I have an 85 with a 383 that currently has stock manifolds that need to go. I'm having a tough choice on what mufflers to order for my new exhaust system. I have ordered hedman elites and plan on doing an x pipe, no cat and mufflers.

Previously I had a gutted cat and elims behind the manifold and I loved the sound outside the car but it was too noisy inside. I'm still young and want something very aggresive, but I don't want to go deaf from the resonance. I can tolerate a moderate amount, just not as much as I had with straight pipes.

I love the sound of flowmaster 40 series, that is what I want on the outside. Deep and aggresive. I'm afraid though that there will be too much resonance.

Any comments or suggestions?

Also, why does this pypes kit not work on an 85? What would it take to make it work?
http://www.corvetteguys.com/pypes-co...ader-back.html

 

its probably an exact fit for those years and would need some 'fittiment' to hook up to 84/85

 

With the system you have planned out, why not take the car to a muffler shop after the headers are installed and have them build the rest of the exhaust? Chances are it will be much cheaper than buying something like the Pypes system. If you look at some of the catalog places, they offer "true" dual systems withhout mufflers for just over $250.

Most all muffler shops have tube benders that will allow the shop to build the design needed.

What you may have to do is to trailer the car there (a car trailer from U-Haul will work). What you should also do is to remove the license plates and tell the shop the car is for "off-road use only". This will help to get the shop around federal emission laws regarding cats.

Give them the X-pipe and they can build everything else. The X-pipe will reduce some of the noise from the Flowmaster 40's Without it, you may have some very nasty resonance inside the car with the 40's.

I have a pair of DynoMax Ultra Flo Race Mufflers on my 87 and true duals. These were very loud at WOT but once I added an X-pipe, the resonance went away and the exhaust note was a lot quieter at WOT. The car feels stronger at low to mid-RPM ranges after the X-pipe too.

Are you keeping the O2 sensor? Hedman makes a collector reducer with a bung already installed. You may need a heated O2 sensor to get the ECM to go into closed loop if the O@ sensor is too far from the engine.

 

i have that pypes system on my car.
i also have the hedman elite headers.
it has a low rumble at idle, quiet at hwy cruise @70mph, aggressive sound at wot.
i installed it myself. actually pretty easy.
just some minor cutting.
all the local shops i tried just wanted to do stock replacement only--one main 3" cat, etc.

 

Thanks for the advice guys. This whole exhaust thing is a headache. After talking to some more shops who were unwilling to help me out unless I put in cats I decided to just stay with what I have. Bought myself a Springfield XD and still kept a few months worth of rent in my pocket.

 

ive tried them all on my 86 and ended up with hooker 1 7/8 headers, dynomax pipes and converter, and had to take off the flowmasters 40s and put GM performance on because of the resonance, it knocked my ears off in the car and could not tell one bit of difference in power, my even impoved a little