Ok, true duals, true duals...you all know my opinion...Bassani products all the way! but enough of that, not here to be a commercial (I know a first for me). Consider for just a moment the idea that running duals does NOT mean you have to choose TWO routes for the pipes to run. Bassani's 3" stainless SINGLE setup follows the OEM route from the headers all the way to the tip of the tailpipe! Its nearly TWICE the diameter of the OEM exhaust and there is STILL plenty of room around the 3" bassani pipe. One could very easily run BOTH pipes along the same route! Twin 2.5" tips (well the tip has "gotta" be bigger around than the actual pipe right?) in the stock exit location would look sharp . I mean the E-series 3/4 and 1 ton vans had a setup very similar to this. The cat actually split the exhaust into two pipes so it wasn't true duals but there were still two pipes running along the same route aft of the cat. What if the Bassani Y-pipe didn't "Y"? What if instead, the two pipes came down from the headers with an H-pipe where the O2 sensor needs to be and then contintued on to cats and mufflers that were staggered enough to leave the pipes fairly close to each other. Then the pipes come back together side by side and stay that way until the exit behind the passenger side rear wheel.

Its an idea (in spite of the fact that I don't see a need for it when things like Bassani's 3" SINGLE setup work so well and sound so good) that might be worth a look see. Or I could just be inhaling too many exhaust fumes.

 

Let me go over the data presented here, if I may.

1. Bassani produces a nifty stainless steel Y-pipe that's well and truly flowed from 2.25 in. or 2.5 in. down pipes into a single 3 in. pipe.

2. Bassani may or may not produce a three inch muffler system compatible with the above?

3. A mandrel swaged, full three inch exhaust would fit much better than any kluged up 2-2.5 inch full dual system one would be likely to install?

4. And last, has anyone tried the Gibson system on their Bronco? This is a three inch (maybe, I'm writing them this week to verify) mandrel bent cat or sans cat system that dumps near to the factory location. As a side note; I installed their system on my ex-2002 S-10 ZR2 Blazer and it was just about the best made system I've had the pleasure to work with. See My Blazer exhaust photo album to see a comparison betwen the nearly new factory system and the Gibson system. Keep in mind that the 4.3 Blazer system is a 2.5 inch system, not 3 inch.

 

I was thinking about the c02 leak you all were talking about. I spent all of last winter driving with the windows down, pouring rain and freezing my A off. And don't think you'll be turning on the heater, It pulls the exhaust right on in and traps it. Having the improper setup can really suck big time. Now I realize that I tore up my pipes underneath (dislodged after the cat. converter) and I had brittle broken exhaust manifolds... but wow, was the smell terrible. Now one year later, I welded it back together myself and my cousin replaced the broke manifolds (lotsa cussing and scrapped knuckles); it still gets exhaust into the vehicle when I'm at a light with the rear window down. I think the way, and where the single pipe exits could be improved. I doubt very much that dual exhaust would help the problem.
Also during the time when for the most part I had zero pipe hooked up, it really seemed to breath and perform better. Seriously. On the freeway it downshifted easier and any loss of power... well, heck I never saw any. In a way now that I'm all legal again, it seems sluggish frankly.

 

True. It is available with our without a catalytic converter and can be ordered to fit 96 models with OBD-II that requires holes for two additional O2 sensors. It will also bolt directly to the OEM manifolds with no modifications OR their own shortie equal-length headers.
They make a complete system that is 3" all the way to the tailpipe including muffler. The entire system is stainless and runs the exact route under the truck that the OEM exhaust runs. Heck it even re-uses the stock hangers.
For the time and expense of having a custom true dual system built, the Bassani equipment is top of the line and a better investment. Truck engines NEED that extra back pressure that duals would relieve to develope their torque down low in the rpm range. This is important since you are trying to move something that outweighs most CARS by a good bit.
As I recall there are one or two here that are running the Bassani Y-pipe with a Gibson cat-back system behind it.

 

More along the line of your question, if pipe a few inches back of truck.
I don't know how your truck really looks, so I can't say for sure on that, but I know I'll be running duals exiting behind the rear wheels.
I'm currently running duals on my 77 F-100 straight back, with 2.25" pipeing, and I think it looks, sounds, and performs great.
I'll be putting the same set up on my 79 Bronco just exiting behind rear wheels.

