Im gonna do an exhaust upgrade on my 95 Bronco 302..
I wondered what you all have used and whats the best?
I may add headers but im not sure...
Give me your thoughts..

Thanks

 

I'd recommend sticking with the stock exhaust; it's made with good materials, and has as low a backpressure as your 302 needs. It will also keep the inside of your truck Bronco from sounding as if you're riding around in a Freightliner, which is important if you ever listen to music in it!
Of course, if your objective is to simply make lots of noise, you can always spend hundreds of dollars on an aftermarket exhaust, and then if you try really really hard, you can convince yourself you've improved your performance.

 

Something to think about. I was thinking of upgrading mine too(my wife makes fun of the way it sounds now), but would like to see some numbers showing the difference in HP and MPG.

GearJammer
'92 Bronco, 302 w/5spd
'97 F350, 460 w/AOD (Tow Truck)

 

If you can wait a couple of weeks, I'll hopefully be able to give you some (whether good or bad). I've got an '85 with the 302 EFI. With the exception of a 2.25" single in and out Flowmaster 3-chamber muffler used to replace the stock can three years ago, the truck and it's exhaust are bone stock mechanically. It's in good tune, with all new sensors, and the 302 is in great condition. With the age and 140K miles on the cat, I've made the decision to upgrade and replace the existing system, though I WILL be keeping what I have legal from an emissions standpoint, regardless of whether I'm ever checked. I've purchased a Bassani high-flow Y-pipe and cat setup (2.5" mandrel bent pipes off of the manifolds or headers, which feed into a 3" single, running through a 3" high-flow cat.) and will be running the 3" intermediate pipe into a single in, dual 2.5" out performance muffler (likely another Flowmaster). This will be installed in about a week...... HP numbers will be strictly seat of the pants (I don't have a dyno :-( ), but I have determined that my present MPG is 11.5 city / 14.5 hwy.) I'll be able to run a comparison after the installation. I won't be embarrassed to tell you if I'm disappointed..... I need a new exhaust, anyway, and the Bassani pipes are quality (stainless steel). Maybe this will help with your decision, especially if the results are favorable. I'll let you know.

 

I have an 86 302EFI that i just overhauled. I put a K&N filter and replaced the cat on back with a 3" single cat pipes and high flow muffler (Dynamax, I think). I left the manifold and manifold pipes original. The pipes coming out of the manifold to the cat are stainless steel stock and are still in good condition. That combination probably gives a 3% increase in HP. :-) It makes a big difference on the highway and pulling a boat.

Steve

 

Back pressure??? Come on guys, this is a 5.0 bronco not a v-tec honda. i recently got headers, 2.5 inch pipes, no cats, and 2 40 series flowmasters. The truck idles and accelerates much better than previous, and i did notice a horsepower gain in the UPPER rpm's. While i'm sure there may not be a whole lot of back pressure, this is fine for this kind of dual exhaust application. the only time when you would have to worry about the lack of backpressure burning up the valves is if u run straight headers or something like that at idle for a long time. Go for it, and make it loud. Mine sounds like a freight train and i love it.

kyle

 

Headers are the way to go. I replaced the exhaust a few months ago and it made virtually no difference. I bought headers and everything about the engine has improved. Smoother, better gas mileage, and yes, much more responsive. i did notice a increase in the upper RPM range also.

 

I'll stick with my original recommendation - go with the original equipment unless you've got a heavily "built" engine. It'll sound better, last longer, won't wake your neighbors when you leave for work. Advertising hype notwithstanding, there isn't any exhaust system that will gain you more than a couple horsepower, nor any fuel economy improvement at all. If you want horsepower, modify the engine: intake, cam, etc.
If anyone's got good dyno numbers (same dyno, same day), I'll listen, but here's MY qualifications:
Owner: '78 Bronco, 400, Holley-4V, with 200k miles; have run every conceivable exhaust configuration: OEM single, true duals, dual-in/single-muffler, single-in/dual-tailpipe, etc.
Engineer: As a Ford engineer from '74 to '89, I developed almost all the Bronco systems from the '79 model through the '90 models, as well as the first Explorer, the 6.9/7.3 Diesels, and the Holley-equipped 460 F-series and E-series.
I *think* I know what I'm talking about. Or, I might be a maroon baboon. :-)

