Jump to content


Donating Members
  • Content Count

  • Donations

    60.00 USD 
  • Joined

  • Last visited

  • Days Won

  • Feedback


jgkurz last won the day on June 12 2018

jgkurz had the most liked content!

Community Reputation

12 Good

About jgkurz

  • Rank
    Slowest Indian
  • Birthday 11/17/1968

Contact Methods

  • Website URL

Profile Information

  • Gender
  • Location

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. Just spoke to Hitachi Automotive Systems@ 1-800-548-2549. They bought Tokico. To honor the lifetime warranty, they are giving me a full refund after I send the original receipt and struts in for inspection. Not ideal but I guess that will work. Now the question is...do I go Koni or Bilstein? Hmmmm
  2. I know this is a very old post but I thought I'd add some new data. I finally dusted the cobwebs off the Z and did some back pressure testing. I changed to a new GTX3576R Gen I as stated above but went with a .63 turbine because I made 455whp in the past with a .63 and didn't want to sacrifice driveability. The new turbo couldn't muster more than 402whp which was disappointed to say the least. I have a custom adapter between my exhaust manifold and the turbo that I tapped for the back pressure fitting. I hooked up a DynoJet sensor on my intake and one on the newly tapped turbo adapter using a brake line as TimZ suggested. At 23.4psi gauge (262.75kpa) I was getting 33.78psi (334.29kpa) at the turbine inlet. The pressures started diverging at 3500rpm and got worse all the way to readline. In the end, I had 10psi worth of back pressure. WOW! I have ordered a new .82 turbine housing since that is the only possible restriction. My 3" mandrel exhaust is the same as before. One interesting side note. The GTX35 series turbos from Garret all have the exact same turbine wheel as mine and claim to support up to 1000hp (GTX3584R) The .63 turbine must be for a much different engine because it didn't work well for me. Also, the compressor on the GTX3576R must be moving a ton more air at lower boost vs my old t3/t4 hybrid to create such a restriction. The old L6 is flowing better than I thought. I hope to get back to the 450ish whp with the new turbine. I have seen the EVO and Subie crowd get almost 600whp with my turbo so 450-500 whp should be doable with the MUCH less efficient L6. Stay tuned..
  3. It looks like Tokico is now owned by Hitachi. I will contact them regarding warranty replacement but I am not hopeful. http://www.hitachi-automotive.co.jp/en/products/shock/catalogue/
  4. Yes, the downpipe needed to be completely re-fabricated. Like you, I hoped it would be a simple flange change but it was not in my case.
  5. Not fixed yet. Ordered a .83 housing, but still while off from completing the install. I'll be sure to post results when I get the car back on the dyno.
  6. Thanks for the offer. You are definitely close. If I can find a way to repair or replace a single strut, that would be ideal. If I have to replace both I’ll probably just go with the Koni adjustables.
  7. Hi all, I have Tokico Illumina adjustable struts on my 77 280z. For a few months, I have been trying to figure out a mystery clunk in the rear of my car. Yesterday I finally found the problem. My right rear strut had failed and is clunking around in the strut tube. I know these struts are difficult if not impossible to find these days. The failed strut is pn BZ3013. What are my options? Does anybody sell these new or used? Can they be repaired? Thank you.
  8. Hi all, Just a quick update. I finally got some time to work on this project and made an interesting discovery. I tapped my new adapter between the turbine and the exhaust manifold so I could test back pressure. I used the sensors from the DynoJet to log pre-turbine pressure and intake pressure. The pre-turbine sensor read a full 10psi higher than the intake. I have confirmed that back pressure due to my .63 a/r turbine is the issue. What I find interesting is that this new setup uses the same .63 a/r turbine size as the old t3/4 but makes a lot less power. It makes me wonder whether they really are the same even though on paper they are supposed to be. Maybe the combined T350 turbine wheel / .63 modified turbine housing on my old turbo flows more than the GTX3576R with the .63. Its really the only explanation I can think of. The question now is whether I should go to a .82 or 1.03. I’m sure a 1.03 would be great for peak power but would be miserable to drive on the street. I am leaning heavily towards a .82.
  9. Thanks for the comments and re-assurance. The dyno chart is before and after (old turbo vs new turbo). Different dyno's but the same DynoJet model. The fact that the lines match up so perfectly at the starts leads me to believe the data is good. No other changes to the air flow of the engine other than a large 4" inlet to the turbo and a equally large K&N filter. The downpipe is new and all mandrel 3" like before. Here's a pic of the flange we made for the v-band and the new DP. I'll work on the AFR, boost, and timing graphs. P.S. How do you shove 34psi in a 10:1 engine on 93 octane? I know the EVO engines are state-of-the- art but the compression at 34psi would be about 18:1. Just curious how that is even accomplished. I have a friend who gets similar power out of Toyota MR2 engines. Simply astounding your engines stay together. P.S.S. I am pleased you are working on another Z project. I can't wait to see how it comes together.
  10. I did a full leak-down and compression test recently just prior to the turbo upgrade. All cylinders checked out. I do need to check the plugs as well. I have ordered my new .82 housing and will report back as soon as it is installed and re-dyno'd.
  11. Excellent info James. Thank you. That EVO has to be a handful at those power levels. It's amazing the drivetrain doesn't fly out of the car. You probably don't remember, but my car was built with much of your advice. You guided me through several build questions on email and over the phone. It's been a LONG time. I think you had your yellow 240 back then. The only thing I regret on my engine is my choice to run low compression. Oh well. I can just run more boost.
  12. I read through the Perrin link again and it is interesting for sure. Notice the Dynapack dyno is showing flywheel HP and TQ which is different. I initially saw his GTX3582R with the .63 turbine housing reach 497hp so I figured I'd be able to make 455hp again with my old L28. WRONG! His 487 is flywheel. My 455 is rwhp so not the same. 487 crank hp will be in the neighborhood of 414rwhp if 15% drivetrain loss is used. The weird thing about my issue is that the new GTX3576R is worse all around, not just top end. If it was just worse at top end I'd be super confident that the .63 was the issue. I am going to try a .82 but I also may have boost leak issue that needs to be resolved although I have no idea where. On a postive note. if the .63 housing is indeed choking the HP as low 3000rpm there may be significant gains possible across the whole RPM range with the larger .82 housing. I call it pent up demand. Just a theory at this point.
  13. Hi Bernardd, I have been stubborn about keeping the .63 due to spool but I think it's time to make the change. The dyno shop I work with wants to tap my exhaust manifold to check back pressure, which would prove all this scientifically, but that adds even more cost and time. My turbine is a Tial v-band setup. Is that what JeffP uses? I have not checked my BOV and WG because they seemed to be working as they should. My Tial 44mm wastegate has springs that put me at 13psi with the boost controller off. It is controlling boost well until 22psi. I am bleeding boost after the "stonewall" occurrs. Boost is super stable until then. How would I check my BOV? Just increase BOV spring pressure and run it up to max boost again?
  14. Thanks for the the link from 2009. It certainly seems to apply here. I even commented haha. I think I'm going to swap in a .82 exhaust turbine after I check for the obvious issues. I was worried about spool so I went with the .63. My guess is that the new (larger) compressor is choked earlier than I expected. Looking at the dyno graphs, the engine goes worse as early as 3K RPM. My hope is that the .82 get's me back to my older dyno results plus a bit better.
  15. I have read parts of that article in the past. It is an excellent piece. It's amazing that a street 4-cyl can support a GTX3582R.
  • Create New...