BIGJIM Posted June 15, 2005 Share Posted June 15, 2005 Im about to put together a 260z with a mild chevy 350 with an auto trans. Im running stainless block hugger headers. What exaust should i run? Im thinking 3 inch snigle, or 2 1/2 duals, but im not sure how this would fit under the car. It will be lowered using tockico hp struts and springs. Whats my best choice? Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted June 15, 2005 Share Posted June 15, 2005 Are you ever "going big" or is this engine going to remain mild? Quote Link to comment Share on other sites More sharing options...
BIGJIM Posted June 15, 2005 Author Share Posted June 15, 2005 Nah, this is the engine its getting, 350 bored .030 over, comp cams 230 duration (i forget the lift but its not that big) with roller rockers, flat top pistons with 64cc chevy heads, mild port work done, edelbrock performer intake, stainless shorty headers and a 750 double pumper holley carb. Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted June 15, 2005 Share Posted June 15, 2005 I would vote 3" single. It will save a little money and shouldn't restrict a mild 350. Quote Link to comment Share on other sites More sharing options...
HICKL Posted June 16, 2005 Share Posted June 16, 2005 I have a 3" single with a flowmaster and am very pleased with it. Not sure of my HP but ir runs high 12's with the pipe on. Jeff Quote Link to comment Share on other sites More sharing options...
Bartman Posted June 16, 2005 Share Posted June 16, 2005 It seem's like a lot of people on this site like single 3" exhaust, but personally I like 2.5" duals. When you have a low car, getting the exhaust up as high as possible makes a big difference; and an extra half inch could make the difference in whether you scrape something or not. I'm looking at switching to 2.5" duals and I want to try and get it tucked up as high as Pete's is. According to this link from Pete's site http://alteredz.com/exhaust.htm the only place where it is lower than the rest of the car is under the trans mount (by 1/4"). Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted June 16, 2005 Share Posted June 16, 2005 I'm running a pretty stout 383 out of a 2 1/2" single pipe w/o cat through a magnaflow. A trick cut-out is my next performance upgrade but if the 2 1/2" pipe is chocking it I can't tell it. I guess we'll know once I get the cut-out installed. You will do fine as far as performance out of a 3" with a mild 350. Quote Link to comment Share on other sites More sharing options...
HICKL Posted June 17, 2005 Share Posted June 17, 2005 I'm sure it is "choking it" a little. With my single 3" (no cat), I can shave almost .2 in the 1/4 by removing my exhaust. Mine has a flange right about under my feet and I can remove the entire back section from there. I agree that duals would be sweeter, but $$ was an issue and mine was cheap! Quote Link to comment Share on other sites More sharing options...
ThomaZ Posted June 17, 2005 Share Posted June 17, 2005 I have a rather mild 355 with a T5 gearbox and R200 diff in my -72 240Z. I went for a 2 ¼†dual system mostly because the JTR manual recommended 2 ¼â€. I used Summit block hugging headers, Speedway down pipes #910-13385, and two Magnaflow mufflers. Both are two-in-two-out with #11378 in front of the diff and the longer #11385 at the stock location in the rear. The rest of the system I fabricated from strait pipes and 90 degree bends. It took much longer time then expected mainly because I am a beginner in welding and it was the first time I made my own exhaust. In my fist setup I had an X-pipe in front of the diff and only the rear muffler but that was too loud for street use, so I replaced the X-pipe with an extra muffler. It was a tight fit in the transmission tunnel I actually had to hammer some clearances for it. But nothing scrapes when going over speed bumps and I am pleased with the present sound. There are pics of both setups in my photo album under “Engine change†ThomaZ Quote Link to comment Share on other sites More sharing options...
Pyro Posted June 17, 2005 Share Posted June 17, 2005 Run both! Run dual 2.5" to the diff, then do a nice flowing Y-pipe into a single 3 or 2.75" pipe to go under the diff and out the back with a 3" muffler. I have dual 2.5's on my Z car but had to install a fuel cell first. Duals on a V8 z' make it sound like a mustang. Your car will make a little more power but will lose the import sound. Believe it or not, I didn't like the dual exhaust sound coming from my V8 Z, which was a big surprise to me. Quote Link to comment Share on other sites More sharing options...
Phantom Posted June 17, 2005 Share Posted June 17, 2005 If you are running a lowered car I would definitely go the dual something approach rather than a single 3". I'm running stock height and occaisionally drag my dual 2 1/2" pipes on a steep break-over. Magna flow has a nice-sounding muffler with dual 2 1/4" or 2 1/2" inlet and a single 2 1/2" or 3" outlet. That's what I'm running. Dual 2 1/2" ffrom headers to a true 'X' pipe and then one 2 1/2" pipe routed the standard route with the other crossing the R200 mount on the passenger side using a 'frame clearance tube' and then both swing over to the drivers side to the muffler in the stock position. With a mild 350 sbc you should be fine with a 2 1/4" and it will help with cost & clearance issues. Quote Link to comment Share on other sites More sharing options...
Guest NavySupra Posted June 19, 2005 Share Posted June 19, 2005 We have 3" true dual on our Z. Though to do it right it means building a new fuel tank for the car. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted June 20, 2005 Share Posted June 20, 2005 Good looking Scarab--silver works for me Davy Quote Link to comment Share on other sites More sharing options...
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