1993 Bronco 351.

Im thinking of doing a set of OBX Long tube headers, and having a shop make me a Y pipe. The OBX headers are 3 inch collector.

Should i buy a 3 inch cat or go back to 2.5 inch?

I will deff still run a muffler, im wanting to keep the truck resonably quite, some bark is fine, but no highway drone.

Im not sure weather to run duals or where to exit the truck at? Duals out the back seem like it would be a PITA. Is it?

And the driveshaft seems to be in the way of exiting on the drivers side infront of the tire. Might just stick with the SI/SO Flowmaster that is already on the truck.

Im wanting to do this cheap, so that may be the best option.

Anybody know any other solutions to keeping the sound down? Run a glass pack instead of a cat and still have a muffler behind it? Would that be cheaper?

Thanks for any input.

 

NEVER exit the exhaust out the back of a Bronco! It will draw back into the cabin through the drain holes in the tailgate.

The stock location or in front of the rear wheels are the best options. 3" is all the bigger I'd go with it if you run single. If you go dual, you can always run two pipes along the stock route just keep them to about 1.5" diameter each. Just make sure that no matter what you end up doing, you make certain to keep the O2 sensor either in the same location in the Y-pipe as it is with the stock setup OR you located the O2 sensor in the crossover (X-pipe) if you run duals.

 

2000 posts. Wooot.


So when you say in the Y pipe, do i have to build a dum little cross over tube infront of it like they did from the factory, or can i just put it a few inches downstream of the Y.

 

Congrats on 2k!

You just want it as close to the Y as you can but not in just one arm because then the O2 sensor is only reading four cylinders out of eight. I have always marveled at the silly little cross pipe in the OEM Y-pipe myself. The base of the Y should be fine.

 

Thats what i was thinking, but i wanted to clarify in case i was missing something.

So i will run 3" back to a high flow cat, and then through a SI/SO Flowmaster chamber muffler and then exit out the back like stock.

Should be cheap enough.

 

I do have one more question.

In the quest for more hp. Is it worth just buying an aftermarket Y pipe and leaving the stock manfolds? If a person had only x amount to spend? I read that the Y pipe is probably the most restrictive part of the OEM exhaust.

Later i could come back with some aftermarket shortys. I know not as good as LT's but should still be more gains right?

 

I have personally run the Bassani Y-pipe for many years with zero issues. The nice part is that it will bolt directly to stock manifolds OR their shorty headers. Some guys will whine about how pricey it is but then I have a 9 year-old stainless y-pipe that shows no signs of deterioration. Was worth every penny if you ask me. For less expensive or custom units I will simply say, you get what you pay for.

Yes, behind the rear passenger wheel is the best location and it allows you to keep your stock hangers and brackets.

(BTW, my Bassani Y-pipe had the cat in it originally. The substrate inside did fail about 5 years in like most cats. do. It has been gutted and non-functioning ever since. Missouri does not require emissions testing on anything older than 1996 so neither the Bronco nor I miss it).

 

What are you runing for manifolds?

Is your truck very loud without the cat?

What muffler did you run?

I would assume that the Y pipe made a signifigant difference in power?

 

I am running the entire Bassani "Street Thunder" package. I don't think they call it that anymore. Their equal-length short headers, their Y-pipe and their "cat-back" setup. The Y-pipe has 1.5" arms running into a 3" collector and a single 3" pipe that runs all the way back and follows the OEM exhaust routing under the truck. All stock hangers and brackets are used. Keep in mind that headers long or short are most effective if they are equal length. The shorties I'm running yield a good 15-20 more HP over the OEM manifolds and even though they are a bit more bulky, the fit is the same as the manifolds. I attempted to explain the benefits of equal-length headers HERE.

The Bassani muffler is a little "drony" under hard acceleration but mellows out at cruising speeds. Upping the main pipe diameter to 3" help significantly with the breathability of the system. (It IS fun to romp on it in a parking garage full of cars with their alarms set. They will all start "waking up" from the vibrations).

There was zero auditory change after having to gut the cat. Its too far upstream to really cause any tonal change.