gringott

iTrader: (17)

I have the Xerd test pipes with a NISMO cat back, and they were just too loud at highway speeds (drone). Went to stock cats and the resulting loss in power and, because of the turbos, too quiet for me. The cost of hi flow cats is just plain crazy, I would rather spend the money on something else. I found these Car Chemistry Inserts that fit 2.5" pipe, 7" long, so they would fit in the lower part of the test pipes. Cost is around a $100 for two, and they come in two disk and three disk setups, with caps for further sound reduction if needed. A post on the company's website stated it removed drone. Has anybody used these? If so, did they remove rasp and drone? Thanks.

protocav

iTrader: (3)

those look good for a 69 mustang, but i'm not sure i would put those in a Z. i would just weld in a 3" resonator after your y-pipe merge, or somewhere on your b pipe.

HyperSprite

iTrader: (6)

Restriction is not the way to go, you might as well run the stock cats (that stock cats may actually flow better than those).

Chris

Blue_pen

Was the sound droning befor your TT setup or after?

Hydrazine

iTrader: (53)

They'll reduce the drone for sure but they will almost surely reduce power too.

You might want to try putting in an extra set of resonators. Get some magnaflow straight through mufflers for cheap. Put them in just about anywhere in the exhaust system and it will reduce the drone without killing your HP.

It would cost a little more and take a little more effort, but you would be happy with the results.

gringott

iTrader: (17)

I did not have test pipes before the TT. Can't imagine how loud without TT. These are resonators that fit in the pipe instead of a seperate unit. You can buy these as a unit, and insert them into the exhuast system, or just put these in a section of straight pipe, and tack weld. They also make a set for use in header collectors. They claim minimal hp loss, or even some gain due to scavenger effect.

gringott

iTrader: (17)

Look at the evo-r test pipes in the closed thread posted today. Several peeps said they looked like hi flow cats. To me they look like they put in something like this picture.

gringott

iTrader: (17)

After viewing the prices on high flow cats worst case I will buy generic high flows and have them welded into the test pipes, or gut my cats, at least the secondaries.