Turbo Meister

According to my Dyno-Sim computer program, my TT383Z is developing a maximum of 750 hp and 822 ftlbs of torque at 17 psi at the flywheel. I'm finally at the point where the carb, fuel pump, and ignition timing have reached a happy compromise to allow smooth low speed cruising and WOT blasts (knock on wood). The good part is that I never have a problem with insufficient power to blend into the freeway traffic from the on-ramp. My 383 engine only has 8:1 compression ratio and is not very radical. It's the turbos that generate the power but only when I want them to. But power is not enough. The chassis, transmission and rear end need to be able to handle it. And 12" wide sticky tires are handy for getting it to the ground. At MSA, last Sunday, the Z idled like a stocker for at least 30 minutes while inching forward to get lined up. Then, while jockeying for position, I accidentally turned on my fuel pump booster and turned off my fan. Took me a while to figure out why the Z wanted to stall and get hot. ...now if we could just eliminate the human factor.... Hanns

Larry, Looks great. Does it sound any different? Or still as good as before? Hanns

Congratulations on your win and I'm amazed that MSA would actually honor a hybrid Z. You have a great looking Z and deserve the trophy. Hanns

Yes, I saw your Z and immediately liked that "RED" color. Hanns

Notice... It's got TWIN TURBOS. :-D Hanns

I'm constantly encouraging my wife to buy things for herself or the house because it will allow me to expend an equal amount on the Z. Unfortunately, my wife's spending has yet to catch up with my Z expenditures. Hanns

And I read Tony D's clarification. Although I'm still learning about carbs and turbos I do have my own set of personal experiences in that category. When racing my TT383 Chevy engine 240Z, overjetting was required in a blow through application, to keep pistons alive. Perhaps it is the amount of boost that dictates if overjetting is necessary. Racing with 17 psi and overjetting has saved me from having to replace melted pistons. Whenever I jetted the 750 DP down, even slightly from my 79 primary and 95 secondary setting, disaster resulted. The Z is running well despite being rich but safe. Hanns

All right!! Glad to hear it's running and, obviously, running well. Hanns

Terry, Congratulations on your 10 second runs. I knew it was just a matter of time before you did it. You should be proud of your achievement because there aren't many street driven cars that can run those numbers. Yes, now it's on to the 9 second zone. Too bad you have to wait until you come back from your trip before that goal can become a reality. Hanns

The Z is running great. However, I haven't got any new video because my friend, who normally tapes me, has been too busy to go with me. I recently ran my best 1/8 th mile time at Irwindale: 6.22 seconds at 113 mph, with a 1.40 - 60 ft. time. But it won't be long before the next video is posted. Thanks for the interest. Hanns

Guess I'll see you at Irwindale Raceway again, before long. You will not need a tow truck, with those beauties, next time. Hanns

I didn't know that was you. I've been following that Challenge in GRM for several years and laughed my head off when I read about your bribery attempt. Congratulations and keep on trying, you might win yet. Hanns

Dan, I have the 6" rod for my TT383 Chevy. However, if I had to do it again I would go the 5.7" rod because the wrist pin would not intrude into the oil ring groove. The 6" rod, thus, requires a special support ring in addition to the oil ring to strengthen this area. Also, the 5.7 rod allows more meat to be located at the piston crown to handle elevated cylinder pressures. There are other considerations but for boost pressures I vote for the short rod. Hanns

I bought the MSA mounts and 1-3/4" long tube S&S headers in 2000. After 3 days of dimpling headers, adjusting motor mounts, and trying to make it fit, I gave up and ordered the JTR mounts. Everything just dropped into place. Eventually, MSA returned my money for the mounts and they said they never had a problem with fitment of the 1-5/8" headers. I even returned their hood latch relocation plates because they wouldn't fit. The JTR plates bolted right in. Since others have not had similar negative experiences with the MSA kits it could merely be a matter of inconsistent quality control. Hanns

Terry, Whatever it takes. Because if you don't get a 10 second slip, you will have 3-5 years wondering "WHAT IF". Good Luck, Hanns

Count on it !!

It's just an old Holley 750 dp that I slightly modified: Removed Choke Horn Nitrophyl Floats Secondary Float Bowl jet extensions 79 primary jets with PV, 95 secondary jets with PV plugs .120 inlet needle and seat Hanns

That is a very respectable run and totally amazing with an open diff. Hanns

While at Irwindale raceway, last night, I was sporting my new HybridZ Cap and the HybridZ decal was on the Z (Thanks Tim). After I thoroughly spanked a few race cars with big hoodscoops, loud exhaust and racing decals, numerous spectators looked at the Z. I got a kick out of several people who asked if HybridZ was a high performance shop specializing in modifying Z cars. I responded that it was not a shop but a large group of enthusiastic individuals, who are in the process of, or have already modified their Z cars for high performance. We might have a few more guests on the site today. Hanns

Yes, you are correct. Since the carb is totally sealed inside the Air-Box, the airflow from the turbos is forced through the carb and can only travel into the intake manifold/engine or out the Blow-Off-Valve when the throttle is closed. The tough part is supplying enough fuel to match the boosted airflow. I don't have wastegates but I use my "leaky" Greddy BOV to regulate boost by either forcing boost into the BOV vent or by leaving the vent open to atmosphere. With the small turbine housings and open vent I get 30 psi. With my large turbine housings and open vent I get 15/17 psi. As I said before, for my purposes 30 psi is too much. But I'm saving up for wastegates, :nono: just in case.

I really appreciate all the complementary comments by everyone. It is great to read your posts because you can understand the amount of effort required to make the Z run like it does. I just got back from Irwindale Raceway where I ran the 1/8th mile in 6.34 seconds at only 111mph. I was trying out smaller exhaust housings(turbines) for the turbos to spool up faster and make more boost and to stay ahead of Tim's anticipated 700 wheel hp. Talk about torque, I liquified my 12 " wide Hoosier tires when I left the line at 30 lbs of boost on the gauge (as seen on the video). They didn't make as much HP as my larger housings, as indicated by the 111mph, but the torque was so unbelieveable that only Funny Car sized slicks could handle it. I'm going back to my old housings because that was just a waste of power which I'll never be able to harness in a Street Car. The interesting thing is that my blow-through holley carb actually handled 30 psi of non-intercooled boost. I'm not sure if this would have been possible in the quarter mile. The tech staff sent me home early again because the 6.34 run is like a high 9 second qtr mile run and I have no competition license. But I did spank a supercharged mustang and a few others along the way. Hanns