New to me 1988 GT Convertible.

[lemosley1973]

I thought I had an account here years ago, but I guess not!

I just purchased a pretty much unmolested 1988 GT convertible. I'm relatively new to the fox/5.0 platform but not Mustangs having had a '96 GT, 99 Cobra, currently a 2003 Cobra. I had a turbo-swapped Fox for about a year, but didn't do much with it.

Known mods are xpipe + catback, bbk cai, bbk 70mm throttle body, Accel ignition (I think - used to dealing with newer platforms that don't have distributors), and it's lowered with 17" wheels on it (they look like 2003 Mach1 wheels). The clutch was just replaced with a Zoom clutch (or claimed; kind of hard to tell).

The first actual mod done by me will be full-length subframes. The interior is tired, window motor actuators are half dead, etc, so I'll be cleaning up the interior and trying to restore it proper 80s glory. I've just replaced the headlight switch and harness (it was burned from the foglights like probably every other GT ever built).

The clutch has a chirp until depressed. I assume this is a TOB problem (my Cobra has a chirp that goes away when the clutch pedal is depressed).

I'm not going to cut this car up - my plan is a nice, fun street car that I can drive without worries. I'd like to get to around 300HP while maintaining the stock look.

I have no idea what stock headers look like - are these stock?

 

[General karthief]

Yup, they look original

 

[mikestang63]

fyi...shorty headers add maybe 10 -15 hp....mostly for looks and sound

 

[lemosley1973]

10-15 HP isn't bad for a car that started with 205(?) HP! Do they really add that much?

 

[BlakeusMaximus]

They claim 225 hp. 15 might be a little on the high side. I’ve heard 8-10. Mikestang might be right though. Let’s see some pics of the car.

 

[Mustang5L5]

Eh, headers were one of the first mods I did to my '88 when it was stock. I didn't notice anything. I don't think the factory headers are all that bad but if you gave a 2.5" catbanl and h pipe and other mods it might be a better gain.

Rather than headers, if it has the stock intake I'd toss an explorer intake and 65mm TB on it. That was a good SOTP gain on my car

 

[General karthief]

In goes the good air, out goes the bad. As we all know the stock stuff is a good compromise, to take advantage of any bolt on up grade you have to look at the big picture. The only mod that come to mind that you can feel without any other changes is the final drive gears. Really good bang for the buck but still limited because the working rpm range of a stock engine. Some claim as much as 25 hp from aftermarket headers but reality is more like 5 hp with no other mods.
grab an explorer intake, some aftermarket headers, and a 355 rear gear, you could toss on an explorer tb too. Then you will feel the difference. After that you will be hooked and you can toss your retirement money at a turbo or supercharger because well, it's an addiction, just remember to invest in a good set of jack stands.

 

[Mstng93SSP]

I like and the way the car sounds with shorty headers.

 

[Blown88GT]

Seems like '88's are showing up all at once.
Without increasing intake air flow, headers won't help much.
Suspension items make the biggest difference, which is what I started with.
Then stiffen up the body.
First the subframes
Second, strut tower brace.
Third, shocks & struts. Tokicos are among the best.
The verts are notorious for sagging engine & transmission mounts. If needed, get the Energy Suspension polys.
Karthief mentioned gears, stock are 2.73, not much for getting going.
Most of this is in my sig.

 

[lemosley1973]

Pic (as requested eariler).

FLSC are the first item on the list. No performance mods until that is done.

I"m not sure what gears are in it - I need to verify it still has stock gears, since you can't see if that is the case. The trip home was eventful because the BBK TB would stick closed and I didn't have good throttle control trying to break it free. I found that the idle screw was all the way out, so I screwed i int until it just barely keeps the plate off of fully closed. Needless to say, a trip on wet roads with a sticking TB in an unfamliar car was something I won't forget.

I'm also getting the foglight brackets so I can install new fogs. I have a new driver window switch. The marks along the body are where the skirts were, but they were cracked and removed, and someone decided bondo'ing it would be a good idea (sigh...).

I was under the car today figuring out the bracket install and it looks like I have a leak from the water pump or gasket and from powersteering. Not bad from the PS, but it's grimed up the area, so I need to run those down.

WRT to the water pump, should I just go ahead and replace it even if it were a failing gasket? The car has 88,000 miles- what is typical water pump life in these?

 

[General karthief]

Will not hurt to change it, and give you a chance to check other things.

 

[90sickfox]

Nice car. I think the gt convertible is going to be the sought after car in the near future. Convertible high optioned vehicles are always worth more than their siblings.

 

[lemosley1973]

I really like convertibles. Coupes have the advantage in $$$ to go faster, but a proper convertible is a joy to look at, and they expose you to the elements more - it's a much difference experience, and more enjoyable for me.

It's one of the things I enjoy about riding a motorcycle.

 

[deathb4dismount]

You're on the right track with SFCs. @Blown88GT is spot on with the suspension upgrades. I'd take a car with stock power and a nice straight suspension setup over a sloppy riding car that makes good power any day. Replace the shocks, struts, springs with a quality suspension part. Stay away from the house brand parts. Add a quality lower control arm and stock style upper with rubber bushings. Replace worn motor and trans mounts, and any worn bushings. Add a 373 gear then let her rip.

 

[Blown88GT]

I fixed PS leaking with a stop-leak additive. It swells the seals & causes no damage.

 

[lemosley1973]

Thanks Blown88Gt - it's worth a try. I assume that it won't cause any problems if it doesn't stop the leak and I have to start pulling things apart?

 

[lemosley1973]

I think my power steering leak was from the cap. It's full almost to the top and the cap twiisted off easily, so I bought a new one with a new O-ring and now it's much tighter - hoping that takes care of that leak. Still need to run down where the coolant leak is - the area around the weephole on top is dry and shows no indication of coolant - it seems to be coming from the the side or nearer the top.

How much fluid should be in the radiator? it's a couple inches below the cap The overflow was bone dry. I thought it looked empty but couldn't tell with the sensor in the way, so today whlie under the car I checked it and also figured out how to remove the sensor so I can see in the overflow better. I haven't driven it since I brought it home since I wanted to get the fog lights installed first.

I also notice that my fan shroud is held on by 2 zipties at the top (pic below). I assume this is an 'aftermarket' mod - any idea what size screws that takes?

The foglights are installed - that helps the front a lot. I'll be ditching the cowl hood - I dislike how tall this one is (3 or 4 inches) and generally don't care for that look unless there is a big blower underneath or sticking through it.