Today I just orderd a exahust system from Summit.. Its a cat-back system 3inch too dual 3 inch pipes out the rear. It cuast 150.00 bucks not bad really for all I get. I just now got to wait on it to come in the mail.. anybody have any experience with the exhaust? Good? bad? How does it sound? Should I take the cats off? One thing that puzzled me was they didn't ask for what kind of engine Or does all of them have the same exahust system? v8 or I6??

Now I'm tryen to thikn of what to do next I'm wan'ting some kind of intake system. But I can't find any pictures of a homemade one?? So if you got any info or tips or pictures of your homemade cold air intake I would really appricat that!

Adam THroop

 

3 inches in sounds pretty big. i thought you would have something closer to 2 1/4 in. i dont have any experience w/this but some ppl have warned about using large diameter dual pipes because of that lack of back pressure. i heard that dual 2 1/4 or single 2 1/2 work better. let us know how it turns out. good luck

 

Well, I got my exhaust on today. Its sounds good and the kit was awesome..came with everythign didn't take to long to put on. The hardest part was getting old off and spare tire out. IT is not as loud as I wan't to be or what it will be. How long does it take for a muffler to break it to where its loudest? Would my check engine light come on if I take out cat or will it harm anything be sides maken truck alot louder??

At idle my truck sounds awesome..sounds good. and driven don't really ever get the rice sound at all!! I'm satisfied for a 160.00 Exhaust system! Anybody got any questions on it or anything just post. and please asnwer my questions if you got an answer! Thanks!

adam throop

 

With 3" you are running too big of an exhaust system. Your loosing performance from it, and a little bit of exhaust tone from my experience.For the muffler, it can be a little as a month or as long as a year for it to "blow out" You can speed up the process by getting the exhaust good and hot and then sticking a water hose in the muffler and turning it on it is stuffed with a glass material. The loosing performance is NOT (I repeat NOT) from a lack of backpressure, but from a lack of exhaust velocity. What happens when you use too big diameter of a pipe is that the exhaust slows down when it exits the motor and then the motor must work to push it out of the pipes instead of scavenging it's self out with the exhaust pulses.

 

Well, I don't see how it would be harder for gas to leave out of a bigger hole then a smaller one don't make sense. its like you can blow more air out of a water hose then a strawl. but whatever you say. I was not going for performance at all. I'm not racing and I don't pull or lift hardly anything i'm 17 so that was not the purpis at all. and for the breaking in on the muffler I'll just let it break in I'm not going to go shoven water hose or water in it. I don't care that much. I might cut the cat out and just replace it with a pipe. not sure. I just wan'ted it nice and loud. But I figured with a smaller exhaust pipe the more of a pee shoote it would be. what i mean is that it would be a high pitched sound. This sounds deep and really good. But just give me your info on the cat. How loud would it be with out that? Would it harm anything? Would it screw with computer? the trucks an 89. So was not sure. I know it still gots a computer. Just give me your info and I do like the tips and opions keep them coming!!

Adam THroop

 

It has to do with inertia of the column of exhaust gas. With a properly sized system, not only will it not restrict the exhaust flow, but it will actually set up a vacuum behind the closed exhaust valve so when it opens it actually sucks the exhaust out. With a warmed up cam, that vacuum not only sucks out the exhaust but helps draw in the fuel/air charge through the intake that is beginning to open at the end of the exhaust stroke. It's called exhaust scavenging.

The scavenging is what gets you low end torque, if the system's set up to optimally scavenge at low rpms. A bigger system will scavenge at higher rpms and you loose low end torque because at low rpms you don't have the vacuum effect and you're relying entirely on the piston motion to push out the exhaust and pull in the intake charge.

This is what happens, people think you need backpressure, you don't, you do need gas column inertia. The backpressure is what happens when you have a properly sized exhaust that scavenges nicely at a moderate RPM and you rev the hell out of it. More exhaust gas at higher RPMs = backpressure instead of scavenging.

It's a trade-off, but you'd have to run your 300 past redline to get any kind of scavenging with a 3". 3" is for bigger race engines...

Think of scavenging like the draft a good chimney makes. Once the draft is going, it actually sucks air out of the stove. But if you were to somehow try to force more air up that chimney it would choke and only allow so much after a certain point. Best comparison I can think of right now, unfortunately....

You can pull the cat without a problem from the computer on an '89. It wasn't until '96 that they put a second O2 sensor on to detect cat performance.

 

Hey, The Cats or the second ones got the cross member in the way and I can't get anything in there to cut it out?? How can I get it out? Just jack up tranny then unbolt the tranny crossmenber??

Adam THroop

 

That's the only way I've been able to see....

 

blue89f150
you should reread gatesj post, the info will come in handy when you grow up and start playing for real and not for show.

 

Ok, Whats the play for real one day thing? What are you sayen? I don't even have a truck? or anythign I said in the above post? Because if so..I'm getting pictures really soon like within the week. and I'll show you!!

Adam Throop

 

I think basically all he is saying is that bigger is not always better unless you're just doing it for looks. He means actually tuning for performance by "playing for real" instead of just doing something for looks and sound.

3" will hurt your performance and low end torque for reasons I explained above.

That exhaust was probably sold for something with a warmed up 460 or a seriously built race 351. Nothing else flows that much exhaust, I would guess. 3" is what guys put on their drag cars.

 

Well, Like I said I didn't do this for performance i'm 17 I don't need to pull anything and I don't race.. SO mainly for looks and sound.. and I can feel that i have gained a lil power. The other day I was just screwing around at a stop light just tryen to spin some tires and it pilled out better then ever and I didn't even try hard and it left two makrs down on the road. Usally I have alot of wheel hope Now I don't have any! Also gas milage seems to get worse or just may be my driven now showing off the should..Most likely its that.

And for the it was made for 460..Your wrong. because thats the only engine that this exhaust system does not fit on everything els but the 460.. I don't see a point in sharing anything with anybody on this website seems like you only get critasized for stuff you do to your truck. Its just not me but I read it all the time. People allways complaing well you should have not done this and you should have done that. blah blah blah. I just felt like I would give some info to the people that have streight six and like big exhaust. Sorry I'm wrong it screwed up performance it don't look good. But I like it and thats all that matters! Thanks for info and all the torcher you all gave me on what I bought!

Adam Throop

 

I was talking about 3" in general being for a 460.

Sorry dude, just trying to explain how things work. Next time I won't bother.

 

blue89f150
the differnece between you and me, when I was 17, is the information that you can get now, I couldn't then. that right the internet wasn't around then, so it wasn't so easy to get info. on others trial and failure and why it failed. if i had 1/2 the money i waste becouse i was guessing what would work, i still have 1/2 the cars/trucks i distroyed, tried and fail with.
as for replacing the rest of your exhaust, keep it small. the way i see it, your cats are the only thing keep your power band down a little.
good luck and its alway cheaper to learn from other, and unless thing have change from when i was 17 cheaper puts more gas in the tank (leaded or not)