SHould I get an S5 GTU or keep looking for an S4 base or sport?
 

I want to build up a daily driver NA. Nothing too crazy since I need it to be reliable and stand up to some track day abuse. I already searched the forum and it looks like the S4 base and sport models are the lightest around. But I found a an 89 GTU for cheap and was wondering if I should buy it? I really want the lightest FC to begin with though. My goal is around 2400-2500 lbs without a stripped to the bone interior. The S5 is cheap but I don't know if it is what I want. The sport really is the lightest to begin with. :wallbash:

S5s are fat pigs, get the S4 Sport as it has superior suspension and brakes to an S5 GTU.

I'd say get the absolute best condition car you can afford. It'll save you many headaches down the road.

I paid quite a bit more for my car than many of the ones I looked at, but the others were all older and in nowhere near as nice a condition as mine was in, and mine had a freshly rebuilt engine. I'm sure that I would have had many more problems with another car than I've had with mine. It's given me hardly any problems in the over 3 years that I've owned it. I've taken it to the track twice for weekend long driving schools where it did double duty with 2 drivers and it never gave me problems there.

Light weight is important, but having a reliable car in good condition is more important IMHO, especially for a daily driver.

I've got an 87 sport FS for like $300 in western NC. Burgundy Int. Body and paint are in pretty damn good shape. It has a dent on the rear drivers quarter below the trim. (Shameless Plug)

If you can get a good deal on an S5 GTU then get it. I have an S5 GTU and it is great, but soon will be taken apart. I did exactly what you are doing. I've daily driven it and beat on it for the past year and a half now. It's been a great ride. I like the S5 NA motor much better too.

Yes and if it hasn't had a rebuild within 50 or 60k miles then that should also be factored into the price. Depending on what you plan to do with the car or how much time you want to invest into it. If you want one with a blown engine so you can be sure of a rebuild then go that route. But if you're looking for one running then certainly check it out to the best of your ability no matter how cheap it is. Take a look at Aaron Cake's buyers guide. In the FAQ's

Find a GTUs.

HAHA, FIND a GTUs. Thats sound advice, You selling one? Cause that and a GTU are not gonna be anywhere near the same price.

I have an 86 GXL and a 91' "package a" the 91' has the AC and power steering stripped off it and the car is sitting high on the suspension so i know its pretty damn light right now, especially with the aluminum TII hood and other small things. I may gut the sound deadening material and replace it with dynamat in the important spots.

Well, theres a few things to consider:

S4 Sport:
Far superior suspension
Far superior brakes
Super lightweight, more potential for being light
Lower horsepower

S5 GTU:
Crappy suspension, not suitable for racing
Crappy brakes, not safe for racing
Medium fat-ness, less potential for being light
Higher horsepower


S4 Sport/GTU OWNS S5 GTU, hands down. If you could find an S5 GTUs, you'd want to get that, though. But, the perfect car..S4 Sport/GTU with an S5 engine. :)

pfft, the guy that sold me his fc for 500 bucks didn't realize it was an 86 sport. He thought it was a GXL! And yes, I scored big. But now the car has a dent on the rear quarter because of an accident.

One of the reasons the S4 Sport is lightweight is because of the cheaper carpet correct?

Considering you are talking about weekend track days occasionally, I would recommend the S5. For one, you can get it now. Second, you can lighten it up with minimal effort. Third, you get the stronger powerplant (even if you have to rebuild soon). Fourth (and my honest but piddly opinion) it looks nicer than the S4. If you take the other advice of getting a GTUs, well, you will be absolutely no closer to track days than you are now. GTUs is a highly regarded, hard to get vehicle. I have only seen 2 in my days, and I am 39 and have been a rotorhead for 20 years. So go S5 GTU (I actually have one, and it is also an 89) and hit the road.

adrock3217: You have a lot to learn about the suspension and brakes of the FC.

The S4 and S5's suspension differs very little. The sport models have slightly stiffer springs and roll bars, but not much over the others, and the S5 is not much softer at all. These differences are very minor, on the order of less than 10% IIRC. The S5 has superior swaybar endlinks. The S4 has the replaceable front balljoints. The basic suspension design is IDENTICAL. With aftermarket springs and shcoks, as would be done to any serious track day car, they'll be the same other than the endlinks and balljoints.

The 4 pot brakes on the S4's and S5's are the same, and the single pot brakes on the 5 lug cars are the same as well. In fact the only difference comes with the S4's and the base models with the 4 lud brakes which are significantly smaller.

I'll have you know that I've had my car (on stock suspension) out on track at two seperate driving schools where at each one it did two days straight double duty with two students, meaning it was on track half the time and it never gave me any problems. The suspension was very well behaved and you could give it absolute hell and it never bit back. It gave 3 seperate people an introduction (or re-introduction for 1) to the track and was an amazingly good learner's car. I have the single piston brakes and I never had any fade or other problems with them, even with using only track day pads, and not real racing pads (Hawk HP+), and using only Ford DOT 3 fluid, not the fany racing fluid that costs 4x as much.

So I fail to see how the S4 could be "far superior" and how the S5 is "unsafe for racing" and "unsuitable for racing".

So please get your facts straight, stop over exagerating, making up stuff and talking out your ass.

You have a lot to learn about the suspension and brakes of the FC.

True that!

The S4 and S5's suspension differs very little. The sport models have slightly stiffer springs and roll bars, but not much over the others, and the S5 is not much softer at all. These differences are very minor, on the order of less than 10% IIRC. The S5 has superior swaybar endlinks. The S4 has the replaceable front balljoints. The basic suspension design is IDENTICAL. With aftermarket springs and shcoks, as would be done to any serious track day car, they'll be the same other than the endlinks and balljoints.

