I have the N10 exhaust that's supposed to free up 13% more power. I look at it and it still looks very restrictive. And I only see 1 catalytic converter. Was the N10 a dual pipe system or is it the typical 2 headers goes into 1 pipe which goes into large muffler which branches out to the two "dual" exhaust tips? Or is there a pre-cat I'm not seeing? I'm not looking into upgrading until the basics on the car are fixed but I do have a general idea. I guess I'm just curious as to where that 13% power improvement came from.

 

N10 = 2 cats. If yours only has one, it's not an N10.

 

Uh based on the paperwork I have, the exhaust is stock and never changed. I have an '89 GTA 305 which has the N10 standard, no? I've been looking for a reference photo of the stock N10 to compare my system with...so far no dice. You'd think google images would have something :\

 

What's your rear end gear ratio?

 

Whatever came with the GTA trim level; 3.45:1. That's for the manual transmission, right? Nothing was replaced in this car.

 

Proof is in the pudding. Stick your noggin under the car and take a peek.

JamesC

 

I did the other day, hence the confusion...I see both headers going into one pipe and one cat, with the pipe running into one large muffler which goes out into the two faux dual exhaust pipes. Must have been an unrecorded job...crap. Oh well...

If it helps, I have a vid where you can clearly see the muffler i'm talking about.

 

Like James said, just look under the car on the passenger side. Your SPID sticker in the console would also say N10.

One thing though, the N10 wasn't available until late MY '89.

 

Sounds like a typical OE exhaust system.

JamesC

 

If that MY means May of 1989 my car rolled off the assembly line in June 1989.

 

Model Year.


Take a pic of your Y pipe cat area and we'll tell you. But if you have an LB9/T5/3.45 combo built late in the '89 model year, you should have dual cats.

 

Yup, looked under the passenger side this morning and saw the two cats. Made the mistake last time by looking at the driver's side. Whoops, just not used to a layout like that :\ Looks like everything was swept to the passenger side...

 

You got pretty much the ideally optioned thirdgen. Good gears, good trans, TPI... That should be a nice car. One worth keeping in good condition, and, IMO, worth keeping stock unless it's a little worn out with higher miles on it.

 

I was going to upgrade the exhaust from header on and up, cams, and the Stealth Ram intake manifold, as well as replace the bushings on the entire suspension system with the kit they provided. I was going to a KITT conversion on the front end only and repaint the car satin black, but since it's literally a matching numbers car, I'll simply restore the exterior and interior and do the upgrades I said I was going to do.