1991 TT garage queen with 137k

[jordanmw]

I was recently given my father's pride and joy just before he passed about a year and a half ago. He bought it used with about 30k on the clock from a dentist who had it since new. It's a 91 super white twin turbo with charcoal interior leather/tweed with all the options and original paint. He took great care of it with papers for every repair and improvement. Here is a list of what he has done, and what I have:
Him: Front lower lip repainted oem(never damaged), spoiler replaced with stock design improved materials, rear decal replaced, newer style injectors installed, Borla exhaust from headers- stock design, head unit replaced with eclipse CD player.
Me: Timing belt kit with seals done with gates belt, all fluids replaced with premium, lower clutch line, clutch slave cylinder, power antenna.
Broken: Abs speed sensors, clock, warped front rotors, shift knob scuffed, slightly scuffed OEM wheels, a few oil spots per week..

This car has been in climate controlled storage since I graduated high school and only comes out when the weather will be perfect. He has taken excellent care of it and treated the hoses and gaskets with silicone for years, with hand washing and waxing being the norm.

I am looking for some advice on what I can do about the few issues that have popped up and make a few improvements while respecting the original styling and OEM looks.
I would like to see about getting a set of 18"s of these: https://rimscarnated.com/products/rimsc ... ave-wheels
Not sure what else I will do, but I would like to make a bit more power. Inter-coolers, intake, fuel system, exhaust(again), are all on the table, and suggestions would be helpful. I would love to find some suspension upgrade that allows me to keep the switch for the ride adjust- maybe I can find a way to adapt that to still function after the upgrade.

I know the clutch will have to be done soon and have a 6 puck with a lighter flywheel that I'll be swapping in. I was also thinking of going to a 1 piece carbon fiber drive shaft, since it can reduce weight and rotational mass. The shifter feels pretty good but I think the bushings could do with replacement also- is that a job that I can do easily? I would also love to replace the head unit again with something with a larger screen and get apps to read engine data, is that harder with OBD 1? An ECU swap or chip upgrade sounds like it's almost an instant big gain- if I want to keep all my stock gauges and go that route- what is the best option?

Help me find a direction and make the best out of this amazing machine...

[itsa300zx]

Sounds like you are heading in the right direction with all those expensive parts.
Clock issues usually the resister fails, see here. http://twinturbo.net/net/viewmsg.aspx?f ... id=1163937

Borla exhaust is nice, I'd just keep it.

What are your power goals? If under 400 hp, chip and tune intake will take you close.

Shifter? I rebuild them. Contact if interested

[Daspyda]

I'd worry about the fundamentals before your upgrades.

Have you had the engine compression-checked? Is it leaking any oil? Rear main seal leaking is a common problem. Replace brake lines with stainless steel.

Replace the bushings and bearings. Inspect t-top seals.

Garage or not, seals get old.

You can have a rocket, but you need suspension integrity so you don't wind up in a wall during your cornering.

The transmission has been known to have weak 2nd and 3rd gear synchros. You can rebuild, but better option is Z1 MY96+ JDM transmission as it's strengthened. Z1 has a short shifter that's sublime.

Billy Boat dual catback exhaust is phenomenal. They primarily make Porsche units.

[jordanmw]

Clock issues usually the resister fails, see here. http://twinturbo.net/net/viewmsg.aspx?f ... id=1163937

Borla exhaust is nice, I'd just keep it.

What are your power goals? If under 400 hp, chip and tune intake will take you close.

Shifter? I rebuild them. Contact if interested

Thanks for the clock link- I am pretty good at soldering- I'll try that out.
The Borla is okay but really sounds stock- not much growl.

Power goals are 500+ but really looking to keep mostly stock with exception of the fuel system- which I'll start with the hanger and dual walbro pumps.
Shifter rebuild you say? How much of a PITA is it to get that assembly out for rebuild?

[jordanmw]

I'd worry about the fundamentals before your upgrades.

Have you had the engine compression-checked? Is it leaking any oil? Rear main seal leaking is a common problem. Replace brake lines with stainless steel.

Replace the bushings and bearings. Inspect t-top seals.

Garage or not, seals get old.

You can have a rocket, but you need suspension integrity so you don't wind up in a wall during your cornering.

