Increase Power 1985
Thread Starter
Intermediate
Joined: Oct 2009
Posts: 43
Likes: 0
Increase Power 1985
I have a 1985 coupe with just under 60,000 miles and am asking what would be the most bang for the buck in adding more horsepower. Don't want to spend mega bucks but would like to get a few more horses. Please give me ideas. Thanks.
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Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Read Vader86's web site as a start.
The 85 responds well to modified exhaust......I drop my cat for racing. Headers if you can run them in your state will also help. Intake modifications, larger runners. 1.5 and 1.6 Roller Rockers will add 10 HP (you will not feel much seat of the pants performance but they help). Cut the air box lid.
After those......$$$ for heads and cam.
The 85 responds well to modified exhaust......I drop my cat for racing. Headers if you can run them in your state will also help. Intake modifications, larger runners. 1.5 and 1.6 Roller Rockers will add 10 HP (you will not feel much seat of the pants performance but they help). Cut the air box lid.
After those......$$$ for heads and cam.
Le Mans Master
Joined: May 2007
Posts: 8,448
Likes: 27
From: Valparaiso
Read Vader86's web site as a start.
The 85 responds well to modified exhaust......I drop my cat for racing. Headers if you can run them in your state will also help. Intake modifications, larger runners. 1.5 and 1.6 Roller Rockers will add 10 HP (you will not feel much seat of the pants performance but they help). Cut the air box lid.
After those......$$$ for heads and cam.
The 85 responds well to modified exhaust......I drop my cat for racing. Headers if you can run them in your state will also help. Intake modifications, larger runners. 1.5 and 1.6 Roller Rockers will add 10 HP (you will not feel much seat of the pants performance but they help). Cut the air box lid.
After those......$$$ for heads and cam.
Thread Starter
Intermediate
Joined: Oct 2009
Posts: 43
Likes: 0
Thanks all - I have put on K&N filter and changed the air filter lid to the open one, what brand of headers would you recommend? I had always been told by GM that they needed the back pressure from the cat to run correctly - is that true? The other stuff like the Corvette TPI Intake Air Foil, 1985-1995 Part # A5965 from Ecklers etc. do they do anything or is it a waste of money?
Team Owner
Joined: Sep 2001
Posts: 62,154
Likes: 1,731
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
TPiS or Hooker 2149s.
Nope.
Pick your magazine up, order a hat, maybe a poster, and throw the thing away.
I had always been told by GM that they needed the back pressure from the cat to run correctly - is that true?
The other stuff like the Corvette TPI Intake Air Foil, 1985-1995 Part # A5965 from Ecklers etc. do they do anything or is it a waste of money?
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Verdad Gallardo
Pro
Joined: Mar 1999
Posts: 678
Likes: 0
From: Oslo, Norway
Hi. I have an 85 too and modified it.
What VAder said is right as always. I bought TPIS headers and you can bolt it on without any mods except for the airtube to the cat, but taking the cat away or put in an race metallic one you need not this tube.
You will get about 15 hp I think. Do change the catback to more free flow.
You will not feel any change with the airfoil on a 1985.
I changed the fuelinjectors to Bosch gen III. The engine runs much smoother and it seems to respond better but power increase? I don't know Have not dynoed it .May be it is the placebo effect.
Good luck
What VAder said is right as always. I bought TPIS headers and you can bolt it on without any mods except for the airtube to the cat, but taking the cat away or put in an race metallic one you need not this tube.
You will get about 15 hp I think. Do change the catback to more free flow.
You will not feel any change with the airfoil on a 1985.
I changed the fuelinjectors to Bosch gen III. The engine runs much smoother and it seems to respond better but power increase? I don't know Have not dynoed it .May be it is the placebo effect.
Good luck
