86 GT Convertible

Dino

Active Member
Nov 17, 1999
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Halifax, NS, Canada
86 GT Convertible (intake and heads Q's)

I owned this car about 10 years ago and my father bought it off me when I got my 96 GT. If I’m able to get a garage built at my house then I was told I could have it back since it has basically just sat for the last several years in his garage and hasn’t been used.

The mods it has on it are: Dynomax ¾ length headers, off-road H-pipe, custom cat-back with Dynomax Super Turbo mufflers, 3.55’s, s/f connectors, strut tower brace, it also has a generic APR Superchip (I think that’s what it’s called – I don’t think it really did anything though).

It’s speed density so I may look at changing that. Would I see a noticeable hp increase from changing the lower/upper intakes? If so, what one do you recommend? Do I need to switch to MAF before doing the intakes? I’ve been reading on here that the 86 GT’s had flat top pistons so aftermarket heads won’t work. Are there any that will?

Any other info/tips you can provide on the 86’s would be appreciated.
 
I've never heard of anyone willing to shell out 12 Large for a garage to put an 86 anything in so I guess you must love this car.

I just went thru the mechanicals of an 86GT conv after it sat for about 4 years in a garage. You will put $1500 into the car to make it reliable again. I still have to buy a new top for $750 installed. Good thing you are getting the actual car for "free". I kept my wife's car bone stock as I compete in autocross stock class and am very happy with the power/streetability of the car. She loves the AOD:)

Do a search for the 86 - 5.0 as currently there are many threads on this upgrade and alot of ways to go. Yes it has flat top pistons but there are still 2-3 ways to go with heads all detailed at length on the board.

At least you will have a garage to work in to do all this.

Good luck.
 
I owned this car about 10 years ago and my father bought it off me when I got my 96 GT. If I’m able to get a garage built at my house then I was told I could have it back since it has basically just sat for the last several years in his garage and hasn’t been used.

The mods it has on it are: Dynomax ¾ length headers, off-road H-pipe, custom cat-back with Dynomax Super Turbo mufflers, 3.55’s, s/f connectors, strut tower brace, it also has a generic APR Superchip (I think that’s what it’s called – I don’t think it really did anything though).

It’s speed density so I may look at changing that. Would I see a noticeable hp increase from changing the lower/upper intakes? If so, what one do you recommend? Do I need to switch to MAF before doing the intakes? I’ve been reading on here that the 86 GT’s had flat top pistons so aftermarket heads won’t work. Are there any that will?

Any other info/tips you can provide on the 86’s would be appreciated.

The 86 has a smaller intake and throttle body. The heads are a bit different, and the pistons are in fact flat top. My suggestion would be to get an aftermarket intake/TB on it first. An electric fan is worth a few ponies.

I miss mine. I drove an 86 GT vert for 5 years when I was a teenager. :nice:
 
I've never heard of anyone willing to shell out 12 Large for a garage to put an 86 anything in so I guess you must love this car.

It's not for the car. :D
I am wanting to have a garage for my woodworking and storing things in that are currently in the basement.
My parents just told me that if I ever got a garage they would send it up to me since it would need to be stored somewhere during the winter and couldn't be left outside.
 
I just went thru the mechanicals of an 86GT conv after it sat for about 4 years in a garage. You will put $1500 into the car to make it reliable again. I still have to buy a new top for $750 installed. Good thing you are getting the actual car for "free".

It was working fine when it was last out a few years ago. I shouldn't say it hasn't been driven in years. It has seen very minimal mileage. Maybe a handful of short drives in the summer. The top is also fairly new and has seen minimal sun and rain since it's mostly be in the garage. I just saw it a month ago and the top still looked great.
 
mass air swap won't make a damned difference in the world, unless you swap out the cam, which isn't happening with those pistons.

my suggestion is to swap out the motor with one with notched pistons.

however, if it's in good shape, tfs makes heads that will bolt right on, and I think you can even use a cam too. That would be my suggestion if the motor is still strong.

If you don't want to go that route, just swap on an 87+ upper intake and t/b (lowers are the same)..that alone will help.

don't go too crazy on the rear gears though, as the stock heads die around 4800 rpms...gears will turn that little 86 motor into a dump truck.
 
I think the heads, tb, and upper intake were 86 only. The tb is a 58 mm and it was for lowend torque. the upper intake had that black rubber thing on the right side, the 87+ ones flowed better. Before I rebuild, I switched out the upper and tb and it felt like it had more topend.
 
Currently the car has Dynomax ¾ length headers, off-road H-pipe, custom dynomax super turbo catback, and 3.55’s.

I read on here that the Trickflow heads will work with the 86 flat top pistons with no modifications.

So what sort of gains would be seen with an 87+ intake, tb and Trickflow heads?
 
Currently the car has Dynomax ¾ length headers, off-road H-pipe, custom dynomax super turbo catback, and 3.55’s.

I read on here that the Trickflow heads will work with the 86 flat top pistons with no modifications.

So what sort of gains would be seen with an 87+ intake, tb and Trickflow heads?

If you're going to put TW heads on it, you should just go with an aftermarket intake/throttle body. Even the '87 intake manifold would be really holding those heads back.
 
Okay thanks!

So what about the Cobra intake (upper/lower) with those heads?

Meh. I'd go bigger personally. GT-40 style intakes, like the Cobra, are good for mild street applications, but really it is a outdated design. It's nearly 20 years old now. There are other intakes out there that will perform better. Some guys successfully make GT-40 stuff go fast, no doubt, but if you've got money to spend, I'd reach for something bigger.