Things I've learned... ENGINE & DRIVETRAIN

Things I've learned about the ENGINE & DRIVETRAIN of my Z


  • Changing the spark plugs was the first DIY thing I did on Mr. Z. It was kind of a pain, but not really difficult. Except that I broke almost every dumb clip to the coils! Just make sure you have a 10" rachet extension... I spent too much for Splitfires. They do nothing for the VG30DE(TT) anyways, although I'm told they work very well in smaller engines. Next time I'll stick with the NGK Platinums. Maybe the Stillen plugs. Who knows?
  • The much vaunted ECU upgrade is made by Jim Wolf (1-619-442-0680). You can also get it from Stillen (1-800-576-2133). If you ask for Adam (ext. 138) and tell him you're in the IZCC, he'll give you a discount. The ECU is on the floor under the passenger's side floor mat.

  • I ATTEMPTED to change my own water pump. I will not attempt it again. I took out the radiator, fan, fan clutch, pump in/out pipes, drive belts, and an appendix before I discovered that I needed a gear puller & an air rachet to do it right. A quick call to AAA and $750 later, I'm back to where I was before the pump failed. I tried to take the pump to 75K mi. and it didn't do it. I will NOT take this one more than 60K. It was too much of a pain. I will also NOT go back to Jim Click here in Tucson. I went to school with his daughter, and she's a sweetie; he's a nice guy too. But I've just heard too many bad things, along with my own experience to go back. I'll stick with Buck's or maybe Thourobred Nissan.
  • Euro-spec radiators are available from Stillen and (I would imagine but I don't know) maybe Nissan Motorsports? If you plan on doing high speed runs for any amount of time, it might be a good investment.
  • I never noticed my coolant temperature guage depart from the center after the engine warmed up UNTIL about a week before the pump failed. Then, at stop lights, etc, it would go warmer; presumably because it lacked airflow over the radiator...

  • If & when you do the water pump, you will have to replace the timing belt as well. I guess coolant is corrosive to the belt material or something. Make sure that whoever does it inspects the timing belt tensioner as well. If it needs replacing, it's cheaper to do it when they're already in there than to have to go back later. That's another reason why I'm not going back to Jim Click... My tensioner was making a squeaking sound on startup when the engine was cold. If yours does this, I feel sorry for you. If you plan to do the timing belt YOURSELF, then we have a DIY page at How to... timing belt

  • The way to make your Z "Stage I" is to buy an air induction system from either Stillen or Jim Wolf. (About $150). This should give you approximately 18 extra hp. on the TT, and somewhere around 6 or 8 on the NA? There's a How to... air filter by Andy Woo to walk you through it. Remember to take the top off of the stock airbox before you try to remove it!! It's much easier to get to the bolts that way.
  • Stillen also sells an intake manifold, but I don't have it, neither have I priced it.

  • In July (or was it August...?) '97 I changed my clutch. After 6 hours and getting almost nowhere, I called a mechanic and for $60 he helped me. We finished in 3 hours after that. It's very involved. You have to take out your exhaust system, drive shaft, and drop the tranny. I could do it again, but not right away... there's an excellent How to... clutch at One thing to remember that our esteemed author, Brian Duley left out was this: just like me, he did not replace his pilot bushing. A few months later, when I had the tranny out again, I had the bushing changed, and it was in REALLY BAD SHAPE. So if you're going to DIY, then be sure to change the bushing as well. Of course, I also neglected to change the rear crankshaft oil seal, so next time I'm in there, that'll have to come out too...
  • One other thing... to remove the drive shaft you have to take out 4 bolts back by the differential. But torquing them caused the whole assembly to rotate. Made it very difficult, until I jumped up and put Mr. Z in 1st gear. That fixed it right away!


  • If your Z is pulling to one side, have your alignment checked. It COULD be that your CASTER is off. Measurements should be from 8 to 10 degrees. Mine were different. 4 and 6 I believe. To fix this you can either go to a frame shop and have it BENT, or you can buy ADJUSTABLE tension rods. They are available from Stillen at approx. $350. The old ones may have bent or become damaged by hitting a curb, pothole, etc.. Getting at them is easier if you remove the UNDERCOVER, but some of the bolts won't want to go back in, so be warned. This seems to be a common problem. For further advice, see the How to... Tension rods page at
  • The upper control arms are NOT that difficult to replace. Most shop manuals call for one hour, but that'd be for two of them I guess. One on each side. It only took about 15 minutes to do one. Pull off the wheel, and you've got access right there. Just take out three bolts and pound it out.

  • The transmission is VERY HEAVY. When I did my clutch, the two of us tried to drop it ourselves, and we sure did! Dropped it and caught it about 2" off the floor! Next time we'll use 3 people at least! Putting Amsoil or Red Line synthetic fluid into your transmission will make shifting smoother and you'll most likely have less power loss, as well. I used Amsoil 75W-90; feels GREAT!
  • I also put the Amsoil 75W-90 in my rear differential. I don't notice any difference, but heck; it's better than Dino-Juice, right?


  • Unless you're really strange, you're not going to go out and spend $30 on a big 4" exhaust tip that will slide over your existing one, right? Most aftermarket exhaust systems for our Zs (be they from Jim Wolf, Stillen, GReddy, etc...) are Cat-back systems. That means that you take off the stock exhaust from the catalytic converters on back. Not really that much work. The mufflers have two hangers each, up under the bumper. There's a few going on up to the cats. I'll be getting new exhaust hopefully in 6 or 7/98. I noticed that the bolts connecting the cats to the cat-back exhaust are rusted together. I will need new ones, since they're gonna have to be drilled, most likely.
  • Replacing your exhaust is STAGE II; this will give the TT owner another 18HP or so. Some people do the intake first, some do the exhaust first. I don't really think it matters, but even with the IZCC discount, the Stillen exhaust is $900. The intake is $150, so for a quick 18HP, most people are gonna go with the intake, I think.
  • I guess the cats don't contribute to back pressure that much. But what about cat-forward exhaust? Why doesn't THAT exist? And what gives with Stillen making headers for the NA but not for the TTs? Although, I hear that they're working on downpipe replacements for our pre-cats, since there's very few places requiring cold-start emissions anymore. Sorry, just some misc. ramblings. If you have answers for THOSE questions, then MAIL ME; I'd love to know.

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