Clutch and tranny Upgrade questions,maybe afew more to

[Okay Z]

Hi,I have been looking at this site for a little while and now I thought I'd post with some questions.,I have also been at aZcar.com, and have read all of the info at jason's site www.redz31.com[Great site]but now I need some advice. I have a 1984 turbo 5 spd mostly rust free[very rare in MI]It has 198000 miles on it,I got it for 1750 delivered.I have had it for about a year now.It had two owners I think the first owner babied the car and took good care of it,and only drove it in the summer[well I'm guesing that as it's mostly rust free]and the manual had all the records that he did[he took it to the shops to have the any work donenoil changes,timing belt ect].The second owner a young kid about 20ish who owned it for about a year and he didn'tr take so good care of it,put a huge *** speaker in the back and a manual boost controller and set the boost to 10psi,he also left the carpet in the car after being wet [the t tops leak a little and the window in the hatch leaks a bit]so the the back area has surface rust[gona fix it soon,a guy at my church used to own a body shop and he said he would help me fix it and fix a fist sized rused spot that is on the lower left panel by the rear tire.

When I got it the clutch was slipping and I replaced it[my unlce did most of the work and we also rplaced the ball joints and U joints]we replaced the clutch with a stock clutch.but it starts to slip at 8spi and when you stomp on it.

 

Anyway My goal is to get around 350-400 wrhp eventually.The fisrt thing I need to replace is the transmition[mine is slowly leaking],an upgrade the clutch.I'm thinking of going ACT but not sure what model to go with, don't plan to race at a track or seriously drag race,Just cruise around and maybe friendly race a little.What stage do you recomend?the stage 3 holds the most but they say it's now really for driving on the street.

Also where can I get a transmiton at a good price?I read that the 87 turbo is the best but kinda hard to find,would a 5 spd from a z32tt fit without mods?they are easier to find.sorry to ask but I searched and couldn't find anythin and Jason's site didn't have any info.Also should I get an aluminum fly wheel or get an oem?

 

After doing these upgrades I plan on upgrading the exhoust,I'm thinking of cutting the pipe just before the first bend,as In MI they don't do emisons test and I have heard that turbos don't really need a muffler,What do you guys think?If I need to get an exhoust system what do you think it will cost?.Then I plan to add an intercooler off ebay,[i can't afford a spearco,but Jason says you can get some good ones off ebay and make custom piping,but what makes a good intercooler?what dimentions are good?what do I look for?]and set the boost to 12 psi.Then when when I get some money Upgrade the fuel injectorspump,ecu turbo and rebuild the engine and port an polish the heards.I have a TSC[tractor supply co]in my town and was wondering if they are the same tractor suply that jason sent his turbo to? could I send my turbo and housing to and have them bore the hosuing out and put a bigger turbo in the housing?waht turbo would you recommend.

 

I have a buddy that works on nissan[he is suping up a 240sx now]and he said he would hel me install and work on my car,so pretty much all I have to buy is the parts.do you think I could get 350-400 rwhp for around $3000?

Any comments and advice would be apreciated and I'd be gratefull if you help out a noob.Thanks

[mtcookson]

Clutch: I'd probably go with a SPEC or RPS clutch. The SPEC clutches can hold a decent amount of power yet are still streetable. They have a "stage 3" that is the last sprung hub clutch (easier for street driving) before the racing type clutches for the 84-86 Turbo that will handle 515 ft. lb. of torque. I bought one of those for my Maxima and its pretty nice... definitely on the overkill side at the moment but hopefully down the road I'll make enough torque to need that.

 

Tranny wise you should be able to use the 90-96 300ZX N/A 5-speed. The twin turbo version of that tranny is exactly the same except for where the starter bolts to the bell housing. There is slightly more material at that spot on the twin turbo version due to them using a 250 mm clutch/flywheel setup. I believe the 87-89 300ZX Turbo tranny is also the same as the those two but is more similar to the TT tranny is it uses a 250 mm clutch setup as well.

 

Those trannies are definitely a lot stronger than the pos borg warner t5 in the earlier 300ZX turbo. The t5's definitely seem to have some serious issues with handling power... as do most borg warner trannies except for maybe the T5 world class and definitely the T56, but I've had nothing but headaches from borg warner's ****.

