View Full Version : Unexpected performance gains...and a new exhaust
11-29-2005, 08:06 AM
I took a trip to Detroit this past weekend, and noticed that my exhaust note changed slightly on the trip. So, upon arrival, I checked out the exhaust for leaks to find that my muffer was completely gone! Thats right, my stock muffler is one of those lonely items you see littering the highways around Detroit. I guess the motor city loves to destroy cars.
Anyway, I was really surprised that it wasn't a lot louder without a muffler. I could barely tell the difference under 2000 rpm. I guess the factory cat and y-pipe are quite restrictive and quiet the exhaust down. On a positive note, I did notice a little SOTP improvement, but maybe that's all in my head.
This opens the door for some exhaust improvements...I was thinking hooker long tubes, x-pipe, and dual magnaflows. Anyone have any suggestions?
11-29-2005, 07:15 PM
You lost the muffler and didn't know it, that is funny. Mine got pretty loud when the stocker blew out but the sound went right up the back of the cab too. Hookers are good as are hedmans. I went with painted hedman long tubes because of cost and I was shocked at just how good the qaulity was for a cheap set of headers. The welds are great, everything was precise and fit like a glove. People cuss exhaust leaks with headers but I have had them on since May of this year and have yet to have a single leak anywhere. Its all in the heat cycles and retorqing that keeps them from leaking. Duals and an x pipe are the only way to go IMO. Magnaflows should sound sweet. As for pipe size you will want to run either 2 1/4 or 2 1/2. I went with 2 1/2 BTW. Most will tell you that is too much but I actually gained lowend so it worked out great for me.
11-29-2005, 11:31 PM
I use Hooker Competition headers, they are true longtubes with 1 5/8 primaries and 2.5" collectors, I have had them installed thru 5 daily driven winters. they are ceramic coated.
I did exhaust, headers and tune and got a 3/4 reduction in 1/4 mile times.
I am using the headers that fwill fit your TBI truck, it actually has the O2 bung for your truck, I dint drill it out for my truck though.
12-05-2005, 04:37 PM
Yeah I was surprised that it wasn't a lot louder with no muffler, but the factory y-pipe and cat must be so restrictive that they muffle the sound quite a bit. The Hoe with no muffler was actually not as loud as my 1990 Park Avenue beater with no muffler! :eyecrzy:
Thanks for the advice on exhaust and headers. I did a little research and it looks like no one makes long tubes for the TBI with AIR fittings so I was considering the Thorleys. I know the TBI Thorleys normally come with the y-pipe but I can get them without the pipe to run duals. Has anyone found longtubes that have the AIR fittings?
12-06-2005, 07:48 AM
Has anyone found longtubes that have the AIR fittings?
you mean the o2 sensor bung?
If so, you buy them from Napa, I think I got mine for $3 and drilled a 3/4 inch hole and welded it in
12-07-2005, 07:41 AM
The y-pipe has the O2 bung, but I was talking about the Air injection fitting. It injects fresh air into the exhaust to burn any remaining fuel and save your cats.
Any ideas on that one?
12-07-2005, 10:39 AM
There are a few shorty headers I have found with teh AIR fittings.
On your truck, does the AIR system have 1 tube for each primary tube or is their just 1 for each 4 cylinders both passenger and drivers side?
A.I.R. stands for air injection reactor.
If you got some lng tubes, it would be easy to add the AIR bungs and screw in the stock AIR tubes.
The 1986-90 Corvettes used a nice little stainless header/manifold that had 1 AIR tube for each primary header tube. I dont know if they would fit though.
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