Draw Through Turbo project for my 2.9 Stroker L series COMPLETE 5 MONTHS 20 DAYS

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I have received warnings about this psi regulator.  So, I ordered one from Summit racing to replace it.

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03-01-2025 TURBO PROJECT UPDATE.  Carb is out with John at V-Performance being gone through again, as something I can't find is wrong.  At any rate, I used the day to get back in the car, and go through the wiring.  The Water/Meth injection pump wasn't coming on like it's supposed to.  I did some rewiring and changed the point where my switch is in line with the main power to the pump instead of the relay switching power.  IT WORKS!  So all is cleaned up now and I snapped a pic.  I think I am going to get a piece of black leather or vinyl and cut out a flap that will cover some of the setup on the side of the tunnel, cover the wiring so I can still see my stuff, but all the wiring is hid a little better.  I also wired in a very small amber light that comes on to let me know when the pump is running and providing water/methanol.  I Tightened up the motor mounts I had left loose for insulating the brake master cylinder area, and cut out 2 plates of aluminum to cover some spots on the firewall.  I normally polish them then install......later I can quickly take them off, polish them to match the others and quickly re-install.  I also happened to notice my fan belt snapped, so I ran down and got another.  Weird that it was worn out in 500 miles, but then the guy at Oreilley's was reading about it, and said the belt I was using was for under 1 horsepower usage.  I had picked it originally as it was the right length and size for what I need.....I put another new one on for now and will need to find the same size in a fan belt that is heavy duty and won't wear out.  Anyone know of a place that makes them out of Kevlar fiber?   Anyway, that was today.  I just need the carb back and then go to the muffler shop to tie the exhaust together and the project will be done.  Fine tune and maybe DYNO test.  Pics follow 

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03-08-2025 TURBO PROJECT UPDATE:  As the carb is still at the shop, I did a few other things today.  I received the reproduction Fuse box console cover, and moved all the factory attachments to the new plate and reinstalled, then I worked on the cover of the wiring exposed in the passenger side trans tunnel.  The material is a faux leather material I got on eBay as well as a button kit.  After figuring out how the buttons are installed, I then held the upholstery in and kept trimming it with scissors until I had the pattern I wanted and then added the snaps.  I had to use tape, and tools, wood block etc. to hold them in place as the Gorilla glue dried, so in looking at the pics you will see the tools being used moved as they are being used to hold the snaps in place while the glue dries.  Lastly, I had to make a trip to Lowes for additional hardware, but was able to get the upgraded fuel pressure regulator setup installed and sealed up with thread sealing dope.  See pics attached.  Cheers!

[jhaag]

Outstanding job of documenting your work with numerous photos and written descriptions! I wish I had taken a lot more photos of my ZX project.

 

John

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Thanks,  just dealing with some carburetor woes, not a big deal.  I will do some cleaning and detailing before calling it 100% complete.

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03-23-2025 TURBO PROJECT UPDATE: here are float bowls for the Mikuni HSR carb for my turbo setup. You can see the difference between an unmodified one and the modified one on the left. the overflow tube, look how much larger diameter it is, and the upper right-hand corner of the float bowl is modified, to increase flow for the accelerator pump, advertised as 50% more fuel flow! I had so many problems with my mikuni that I ordered a china copy off of Amazon for $113 shipped to learn about the carb......when it arrived it is EXACTLY the same carb! Some of the knockoffs are not similar, but this is a carbon copy. My mikuni I am convinced is a factory defect. I went ahead and changed all the jets in the china carb to mikuni jets, and put the modified float bowl on there. It is now "correct" and ready to go on!

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04-09-2025 TURBO UPGRADE UPDATE:  So, I started the day by pulling carb off and changed the pilot jet out to 37.5 and then dropped the needle back to the stock range and put everything together. she still won't run! so i put the largest pilot jet i have in the carb a 42.5 with the air screw all the way in she runs great! but won't idle.  There is still not enough fuel to idle, so I have to pump it, and so i got it running, and then I leaned out the door and sprayed starter fluid on places where there could be a vacuum leak and I found 3 places. Then I decided to get some permatek black gasket maker and run a bead on those spots then wipe it clean. once it is dry enough i will try again. Right now, with the 42.5 pilot jet AND the choke pulled she ALMOST idles! it's a big engine, so she wants fuel!  Right now she will start without starting fluid using the 70-accelerator nozzle. so, iII went ahead and ordered some pilot jets that are even richer which will be here in a couple days off of Amazon.  For the first time in 5 months the car left the garage and i was able to sweep it out and put the Z car back in the garage with the tail facing out. Laugh if you want but after 5 months of mental hell that is a huge deal! i almost have her ready to go! can you believe she likes a 42.5 pilot AND choke?!? but still wants more to idle on her own. 2.9 litre, she wants fuel!  After letting hte gasket maker harden up for an hour, she still wants more fuel, so when the Idle jets come in we will continue to feed the beast until she will idle on her own!  SO cool to actually get her out even if just in the parking lot.....progess is progress.  FWIW a neighbor commented on the car while it was out.
Sent from my iPhone

