Quick question. Are the exhaust manifolds on Z28s (and Trans Ams) bigger than the manifolds on my RS? I would imagine they are. And, if so, are the manifolds on the TPI 350 bigger than the manifolds on the TPI 305?
I'm asking because I want to open up the exhaust on my '92 a bit. But I'm too cheap to buy headers and get custom work done. So I figured I'd pick the manifolds and Y-pipe out of the junkyard, get a nice cat-back, and call it a day.
I have no clue if this is correct but i vaguely remember reading something like l98 and lb9 G92 cars had the same size manifolds...but non g92 lb9's and lo3's had the same size manifolds?? i hope thats not the case but that is what i remember reading...
__________________
1992 RS Heritage Edition **RIP**
1992 Z28 Heritage Edition 32,000 Miles
Black (w/ Red Stripes) & Black Interior
**Z03**G80**LB9**CC1**
Honestly, you're probably better of saving your money. All thirdgen manifolds and y pipes suck. It's not worth spending a penny on and you probably wont see any noticable gains. You should hold off and try to find some used stuff.
The L69 (and its exhaust) was an a$$ kicker in its day. If you check out its Y pipe in the above link, you'll see how it compares against the LG4 for example. I swapped on a complete L69 exhaust--manifolds, Y pipe (and high-flow cat), and intermediate pipe, which was larger than the after market catback I had put on the LG4. Along with an L69 air box, the L69 exhaust turned out to be pretty impressive on the butt dyno. I purchased the whole business at a yard for less than a hundred bucks. Considering cost vs performance, I thought I'd spent wisely. And, yes, headers would be the best choice.
That's what I mean. You're probably going to spend almost 100 bucks all said and done. You might aswell hold off and spend 200 and find some used stuff. *shrug*
I mean i dont even know if it would be practical because for the same price you could probably buy headers...but if you wanted a stock/sleeper look a pair of 2 1/4" ported manifolds and 3 in-ypipe would probably be pretty lethal....
I'm asking because I want to open up the exhaust on my '92 a bit. But I'm too cheap to buy headers and get custom work done. So I figured I'd pick the manifolds and Y-pipe out of the junkyard, get a nice cat-back, and call it a day.
I was satisfied with my little venture, and something similiar will work for you too (without the headaches sometimes encountered with headers).
Headers would definitely be better. But this route is cheaper and easier. The car is my daily driver, so I'm really doing it more for the gas mileage if anything. Not the speed.
The car is my daily driver, so I'm really doing it more for the gas mileage if anything.
With my modded LG4--cam, intake, carb tweaks, complete L69 air box and exhaust--I was getting 24 mpg highway, which I thought was pretty darned good. And the gravy? More grunt (but nothing like the 350 HO Deluxe I'm now running. Highway 18 .
So I figured I'd pick the manifolds and Y-pipe out of the junkyard, get a nice cat-back, and call it a day.
.
