My O2 sensor is before the cat but I have emissions where I live. I doubt that I will just cut it off eventhough it would be OK if I just cut it off. I will probably just hollow the cat out. That should open up the exhaust some. Next year I will prob get any entirely new exhaust from the headers back. Will 3" pipng be too much or is 2 1/2" piping good? I see in other forums that piping diameter is also a very big issue, too much and you lose torque and too small and you choke the exhaust. What will my truck sound like if I just hollow out the cat??

 

Well if your really worried about emissions you might as well just leave the cat on. I dont care about emissions because when i make my dual exhaust set up i will be putting ball and socket flanges on the exhaust so i can easily remove it and re-install it anytime i want. So when sniffer test comes around i can easily re-install my stock exhaust. Its hard to say what it is going to sound like just removing a cat. Every engine sounds different, every exhaust set up sounds different. Obviously you will hear a difference, you will freeing up the flow.....you just have to take it off and beat the stuffy out of it and find out for yourself.

And for true duals, 3" is WAY to big for just a 351....even 2 1/2 is quite large for just a stock engine. I would go with 2 1/4, that would be about the perfect size. Take a piece of 2 1/4 and compare it to a 2 1/2......there is a huge difference in size even though it is just a 1/4 of an inch.

 

not to hijack a thread but i would like some suggestions for my exhaust
88' bronco 351w daily driver no emissions testing in arkansas

i was thinking about removing the y pipe and replacing it with a new muffler (dual inlets) also would be removing the cats ... after the muffler i was thinking about just pointing the exhaust towards the ground and leaving it venting under the mid section of the truck

i have seen this done before and it sounded good but i was wondering if it would hurt me offroad like getting water in the exhaust easier

another possibility is to remove y pipe replace with two pipes for dual exhuast with or without muffler

what do yall think
i want a nice deep grumble and maybe a little extra power but not to loud ... im putting in spray in bed liner for flooring and im sure it doesnt help keep sound out as well as carpet

 

well i guess i am sorta hijacking the thread but i thought a mid vehicle venting might help mycktor avoid having to run so much new exhaust pipe to get duals and without mufflers a short exhaust would be really LOUD if you want that

 

Well I think if your going to take the time to get rid of the y-pipe and the cats and plan on putting a new muffler on, you might as well and go ahead and get true duals. Just sounds so much better than one muffler. Dont take my word on it, but i have heard if you have any kind of leaky seals on the bronco's you are going to have major problems with exhaust fumes getting into the cab. Just something to think about if you plan on putting turn downs right underneath of the truck.

 

Snowmobilerfreak, I want to wake my engine up. You have the same engine. What can i do?? Like exhaust manifold, cams, heads, all of that good stuff. What does our engine have as a base horsepower? I would like to have over 300. Any help you could give me would be great. This is all for my "to do" list and will be appreciated. Exhuast will be taken care of. I am knocking the honeycomb out of my cat on Thursday night and will let you know what I think about the sound. Later

 

You have to remember I have not one performance thing done to my engine as we speak so im not sure what the gains of anything like a header, dual exhaust, a cam, not even a K&N filter intake are going to do for this engine.

The only thing I can tell you and recommend is just mostly common sense stuff which you know will help your engine. First of all the 88-96 5.8 are only putting out about 200hp and 310lb-ft so it is going to take some big money to get it up running around 300hp. Unless you go with a chip but i have no idea what they have to offer out on the aftermarket as far as the 88-96 5.8's goes. Its just wasnt as popular as the 5.0.

All I can recomend is what everyone else will tell you to get. Start with headers, true duals, High Flow intake, obviously a cam would be a good direction to go but then again I dont know what kind of high performance roller cams they have to offer for that year of engine. You could even go with a better ignition, maybe MSD or HEI have something for that engine. But I dont think even with what I have recomended will get you up around 300hp.

Im only 19 so I dont have knowledge most of these guys have who have been doing this stuff for 20+ years. Just wait and see what some of these other guys have to say.

 

do the HEI conversion if you are going to do any ignition changes. the stock tfi makes good spark up until around 10,000 rpm and the hei thing, i've heard cuts off around 4000-7000. the tfi is one of the best ignitions back in the time it was offered. i have also heard that the msd stuff burns out pretty easily. do not get a different distributor unless you want it for looks because that is all they are good for. i am not sure about the boxes but i know mallory makes some good stuff. i have never heard any bad things about them. i did the HEI conversion though only because i swapped my mustang to a carbed engine and the tfi won't work with a carbed engine unless i have a feedback carb which will not happen. do everything that was already said though. i know a guy at stangnet that ports out stock intakes for 100 buck i believe. do that if ya want. get a cam and some long tube headers and an electric fan. if your truck does not have 4.10's in the rear end already, definately do it since you have an overdrive tranny. do those things and you won't recognize your truck anymore.

 

Well now that i mentioned the cam and you did too I have got my self curious. Do you know of anyone who offers a cam for the 90's 5.8? Also the HEI conversion?

 

Cams are available from a couple different companies. Just look in Summit magazie or Jegs. I am sure that you will be able to find one in there. They are at a decent price for the cam and lifters but I doubt that I could do that on my own. I definitely do not have a huge garage to do all that in. It would probablt require ripping half of the engine apart or am I worng? Will installation be hard or not? fill me in on the info Snowmobilefreak.

 

if you wanna do a homemade HEI conversion, all you need is the 4 pin hei module, a duraspark dizzy for a 351 with a steel gear if you have a roller cam,some wire and some connectors. i have the info and diagram i will send you both later in a PM or email. if you wanna do the HEI thing professionally, there is a company called DUI or davis unified ignitions that make an hei distributor custom for you. it looks just like a gm hei dizzy but it fits a ford. go to jegs or summit for the cam. everybody makes them for your application. you could get a 5.0 HO cam if you like, they fit. if you have mass air flow efi instead of the other efi system that was offered way back when, then you can run anycam you want, just don't run a big cam that will affect you power band. get one that has power at idle.

 

Well, I had to do the head gaskets on the truck not to long ago so a bunch of crap i going to have to come off. Valve covers, rocker arms, pushrods, the upper intake, then all the vacuum stuff on top, then the fuel rail, all the electrical stuff on top, the intake manifold, then all the lifters.....then you have to take the a/c pump so just take the whole bracket off and move it out of the way without disconnecting the a/c hoses, then the fan, next the water pump, then the timing chain cover, next you have to take the timing gears off with chain.....then the cam slides right out. I cant remember if you have to take the alternator bracket off or not, i dont believe so....i would know if i looked at the truck real quick but i dont feel like it.

thats about it

 

Oh yeah, i completely forgot. A larger throttle body will boost you some more ponies. Hmmm, dunno how i forgot that "DUH"

 

you gotta take off the radiator and all that to put a cam in to. who wants the HEI info.

 

I wouldnt mind looking at it