LT4 Breathing improvements

[TANWare]

I ordered the K&N filter for the stock box and breather system. I did not want to go with cold air or SLP as it would change appearance too much under hood. My next question though is to the exhaust.

I am thinking long tube headers and 3" exhaust but I do have one criteria. I want about s quiet as stock but improved breathing! Not too sure if this is even possible. So has anyone else went with a quiet system and seen improvements, if so what did you put in?

 

[Hib Halverson]

(snip) but I do have one criteria. I want about s quiet as stock but improved breathing! Not too sure if this is even possible.

That's soooo not gonna happen.

If you want to reduce restriction enough to see a practical improvement in performance, you're going to have to put on an aftermarket system and none of them are as quiet as stock.

 

[TANWare]

I know back in the day this was the case as well but I had hoped it had changed.

 

[jmhorn52]

The Corsa exhaust nd headers on my LT4 make it sound great. I love the exhaust sound. I dont find it to loud. But the sound is an individual thing.

 

[Huskerman]

More then the loud factor is the resonance factor on the C4. IMO the best system out there is the Corsa X pipe cat back systems. Quiet on the road and a great sound when you hit the go pedal........Pricey though......and I think 2.5 inch pipes are more then adequate for the power your car makes......and that will save some money....

I have run the Corsas on my C5 and now my C6 and love to listen to them make music.......

 

[96gs917]

I have the Corsa Cat back system on my polo green LT4 and love the sound. Its not to much
while crusing but you definately here it when you run through the gears. I don't even listen to
the radion anymore.

 

[wingnut96lt4]

Exhaust

Guys I have the Exhaust Eliminators thru the cats 3"" and idon't hear the sound inside BUT outside when on it it is great. Cruising at 55-65 in sixthgear quiet as a mouse radio automaticly gets louder as noise increases so I hear it fine The exhaust is 3"" stock so why make it smaller ??

 

[Huskerman]

Guys I have the Exhaust Eliminators thru the cats 3"" and idon't hear the sound inside BUT outside when on it it is great. Cruising at 55-65 in sixthgear quiet as a mouse radio automaticly gets louder as noise increases so I hear it fine The exhaust is 3"" stock so why make it smaller ??

Yeah you're right 2.5" is too small for the LT-4.....but I think I saw them listed at 2 3/4" as the stock size. So 3" would work.....was the LT-1 2.5"?

 

[TANWare]

Wow, thanks for all the responses. I didn't even know the LT had over 2.5's. Now the Corsa's was that with long tubes as well?...........

 

[jmhorn52]

The corsa to my knowledge is from the cts back,, but I will say it sounds great and doesnt drone at hwy speeds.

 

[jmhorn52]

I saw them at Mid America corvette parts on sale for 1600.00. Its made from stainless and has 4 outlets 2 on each side. I like that look better than the rectangular one that was stock

 

[TANWare]

I think I am confusing some of the modern terminology, is there a definition link? IE are long tubes equal too long tube headers etc.?

 

[Huskerman]

I think I am confusing some of the modern terminology, is there a definition link? IE are long tubes equal too long tube headers etc.?

Yes they are. For more power the stock exhaust manifolds are replaced by long tube headers and then the cats and then the Corsa set up. Some leave the cats off at that point but you will not pass inspection in most States.

 

[TANWare]

Yes they are. For more power the stock exhaust manifolds are replaced by long tube headers and then the cats and then the Corsa set up. Some leave the cats off at that point but you will not pass inspection in most States.

Thanks, I am kind of an Eco guy so the cat's stay. When I was looking for a second car at first a Vette was not a consideration until I learned I could easily get 28-30 MPG highway. With the 6 speed you get mileage/performance ratio as more user controllable than with an automatic trans. I went trough a lot of sould searching before this purchase.

