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Dual Exhaust for my 88 (HEAVY PIC WARNING!)

19205 Views 31 Replies 21 Participants Last post by  cheap sunglasses
I've seen a few grumblings in various threads on the FSB forum from other Virginia Bronco (and a few other) owners reguarding exhaust and emissions laws in the Old Dominion State.

I recently rebuilt and installed a 302 HO out of a 93 Mustang. Changed the cam to one more suitable for the low end power that Bronco's crave. Added a few other bolt on performance goodies including a set of shorty headers off of a 93 Mercury. Now what I needed was a good dual exhaust system!

Canning the cat is sure way to not pass Virginia state inspections. In addition it can also negatively affect the truck's performance not to mention the detremential effects to the atmosphere.

Since I do not have the equipment to fabricate a custom exhaust, the search was one for a good price for true dual exhaust from a local shop.

Every shop I contacted in my area (south east Virginia) stated that they could not do the job since it involved altering the factory emission system. Even though I was going to be using two catalytic converters instead of one, the answer was still NO.

I found a shop down in Elizabeth City, NC that could do the job for what ended up being a fair price (at least in this area). The upside was, that even though a VA shop will not do the work, the truck will pass Virginia state inspection with a true dual exhaust system as long as there are catalytic converters installed. (Assuming they don't notice that missing smog pump thingy? :shrug )

I think as most of us know, it's a pretty tight fit up under a Bronco. There's not a lot of area to run a dual exhaust system so the fit has to be fairly precise.

The run coming down off of the drivers side header curls down and over to the passenger side tight up under the bell housing.

The passenger side was mostly a straight drop down heading towards the back between the starter and the frame. A new O2 sensor socket was fabricated and welded into the pipe.

The mechanic installed the pipes "over and under" fashioned. They run back between the transmission and the frame up over the transmission mount and drop down towards the skid plate where there is room to install the cats and the mufflers.

I opted for two CatCo high flow converters. The write up on them from Summit says:

Since you have to use a catalytic converter anyway, you might as well use one that's going to last a long time and maintain your vehicle's performance level in the process. This converter not only outflows the stock converter, it features aluminized dual steel heat shields, 409 stainless steel shells, 16-gauge stainless steel pipes and nipples, and a heat resistant sealed mat, all of which help the converter last longer. This converter has a steel air tube with perforated holes to help distribute the air flow evenly without robbing power.

2 Catco CTO-6005 catalytic converters - $110.00

Like I said.... it's a tight fit up in there for dual exhaust and I was very impressed with how the guy installed the pipe runs.

A short run after cats come the mufflers.

When I got it to the shop, they asked me how I wanted the truck to sound? I replied not to loud but certainly "throaty."

The issue here again is space. The mufflers have to fit between the frame and the drive shaft. They reccomended a set of Flowmaster Hushpower II's because they are "tubular" instead of the traditional box and would fit with a lot less chance of ever hitting the drive shaft.

I agreed, but they didn't have them in stock. Since this is my daily driver, I couldn't leave it at the shop for the three days it was going to take to get them (holiday and weekend). So I opted for a "generic" version of similar flow and quality.

2 Hi-flow mufflers - $45.55

After the mufflers, the pipes turn back up to go over the rear end and branch out towards the left and right behind the rear tires. I opted for this set up instead of straight back so I'm not choking on exhaust fumes when I'm riding around with the rear window down.

The pipe size is 2 1/4" because bigger is not always better. To big and you can actually end up losing performance.

All total with the two cats, mufflers, pipe, fittings, hangers, and labor the job cost me $410.00. I didn't think that was to bad considering I've seen "cat back dual exhaust" systems selling for $250 - $300! And that's just the parts.

Once I fired that sucker up.......

Man Oh Man! :thumbup

She growled oh so nice! I mean it did sound a little loud still, but hell! I'd been driving it for 3 days on mostly un-capped headers. So it was quieter that what I was used too.

