Custom Exhaust

[jonszr1]

Originally Posted by Z51JEFF

You live in Ca,how did you get around the smog issue on a Ca car?

h is right inyo county one only has to smog rhier car when buying or selling. sure tou can have the back yard its 29 acres

[jonszr1]

sorry fo the typos i didnt have my glasses . it should read he is right . inyo county,one only has to smog their car when buying or selling. sure you can have the back yard its 29 acres

[jonszr1]

if one wants to use the lt1 tips , just step up to a 3 in super turbo muffler. then you dont have a cork in the system . the key is the super turbo. the ultra flows will drone. we tried them and sent them back on the dyno max 30 day return if you dont like them . my exhaust is as quiet as the stk exhaust with headers and just the right amount of sound when you floor it . as i shared before there is a vidoe on utube of the car ayt fontana on 2-28.its the one jetta vs corvetteat acd

[WVZR-1]

Originally Posted by jeasen

Any one considering the Dynomax Super Turbo mufflers (Part Number 17689 & 17690) on a 92 to 95 ZR1 should read this before ordering.

I have been looking for a stock looking muffler with the LT1 rectangular tips to replace my restrictive factory mufflers on my 1994 ZR1 for sometime. All the mufflers I have found have a 2 1/4" outlet. Not acceptable when I am looking to replace my perfectly good restrictive factory mufflers.

I was all excited when I read this post and read that the Dynomax mufflers cited above were a true 2 3/4" inlet and outlet muffler. I was going to order them but decided to check with Dynomax before going thru the exercise of ordering and then having to return them because they are exactly the same as the other mufflers with the 2 1/4" outlet.

I called the Dynomax tech line and found out that they do have a 2 3/4" inlet but only a 2 1/4" outlet the same as all the other mufflers out there.
The only way to get a 2 3/4" inlet and outlet is to order mufflers separately and make up the mufflers with LT1 tips yourself. I found that Pypes makes a LT1 tip for a 3" pipe.

Now that everyone knows about the Dynomax mufflers and the fact that they are a 2 1/4" outlet mufflers we need to consider something else to replace the restrictive factory mufflers with. BTW, the best price I found for the Dynomax mufflers is at Summit Racing is someone is going to order anyway.

The muffler options out there are endless we just need to figure out which ones do not drone. I hate drone! Any ideas? I would like to change mine soon. I hope this information helps a fellow ZR1 owner.

I haven't seen anything in this thread that indicated the 17689/17690 were 2 3/4 inlet and outlet. My comment was "2 3/4 inlet and retains LT tips". I'd still consider this a very viable system that should flow well and resonance should be manageable!

The C4 exhaust as it's suspended/hung from the chassis with metal hangers and only coiled springs is going to be very susceptible to resonance in the cabin. A potential fix for this although unsightly could likely be ballast. An exhaust tip extending beyond the fascia by a good bit is also a plus.

How much restriction would you expect is created by the 2 1/4 outlet? Bettcha there's no "SOP" feel! Is there a definitive difference on dyno test vs. anything else? Probably on nothing other than larger cubed or modified cars. Maybe even then, NOT!

It's certainly a "cost effective" option that retains "the look"! I believe that was/is the OP's goal!!

[jonszr1]

you could put in a a 21/2 in xpipe and the do the 3 in super turbo mufflers and transfer the tips off your old exhaust as i did .i want the 4 outlets like the 90 on my 92 , x pipe cost 175 mufflers 115 inc shipping and 150 maybe in muffler shop labor cost .paint the mufflers and tips black and it will look stk to most .if one really wanted to fool people you could cut the case off your stk resonator and cover the xpipe with it .