 

Anyways... an aluminum flywheel is definitely a nice upgrade as would be an aluminum or at the least a one piece driveshaft to save some more weight. It just helps the engine spin faster and frees up more power in doing so. They also increase throttle response as well. I put one on my Maxima and it helped out in all of those areas.

 

I'd probably run a full 3 inch exhaust if possible. On a turbo vehicle that usually frees up a good amount of power and allows the turbo to spool faster. I probably would run a muffler just to be on the safe side though. Wouldn't want to get pulled over for noise violation.

 

A Magnaflow, Dynamax, or similar straight through muffler will give you the best flow. They're the louder of all of the mufflers but with the turbocharger aren't all that bad. I have a Magnaflow on my Maxima and there's only a certain spot where the exhaust drones but it is below the rpm I usually cruise at so it never bothers me at all.

 

Aftercooler wise you don't want to go too big and don't want to go too small. I'd probably stick with an aftercooler that has a 2.5 inch inlet and outlet. I definitely wouldn't go any thicker than 3 inches. 2.5 to 3 inches thick should be more than enough.

 

Dimension wise I'd first measure where you want to put it. On the 85 Z31 Turbo I'm working on, I'm planning on standing the radiator up and putting an aftercooler where the radiator was with some electric fans on both to be on the safe side. Once you find your measurements I'd base the size off of that. I wouldn't go overly big like the radiator big but slightly smaller than that should work pretty good. Also, you'll want to look at the flow numbers of the aftercooler you're looking at. Most of them will have a flow and/or power rating on them so that'll help you figure out which size works best for you.

 

The best style of aftercooler core would be a bar and plate. They're much more free flowing than a tube and fin style which means less pressure loss and more flow. Here's a bar and plate:

 

 

I have a couple tube and fin aftercoolers in the garage but have yet to take a picture of them. If I remember to I'll try getting some comparison pictures tonight.

 

I believe the TSC that you're speaking of might be different than the one the turbo was sent to. If its like the one around here that I'm thinking of, they're more of just odds and ends supply, I don't believe they actually deal with any mechanical stuff like that. I'm not positive though. I would think a good diesel performance shop would be able to do something with it though. I'd call around different places in you area and see if anyone them do any sort of work like that.

[Guest Jason84NA-T]

For one, I'm glad you posted this here because you probably would have been mocked into the ground on Z31.com.

 

STOP visiting Zcar.com. That site is a complete mecca of utter stupidity for all Z31-related items. I would never recommend anyone ever visit that site for Z31 info.

 

Clutch:

 

A stock clutch should not be slipping at 8PSI. Make sure you have the medal freeplay adjusted and the clutch bled according to the FSM. The stock clutch should let you do 12+ PSI or ~280rwtq before it starts slipping.

 

Personally I had a bad experience with a SPEC clutch and will never buy another one. My stage 3 (which are in fact available unsprung BTW) started slipping after only a few thousand miles. I replaced it with an ACT and have 10K miles on it so far with no issues at all. I believe the problem with the spec unit is the softer clamping load combined with a harder friction material on the pucks; it wears the **** out of the pressure plate and flywheel VERY fast compared to the ACT.

 

Do the exhaust first, everything mtcookson said is correct. I have put single 3" systems with straight through mufflers on 5 or 6 Z31's and all of them have sounded great while still remaining below the legal sound limit.

 

If you don't mind me saying... You're getting a little ahead of yourself. Have you read the new turbo faq on my site yet completely? Go one step at a time. Don't just throw parts at the car and expect it to be fast.

 

You make no mention of fuel system components other than "upgrading". This is the most critical part short of a turbo/ic selection. Proper tuning is key to making power. My 260K mile junkyard motor would never have made almost 400rwhp with low compression and lots of blowby if it were not for good tuning on a capable setup.

 

Transmission information (The Z32 trans is the same as Z31 except for the noted exceptions):

http://z31.com/board/read.php?id=373

http://z31.com/transmission.shtml

 

Don't replace a transmission because it's leaking... just re-seal the damn case! I would spend your $300 in another place to make more power; use a stock flywheel.