Now that I've had it for a while, I would have opted for mufflers that were a little quieter. But since I've got it... I'm learing to love it. Once the novelty of the sound wears off, I will be able to figure out what my gas mileage is since the rebuild. Right now I just can't seem to keep my foot out of it... :chili:


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My dodge has dual stacks, 4in downpipe off the turbo, through the bed, y pipe with a "smoke splitter" plate, into 4"x5" 90* elbows and big ol 5" stacks from the Chome Depot baby :thumbup
i just got my new high flow cat yesterday, i really dont wanna put it on, but i gotta pass going 2 take my old cat and look about gutting it and installing that 1 after inspection...
why? just install the hi-flow. No one in jersey seems to care that i have a single hi-flow under mine :shrug
Ironclad and Stokes... I have a question about the actual routing. Did the "cross" them to try to match the length of each side? Like, does the passenger side header lead to the drivers side exit. and vice-versa??
Yah, Fireguy, same thing happened to me about my duals I put on. They did horrible job on the bends, the mufflers were crap, and they didn't even move my brake line. I had to cut it all off like a month later and had a friend of mine re-do it for me. So it's jus catback with 2 flowmaster 40's on it. I would like to go back to tru duals, but this isn't a bad setup I got now.
Well I got a pretty bad exhaust leak on mine so i started calling around, and of course they wont completely remove the CATs but they will take it down to one CAT. he said routed anyway i want it, dual pipes for 280
I am now convinced that all the tail pipe shops work for the same god...everyone including me has basically the same setup, headers, custom "Y" pipe, cat, muffler etc, all routed the same, and all under the damn tranny. However I went w. hooker full lenght on mine, just to complicate matters.
Nice exhaust works guys but I'm thinking of doing mine differantly by having both tail pipes exit in the stock postion. Get the performance with out the trouble of crossing over at the rear. Kinda like the lightnings.
You know, there's honestly very little to no performance benefit to duals without a balance tube. I couldn't justify it when I did my exhaust a couple of years ago, so I went 2-1/4" downpipes to a 2-1/2" single. Works like a charm, and the way I routed it, I had no trouble working around it to get my E4OD out (again, grrr).

In my case, I built the system myself as a welding practice project. Was able to do the entire system, 16ga, mandrel bent, plus headers, for $280 plus a few bucks worth of MIG wire -- important since I was on a very tight budget at the time, having just bought a house. I kept the price down by skimping on parts that can easily be replaced later, such as the Paces#itter headers, plain Catco cat, and $17 Thrush glasspack with the same dimensions as a decent Flowmaster. :toothless I couldn't see putting a decent cat on the truck yet, since it was still burning oil ... why kill a good catalytic in under two years when you can kill a cheap one?

VA laws regarding exhaust aren't too hard to work around, you just have to give it a little extra thought ... as you found out. :thumbup And as for local exhaust shops, the only exhaust shop I'd recommend is four hours away. I've never seen a single piece of good exhaust work done in Hampton Roads.
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Ironclad said:
Oh yeah.... Truck Porno my @$$!

Man... that's a sneaky way to get traffic to your profile page! :lowblow
HA! I just saw that too.

Im happy with my duals. They wound up running the drivers side pipe out towards the left frame rail, under the t-case, and back up over the axle and out the back. They look good. I wasnt able to be with the truck so I could not tell them I wanted them to angle the tips out. I am happy with the work. The only thing it, until the finish wears down, I can see the bottom edge of the pipe under the truck from far away. I dont heavily wheel the truck so it doesnt really matter about the lower pipe. I have no cats yet because I have kept the truck off the road (gas mileage). I was sick of the leaky cracked manifolds so I installed headers and finally had the true duals installed. Now all I need is a new fan clutch and cats and I will be ready for winter.

Looks like it turned out pretty well :twotu:
Ironclad said:
The pipe size is 2 1/4" because bigger is not always better. To big and you can actually end up losing performance.
Do you know the technical explanation for this? I believe it but my mind is having trouble explaining why unless it's a much bigger diameter difference (than say between 2 1/4" and 2 1/2" or even 3") :doh0715:
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