 

allright, i do admit u have probably forgotten more than i will ever know, but i didnt spend a ton of money, and i'm happy with it. isn't that the most important part? plus i kind of like wakin up the neighbors. i got headers $99 and mufflers $120. 200 installed and thats it. i know its a lot of money, and i agree the horsepower wasnt that significant. i noticed it mostly in the upper rpm's, but i disagree on gas mileage. i know for a fact that my mileage increased at least 25 miles to the tank, and probably more. this may have been due to the plugged up cats, but gas mileage is gas mileage. While i dont mean to disrespect your years of engineering, i feel that the money i spent was well worth it. while i'm only 17 and full of myself, i know that i dont have the money to put in a new cam, do intake beyond k&n, or any other major modifications yet. i'm happy to have the garbage, rusted, quiet exhaust out and the new aluminized loud exhaust in.

kyle

 

how did it come out?

 

what kind of headers??what about O2 sensor?do you still use it??

 

Are you the same guy that engineered that fine oil pan that rots from the inside out that can only be changed by having to raise the engine?

 

Not trying to contradict you, I am not an engineer but I do manage a survey/engineer office and I ran the #s through Hazen-Williams and Darcy-Weisburg programs. With a 400 (which I am considering), you would need a 4.25" pipe on each side to produce 1' of headloss (back pressure). I realize that you will develop more than that in the muffler alone, but what the hell. The only reason I did this was to see if it was viable to run 3" over 2.5". There would be an increase of at least $100 for the different pipe/muffler. I have a '78 bronco with absolutly NO emission control (someone before me stripped it). I have exhaust leaks at the manifold/wye and this damned thing doesn't have a donut. I would spend as much for a new wye as a pair of headers (the cheap ones $100± at JC Whitney) so I don't see a reason to stay with the stock pipes. I did check on a dyno program and according to it, headers alone on my 351M would make a 25hp increase. There again, I don't know who sponsored the program and it might be a bit biased. If someone can tell me a reason not to go with the headers, PLEASE do. I am fairly new to rebuilds and hate to find out through trial and error.

 

[updated:LAST EDITED ON 05-Mar-02 AT 06:48 PM (EST)]>allright, i do admit u have probably forgotten more than i
>will ever know, but i didnt spend a ton of money, and i'm
>happy with it. isn't that the most important part? plus i
>kind of like wakin up the neighbors. i got headers $99 and
>mufflers $120. 200 installed and thats it. i know its a
>lot of money, and i agree the horsepower wasnt that
>significant. i noticed it mostly in the upper rpm's, but i
>disagree on gas mileage. i know for a fact that my mileage
>increased at least 25 miles to the tank, and probably more.
>this may have been due to the plugged up cats, but gas
>mileage is gas mileage. While i dont mean to disrespect
>your years of engineering, i feel that the money i spent was
>well worth it. while i'm only 17 and full of myself, i know
>that i dont have the money to put in a new cam, do intake
>beyond k&n, or any other major modifications yet. i'm happy
>to have the garbage, rusted, quiet exhaust out and the new
>aluminized loud exhaust in.
>
>kyle

Kyle, where did you get your exhaust system from? I have an 87 302. My manifolds are cracked and the rest is rusted out. 200k on the cats too, don't care to buy new ones. No emissions here so I want headers, offroad pipe(s) (y-pipe or x doesn't matter), and cat-back exhaust system with duals out the back. I need a bolt on system. Some have said go to an exhaust shop and have them fab up an offroad pipe to the headers. I can't find anyone to do it but we have no emissions laws here either. They can't by law take them off for offroads but if I can halfway get them on I can 'limp' there and they will do the rest.

Let me know what you bought and if the install $$ required custom bending or anything else. Thanks.

 

From what I've been told, buying the cheaper headers with thinner flanges will result in the leaking and possibly warping over time. That's all I know about negative sides to headers. I have JBA shorty headers, 10,000 miles so far with no problems.