i'm trying to decide on what inch exhaust to run on my car. what i have on it now are 1-5/8 primary headers going into a 3'' collector. should i keep it 3'' all the way out or neck it down to 2-1/2? it seems alot of people are still running 2-1/2 even on the more radical cars so i dont know if 3 is a little much. it wont have cats and it'll exit in front of the rear wheels.
its a 347 with about 10.5:1 and canfeild heads and a CI cam.
thanks
I'd stay 3" to keep good flow. with my setup I went with the 3" to 2.5" reducer since its pretty much a stock HO.
If you want to make power: 3". I'm pretty sure you've been on sbftech.com and seen the myths and rumors section. It's been beaten to death over there.
If you want quieter: 2 1/2".
I have 3" on my 347 and 2 1/2 on the S/C 306. The 347 sets off car alarms (but there are no tail pipes on it).
Stay with the 2.5 inch, it's big enough for any small block. Also you can get good buys on Mustang syetems already set up nicely to this size.
TED
ive heard 88turbo's car ,,i like his set up sounds mean
i'm not worried about buying a kit. the shop i work at makes custom exhausts. plus it'll dump out the sides, not really kits for that. just didn't know if 3 was too much. also, im trying to decide between a magnaflow round ler or a borla xr1. im mostly conserned about how good it sounds not really sound level. any expiriences?
How good it sounds depends on each engine and the cam used, it's very hard to say. What "sound" are you looking for? I had an engine with a big cam and it was loud and mean sounding. Then I went to a stock engine for a while and the exact same exhaust was very mild sounding. Now I'm back to a mean engine and a mean exhaust.
When he puts side dumps on your car can you post a picture to see how he does it and how it is bent? I currently have dumps at the front of the axle and cannot seem to figure out how to bend the pipes to be side dumps, flow clean, and miss everything to give good ground clearance. I think you can get lers that inter and exit in the same end and may this is what they will use?
Will your local shop put on an exhaust for you without cats? This is the main reason I went to the kit. Also the kit has mandrel bends that most local shops cannot do. A 2.5 inch mandrel bend system is equal to a 3 inch crunch bent system in my mind. You can buy the kits from Summit or Jegs and do the work yourself and save a good bit of money.
Recently I ran a 11.4 quarter with 2.5 exhaust. Would it have been faster with a 3? Who knows.
Good luck and have fun.
TED
Ask jay allen. What intake are you running? He was going to run a 347 with 3.5" ovular exhaust. I know which one will be faster from what I read.
yeah i know it will differ from engine to engine, but a rough idea would be nice. if every had replied with 'i never heard a car with borla sound nice' then i would not buy the borla or vice versa.and yeah i can take some pics when its done.
and its a trickflow track heat
I think you would be killing it with the 1 5/8" primaries. You should probably go with 1 3/4 or bigger. If your not going to upgrade headers, I doubt there would be any point in going with bigger then 2.5". I really think you should step it up a notch or two. What did you put on your build sheet?
what do you mean by that?
yeah, i know 1-3/4 would be better, but when i saw they were hella expensive compared to 1-5/8, these seemed good. and i had a hard enough time getting these to squeeze in there, i cant imagine what it would be like if they were bigger.
I was just saying, you have really good heads with really good intake, and then your gonna put restrictive exhaust on it. I'm not trying to come acrossed in a mean way, but if I had that much money into a setup, I would try really hard to get the most out of it I could. But times are tough right now, and sometimes you have to use what you have. Just remember though, you don't have forced induction, and your engine is quite a bit bigger then a 302. It is going to need more air, both in and out, then a 302.
yeah i realize that. but these where cheaper and easier to put on. if i find myself unsatisfied with these or end up saving some money i can always get bigger and change them out. i went all out on the motor cause thats what counts most to me. its tough to change the headers on this, but not as bad as a cam. and its kinda too late now, it'd be just as tough for me to change it now as it would be in a year or two. so i can wait
Fair enough. So you about ready to get it running? You going to be able to hit a track?
it runs. sounds real mean. its a little on the rich side. hopefully the exhaust will help some cause i've heard running open headers can change the way they run since there is absolutly no backpressure. when its in the shop i'll pull some koer codes. i did a koeo test and all i got was a 95 secondary fuel pump wire, but thats supposedly not going to affect the way it runs. but yeah, sounds real mean
you could always wire in cutouts after the headers. According to almost everyone on SBFtech, the only problem with low end and back pressure is the changed A/F ratio.
well, im not sure if its entirely because its open headers or theres another problem(need to wait for KOER test) but the A/F ratio is off. but wont be for a couple days but i'll let you all know what ends up happening.
Please do update. When I get back on my feet, I'm planning on getting a CI cam, so I would really like some un-biased info.
You don't have a leak before the oxygen sensors do you? That would screw with the A/F ratio.
it turned out that the connector at the maf sensor was never crimped or soldered from the manufacterer. i bought it from granetteli, dont think i'll buy another from them cause thats just down right stupid. but she's running good now, have about 100 miles on it so far.
heres some pics of the side exhaust cause you all wanted to know how they were routed. not the best angles, but i had no lift. should be good enough you get the idea.
(http://i43.photobucket.com/albums/e359/grutinator/HPIM6361.jpg)
(http://i43.photobucket.com/albums/e359/grutinator/HPIM6362.jpg)
(http://i43.photobucket.com/albums/e359/grutinator/HPIM6363.jpg)
(http://i43.photobucket.com/albums/e359/grutinator/HPIM6364.jpg)
(http://i43.photobucket.com/albums/e359/grutinator/HPIM6377.jpg)
You know magnaflow has a dual in/dual out ler right? Like a led x-pipe.
just a few more pics pics. of the car itself.
and yeah i know. i wanted these :D
(http://i43.photobucket.com/albums/e359/grutinator/HPIM6373.jpg)
(http://i43.photobucket.com/albums/e359/grutinator/HPIM6374.jpg)
(http://i43.photobucket.com/albums/e359/grutinator/HPIM6389.jpg)
(http://i43.photobucket.com/albums/e359/grutinator/HPIM6383-1.jpg)
(http://i43.photobucket.com/albums/e359/grutinator/HPIM6384-1.jpg)
got some hood clearance problems?
Do you have a three foot intake on that thing? ;)
The side exits look familiar.....Had the same look until I redid mine a couple of years back. ;)
yeah. the side exhaust is so bad ass. they really turned out well. i love it.
and nope. its all stock. i only raised the hood up to make people
think its fast.
(http://i43.photobucket.com/albums/e359/grutinator/HPIM6350.jpg)
i had to raise the rear 3'' to clear. i think it looks pretty cool this way too :evilgrin:
What intake are you running on that 347? A Typhoon? I hear those make maaadddd power with an E cam. :rollin:
One day I WILL make a lamp out of an E-cam for my desk table....