 

Where in Michigan do you live? I am near Grand Rapids, and there are a few other Z31 freaks around. Though, none of THEM have 6 Z31's in their back yard

 

Tractor supply company is completely NOT the same thing... sure, the names sound similar....

 

How much money do you want to spend? I'm sure I could make a stock Z31 run 11's for $3000 in mods, but there's a lot more to it if you want both safety and street drivability.

 

-Jason

[mtcookson]

I've heard of some people having that issue with SPEC before. I like mine but I think the next one I want to try will be an RPS as I'm thinking about using one of their high dollar ones for the VH swap so I want to make sure their lower end ones are made just as well. I can never decide though.

 

That's interesting about those trannies. I wouldn't have guessed that the Z31 tranny would have been so much shorter. I hate when they make changes like that yet keep the numbers the same.

[Okay Z]

Hi again,thanks for taking the time to answer my questions guys.I did [and still do ]use Jason's site[great site!]but there was nothing on tranny upgrades or clutch info,so i'm posting here.Jason you'r right I do get ahead of my self sometimes,but I'm trying to get a list of everything I'll need so I can keep my eye out for deals and bargains.

 

I guess I'll go with a stage 3 ACT clutch since that is what most people recomend,where should I buy the clutch from?

Thanks for the info on the tranny swap,which do you think I should go with?the Z32 tranny becouse i's stronger but harder to do,or the tranny from a 240sx,becouse it is easier to do and easier to find.Or could I rebuild the stock tranny to handle the ammount of power I want ?

 

The Reason I think the clutch went bad was that My unlce helped me replace it a little after I got it and the pedal felt mushy and it didn't want to bounce back up so me and my dad adjusted the screw under the pedal untill it did but it sliped like a bitch,we later found out that the slave clynder was bad and that the clutch damper was bad too,so after we replaced them and the master clynder it got a better and held for a while but it's slipping again not bad abut a little,so I guess we killed it,Oh well live and learn.

 

About the intercoolers,is there a certain brand or a certain carmodel I should get one from?a lot of people use the intercooler from a supra mkIV but they are sorta expensive and hard to find,MTcookson If you have some you don't use and want to sell Il be intereted as soon as I get a little money.

 

When I posted earlier and said fuel upgrades I meant what Jason had listed on his site,mercedes injectors,and a megasquirt ecu.

 

Jason The Reason I listed $3000 as thats about the most I'll be able to afford this summer from my summer job,I almost have enough for a tranny and clutch upgrade now, and 3000 is the price I got for the upgrades nescesary to get the pereformance I want,I did a little price shopping at some places online,I only checked places that sell new or rebuilt,so I might get cheaper prices if someone is selling their older stuff,or If I can get some off Ebay.anyway here is what I got:

 

350 for an ACTstage3 clutch kit,500 for a tranny,350 for megasquirt ecu,400 for intercooler and piping,700 for turbo upgrade,my buddy thought about 700 to rebuild the engine,250 for a fuel pump upgrad from a z32,2-300 for mercedes injectors from Napa or autozone,about 300 for the heads to be ported and polished[maybe less if my other uncle who is a machinest might do it for a little money]150 for new lifter springs[i don't know if that was included in the estamit for the engine rebuild]and 200 for

regrinding the cams.I probly overestimated the ammount of money I need to spend but I tried to ballpark it.I'm trying for around 400 rwhp as that sounds like that is about the most you can get without some seriouse modding and money.I want a car that can beat mustangs and be on the level of an older corvette[not one of the new Z06s]I would be happy with the power you'r car has,how much would that cost?But I also don't want to cheap out I mean if for a little more money I can get a noticeable difference I would probly opt for spending the extra money if it's a little more not spending an extra 600 for 20 hp upgrade.

 

At first I'll just up the tranny and clutch and put on an intercooler and set the boost to 12psi untill I can afford the rest of the upgrades,I mean I am going to rebuild the engine anywa,so If I blow it nothing's lost,and you'r 400 hp engine with 260,000 miles on it gives me hope.

 

I live in Ionia MI,[prison capital of MI]about 45 minutes from Grand Rapids.

 

Thanks for your' input guys.