would my stock 289's performance suffer if i ran a sinlge exhaust system(2 1/4 or 2 1/2) with a glasspack muffler(cherry bomb or Thrush)? just wondering
Run the biggest pipe you can get away with and the best flowing muffler you can find. The LS1 Camaro had single exhaust. Mine made GOBs of power through 2.5" Y-pipes and 2.75" intermediate pipe, with a 3" Dynomax race bullet (flows like open pipe). The exhaust was all stock except for the bullet, and it supported 330 at the rear wheels. Therefore I'd say no, as long as you thought it out well. Also, make sure to use mandrel bent pipe. Most exhaust shops can't mandrel bend either. 2" mandrel bent pipe flows like 2.5" pinch bent pipe! It makes a huge difference. If you aren't running headers, dual exhaust won't mean much anyway... Yes it helps, but the manifolds are a huge bottleneck, so you won't feel much difference. Run the biggest pipe your manifolds will allow, Y it into 2.5" pipe, then through a 2.5" race bullet. Oh, and regular glasspacks, like Cherry Bombs or whatever, DON'T flow anywhere near as good as the Dynomax. The muffler is pretty cheap, so don't skimp. It looks like a glasspack on the outside, but it definately is not a glasspack. The 3" on my Z-28 was very mellow at idle, more deep bass than noise, but sounded like a Nascar at WOT. I had stock headers, stock mandrel exhaust, dual tips out the back, and cats. Without cats, you'll be a bit louder.
got another idea . Y pipe to 2.5 bullet then have a Y splitter at the end of the bullit and run dual pipes from that point. how about that?
That is exactly what I did to my Z. I used all the stock exhaust, but the stock muffler was a single in, dual out type. I put the bullet in the I-pipe (under the car, before the rear), then took out the stock muffer behind the rear. I replaced the stock muffler with a Y-pipe, with the ends right where the stock muffler attached to the tailpipes, then reinstalled the stock tail pipes. You would want to do something similar with a Maverick. The driver's side is a bear to get pipe over. It can be done, but if you didn't split into dual pipes until after the rear end, you'd have a much easier time. Then you just run a pipe behind the rear, in front of the fuel tank, over to the driver's side and make a tail pipe from there. Send the right pipe straight out the back, and then shoot over to the left and mirror the right.
I wonder if a stock Z28 I-pipe would fit under a Maverick??? 2.75" pipe over the axle... F-body guys throw those stock I-pipes and such away all the time. You could probably find one free/cheap if you hang out on one of the F-body boards. It's all mandrel bent stainless steel. The 93-02 Zs had very tight clearance over the axle, so it might be bent very nicely for our cars. ???
bite the bullet, spend a couple hundred and do dual exhaust from the manifolds back. Single exhaust will kill your performance (unless it is 4"+ from the Y to the back)
The LSx F-bodies run 2.75" single exhaust and will pull 300 rear wheel HP through the stock muffler. Much more with an aftermarket muffler. It is not the pipe size holding them back, just the muffler, obviously. So I don't think you need to go 4"... Unless you have 500 rwhp and the 4" pipe is pinch bent. Two 2" exhaust pipes DON'T equal one 4" pipe, if that is what you are thinking. Four 2" pipes don't quite make one 4" pipe. Knowing that, and that the Dynomax bullet flows 2200 cfm (One muffler alone... 2 flow 4400 cfm!), it's pretty obvious that will do the trick. A stock muffler flows around 200 cfm! Flowmasters flow around 500 cfm. Make sense now?
A racing buddy i work with told me that a single mandrel bent 3 inch exhaust flows just as good if not a little better than dual 2.5 mandrel bent pipes. he also told me that magna flows are nicer than flowmasters because you get the same power with out all that useless noise.
For a stock engine or near a 2.5-3 incher would be fine and wouldn't be too restrictive. A near stock engine only makes 200hp or so anyway.
IIRC the Flowmasters flow just under 500 cfm each, while the Magnaflows are around 700 cfm each. Which series muffler, pipe diameter, and inlet/outlet positions make a difference. IIRC, these specs were comparing 3" diameter pipe. Magnaflow is the best flowing of the rectangular mufflers. Believe it or not, glasspacks are not any better. They have large fins disrupting the airflow through the core.