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for curiosity, on an HSR carb, the pilot jet for idle sprays into the bore right behind the needle.  here is a pic.  When I looked online I couldn't find a pic anywhere.

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My BIG pilot jets for the HSR carb arrived today.....at some point the beast will have enough fuel to idle!  cheap at amazon! No name China made, but they work.

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04-13-2025 TURBO PROJECT UPDATE: so now I am in the world of carb, carb, carb. I must have taken the carb off, changed jets and re-installed about 10 times today, I didn't keep count, but at any rate it was a lot! I got tan idea from another guy to use "Chat GPT" and when you give it all your information, you would be amazed at how well it can give you an idea on tuning everything in! I did manage to drive the Z to the nearby gas station to get some gas....and although it wouldn't idle without giving it gas, and it was rich, once I got into the mid range circuit of the carb it started running better, when I hit wide open throttle the sound, everything changed and it roared like a wild beast! seat of the pants it felt like 300 h.p. or close to it. I......Couldn't tell the boost, my AEM gauge is wonky....., it had to have been over 10 psi it felt like, FWIW. Then I heard a loud "POP" and the engine died. I pulled over and checked everything and everything seemed ok. I started it back up and drove it back home, and it didn't pull like that first time, but wasn't sure why. Later I was running it and watching it, and I could see a burning charge coming out of my main turbo coupler! So, the POP was the coupling giving out. No wonder I can't get it to idle. BUT, CHAT GPT gave me a lot of experience with it, and it is now sitting with a 47.5 pilot jet in it. I just ordered the coupling, so God willing we will give it a go at a later date! Here is a crummy pic, but you can kind of see how my customer center dash piece turned out.~Joe

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04-20-2025 TURBO PROJECT UPDATE:  I replaced the main turbo hose as the original was leaking and causing me to lose vacuum.  I cut it off and then held up the replacement hose I got online, made by HPS, it has an offset bend it in, which from the pics, you can see i needed.  it is of a much more sturdy design, and I had to take measurements and then wrap it and cut it with a cutting wheel in my Dremel.  it is VERY difficult to get on there.  you have to remove the manifold and then once together, you have to use a small pipe as a lever to get it started, but then it pops on, saving HOURS of work to put it on without using this trick.  After this, I started cutting and installing a piece of carbon fiber I got off of eBay.  It is sticky on one side, so it was simply the task to cut and fit, then peel off the back and install.  This is part of the final beautification to finish the project off.  Then it was time for a drive. I have a weird situation with a hanging throttle, and it allowed me to get it idling and I was able to fine tune the air screw on the carb to make it better, but  I think it is too rich.  but I am not sure, as it easily dies if you blip the throttle and let it come down on it's own to idle.....50/50 chance it idles or dies, so maybe it needs MORE fuel?  this is part of the idle or pilot circuit from idle to 1/4 throttle, the transition to the needle "feels fat".....I think it is just too rich.  I had moved the needle up to get more fuel, and now I think i need to lean it out.  once I hit 3/4 throttle and go on to the main jet, it reacts like a power band on a 2 stroke engine, night and day performance, it squats the rear and rips up to about 4500 then falls flat, so I guess it doesn't have enough fuel?  I will also have to go through my checklist on my ignition knock sensor.   A major issue is coming up to a stop, and the idle just hands up at a high RPM until I blip the the throttle and then it falls.  Any ideas?  Thanks.  Pics follow: 

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04-21-20205 UPDATE: I went ahead and dropped the needle, went down to a 45 pilot and increased the main jet to 230 from a 210. quick drive, starts and idles easy at 1.5 turns out on the pilot screw now, needle movement was too much, as soon as the throttle rolls into the needle, A/F ratio goes to 16/17 to 1 I managed to get through that and on to the main jet, instead of fall flat, now just pop and sputter....LEAN..... SO......I will richen the needle 1 slot, go from 230 main to 240 and see what happens. I lost the plastic washer under the clip for the needle and installed anyway, seems to have the effect of leaning it out 1 slot, I ordered some plastic washers for it, if they don't come in before I work on it again, will adjust needle and main and see what happens. I can't believe it finally idles on it's own. Once this is better then I can take it down and get the exhaust fixed. 99% done. 

