2.5 inch or 3 inch

-
No doubt! Post the build and it's known power leves if possible.
 
rumblefish360 said:
No doubt! Post the build and it's known power leves if possible.
Click to expand...
Well I Would Estimate HP At Around 500-550. Bored 30 Thou Trw Pistons Eddy ,Racer Brown Cam, 6 Pack Rods All Balanced, So On So On. It Is Street Only But You Know I'll Have To Hammer On It Some Too. Oh Yea 830 DP Holley With Annular Spray. Electric Fuel Pump With 3/8 Fuel Line, Any Thing Else You Need Too Know.
 
Is all depends in what you want, my friend, if you want to squeze the most of your combo, go for the 3" if noise and comfty is an issue go for the 2.5" IMO the easyer to expell the burnt gasses the best for your engine performance, i know some people will say back preassure flabla blabla hell no, race cars do it with open headers and do it better think about it!
 
demon1515 said:
i know some people will say back preassure flabla blabla hell no, race cars do it with open headers and do it better think about it!
Click to expand...

Back pressures for small engines that do not produce enough torque at lower rpms on the street.. So with a built 440, I'd say 3inch for performance, 2.5 for street manners, but who needs those? 8)
 
I'm running 2 1/2" with a small block, so I'd say go with 3" for your big block.

The only issue I can think of, is clearance between the gas tank corners and shocks, with the 3" pipe.
 
I feel 2.5" would be plenty for what you have and what you are using it for. I don't know what size you have now but if it's 2.5", I wouldn't change it.

If you NEED new exhaust go with whichever you want, but don't expect big gains from the extra money you spend for the 3" (you may see nothing at all from it).

Really….. The extra info you gave is still very vague.
 
www.spintech.com has some really cool exhaust tubing options. You can run oval tubing and have way more flow and still maintain your ground clearance and make it past the gas tank + the Spintech's sound killer!

pricey but.....
 
1968FormulaS340 said:
I feel 2.5" would be plenty for what you have and what you are using it for. I don't know what size you have now but if it's 2.5", I wouldn't change it.

If you NEED new exhaust go with whichever you want, but don't expect big gains from the extra money you spend for the 3" (you may see nothing at all from it).

Really….. The extra info you gave is still very vague.
Click to expand...

Thanks Guys. I Had 3 Inch On A Stock Build And It Was Peaked For Noise. I Had Glass Packs. This Build Will Make It So Loud That I Think I Will Need Mufflers. I Have A Good Set Of 2.5 ID And All I Will Need Is To Purchase Some Long 2.5 Inch Pipe And Make My Own Up, My Plan Is To Get It Out The Back. I Know The 3 Inch Will Be Tough To Get Past The Tank, I Did Some Searches And Came Up With Having To Go With A Fuel Cell, Not An Option To Get It Routed Past The Stock Tank. So I Was Just Wondering If 2.5 Would Still Work Without Taking Much From The Build. Again Thanks Guys. New Clutch Came In So Its Time To Put It In Then Finish The Exhaust Up Then Do Break In. What Info Would You Need. Just Don't Want To Get Pulled Over All The Time From The Police.
 
Moparwedden, a large high flow exhaust pipe does not mandate that it be loud. You can use big pipes, oval if required for clearance or trickness=P~, and make it as quiet or as loud as you like. I'm assuming that you have issues up there with sound level laws...you can use a quieter muff with the 3" or greater pipe and still have tons of flow. Best of both worlds.
 
anybody ever read this http://www.perfweldheaders.com/primary.html ? it is not about exhaust diameter, but about header dimensions? any thoughts? when I spoke with Mark a while back he told me that if I knew what size exhaust tubing I was going to use he would be able to build my headers around the exhaust system, so that they worked with each other. any thoughts?
 
Yeah, his stuff works but that level of exhaust is well beyond what I can afford to buy. I could use his ideas to help myself build my own.
 
mopar340dave said:
Yeah, his stuff works but that level of exhaust is well beyond what I can afford to buy. I could use his ideas to help myself build my own.
Click to expand...
can't help but wonder if it is worth it? Mark did tell me when we spoke that he is pricey. I had mentioned a different shop, and he told me that the other guys headers are an outstanding piece, but they will not be matched to the exhaust. at what point to you get to the point of diminishing returns?? you know, spending $100 instead of $10 for very little gain?
 
My bud built his own set for his SBC powered 71 Maverick running S/G. He raced it in some Quick races, too. Best of in the mid 7's on nitrous! His exhaust was worrkin! LOL
What you are really payin for with those guys is the quality and the lack of compromise on the headers construction.
They seem to knoe their stuff about the physics of exhaust flow...how much do ya gain with their stuff? I don't know...what do the record holders run? They specifically mentioned S and SS I think....
 
You must log in or register to reply here.
-

Back
Top