I suppose Mazda called the regular suspension "soft" and the Sport/GTU/GTUs/Turbo suspension "hard" for no reason at all!

The 4 pot brakes on the S4's and S5's are the same, and the single pot brakes on the 5 lug cars are the same as well. In fact the only difference comes with the S4's and the base models with the 4 lud brakes which are significantly smaller.

The S5 GTU has single pot...correct? Wouldn't that rule out your entire argument? Yes. The S5 GTU has 1.1" smaller brake rotors, single piston, and SOLID rotors. Not ventilated. Which would you prefer on the track, hm? Yeah. I don't see what this base model subject has to do with anything, as I didn't ever reccomend him getting one of those. Kthx.

I'll have you know that I've had my car (on stock suspension) out on track at two seperate driving schools where at each one it did two days straight double duty with two students, meaning it was on track half the time and it never gave me any problems. The suspension was very well behaved and you could give it absolute hell and it never bit back. It gave 3 seperate people an introduction (or re-introduction for 1) to the track and was an amazingly good learner's car. I have the single piston brakes and I never had any fade or other problems with them, even with using only track day pads, and not real racing pads (Hawk HP+), and using only Ford DOT 3 fluid, not the fany racing fluid that costs 4x as much.

Yeah..people learning to drive at a driver's school is totally different from someone doing real racing. They wouldn't even come close to pushing it as hard, or for such prolonged periods of time.

So I fail to see how the S4 could be "far superior" and how the S5 is "unsafe for racing" and "unsuitable for racing". But yeah, thats good to know, I wouldn't have expected them to not show fade.

So please get your facts straight, stop over exagerating, making up stuff and talking out your ass.

Well..it seems here that nothing I said was made up, or talking out of my ass. All of my words were facts from Mazda, besides my tiny little opinions here and there. My facts are straight. I may have exagerated a bit on the safety and not suitable part, but hey, I like knowing things are going to work, and work well. I personally wouldn't accept solid rotors and single pistons, but thats just me..

Have you ever driven an S4 Sport or GTU? The "road feel" of any S5 (including the GTUs) is nearly nonexistent by comparison.

is there a number or letter in the vin that identify's a GTUs? Or is there anyway to tell the difference without removing the tires and checking the calipers?

Funny, most of these discussions are about the benefits/detriments of the two series with the stock option packages. The original poster indicated that he was going to do a build up. So if we assume that he is slowly going to be replacing pieces and parts then most of these arguments simply fall out.

1) the bare S4 and S5 shells are almost the exactly same weight. The main weight difference between the cars is a result of different options and packages. If our original poster is looking at gutting the interior (and I assume locating an aluminum hood) then the S4 v. S5 weight debate is a non issue.

2) much more important would be finding a non-sunroof and rust-free shell.

3) the single most expensive-to-replace difference between the two series is the engine, and the S5 wins here.

4) rotors and brakes are relatively easy to update.

As one of the earlier posters said, the most important consideration right now is to find a good straight and rust-free chassis, preferably w/o a sunroof, that will give you a good base platform to build from. I would favor an S5 because the engine/harness/ecu are already in place.

Good luck,

-bill

Actually, I have a 88 GTU and an 89 GTU. So..yes.

I agree with wrankin in all he said, he's got good advice.

The single piston fronts actually use the same exact rotors that the 4 pot brakes use, so there's no difference there. The rear brakes are only 0.4" smaller (10.3" vs 10.7") and they do harly any of the stopping anyway. I agree that the 4 pot brakes are better, but not by much, the rears do hardly any of the braking anyway, and the heat is nowhere near as much of a problem in the rear as it is in the front. Single piston calipers are just as capable of stopping a car as 4 piston ones are, they're just heavier and flex more, they provide just as much stopping power. Besides, it's cheap and easy to do the conversion from a scrapped car.

As for them calling one "hard" and one "soft" that proves nothing. As I said before, it is harder, but not by much, and for a track car it's of little signifigance as it'll probably be getting a new suspension anyway.

I don't feel that the softer suspension is that big a deal. In fact I recently put down a raw time at an autocross (very tight and slow) that would have put me in second place in terms of raw times (out of 5) in SM2 against blown and coilovered or otherwise well suspended Miatas. So much for the soft suspension sucking (the only suspension mods I've got are RB sways, some bracing and poly bushings). I'll even post a link to the results and a description of the cars in question if you really want.

I admit that learning is not as hard on the car as racing, but we were driving it pretty damned hard for 30 minutes at a time, back to back, so that's a pretty good torture test. I know I was outbraking many cars that should have been outbraking me. I even managed to pass a Lotus Esprit S4 amongst others, so I was obviously driving the car pretty hard.

I have driven several S4's, but that was years ago when I was car shopping.

Anyway, I just get tired of people ragging on the S5, the single piston brakes and the softer suspensions. They're perfectly capable of performing very, very well, and I've proven it a number of times myself.

What R the difference's S4,S5
 

I'm a little new to dis but what r the difference's.
I have a 89 NA
no power windows,
Manual tranny,
Sun roof,
oh yeah it has front & rear sway bars
15" rims

So which one do i have guys Hmhmmm

http://rx7.voodoobox.net/infofaq/rx7specs.html

^^All of that information looks correct to me.

The S5 handles better than the S4... Huh, kinda funny huh? Since everyone says the S4 is so much better.

The S5 looks a lot better anyways.

0-60 in 7.2 seconds? Sounds like the wishful thinking of an S5 owner. Whose ass did that chart come out of?

well which 1
 

no serious which one do i have

Uh, just so you know..literally every single detail of that entire chart, less a few of the horsepower figures, is wrong.

http://mazdamark.com/about_the_s5_fc.htm

http://mazdamark.com/about_the_fc.htm