I'm looking to upgrade my exhaust. I'm thinking of going with the gibson swept side. I just have a couple of questions.
First of all....I don't really care about sound I want performance.

1. Is a gibson cat-back better than just a gibson muffler or flowmaster.

2. Reason I asked the previous question, if the gibson cat-back has 3" pipes, will this decrease low end torque

3. Does anyone have PERFORMANCE experience/stories about the gibson cat back or the flowmaster.

Appreciate any replies.

 

You're not going to get alot, if any, performance gains from a cat-back, any cat-back. I have the supertruck, sounds great, but i don't think it runs any better. 3" out of the muffler isn't going to hurt anything, the restrictions from the manifolds back is alot greater. Thus you can't really get any gains or losses from the cat back to the tail. Modifying and opening up the intake then a full performance exhaust sytem would result in gains. At these HP levels, opening up the exhaust after the cats just doesn't do much.

my 2 cents....keep the change...lol

 

So who offers a complete exhaust replacement that will boost performance more than a cat-back system?

 

well, what about gas mileage...will a cat back help this at all. I don't want to do anything before the cat converter because of the warranty.

 

I have a side swept on my '95 302 and it's great. The improvements on my truck seem to be in the 2000 rpm and up range. SOTP no low end loss, maybe a very slight gain. The truck handles towing and heavy loads better without a doubt.

My brother has a side swept on his 4.0 Ranger and had similar results. His main comment was that the truck revved more freely through the gears.

I think the key is reasonable expectations. This applies to just about any modification you do. A cat back isn't going to make the truck a rocket, just fill in some areas of the torque curve some.

As for cat back vs just muffler, that will vary with the application. On my truck the stock tubing bends were terrible and there was a lot of obvious restriction. I think the logic behind big mandrel bends on the cat backs is to make the muffler itself the point of the most flow restriction, and ensure the tubing can dump the gasses.

Gibson vs Flows - depends on what you want. I've had Flows on a couple of vehicles, but none recently. Personally I don't think the Flows are made as well. They do seem to flow good but I don't think they will enhance or help retain the low end the way the Gibson does.

Of all the exhausts and mufflers I've tried I still think the Supertrapp is the best thing going performance wise. I don't have one now, but have had several. My best car ETs and best bike dyno numbers came with a Supertrapp. They do require some maintenance, and some don't like the look. Although I'm happy overall with my Gibson, I might get a Supertrapp and try it on this truck as well.

 

signmaster's post pretty much say's it all. I've got the SS and really like it. I feel it's claims of increasing the low end is valid. Improving gas mileage, well, that's all speculative anyway. Too many varibles that can skew it. Overall, I think I may be getting 1 mpg more on average....... Seems I averaged 14 mpg after I first got the truck, and now average 15 mpg.

 

thanks for the info guys