Dual Exhaust Question

[pontiacman469]

My Old Cutlass had 2 1/4 pipes with a H-Kit into Dynomax mufflers Spitting thru Monte SS Tailpipes I think i had $150 In it,Sounded Good Also.

 

[dan2286]

Is there any other mods i would havbe to other than all new pipes?

Open manifolds/headers. :lol:

 

[TBRtat2]

One thing you should check before you start, what manifolds do you have, some of the old oldsmobile manifolds had a stupid design, instead of using a y-pipe from the factory, the exhaust went from one manifold into the other manifol, then back out of the second manifold, then out to the rear.

If this is what you have, you will have to have one of the outlets would have to be blocked, if you dont want to remove the manifolds.

I had those stupid manifolds on my 403 to begin with, but now have a set of hedman headers

 

[megaladon6]

http://pypesexhaust.com/sys-mc.html
matter of fact our sponsor sells them. if you want LOUD i'd pobably go to the race pro's or the violaters. i have the street pro's and they sound really good, but aren't extremely loud.

 

[Blake442]

If i go 2.5 in on my stock 307 will the sound be noticebly louder than if i stuck with the 2.25? Is there any other mods i would havbe to other than all new pipes?

2.5 will not be have any noticible difference in sound over 2.25.
The only other modifications will be the addition of a few hangers for the new pipes.

You should get a set of headers if you haven't done so already. Flowmaster 40's are pretty loud, you might like them. Are you going to add anything like an H or X pipe? Are you planning on a motor swap anytime in the future? If you are, than 2.5" would be a good choice, as it leaves some room for improvement. 2.25" is fine if you plan on leaving it mostly stock, or at least not going wild with mods. 3" is too big for a 307, the lack of back pressure would probably cause you to lose power.

 

[pontiacman469]

Speaking of the crossover pipe...not like this right but a cheap way i cut mine on a 307 once and with a big hammer bent it over and flatten it tight...never leaked,not right but $0.. :lol:

 

[86CutlassUCF]

i think i may have that design by my manifolds. Would an 86 Cutlass Salon with a 307 have that? How is this going to affect me getting dual exhaust? I rather not get headers unless I HAVE to.

I am going to keep the 307, so no plans on engine swap anytime soon.

Anyone know how loud the aerochambers might be?

 

[TBRtat2]

If you them, and dont want headers, I would say hit the bone yards and find the manifolds that use a normal y-pipe, and get the one side. Older manifolds did not have the built in cross over.

Or block the one pipe like pontiacman469, and loads of other ppl

Or are you just wanting dual tips, not true duals

Depending on your motor, you will get a power gain by replacing the one manifold, cause the design is very restrictive, but then again most stock manifolds are.

I know my motor loved getting rid of those manifolds, but mine is a 40 over 403, and man does it move some air.

 

[86CutlassUCF]

so i think im going to save a little longer and go with the flowtech headers, and 2 aerochambers coming down before the rear axle. the 307 is pretty stock but im looking more for loud while sounding very good, than power. should i go up to the 2.5" or stick with 2.25"? maybe add an h-pipe or x pipe?

 

[TBRtat2]

Dont forget a heat shield for the starter, and watch the oil filter.

On my olds 403, the headers go right under the stock oil filter, less then an inch from the bottom of the filter, so changing your oil becomes a b*tch.
I spent the $50.00 and got a remote oil filter kit for it, my filter now lays on it side mounted to the frame rail but make sure it doesnt hang down below your frame, thats one thing you dont want to bottom out or git hit by a jack.
without the remote oil filter, i would have to unbolt the right header to change the filter, and would more then likely end up with oil on the header.
Plus the kit i bought uses a bigger filter then the stock.