exhaust system, HP gain?
Thread Starter
Burning Brakes
Joined: Aug 2006
Posts: 793
Likes: 11
From: Grafton MA
exhaust system, HP gain?
The previous owner of my '71 LT-1 put the wrong exhaust on the car (currently has 2'' pipes instead of 2 1/2''). The car is not as quick as it should be, and i'm not sure if I put the correct exhaust system on if there will be a noticeable performance improvement...or perhaps the original motor (never rebuilt) is just showing its age.
Thanks.
Paul
Thanks.
Paul
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
Ofcourse the 2" pipes and probably crappy mufflers are hurting power....How much is hard to say.. On a stock motor it may be 20-30 rwhp or less.... A lot depends on if it has the stock exhaust manifolds or not as they are the main restriction.
I would do a nice mandrel bent 2.5" exhaust, x pipe and good flowing straight through mufflers like Dynomax Ultra Flows or Magnaflow. Its worth the investment... Then if you end up refreshing the engine down the road, the exhaust is already done and you will really benefit from it then.
I would do a nice mandrel bent 2.5" exhaust, x pipe and good flowing straight through mufflers like Dynomax Ultra Flows or Magnaflow. Its worth the investment... Then if you end up refreshing the engine down the road, the exhaust is already done and you will really benefit from it then.
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
Ofcourse the 2" pipes and probably crappy mufflers are hurting power....How much is hard to say.. On a stock motor it may be 20-30 rwhp or less.... A lot depends on if it has the stock exhaust manifolds or not as they are the main restriction.
I would do a nice mandrel bent 2.5" exhaust, x pipe and good flowing straight through mufflers like Dynomax Ultra Flows or Magnaflow. Its worth the investment... Then if you end up refreshing the engine down the road, the exhaust is already done and you will really benefit from it then.
I would do a nice mandrel bent 2.5" exhaust, x pipe and good flowing straight through mufflers like Dynomax Ultra Flows or Magnaflow. Its worth the investment... Then if you end up refreshing the engine down the road, the exhaust is already done and you will really benefit from it then.
I can tell you going from 2.25 to 2.5" on my L48 was a BIG improvement... going to headers bigger still. The effect on an LT1 would by comparison be greater.
Thread Starter
Burning Brakes
Joined: Aug 2006
Posts: 793
Likes: 11
From: Grafton MA
Thanks guys. The car has the stock manifolds, so i would probably get the correct exhaust for the car which has the 2'' pipe that opens up to 2 1/2 inch just below the manifolds. Sounds like it's worth the investment.
Instructor
Joined: Aug 2011
Posts: 131
Likes: 9
Hi Paul
I have a stock 71 LTI
I just put on headers and magnaflow exhaust
The horespower and off the line performance has certainly increased
I cannot tell you by how much, but certainly has more jump and worth the investment
Hope this helps
Fun Car!!
I have a stock 71 LTI
I just put on headers and magnaflow exhaust
The horespower and off the line performance has certainly increased
I cannot tell you by how much, but certainly has more jump and worth the investment
Hope this helps
Fun Car!!
