear it a block away, with it closed I don't hear the car till it's pulling into the garage. System is not cheap, but it is quality! All my C4 and C5 friends that have heard it want to put it on thier cars.

 

[Denny Nelson]

exhaust final answer

Here is what I ended up with-Flowmaster 14's. With the rectangular steel/chrome tips that fit the body sculpture they were pretty, but waaay too much resonance, especially as you worked your way up through the 6 gears. Then I stumbled upon round chrome tips that are similar in design to the old VW tips -- in other words there is an inner liner with small holes that acts as a final 'muffler' but they are 3 inch ID. I am now in exhaust heaven. the sound is a heavy rumble that still is muffled and when you get on it, it is still quiet enough but you can tell that there is no resistance. On deceleration it tries to pop and snort, but again, is still nicely muffled. Exhaust sounds are very subjective, but I get loads of compliments. If you are serious about the details, email me and I will get the particluars on the tips--they are the key.

 

[CKA_Racing]

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.

 

[stumpy]

Torque is far more important on the street than hp. I would never sacrafice tq for more hp in a street/strip car. In fact I'd go the other way in a heart beat. Give me 50 more tq and the other guy 50 more hp and he'll give up in frustration.

Nascar on the otherhand is a totaly different story.

 

[sbu8999]

LT4 with Borla's - ouch

My recently acquired LT4 has Borla exhausts -- they sound great at the curb but anything between 1500 and 2000 rpm has a resonance that drives us deaf. I'm looking for a more civil growl.

By the way, at 1700 Im clocking 80mph, so when I read the forum and 2000 rpm, are you guys flying or what? Clue: I'm new to LT4s, so I can't tell anyone how this one is configured, but it sure is fun to drive! :cool

 

[GusVette]

I agree with CKA Racing.
I installed "Power Effects" on my 85' and it sounded great! It was an easy installation too!
just my $.02

 

[Denny Nelson]

to sbu8999

My recently acquired LT4 has Borla exhausts -- they sound great at the curb but anything between 1500 and 2000 rpm has a resonance that drives us deaf. I'm looking for a more civil growl.

By the way, at 1700 Im clocking 80mph, so when I read the forum and 2000 rpm, are you guys flying or what? Clue: I'm new to LT4s, so I can't tell anyone how this one is configured, but it sure is fun to drive! :cool

I am in California and part of I-5 is 75 mph speed limit, so if I am going a modest 10 over I am at 2000 rpm [only to pass, of course]. BTW, I had resonance issues with Flowmaster 14" and not only solved all of my exhaust noise/resonance problems with special exhaust tips [next paragraph], but I now have the sweetest sound I could ask for and excellent flow.

I went to Marcos Mufflers in Roseville Calif. and they happen to have a round chrome tip that is 3.5" OD and 3" ID. The outer shell is typical chrome, the inner shell is drilled with dozens of 1/8"+/- holes [much like the old VW tips from the 60's]. The pair were about $80. If you are REALLY interested and cannot find them, email me and I will try to get make/manuf. Denny Nelson