I recently got a 94 coupe manual and was wanting to start with some performance mods. I know headers will get me some performance but will a cat back system do anything? I've heard the stock system is really efficient already. If I mainly care about performance (and a little sound) would just doing headers and then a new muffler for some sound lose any power compared to a full cat back ?

 

Change the catback based on sound preference, no real power gains to get here. Maybe 5hp or so. Just find one you like.

Headers will bring power, even with stock system in place. No you won't lose anything.

 

First of all, if you only change the mufflers to free flow ones, you'll increase the exhaust sound and most likely interior drone. I'd either do a Corsa Cat-Back system (with or without headers), or headers with the stock mufflers or new turbo baffled mufflers. Of course it all depends on your budget. The cheapest thing you could try would be this: If your exhaust system has a resonator mounted in the middle of exhaust before the mufflers (like my '96) you could remove that and put an X-pipe or straight pipes there to experiment with sound. I'd only clamp and bolt this experiment until you find out if you like it.

 

I have a Allen's Stainless Chambered Cat-back system and it works and sounds great. After replacing the common catalytic converter in my 1988 C4 with the L98 and the new exhaust system I gained almost 14 hp according to my Gtech. I used a hi-flow cat so that helped a lot but the chambered pipes make a great sound out back behind you. I don't have any drone issue with my system. The nice part of the chambered pipes is you get rid of those two muffler cans in the rear of the car. I also have one of Allen's chambered systems on a Big Block with headers.

My cat back system is over 20 years old and still works and sounds great. I strongly recommend the Allen's Stainless Exhaust to anybody who wants a great sound without breaking the bank getting it. My two chambered systems are both from Allen's and both are fully functional and rust free. If you really want it they would be happy to make the parts out of Stainless Steel instead of the Aluminized Steel my systems were made of. Either way you will get a great system that sounds like a Corvette should sound.

I hope that this helps you a bit! Good Luck!

Best regards,
Chris

P.S. Allen's makes them for many years of Corvettes and I am 99% sure they would help you out!

 

The stock LT1 and LT4 exhaust system is capable of supporting way more power than you can make without building a serious engine.

I built a car on this board that made over 460RWHP NA and ran 11.0x@125MPH with the stock cat back attached to long tube headers. It even sounds really good..... totally different sound with a real engine long tubes and no cats infront of it as opposed to the stock 300HP. We have swapped back and forth from the stock exhaust to a Magnaflow with no difference in ET at the track.

I always recommend people that are going to do long tubes anyway at least try the stock exhaust first because it's going change sound totally and it may be what your looking for..... If it's not, Corsa is my preferred cat back. No drone. I have built C4s with Magnaflow, B&B, Power Effects and Corsa exhaust..... The drone on everything but Corsa and factory is quite annoying. I'm dealing with that same thing right now with my 11 CTS-V which the PO installed a B&B exhaust on...... It doesn't seem to drone as badly as the C4 systems because it's a bigger car and the tips are further way from the driver but it's still noticeable at certain cruise speeds and I absolutely hate it.

Now L98 and L83 cars can benefit greatly from an exhaust swap..... the single converter and dual Y Pipe system they have stock is a power killer. The lead pipes are smaller and I don't think the factory mufflers are nearly as good either. For a long time swapping a factory LTX cat back to L98s was a popular choice. When I put a Corsa on my 92 6spd, I gave the factory exhaust to a guy with a 91 L98.
Will

 

I did heads, intake, camshaft, headers, and exhaust system.
I had the original mufflers expanded to fit the new system (melrose), and i managed to blow much of the insides out of the stock 84 mufflers.

It started to drone a bit afterwards.

Later i installed flowmaster 40's, I'm happy with my setup.

 

Where do you live? If your an emissions state then take the advice of someone that dealt with the same. If your in a southern state like mine OK, then don't worry about paying the high cost for an aftermarket catback. Do your ceramic long tubes, have your local muffler guy put cross over for an H about the end of transmission and pick out your flowmasters or Borla etc. dont forget to put your o2 sensor on the collector , the non ceramic part. youll need it to keep your ECM from screwing up your mix. Ill get some pictures up when I finish mine.

 

One thing to keep in mind is that if you install long-tubes, you will want to compensate with a more moderate catback so you don't end up with something that ear-piercingly loud and uncomfortable to drive. Our Street Catback system pairs very well with LTHs to give your car the perfect street volume and deep tone!

 

If you change out your headers,which hopefully you do, make sure you have a new bungle welded in so you can add your o2 sensor back or your ECM will not calculate correctly like mine did. Install it on the collector that way doesn't mess up your ceramic when your welding.