Hi,
I'm in the market for a catback system for my 1990,F-150,302,V8.
I am trying to decide wether to get a Flowmaster(70 series) or Dynomax catback system. Which one of these two will give me better performance?. I definitely want it to be as quietas possible inside the cabin.
Also, I want to keep the factory single pipe routing and is there a big difference in going up to 3" in pipe size or staying at 2.5"?
I spoke to Flowmaster and they recommend to go up to 3", but I hear all this talk about backpressure?
Thanks in advance!

 

[updated:LAST EDITED ON 13-May-02 AT 08:39 PM (EST)]Unless your running open headers, dont worry about back pressure. If you plan on keeping you cats in tact, i would purchase a 50 series delta flow flowmaster. You would get a nice exhaust note and good flow with minimal noise. The cats alone are where all the restriction is at. You probably would not even notice any power gains with just a muffler swap, but you would get a better exhaust sound.

By the way i have a single 3" system with no cats and headers w/ a Flowmaster and it sounds great, very deep tone, but still quieter that duels. You can listen to a clip by clicking on my gallery ( there is a link at the bottom of the gallery).

 

Will I notice any power gains with a whole cat back system if I leave the cats alone?

 

 

1989 F150 5.0l I replaced my cat with a 3"in/out hi-flo cat it was about $107.00 then i want to a 3" in/out dynamax Ultiflow muffler 6" diameter x 16" long straight-thru stainless $109.00 and then continued to exit out the rear corner like the stock. i paid the local muffler shop about $125.00 for the 3" pipe and labor to install it. I left the front cat alone and in place or i really think it is a heat exchanger but it acts as my Y-pipe and that is where o2 sensor is located. The truck has a real nice sound to it and performance seems better. I did add a K&N air filter and i removed the freash air pipe and cut the baffles out then reinstalled it when i did the exhaust. all and all i am happy with it. I also read alot about different exhaust combos and recall that i found that a single 3" would work best with a 302 ci engine up to about 375hp.


cat
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