2" exhaust big enough?

[jamesf7278]

got quoted 800 bucks at every shop in town to do my exhaust..... not gonna happen lol, I have a bender but does a max of 2", works very well. was going to bend my own dual 2" and was wondering if it is enough for a stock 71 302? probably run a glass pack style muffler (cherry bomb or magnaflow straight)

 

[broncodriver99]

I am running a 2" 2 into 1 setup with a 2.25" tail pipe and it is more than enough.

2" for duals would leave plenty of headroom.

 

[bronconut73]

2" with mandrel bends would probably flow as well as 2.25" with typical crimped bends....

Gosh $800 seems high. Here in La Florida it would run about $400 on the high end and $250 on the low end.....unless you are talking about headers too....that could get real expensive since header prices are of course all over the place, cheap to pricey...

 

[mudstud]

Did a quick search and came up with this. I cannot speak for the accuracy but here it is. http://forums.hotrod.com/popular-hot-rodding/70/9544513/popular-hot-rodding-technical-articles/how-to-calculate-muffler-size-and-exhaust-pipe-dia/

 

[jamesf7278]

800 for dual 2.25 with generic shit mufflers, manifolds back. 700 for single 2.25.
I tried to explain that these things are super easy for exhaust and he just said yep 800 lol. contacted heartthrob exhaust and could get it shipped just below the border a few hours away but still over 400, I could build my own for under 150 I bet... Canada not so good for some things.

 

[blubuckaroo]

It's been a long time, but If memory serves me, my '77 had 1-7/8" head pipes and 2" front/tail pipes.
You're more than doubling the square inches of capacity from stock. I can't see a problem.
Also, the tone is a nice crackle rather than a rumble /drone when you keep duals smaller.
My favorite dual muffler always has been the inexpensive Corvair Turbo muffler. They have a raspy "all business" sound.

 

[bronconut73]

800 for dual 2.25 with generic shit mufflers, manifolds back. 700 for single 2.25.
I tried to explain that these things are super easy for exhaust and he just said yep 800 lol. contacted heartthrob exhaust and could get it shipped just below the border a few hours away but still over 400, I could build my own for under 150 I bet... Canada not so good for some things.

Well Canada is still plenty good and an excellent neighbor.

What about one of Duffs dual exhaust kits.?
They fit really well.
You have a choice of Turbo glass pack, Flowmaster 40, or Cherry Bomb Vortex.
My vote would be the Vortex muffler. Good sound, no dreaded drone.
I have been running a Duff dual exhaust kit and headers since '91.....yup since '91....
Only recently have I thought about getting something different but I don't really "need" too.
Back when I got mine you only had the glass pack muffler choice....maybe I will just swap those out with Duffs Vortex mufflers.....hmmmm....
Anyway.....
Just some more "exhaust food" for thought...lol

 

[g8rb8t]

Love my BCB 2 in 1 and Cherry Bomb Vortex. Nice rumble and no drone....

 

[sykanr0ng]

You might save money by sticking a pair of earplugs in and driving down to the US to an exhaust shop there.

 

[cldonley]

Syk is right-a Bronco brother from central Washington might be able to hook you up with a good shop! But I agree with the others, if you can bend 2 inch yourself, you'll give that 302 plenty of breathing room. I was in Sechelt BC in November buying an airplane. What a gorgeous place Canada is! I guess I could put up with high exhaust prices for that kind of beauty. And four seasons.

 

[B-man]

I got this same question. Going back and forth with a friend of mine who thinks we should go 2.5" on the Rig.. It's a 302, mildy built, nothing crazy.. Hell, I had 2.5" on my 88 351w. LOL..

I was thinking 2.25" or 2"...

 

[pcf_mark]

If you like clamps and / or can weld this works good

http://www.ebay.com/itm/New-Speedwa...end-/261870467693?hash=item3cf8b23a6d&vxp=mtr

If you shop around you can get a box 4 90s, 4 45s, 2 straight 36" pieces. Then add two Summit mufflers and get welding.

 

[Broncobowsher]

I have built several exhaust systems with a welder and a box of bends. Manderal bends no less. A few more splices, but totally functional.

I got a GOOD exhaust stretcher off the snap on truck years ago. This thing has a wheel bearing in it and is stated to be used with impact tools. Not the cheap parts store version that won't remove a U-clamp dimple. I have used this to stretch pipe to make slip fit connections as well.

As for your 2" bender, a real tube bender or a pipe bender?

 

[nvrstuk]

PM me as I'm in Central WA and our local guy here has done several EB systems all custom with us helping/getting in the way! : )

BTW, you don't need anything over 2" for those cubes, especially if it's mandrel.

 

[roostracing]

Sorry but 2 inch is tiny. No less than 2.5. The more airflow coming out the better. Their has been plenty of testing in the racing world. I know we aren't racing but flow is flow.

If you are worried about bending bigger pipe, have you thought about ordering mandrel bends, elbows, straights, from an Internet site that sells pipe? I did with my 95 lightning. ..spent maybe $100 for what I needed...3 inch pipe too on my 351w... Then just weld it up with a mig.

 

[suthernboy]

RE: "The more airflow coming out the better."

Thanks for the insight and credible advise. Just cinched my decision to run zoomies up thru the hood.

Hey Don, if you ain't got one, you can borrow my 4" hole saw!

 

[roostracing]

RE: "The more airflow coming out the better."

Thanks for the insight and credible advise. Just cinched my decision to run zoomies up thru the hood.

Ok...we are talking street bronco aren't we? 2.5 will out flow 2 inch and will be perfect for what is stated..." a mildly modified 302"

So my advice cannot be credible? If you think running zoomies out of ur hood is giving credible advise then wow.

For those that enjoy a good read on myths of "exhaust being too big"

http://sbftech.com/index.php/topic,19160.0.html

 

[nvrstuk]

There's thousands of articles on exhaust pipe sizing... for s t r e e t use. Consistent high rpm? different story...to a limit.

Generally stated, bigger is better to a point because you lose torque (loss of scavenging) and gain tremendous noise levels when over sizing. I'd be willing to bump up to 2 1/4" but no larger. You're talking small cubes, small HP #'s and low rpm for 2 1/4" pipe.

 

[sykanr0ng]

Too large exhaust tubing causes the gases to cool and become stagnant, increasing restriction of flow and reducing scavenging = lost power.

The right size keeps the velocity up and increases power.

 

[blubuckaroo]

If you're considering a motor in the future that is modified or bigger than stock, you might consider a 2.5" exhaust, but even a 2" will flow quite a bit. If you want to get more out of it, you can always put in an "H" pipe.

When building a vehicle, you're always better off starting with a planned "end in mind" rather than leave the results to evolution.
A lot of owners here seem to think that by adding a single piece of performance equipment to the car, you might gain something. Rarely is that the case, and so lot of $$$ is wasted on ignition, carbs, and exhaust when the gearing, compression and cam are left out of the puzzle.?:?
I think the stock exhaust would be an exception to this though. It was pretty restrictive and just the addition of duals helps a lot.