Performance Upgrades
Thread Starter
3rd Gear
Joined: Jan 2004
Posts: 3
Likes: 0
From: Mount Wolf Pa
Performance Upgrades
My father has decided to keep the car a little longer and upgrade some parts. What are your recommendations on upgrades? I know he definitely wants an exhaust, but which company make a good one? I also thought about intake.
The other thing is...since this car was one of the first to be slapped with all the emissions BS, is there any mods that are simple to get the HP about 300?
Thanks
The other thing is...since this car was one of the first to be slapped with all the emissions BS, is there any mods that are simple to get the HP about 300?
Thanks
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Performance Upgrades (8T5 Corvette)
An '85 Vette responds well to some simple mods.
Effective exhaust mods include: full length ceramic coated headers, hi-flow cat, hi-flow cat-back. These will net 30chp or more.
A good intake mod is a K&N air filter with cut air filter lid.
Other simple mods include a 160 deg T-stat and fan switch, increase TPS base setting to .65Vdc, bump base timing a few degrees, install underdrive crank & overdrive alt pulleys, cut back spark plug ground electrodes.
More extensive mods include 1.6:1 RRs but that will require machining the iron heads on an '85 Vette. A more agressive flat tappet cam with the RRs and a set of nice heads will bring some very nice power increases.
To get max. benefit from heads & cam mods some mods to the intake base & runners is needed to enhance top end breathing.
It should be able to get in or very near the 300chp mark without doing heads or cam.
Effective exhaust mods include: full length ceramic coated headers, hi-flow cat, hi-flow cat-back. These will net 30chp or more.
A good intake mod is a K&N air filter with cut air filter lid.
Other simple mods include a 160 deg T-stat and fan switch, increase TPS base setting to .65Vdc, bump base timing a few degrees, install underdrive crank & overdrive alt pulleys, cut back spark plug ground electrodes.
More extensive mods include 1.6:1 RRs but that will require machining the iron heads on an '85 Vette. A more agressive flat tappet cam with the RRs and a set of nice heads will bring some very nice power increases.
To get max. benefit from heads & cam mods some mods to the intake base & runners is needed to enhance top end breathing.
It should be able to get in or very near the 300chp mark without doing heads or cam.
Team Owner
Joined: Sep 2001
Posts: 62,067
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: Performance Upgrades (8T5 Corvette)
The different catback exhausts only differ in sound, so its whatever you prefer for those.
Hooker 2149 or 2151 headers, a new Random Tech cat, and the catback should bring in about 25-30hp altogether. You can get rid of the cat entirely if you dont have a sniffer test where you live.
Removing the AIR emissions pump and the pipes with it dont really do anything to the performance, EGR doesnt work at full throttle so its not hurting you in that respect (though it does add alot of crap back into the motor).
RR, intake portwork, will all help you get closer to 300 crank HP.
Further mods will entail replacement of the intake manifold, and preferably new heads because 84-86E heads suck. But you dont need to think about that stuff if you only want 300. You should be able to find out anything about them in a search though.
Hooker 2149 or 2151 headers, a new Random Tech cat, and the catback should bring in about 25-30hp altogether. You can get rid of the cat entirely if you dont have a sniffer test where you live.
Removing the AIR emissions pump and the pipes with it dont really do anything to the performance, EGR doesnt work at full throttle so its not hurting you in that respect (though it does add alot of crap back into the motor).
RR, intake portwork, will all help you get closer to 300 crank HP.
Further mods will entail replacement of the intake manifold, and preferably new heads because 84-86E heads suck. But you dont need to think about that stuff if you only want 300. You should be able to find out anything about them in a search though.