The transmission has been known to have weak 2nd and 3rd gear synchros. You can rebuild, but better option is Z1 MY96+ JDM transmission as it's strengthened. Z1 has a short shifter that's sublime.

Billy Boat dual catback exhaust is phenomenal. They primarily make Porsche units.

I did check compression, all within the proper range surprisingly. It does have a very slight rear main leak- I would call "seepage" no real drips form anywhere. T-top seals look brand new and shiny- think my dad silicone lubed them often.
I am interested in knowing more about the transmission- what would the cost difference be between a rebuild and 96+ unit? Is it that much more than getting a tremec?

What about all the deletes that people are constantly recommended? Any of those things worth doing?

[Daspyda]

When I was at that decision point on the transmission, it was five years ago. Then, the new transmission was $300 more. Not sure about tremec...

I know of one that's common, the EGR valve. It's at the top rear of engine and requires shifting engine forward. I believe my mechanic did it the same time as the rear main seal.

[Woodnutz78]

Just about all of the "typical" deletes are worth doing - EGR, AIV, PRVR, carbon canister and especially the coolant bypass for the plenum. Anything vacuum-driven that can be deleted should be, as to avoid future vacuum leaks. The plenum coolant bypass, which is likely to have been done if the plenum has aleady been off (for the newer injectors, possibly), should be done the next time the plenum is pulled. It turns a 4-hour plenum pull into about a 30-60 minute pull, depending on how many times you've done it. The EGR delete is another one you'll want to do when doing the clutch... during which, you'll really need to have the plenum out to make it easier to remove the pipes and cap the leftover plenum holes. Getting the valve off the back of the engine may be tricky, but it's not that bad. Doing it with the transmission in... no thank you. I've heard it's been done, but I'll believe it when I see it.

All of that stuff de-clutters some of the engine bay and eliminates future issues.

The OEM transmission is actually quite strong and unless you're having issues, I'd leave it be.

As itsa said, you can get a nice power bump with a chip tune and boost jets/manual boost controller for a couple hundred bucks (I have a manual boost controller for sale, as well as a socketed and chipped ECU, but the latter will be a few hundred bucks on it's own - let me know if interested). That shoud get you in the 360-370whp range, which is really a good bit of fun. If you're looking at closer to 500 whp, you'll need a bit more... and there are different routes to take. E85 conversion (which is what I'm doing) or bigger turbos. Both will cost several thousand to do, but it depends on what you're going for. I wanted to keep the quick spool of the smaller turbos, so my changes primarily consisted of a Haltech setup, 1000cc injectors, several new sensors, fuel pump, new lines and a stronger clutch. One of these days, I'll get it to the dyno for ingition/boost tuning - right now, it's driveable and I'm letting the fuel map self-learn while I work out a few bugs.

I'll give itsa's shifter a vote of approval, too. I have his in my car - it's great. Zero slop in his short shifter and changing it out is quite easy. Bonus is he's also a great guy that's helped me out a number of times as I've learned/grown with my Z. I'll always look to support fellow Z owners whenever possible.

[Woodnutz78]

Clock issues usually the resister fails, see here. http://twinturbo.net/net/viewmsg.aspx?f ... id=1163937

Borla exhaust is nice, I'd just keep it.

What are your power goals? If under 400 hp, chip and tune intake will take you close.

Shifter? I rebuild them. Contact if interested

Thanks for the clock link- I am pretty good at soldering- I'll try that out.
The Borla is okay but really sounds stock- not much growl.

Power goals are 500+ but really looking to keep mostly stock with exception of the fuel system- which I'll start with the hanger and dual walbro pumps.
Shifter rebuild you say? How much of a PITA is it to get that assembly out for rebuild?

To be honest, you can do a dual Walbro if you want, but it's not really necessary unless you're looking to go upwards of 600whp or more. Also, if you do that, you won't want to stay with the rest of the OEM fuel system. You'll need an aftermarket FPR at a minimum to handle the higher flow. I recommend talking to a specialist before making decisions on fueling - Seb at SpecialtyZ and Scott at Zshack. While they've had differing opinions after talking to both, I now see more similarities - at least on the fuel side.

[Daspyda]

Sure, the transmission is stout. However, the 3rd gear synchros are the Achilles Heal.

If the gears aren't grinding, keep the numbers matching unit in there. However, if they are, the 96+ JDM transmission is a worthy upgrade, for you and any buyer in the future.