jgkurz

Thanks Tony! I ended up buying a lower patch and graphed it in to the damaged area on my perfect original fender. I could not find a high quality used fender.

Hi all, I damaged the passenger fender on my low mileage 77 280z and am looking for a replacement. I am surprised how hard it is to find a good fender theses days. I remember when Z parts were plentiful. It it looks like those days have passed. I have heard that 240z and 280z fenders are not identical. Can anyone explain what the differences are, even if they are subtle?  Thank you, John

>>Yeah, more power on less boost is always good but the cost to do this project was crazy expensive. Having a part custom CNC'd on top of an expensive BB turbo added up to big $. The $/hp just didn't work out well. To some degree that is the nature of any car project. I like the car and it is fast so it's all good. >>I think the GTX hotside issue can be attributed to the Tial housing. Their .63 visually looked smaller than my T3/4 .63 housing. I should have taken that cue. >> I may test 27psi some day, but I will need to beef up my valve springs. My Crane springs are 90# at the seat so only 63# if I run 27psi. I think my peak RPM of 5400rpm may be caused by weak valve springs. That and a near stock head and N42 intake. >>I have learned this as well. A journal turbo from a quality manufacturer is still a great option. Thanks for all your comments!

Hi all, I finally got time to install the new .82 housing and dyno test. To close out this thread I wanted to post my results. The new Garrett GTX3576R finally was able to produce 467hp and 496ftlb on a DynoJet chassis dyno. The .63 housing maxed out at 404hp and just under 400ftlb. Boost was 23lbs. The boost lag worsened a fair amount with the larger housing. The boost did come up far smoother which was a positive effect. Also, the old turbo with the small turbine housing use to come up on boost quick which was fun, but it would also reek havoc on clutches. Here's the interesting thing about my upgrade. The old T3/4 hybrid made 451hp and 467ftlb at 27psi WITH a .63 turbine housing and quick spool. My new EXPENSIVE turbo did make more power at a lower boost, but was it worth it over a traditional T3/4 journal bearing? Not really. I started with a .63 housing on new GTX3576R, but it caused 10psi of back pressure and only made 402hp. The old turbo made 451hp with a .63 turbine. The 16hp gain with the GTX3576R wasn't worth the trouble given the boost lag. My cylinder head and intake are near stock which is certainly limiting my engine. Notice the peak power is at 5400rpm. All-in-all, 550hp at the crank is pretty good for an old L28.

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

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..

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/

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.

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.

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.

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.

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.

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.

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.

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.