In your opinion, would you bother upgrading a stock LB9 and TH700R with shorties, high flow cat, and cat back? This is only a fun car for me. I don't race it, I just drive it around, chirp tires, crank the Van Halen, and generally look bitchin' around town.

What am I looking at, 20 HP at the top end? Minor feel? minor sound?

I already have a flowmaster cat back.

 

I probably wouldn't bother if you're happy with what you have now. Headers are kind of a pain. None of them really just replace the manifolds directly. I've got three thirdgens I've owned for 17 years or more that still run the stock manifolds, and there's a set of headers on a shelf not 6 feet away from me right now.

The cat and catback are easier to answer... If your cat is junk, replace it. If you want a different sound, add a catback... If you want more power, there's a little to be gained but it wouldn't be a HUGE improvement.

 

Thanks. I am happy but the younger performance guy in me that won't shut up is always wondering. These little LB9's feel so strangled above 4000 RPM that the better exhaust thoughts nag at me. I know the TPI induction is a culprit too, so uncorking one end isn't going to do much.

 

If you had the OEM exhaust, you might pick up 10 to 20hp by changing the y-pipe, cat, and cat-back. Unfortunately the Magnaflow TPI y-pipe is no longer made to replace what you have on there now - 10x easier than going the header route.

 

If you have the stock Y pipe (really more like a T), getting rid of that with a true Y pipe makes a big difference. The stock pellet type catalytic converter is a bottleneck also.

This post says the Magnaflow y-pipe is available.
https://www.thirdgen.org/forums/exha...ml#post6145937

 

Good stuff. So are you saying...

If I instead go with the Y pipe and maybe the http://www.magnaflow.com/products?partnumber=332019

I would actually get some noticeable results, nevermind the manifolds?

 

Did any years of our third gens come with the pellet style converters? I thought all of our cars had the much more efficient ceramic honeycomb core?

 

I could be wrong on that. But the OEM converter on my 84 TA was nothing like the high flow unit I replaced it with.

 

They flow so much better without that parasite called a catalytic converter. Luckily I don't live in California or New York where they check emissions and such. Anyhow, ive heard the TPI manifolds aren't horrible as much so as is the y-pipe. You can still find the magnaflow replacement y-pipe and I'm certain it would be some help according to what ive read.

 

Do your research, there is no such thing as a "high flow cat" Ca. made Magnaflow remove that from there website and their boxes.
Cats are all made the same today, honey comb core.
Have been since around 1982.

 

IMO, Dyno Don makes the best free flowing Shorty Headers and "Y" Pipe for our cars.

Take a look at this.

 

those are gorgeous.