Winter upgrade suggestions.

[iheardsupport]

Hey guys, I've got my '88 stock GTU n/a garaged for the winter and have got some time/ money to sink into it. What would be your first/most effective mod I should start with?

[My5ABaby]

1. Body/Paint.
2. TII (if you want power)

[Waffles]

your personal goals are going to dictate where you want to start with any car. So, what do plan to be using your car for?

[Pete_89T2]

The first question you need to ask of yourself, that only you can answer, is what are your goals for this car? Share that with forum, along with a summary of where the car stands as of today (i.e., overall condition), and you'll get some really good advice.

[iheardsupport]

OH how frustrating when you have a long post all typed out and you accidentally click the back button on your browser and it deletes it all!!!

Anyway. (shortened version this time) This isn't a daily driver for me, its always been a dream of mine to own a 2nd gen RX-7 so now that i have one i just want to make it my own. Make it visually unique and slightly upgraded performance but not maxxed out or anything!

The body has 110k miles on it, the engine has 17k after a total rebuild. There are no mechanical problems that i know of at all. The body also has pretty much zero rust on it, which is unbelievable for a Michigan car, and one of many reasons i won't drive it in the winter! I'm pretty sure my first order of business is to get new rims/tires because it needs new tires anyway and i don't want to put them on the old OEM rims when im going to get new ones anyway


And this is the car!

[firzen]

I ditto what Pete and Waffles said, although I also want to add a note: take care of whatever that doesn't work. You say everything works mechanically but look through the forum and find out where the typical problems for the car appear. The car has a bit of mileage so <something> is got to be on its way out.

I would help to know how long you've had this car and how many miles you personally put on it.

Edit: Also just saw your thread in the interior section. Get those things fixed first before getting your wheels.

[iheardsupport]

Alright, I'm definitely gunna do that. I've put about 6k miles on it. Now that i think of it when trying to shift into 3rd kinda quickly it sometimes will grind for seemingly no reason, and also grinds going into reverse everytime no matter what?

[My5ABaby]

Originally Posted by iheardsupport

Alright, I'm definitely gunna do that. I've put about 6k miles on it. Now that i think of it when trying to shift into 3rd kinda quickly it sometimes will grind for seemingly no reason, and also grinds going into reverse everytime no matter what?

That's an old and abused (by that I mean driven spiritedly) transmission for you. If you want to TRY to get rid of that, find a low mileage replacement. Good luck though.

[iheardsupport]

Is it a big deal? I got it to the point where i can shift into third without it doing it now, just gotta do it right. I had a mechanic tell me it was possibly the synchro (sp?) is that true?

[Pete_89T2]

Originally Posted by My5ABaby

That's an old and abused (by that I mean driven spiritedly) transmission for you. If you want to TRY to get rid of that, find a low mileage replacement. Good luck though.

Concur with this and what your mechanic said about worn sychros WRT 3rd gear, but the grinding while shifting into reverse sounds like it could also be an issue with the hydraulic clutch linkage. Problems there can lead to grinding in any gear, as the clutch may not properly engage/disengage as it should. Look for signs of fluid leakage around the clutch slave cylinder, especially on its rubber boot - if you squeeze the boot a little and fluid leaks out, it's shot.

[josh18_2k]

all transmissions grind going into reverse if you shift too quickly. clutch in, come to complete stop, wait a sec, then put it in reverse.

if 3rd is the only gear that grinds, its a synchro. not worth replacing, just find another trans if it bothers you enough. they're decently cheap and not very hard to replace (have someone experianced help you)

[NoDOHC]

It seems strange that the 3rd gear synchro is bad... It is almost always the 2nd gear synchro that goes on the Mazda transmissions (the reason for this is the large split between 1st and 2nd).

Originally Posted by josh18_2k

all transmissions grind going into reverse if you shift too quickly. clutch in, come to complete stop, wait a sec, then put it in reverse.

Almost correct, the S5 transmissions had synchros in reverse. However, If that is the original transmission in that car, it would not have synchros.

The grinding occurs because the splines on the shift sleeve are moving at a different rotational speed to the splines on the inside of the gear when they are moved into contact with each other. Synchros avoid this by resisting shifter movement while applying force to draw the splines to the same speed. When the speeds match, the synchro quits resisting shifter movement and allows engagement of the splines.

It is possible to rev match and change gears smoothly without synchros, but it is much more difficult (especially downshifting).

[My5ABaby]

Originally Posted by NoDOHC

It seems strange that the 3rd gear synchro is bad... It is almost always the 2nd gear synchro that goes on the Mazda transmissions (the reason for this is the large split between 1st and 2nd).

My 1st to 2nd is fine but grinds into 3rd.

[iheardsupport]

Thanks for all the info, its actually quite rare when i can get it into reverse without grinding. Something i have noticed is to keep it from grinding i have to push the shifter knob into third at a certain angle, which i can do every time now, and it's not really a problem. Could this be a linkage problem? Kinda feels like its really tight.

[NoDOHC]

Originally Posted by iheardsupport

Thanks for all the info, its actually quite rare when i can get it into reverse without grinding. Something i have noticed is to keep it from grinding i have to push the shifter knob into third at a certain angle, which i can do every time now, and it's not really a problem. Could this be a linkage problem? Kinda feels like its really tight.

If the gear is grinding, the linkage is forcing it in (not a linkage problem). It could be the detent studs on the 3rd gear synchro, but that requires tearing the transmission down too.

I am guessing that if you press the shifter sideways, you take more or less time, allowing the revs to match before pressing the splines together.

The grinding into reverse is normal if your reverse gear is directly behind your 5th gear. If you have to push the shifter more to the right after 5th to get into reverse, it should be synchronized (no grinding). To not grind reverse, the input shaft and countershaft need to be stopped and so does your car. Holding the clutch down for 5 seconds or so and allowing the car to completely stop should allow a smooth shift into reverse.

Originally Posted by My5ABaby

My 1st to 2nd is fine but grinds into 3rd.

Huh, maybe it's just me. I have killed at least 5 RX7 transmissions (that I can remember) and they all followed the same failure pattern:
Weak synchros in second ->
(Change driving style to limp along - do 1st to 5th shift more frequently and skip second) ->
Weak synchros in 5th (duh) ->
(Start rev matching gears while shifting) ->
Interlude of a year or so ->
minor bearing noise ->
louder bearing noise (wrrrrrrrrr at idle) ->
(Get another eBay transmission) ->
Squealing in 5th gear ->
(drives in fourth gear on highway) ->
Squealing in all gears but 4th and reverse ->
(Start looking for a good time to replace transmission) ->
(Find time and replace transmission)

Now process repeats.