dual 3 inch exhaust?

I'm looking at building a new exhaust from the headers down since my car seems a bit choked by the non mandrel bent 2 inch stuff going into a single 3. I have access to pretty cheap mandrel 3 inch, actually a buddy gave me 3 90's yesterday for free, so i'm thinking of redoing my exhaust. Question is, will i be able to fit a true dual 3inch setup under the torque tube? If not, do ya'll think oval tubing side by side will fit? I don't want to throw away my current piping, because it's worked very well so far, i'd just like to add to it...sorry if that seems stupid, but i'm doing this on a pretty tight budget, but i think the car will really appreciate a bigger exhaust coupled with some bigger tubing on the intake side (maybe help with my rich condition?)

thanks guys!

Take a look at Tony G's dual exhaust setup on the old board, it's impressive. The mufflers are mounted upright side by side, it all fit.

Well, I went to take a look, and his gallery is gone, the links is his post that show the pics are invalid, but anyway, it can be done.

awesome! that's what i wanted to hear, i knew that dual 2.5's would fit, since i've seen that done, but i wasn't sure if anyone had done dual 3's. I remember now seeing tony's setup with the upright mufflers, that was pretty sweet.

thanks for the help!

edit!!!

found pictures on his website [You must be registered and logged in to see this link.]

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Gentlemen,
I believe that TonyG's exhaust is 2 1/2" not 3". Tony did a great job building a true dual exhaust.
Max

interesting...looking at the picture there is room on under there for a little bit larger of a system so i guess i'll have to just give it a try huh?

do you guys think it would be necessary and/or beneficial to run an x-pipe or h-pipe with this setup? i'd like to run one but i don't know why exactly it is necessary and i don't know if i'll be able to build one effectively or if i will have to shell out big bucks for a real tight x with 3 inch tubing all around

Though dual 3" back would be cool, it would be over kill. IIRC dual 2-1/2" systems are usually good for 450Hp and dual 3" systems are good to 600hp....
An X-pipe, when put in the right place, will usually improve power a little. Also, the dB level will go down and the exhaust note will become smoother.
Either way I would like to see pictures of your build.

BTW, how much HP/Lb-ft are you making?

Also, PM sent

I love the way my X pipe makes my dual exhaust sound.

overkill is perfectly okay in my book...if i go bigger now, as i upgrade the engine i won't have to upgrade the exhaust and intake, they'll be ready to handle the big numbers if i stroke it or blow it (or both...hehe)

for power and torque numbers, i have no idea right now...i've never had it dynoed. Hopefully i can get it on the rollers this weekend to get some estimates, but i may end up spending the weekend building this new exhaust...we'll see!

Definitely put an X pipe in there, it will increase low-end torque and give the exhaust a more mellow tone.

I have no idea what 2.5" exhaust is good for hp-wise, but it must be at least 600hp. Dual 3" is way overkill. Considering u-bends are about $15-20 each on ebay, if i were going to spend the time, i would just buy 2.5" u-bends.

Even 2.5" dual is overkill, but it's reasonable overkill. 3" duals are for mountain motors.

point taken...I'm going to go with 3 inch for now since i can reuse the flowmaster i have on there. This way i can have the same sized exhaust from the header to the tailpipe, definitely way overkill for the disp. i'm running, but that may change, so i don't really see dual 3's being a problem...it'll be good to at least get mandrel bends in where i had cut bends before...

i'll update as i build. I got a good deal on a bunch of 3 inch mandrel bent pipe, a buddy gave me some and i found a local custom exhaust place that had a great deal on a 3" builders kit.

been working hard the last couple days...got some good work done, take a look!

took my patriot tight tucks, cut off the 2.5 inch collectors and welded further up on the collector where it was closer to 3 inches.

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Coming along well....

thanks a bunch! made some good progress today, no new pics though, they'll be up tomorrow hopefully. I need to pick up some vbands once i get some money back in the bank, for now everything's going to be welded up solid

it's done!!! muhuhahahahaha!



what do ya'll think?

btw, any ideas on the smoke coming out the tailpipe? is that just from not having cats installed yet, or am i running WAY rich?

btw, any ideas on the smoke coming out the tailpipe? is that just from not having cats installed yet, or am i running WAY rich?

Nope. Blue = Oil
That there, Im sorry to say, means your valve train needs attention. Most likely valve guides are shot.

You may want to do a compression test on all eight to see if its a bit of blow-by, but 98% of the time, its the valves.

eh...i'm not too surprised, i've never gotten blue smoke before building this exhaust, which is intriguing. Would an oil change to a thicker oil help at all? at least as a temporary thing until i get a chance to buy new valve guides and pull the heads to change them?

Yeah, it doesnt look too bad yet.....not like Uncle Bucks.

Just wait for winter and get at it.

can i ask what the point of the duals? i mean yea duals are nice but not big, your are hurting your performance more than anything.

preparing for future modifications more than anything...the old exhaust was total trash, so i built the best i could right now, instead of having to rebuild it anytime i do anything to the engine

Sounds good, just like my father in-laws 64 Nova.

I agree with Michael on the blue smoke; it gets thicker when you let off...typical sign of oil getting past the valve guide seals. Thicker oil may make a small diff...

xschop suggested it may be the way old gas in the tank that's creating some smoke, i can always dream right? we'll see what happens with some good gas and some octane additive and fuel system cleaner

I agree with Michael on the blue smoke; it gets thicker when you let off...typical sign of oil getting past the valve guide seals. Thicker oil may make a small diff...

Our 1960 Studebaker (yes im in south bend too) smokes like a SOB just like that and for that reason.

xschop suggested it may be the way old gas in the tank that's creating some smoke, i can always dream right? we'll see what happens with some good gas and some octane additive and fuel system cleaner

Interesting. How old is the gas? The reason why I lean towards valve related is because thats the most common cause for oil getting into the combustion chamber and I noticed you have modified the valve train with those 1.6 RR's. Basically, I wonder if you changed out the springs and if not, maybe one collapsed or got bound up causing valve stem, guide or seal damage???

.....Best to do a compression test right off the bat and see anything jumps out at ya.

huh, well do you think that would cause a miss at wide open throttle? that's what's making me think it's not necessarily oil leaking past yet, because it bogs and blows smoke if i punch it, but if i rev it slowly it doesn't seem to blow much at all out the tailpipe

I see what you mean. Hmm....

Is it possible, and no offense-Ive done it before, that you may have added some gasoline from a can just sitting around that may have had a oil mix in it; like lawn-mower gas? This would cause it.

Its very possible to have missing at WOT with a bad intake valve. Valve train tolerances are finicky! For example, back when engines had to have certain valve lash set (i.e. 0.012" for 60's austin healey and 0.0025" Studebaker just as an for instance), if they were too tight/loose, they would spit and sh** all over the pavement. And trying to tune an engine with valve out-of-adjustment is just impossible. You'd have backfire and afterfire...all sorts of bad stuff.

Regardless, its pretty easy to check if its the gas, valve train or internal or otherwise. Good Luck nonetheless!

well, i know for a fact that i took i think 1/4 turn out of all of the rockers, because i thought i had them too tight...there were other problems that had me believing i had screwed up installing the rockers, so i loosened them just a bit...do you think that could do it? I'll try turning them in 1/8th turn each to see if it changes anything.