 

[QUOTE=ArMAgeDDoN_PoB]Actually, even with my duals now, I still have plenty of low-end. I'm only running 2 inch pipe on each side. It's got plenty of power. I also like the way true duals with 2 inch pipe sound. I've had true duals with 2.25inch, and 2.5inch pipes, and I've also had a single 3inch system on my Bronco (which came on it when I got it, the guy I got it off of had the single 3inch pipe with no cats and a dynomax bullet on it), and I absolutely hated the sound and wasn't really impressed with the power it had with any of those setups.
And now you may say it was the crappy job done by whoever installed the 3 inch that caused the lack of power, the guy that had it before me had access to a mandrel bend machine, and used it to make the exhaust. And I know the guy, and he's been working on vehicles for 20+ years, and knows his stuff.

well 2 inch is good and thats why you had a good amount of low end. but if you buddy has 20+ yrs of experience you would think his setup would be correct short of that dynomax which is not the right muffler for the sound you were looking for. and probably flow to well is why it lacked or there could be other things here contributing to that as well.

any 1 hiflow cat can replace 2 stock oem cats

everyone one that i have talked to that ever ran duals out the rear either turned or strait complained about the exhaust coming in.

 

Well dont get me wrong, with the 3 inch did have a fair amount of power, but in my opinion, the setup I have now, has alittle more. It doesn't really make much sense to me either. I also figured the single 3 inch would run better than the setup with true duals & 2 inch pipe that I have now, but it doesn't seem that way. And really, I've never been a fan of single exhaust, even with a larger pipe. The only single exhaust setup I've ever liked was on my friends 83 Chevy (yes, I know, EVIL!), but it had a cammed 454 running no mufflers on 5 inch pipe done by the local truck shop. That damn thing sounded mean.

I talked to a guy that works at a local garage where I was getting new tires put on my 97 F150 today, and he said that between the 3 Broncos (1979, 1980, and 1989) he's had and the one his sister had (1993) that they all had the exhaust out the back on them, and none of them had a problem with the exhaust coming back in the cab (except as can be expected, with the rear window down), so I figured I'd give it a shot. I ran my idea by him and he said that it should work. I figure the worst that would happen is that I would have to take the Sawzall and cut it off and have to 90 it behind each wheel if it does (which I've already got the parts for, as I kept the 90 degree bends from when I had it done before because I'm a packrat and don't get rid of anything).

I'm gonna get the exhaust installed on the 12th of next month, and then I'll drive it for a week or two and I'll let you know how it turned out, and I'll also upload some pics to let you know how the setup looks. Thanks for all the replies and suggestions guys, but by nature I'm very stubborn and I atleast want to give it a shot. Once I get an idea into my head, it's about impossible to get it out of there. Plus, aside from stacks, and turning the exhaust manifolds upside down, and running pipe through the hood (although I have ran 2inch right from the manifolds to directly behind the front tires on each side, when I used the poor old Bronco as a work truck on the farm) it's the only setup I haven't tried yet. Agian, thanks for all the info guys.

 

well let us know how it goes. just dont go bigger then 2.5". were did you plan on mounting the O2 sensor?

 

Well I'm going to use 2 inch, as thats already whats on there. I'm only replacing it from right infront of the rear axle back as I already have true duals exiting infront of each rear tire. I have the 02 sensor mounted on the passenger side side pipe, close to the stock location. It's been like that for 2 years, with no problems, and no loss of power (that I've noticed, actually as stated above, I've noticed a gain in power), and no tripped codes.

 

What is your fuel mileage like? With that setup you are only getting O2 sensor readings on HALF the engine! Of course you aren't getting any codes, the computer thinks the truck is running lean. Quite frankly, I'm surprised your mileage doesn't completely kill you. The whole reason the O2 sensor is mounted in the stock Y-pipe where it is, is so that it gets readings from BOTH banks of cylinders. With it only reading half the engine, the computer is dumping a LOT more fuel through the system to keep the readings within parameters. That's why you have increased power.

 

is there a way to put two o2 sensors on a truck to have true duals with a EEC-IV efi system?
because i want to have a true dual setup, without any crossover. i like that uneven rumble of duals

 

a crossover is a must. it provides increase scavenging of the exhaust gases. it will improve performance.

 

JetBlack, Kem is right for two reasons... the one he already mentioned along with the fact that a crossover helps equalize the backpressure in the system when you have two exhaust pipes with slightly different bends and lengths that create different flow and backpressure patterns within the rest of the system, AND you can't run O2 sensors in parallel. They will "confuse" the EEC computer because they would BOTH be sending readings down the same wiring back to the computer. The EEC-IV computers only have a provision for ONE O2 sensor input.

 

would an O2 emulator do the trick?

 

the o2 eliminators are for obd-II vehicles only. not eec-IV