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04-21-2025 TURBO PROJECT UPDATE. Well she is done. A 5 month project and it fought me all the way, but she is drivable and just needs to go down and have the exhaust tied in.....but she is running and driving. The HSR carb, being a Motorcycle Carb has a very short throttle when used in a car. I have a 1 inch to maybe just short of 2 inches of travel, but I think it's more like 1.5 inches of travel. So, you have to ease into the power, if you just mash the throttle, it can overwhelm the setup. Granted, this is a hilly billy built, shade tree mechanic, DIY turbo setup. I started with a very dusty box of worn out crown turbo parts that I had to clean up and then order parts that would bolt together, and nothing ever went together like it was supposed to in my mind. I went with a Chinese T04/T3 Hybrid Turbo that I then sent off to the "G POP SHOP" to have them put carbon seals in it (mandatory on draw thru turbos) and go through it and make sure everything was good. I then came up with using the motorcycle carb after seeing other Z car builds other builds, even though they weren't turbocharged, but then finding out that Turbo Corvair guys were using them. My 2.9 stroker with a ported head needed a lot of fuel, even at my 6000 ft. altitude! Endless jet and needles changes, and then finally settling on a 240 main jet, a 45 pilot jet, a Y8 needle jet, a stock needle with the clip on the 2nd to last clip, 1 turn out of the air screw and still having a bit of fussiness, so I then thought out of the box....the choke circuit is a separate circuit. When idling, I pulled onthe choke and the engine got REAL happy! to I looked at the distance of the shaft when I pulled the choke knob. I then took 3 washers and ground them open and stuck them on the choke shaftand then pushed the knob down. Now I had a system where by I could, through trial and error remove a washer or "shim" one at a time to find the sweet spot! 1 washer seems to be it, although still a tad bit extra fuel at the top under wide open throttle. I can udjust some of the fuel out by adjsuting the accelerator pump to not pump during htat situation, which will lean it up and make it run even better, jsut more trial and error. I will fien tune it a bit and then take it and get it put on a syno jsut to see for fun what I have. It would be nice to think my homemade deal would give me 40 horsepower, but we won't know until DYNO day. I have added a few pics and 5 video's of driving the car. keep in mind, the exhaust is loud but you can really hear the turbo. Thanks for all the positive comments over the last 5 months.....and the few that told me "you're going to blow up the engine" ......."it won't work" .........."you're just going to destroy it"....."you are stupid, everyone knows draw through systems and carbs do not work." (even though Corvair guys and air cooled VW guys do it all the time, and were a huge source for info)...... .well, it worked so I guess you aren't as smart as you have led yourself to believe. Cheers! Pics and vid's (5) follow

 

click below for video's.  should be 5 total, one after another.  If it doesn't work, PLEASE let me know.

 

VIDEO link:

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3 layers of insulation brake master hovers around 200 degrees F. No issues. Couple years when I bleed the system I will go to the Motul 600 degree F brake fluid.

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ALL DONE, PROJECT LENGTH, 5 MONTHS, 20 DAYS.

 

I WILL POST DYNO RESULTS HERE, OTHERWISE, THAT'S IT!~

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Just an addendum. Now DYNO is next.

 

"4-22-2025. Things came into the right alignment today, and I was able to get the exhaust tied together at Bud's Muffler here in Colorado Springs, and get a final tune on the Z car. The exhaust threw all the tuning I had done before out the window. My pilot is now at 50, my needle is on the notch above the bottom groove, so more fuel, and 2 turns out on the air screw. washers are no longer under the choke, running just on the intended circuits. She is VERY quiet now, and the added backpressure seems to have made a difference, she acts better now. here are some pics and a walk around video of it all done. I would like to get a DYNO sometime. Now it's back to washing and cleaning and waxing, etc. pics follow. Cheers and God bless."

 

Click below for video:

 

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