exhaust?

greg fulk · 12-20-2009, 03:41 PM

getting ready to put the bracket/street engine in the Z-28. it is a 350 chevy flat top 487 head engine with a preformer cam & intake. right now it has a 600 holley but I'm going to put a Q-jet on it. it has a 350th with a 10" B&M holeshot converter with 3.42 gears. the car has 3/4 length 1 5/8 headers. what size exhaust to go with? 2 1/2 or 3" ? I'm going to put a set of 40 series Flowmasters on it with dumps. thanks guyz!

Marvin Robinson · 12-20-2009, 06:48 PM

I would recommend the 2-1/2" for a street/bracket car, your engine combo is fairly mild, and the larger pipes won't add any noticable power. The 2-1/2" might also have a little more low/mid range torque, but not enough to get excited about -- the smaller system will be substatially quieter on the street as well. Unless the ultimate 7-10 hp you MIGHT gain with the larger/louder/more expensive and harder to fit system is your goal, stick with the smaller stuff.

Marvin

greg fulk · 12-20-2009, 08:25 PM

Very mild combo! I hope it runs in the 13's. It ran 12.88 @ 104 in dad's 67 camaro with a 750 double pumper a 9" 4200 converter & 4.11 gears.

Robert Simpson · 12-21-2009, 07:45 AM

Greg,
Put the 2 1/2" on it you don't need the aggervation and expence of the 3". I have the same exhaust on my 70 nova with the dumps right at the rearend. It can get really loud and resinate real bad at certain RPM's. One other thing if you sit in traffic, which I do at times the exhaust will fill up under the car and it will start to come inside the car. If I did it again I would run the exhaust to the bumper or at least behind the tire. This is just what has happened to me. I drive my car more than I have a chance to race it. If you really want to test it out. When you get your exhaust finished, put a fitting for a pressure guage in fron of the muffler, make a run and at WOT look at the guage, if it is like 5psi or more you need a bigger exhaust.....Just a thought. I would like to see what that converter you have stalls at on the footbrake, when you get it running. Good Luck looks like a good combination.

Robert

rick winchester · 12-21-2009, 05:23 PM

Greg,call me. I have a nice used set of flow masters and complete exhaust on a 74 camaro that I am working on. The reducers are welded along with the mufflers and tailpipes. 513-733-3643 at home or 513-243 -1042 at work . Rick

greg fulk · 12-21-2009, 08:09 PM

will do Rick!

12-20-2009, 03:41 PM	#1
greg fulk VIP Member Join Date: Jan 2003 Location: jackson Posts: 1,165 Likes: 0 Liked 5 Times in 3 Posts	exhaust? getting ready to put the bracket/street engine in the Z-28. it is a 350 chevy flat top 487 head engine with a preformer cam & intake. right now it has a 600 holley but I'm going to put a Q-jet on it. it has a 350th with a 10" B&M holeshot converter with 3.42 gears. the car has 3/4 length 1 5/8 headers. what size exhaust to go with? 2 1/2 or 3" ? I'm going to put a set of 40 series Flowmasters on it with dumps. thanks guyz! __________________ Greg Fulk 308 308X P/SA "ALL AMERICAN"

12-20-2009, 06:48 PM	#2
Marvin Robinson Member Join Date: Jun 2005 Location: Gary, IN Posts: 139 Likes: 0 Liked 0 Times in 0 Posts	Re: exhaust? I would recommend the 2-1/2" for a street/bracket car, your engine combo is fairly mild, and the larger pipes won't add any noticable power. The 2-1/2" might also have a little more low/mid range torque, but not enough to get excited about -- the smaller system will be substatially quieter on the street as well. Unless the ultimate 7-10 hp you MIGHT gain with the larger/louder/more expensive and harder to fit system is your goal, stick with the smaller stuff. Marvin __________________ Marvin Robinson 3188 STK/SS

12-20-2009, 08:25 PM	#3
greg fulk VIP Member Join Date: Jan 2003 Location: jackson Posts: 1,165 Likes: 0 Liked 5 Times in 3 Posts	Re: exhaust? Very mild combo! I hope it runs in the 13's. It ran 12.88 @ 104 in dad's 67 camaro with a 750 double pumper a 9" 4200 converter & 4.11 gears. __________________ Greg Fulk 308 308X P/SA "ALL AMERICAN"

12-21-2009, 07:45 AM	#4
Robert Simpson Senior Member Join Date: Aug 2004 Location: Jacksonville, Florida Posts: 803 Likes: 6 Liked 20 Times in 12 Posts	Re: exhaust? Greg, Put the 2 1/2" on it you don't need the aggervation and expence of the 3". I have the same exhaust on my 70 nova with the dumps right at the rearend. It can get really loud and resinate real bad at certain RPM's. One other thing if you sit in traffic, which I do at times the exhaust will fill up under the car and it will start to come inside the car. If I did it again I would run the exhaust to the bumper or at least behind the tire. This is just what has happened to me. I drive my car more than I have a chance to race it. If you really want to test it out. When you get your exhaust finished, put a fitting for a pressure guage in fron of the muffler, make a run and at WOT look at the guage, if it is like 5psi or more you need a bigger exhaust.....Just a thought. I would like to see what that converter you have stalls at on the footbrake, when you get it running. Good Luck looks like a good combination. Robert

12-21-2009, 05:23 PM	#5
rick winchester Member Join Date: Mar 2003 Location: cincinnati ohio Posts: 205 Likes: 184 Liked 190 Times in 31 Posts	Re: exhaust? Greg,call me. I have a nice used set of flow masters and complete exhaust on a 74 camaro that I am working on. The reducers are welded along with the mufflers and tailpipes. 513-733-3643 at home or 513-243 -1042 at work . Rick

12-21-2009, 08:09 PM	#6
greg fulk VIP Member Join Date: Jan 2003 Location: jackson Posts: 1,165 Likes: 0 Liked 5 Times in 3 Posts	Re: exhaust? will do Rick! __________________ Greg Fulk 308 308X P/SA "ALL AMERICAN"