low miler

Hypothetically speaking, is it possible to run a GTS without its converter and would it do any good if I did? This question is just for entertainment purposes only.

And secondly, what are the three or four best and cheapest ways to make my car faster?

Rich9928p

a. From what I've seen posted, removing catalytic converters doesn't buy you much HP, perhaps 5 HP. The RMB (rear muffler bypass) is said to help with a few HP, most add it to enhance the sound.
The air is bad enough, no need to pollute any more than necessary

b. the cheapest way to make ANY car faster is to remove weight, this gives the most bang per HP.

c. performance chips. From actual dyno, the claims seem to fall short of actual. Chips may reduce the reliability of the engine due to reducing safety margin in the design. Chips are pretty expensive for the HP they say is delivered.

d. Beyond that, there are some exotic exhaust systems (Ott, Devek) etc. that are fairly costly and deliver a few more HP. Anything beyond that is pretty big money and is pretty major work.

Jim_H

Ott X Pipe, without a doubt the best bang for your $. Ran without cats my GT put 301 to the wheels and the tone is the best I have heard on any car.
It is easy to put cats back on for inspection.

Dave Sz.

"Ott X Pipe, without a doubt the best bang for your $. Ran without cats my GT put 301 to the wheels and the tone is the best I have heard on any car."

Jim,

Did you leave the rest of the exhaust stock or did you add an RMB also? I'm told that not cats and an RMB is too loud for urban driving with a GT.

Dave Sz.

SteveG

This has been covered extensively in the archives. Lose weight, go on a diet; I'll never forget my college roommate trying to make (lose) weight in the bathroom!

heinrich

Low, yes. There is much horsepower to be gained from losing the cats. No question. You will need to retain your rear muffler though.

Jim bailey - 928 International

the Ott X-pipe and two high flow mufflers will add nearly 30 HP to an 89 GT . The X-pipe works !! Plus the mixing of the pulses in the X seems to reduce the harshness of the exhaust note compared to an old fashioned H pipe balance tube ....the H is better than nothing but does not compare to an X .

Big Dave

Happy "x" owner here. Get it!

hacker-pschorr

6 - 11psi will give the biggest gain over anything else. I say 6-11 because I don't know the specs of the GTS kit:
www.murf928.com

Sab

I can tell you from personal expirience, do not take that cats off. Your car wil have no noticeable performance increase and it will stink like an old school buss.

Big Dave

My personal experience contradicts yours. Performance has increased in a very noticeable way for me. There is an odor from the unfiltered exhaust, but I rarely smell it.

Mark

I agree w/Big Dave! Most BWAAAAHHH for the $

The cats are darn good mufflers by themselves. My sound is sweet. I wouldn't want it any louder - i.e.-RMB. As it is, I can set off car alarms if I want to!

Jack '84 928s

I could tell a diffrence when i took my cat off and the porsche mufflers.....

ViribusUnits

Much depends on the current condition of your cat. And for that, much depends on the current condition of the other emission controls.

If the cat is partly cloged, highly possible on cars this old, you can get substantial proformance improvement. Not only that, but if the cat is poisioned, you'll have no net change in your emissions. One thing that can cause a cloged cat is a defunct or disconnected smog pump. And if you don't have a cat, the smog pump is pretty much pointless on air injection cats.

So, if your going to remove the smog pump, you have to remove the cat, and if your going to remove the cat, you may as well remove the smog pump.

low miler

Let me get this straight. If I was to order this X pipe thingy from Devek, I would have to keep my original rear mufler on? I just ordered a rear muffler bypass. Should I send it back, or is it possible to use both?