Exhaust
Thread Starter
Intermediate
Joined: Sep 2009
Posts: 41
Likes: 0
Exhaust
HI
I'm having my 87 Vet engine rebuilt.would like to have two pipes all the way back instead of a crossover pipe just below the stock headers.Can't get headers,would like some info.how to run a passenger side pipe to the back end.
Thanks Jim
I'm having my 87 Vet engine rebuilt.would like to have two pipes all the way back instead of a crossover pipe just below the stock headers.Can't get headers,would like some info.how to run a passenger side pipe to the back end.
Thanks Jim
Drifting
Joined: Aug 2009
Posts: 1,970
Likes: 242
LT1 engines came in base model 92-96 cars. They use a true dual exhaust system and supposedly are fairly unrestrictive. They seem to be a popular choice for L98 owners to ‘upgrade’ from their factory system. I’m not certain but I believe it will require the full LT1 system including the 2 cat converters to bolt up to the L98 – also not sure if you can use the stock L98 exhaust manifolds or if the LT1 pieces will be necessary. I’m sure an L98 guy that’s swapped on the LT1 system can provide those details.
As a side note – you can find used LT1 systems for very little. I paid $75 last year for a complete system that I’m installing on my car to replace the too loud for me aftermarket exhaust.
As a side note – you can find used LT1 systems for very little. I paid $75 last year for a complete system that I’m installing on my car to replace the too loud for me aftermarket exhaust.
Le Mans Master
Joined: Nov 2009
Posts: 6,882
Likes: 234
From: Bangkok, Thailand
The inside of that resonator is restrictive as hell and negates the "true dual" idea. It also joins the exhaust inside so again it's not "true duals".
Aside from that, if you can't do headers you could replace the horrid stock headers with LT-1 manifolds like I did and get a significant increase. Technically, you have to keep all 3 cats for Federal smog compliance. Magnaflow is the only company that makes a decent catted y-pipe, but it currently has fit issues that they are working on.
How much power will you make? A single 3" can handle 325 hp effectively.
Aside from that, if you can't do headers you could replace the horrid stock headers with LT-1 manifolds like I did and get a significant increase. Technically, you have to keep all 3 cats for Federal smog compliance. Magnaflow is the only company that makes a decent catted y-pipe, but it currently has fit issues that they are working on.
How much power will you make? A single 3" can handle 325 hp effectively.
Drifting
Joined: Oct 2004
Posts: 1,477
Likes: 80
From: Hawaii
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Le Mans Master
Joined: Nov 2009
Posts: 6,882
Likes: 234
From: Bangkok, Thailand
If you open one up you'll see how it's built. They're just like all of the GM muffler designs of that era. On the TPI Vettes they used "fake" dual outlets on the mufflers (except the 91's) to make it look like it flowed well. On the Chevy trucks of the time the 3" inlet necked down to 2 1/4", then went into a dead chamber. The only outlet from that 2 1/4" pipe were small louvers 1/4 of the way around the pipe, and then the flow reversed though 4 holes each the size of a dime.
The inside of that resonator is effectively one big chamber, although it's divided up into smaller chambers. Everything mixes in there - the pipes don't stay separate.
Aside from all that, a good single exhaust system will make more power than duals, but that's a whole nother conversation.
Le Mans Master
Joined: Oct 2008
Posts: 9,758
Likes: 49
From: Houston Texas
That Is a picture of My exhaust and I took a very long look at the LT1 system before I changed it over. The resonator as you will see here is not restrictive at all.
Last edited by ch@0s; Apr 24, 2013 at 01:53 PM.
Le Mans Master
Joined: Oct 2008
Posts: 9,758
Likes: 49
From: Houston Texas
Here is a picture of the resonator cut out you can see it does neck down there might be some HP to gain but I wouldn't think much. I might go with an X pipe in the future but only because my exhaust is very quiet for me, I'm close to 400RWHP.
Last edited by ch@0s; Apr 24, 2013 at 10:07 PM.
Drifting
Joined: Oct 2004
Posts: 1,477
Likes: 80
From: Hawaii
When I looked at an removed LT1/4 resonator, I was able to see right thru to the other end, on both sides. I can't see how that would be restrictive as hell.
Team Owner
Joined: Jul 2004
Posts: 28,378
Likes: 3,261
From: Hartford WI
Besides the rice factor, what is the point of true duals, especially without the X or H pipe? Why go thru the headaches if it is a DD? Getting good material and having it mandrel bent costs more effort than simply getting a good set of headers, a cat and cat back exhaust from what I can see unless you have a friend with a bender and some mad welding skills.
Melting Slicks
Joined: Jul 2011
Posts: 2,605
Likes: 202
From: Trinity FL
Yeah the resonator is nothing more than 2 perforated tubes in one can. Aside from it necking down a bit, it is not restrictive, nor does it join together anywhere. The stock LT1 Exhaust is a true dual system from the exhaust manifolds all the way back to the tips.
Team Owner
Joined: Dec 2000
Posts: 21,094
Likes: 282
From: Phila., PA burbs
The inside of that resonator is restrictive as hell and negates the "true dual" idea. It also joins the exhaust inside so again it's not "true duals".
Aside from that, if you can't do headers you could replace the horrid stock headers with LT-1 manifolds like I did and get a significant increase. Technically, you have to keep all 3 cats for Federal smog compliance. Magnaflow is the only company that makes a decent catted y-pipe, but it currently has fit issues that they are working on.
How much power will you make? A single 3" can handle 325 hp effectively.
Aside from that, if you can't do headers you could replace the horrid stock headers with LT-1 manifolds like I did and get a significant increase. Technically, you have to keep all 3 cats for Federal smog compliance. Magnaflow is the only company that makes a decent catted y-pipe, but it currently has fit issues that they are working on.
How much power will you make? A single 3" can handle 325 hp effectively.
Le Mans Master
Joined: Nov 2009
Posts: 6,882
Likes: 234
From: Bangkok, Thailand
Le Mans Master
Joined: Nov 2009
Posts: 6,882
Likes: 234
From: Bangkok, Thailand
That looks quite different from the one we cut off the car that the cat-back system we used to prototype the cat-back system for. Of course, that was 20 years ago, but I remember a very different looking resonator interior. Still, that one is a lot more restrictive than you might think since it lets the velocity drop to almost nothing.
Pro
Joined: Mar 2013
Posts: 697
Likes: 162
From: Huntington WV
I cut out my resonator on an otherwise stock car and I didn't notice any power increase but it is just a little louder when I stand on the throttle. No drone, turned out pretty much like I wanted it to.