There in lies the other dilemma for me. The more mods put in the faster fuel can be used up. I refuse to put in mods that will under the same driving conditions and usage use up more fuel or put out more pollutants. Now any mod that could increase fuel economy and/or reduce pollutants without effecting performance is more than welcome, tech does change and improve over 17 years.

 

[96gs917]

Thanks, I am kind of an Eco guy so the cat's stay. When I was looking for a second car at first a Vette was not a consideration until I learned I could easily get 28-30 MPG highway. With the 6 speed you get mileage/performance ratio as more user controllable than with an automatic trans. I went trough a lot of sould searching before this purchase.

Corvettes get great gas milage. You may be able to acheive 28-30 MPG highway on flat, smooth roads doing 55-60 MPH in 6th gear but a more realistic number is 23-25 MPG.
I got 23 MPG on average according to the computer doing 70 on the NYS thruway going up to Lake George a few years ago.

Make sure you tell all your ECO buddies they need to be driving Corvettes as well.

 

[TANWare]

Coming back from VA, the lie-o-meter was showing 28+mpg. I tend to believe it was close as about 60 miles in we filled up and when home we only needed about 10 gallons to fill back up, total trip 363 miles one way not including several rest stops for liquid depletion. So I am happy so far. I just got the K&N in from UPS and installed it.

I will say it appears like the filter has never been changed before. it was extremely dirty and full of lint or something like that. The car though runs a bit better.

I don't know about top end but low end is smoother with a clean air filter. The engine at low RPM's doesn't feel like it is loading up as much or should I say lugging. Slowly but surely the car is feeling better and better.

I have to wonder about the prior owner(s). Dirty Air filter, broken right front TPM, Old oil change sticker was dated "change by 4/2011 or 34,000 miles". With 33,000 miles I can see somewhat delaying maintenance but personally I would not have delayed these things this long. I guess there has to be some forgiveness, as I am the 5th owner so who knows what others have done as there are no real records...............

 

[96gs917]

Thats great mileage TANWare.

The new K&N, or any clean air filter will definately make a big difference in throttle response. I have the K&N, and a Corsa cat back exhaust on my polo green
LT4 and I can definately feel the difference compared to my bone stock Grand Sport.

 

[TANWare]

Yeah, that is what I figured. With only 33,000 even being neglected a bit there is not much of an issue.

 

[LT4CE]

That's soooo not gonna happen.

If you want to reduce restriction enough to see a practical improvement in performance, you're going to have to put on an aftermarket system and none of them are as quiet as stock.

Hib, speaking of 3" exhaust, I was wondering if you had a general opinion of Billy Boat exhausts for the LT4, and the 3" version in particular. (Year: 1996 - LT-4, 3") I suppose I'm mostly asking about overall quality, warranty, etc. Sound is mostly a personal preference, but I'd be interested in any thoughts you have on that, as well. What about Borla?

I ask about Billy Boat and Borla, because my Corvette mechanic has recommended Borla, but says B&B is also very good. I'm leaning towards the B&B because the Borla now use standard LT1 tips, which is not appealing to me. I prefer the dual round tips for each muffler. I figure an exhaust is as much an aesthetic choice (sound and looks) as it is a perfomance choice. I'm not sure which sounds better to me, yet. I have to do some more checking on that.

So, I guess I'm asking for an objective opinion, since I respect your opinion after reading reading many of your posts. (sorry, I'm not really trying to butter your bread, just to get an answer... not too much at least!)

Thanks in advance for any info you have!

 

[wingnut96lt4]

Breathing Improvements

Just my $.02 I had a spoiler on my 84 called a graber it will give you more intaket kinda forced the air to the center into my hood intakes for the T B s they make them for the L T 4 also that may help. I am going to get one from C C in the catolog. about $ 180.00 I think . I also have an air foil piece in my intake it directs the intake equealy i think this makes a difference. worht a try these L T 4s are beasts. check this site Stock L T4s tested HP ran from 340 to 380 off the shelf just stock check it out