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My Twin-Turbo SBC 240Z Build


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She runs!! I just fired it up and checked for any obvious issues... no leaks, no smoke, etc. Compressor spins :2thumbs: Just let it idle a bit then shut it down. Need to set the wastegates for lower boost before I take it for a spin. I want to try things out at 6psi just to make sure all is good. The wastegates are now set for 10psi (checked with my air compressor and boost gauge) so I need to modify. They're the stock inernal wastegates, but I found a write-up on how to decrease the boost with an external spring. Also need to make some changes to the Fuel Management system (Holley Commander 950)

 

Paul

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That's a nice set up. :D

 

Depending on what kind of numbers that motor made before, 400 bhp should be EASILY attainable.

 

I calculated it, and figured your NA motor at 280 hp (just for the sake of the math.) and came up with about 400 bhp on 6psi. Of course if your motor in NA tune made more, then you'll easily be clearing 400 bhp.

 

10 psi on a 280hp motor would be at about 470 and 12 psi would make it sit at about 510.

 

Of course, depending on your trans, subtract 17-20% and you've got your rwhp. :D

 

Personally, I can't wait 'til you build a turbo-specific motor for that setup...that thing will be REALLY screamin'!

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That's a nice set up. :D

 

Depending on what kind of numbers that motor made before, 400 bhp should be EASILY attainable.

 

I calculated it, and figured your NA motor at 280 hp (just for the sake of the math.) and came up with about 400 bhp on 6psi. Of course if your motor in NA tune made more, then you'll easily be clearing 400 bhp.

 

10 psi on a 280hp motor would be at about 470 and 12 psi would make it sit at about 510.

 

Of course, depending on your trans, subtract 17-20% and you've got your rwhp. :D

 

Personally, I can't wait 'til you build a turbo-specific motor for that setup...that thing will be REALLY screamin'!

 

Yes, that is correct. But don't forget about the torque! 350ftlbs will go to 490 ftlbs with 6 psi of boost. Or 590 ftlbs with 10 psi, and 635 ftlbs with 12 psi of boost. torque is what gets the car moving!!

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I set the wastegates to start opening at 6psi (added the external spring), down from the stock setting of about 10 psi.

 

100_0949.jpg

 

got them re-mounted and just started tuning. I've got the fuel map set so that it's running pretty rich right now. Hope I can find the time to do some serious tuning soon.

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Well..... :) how does she feel?

 

Don't know :( I haven't taken it out of the garage yet. I just got the tune set tonite so it will idle good now. When I rev it up, it bucks a little before smoothing out, but the A/F meter shows about 11.5:1, so I know I have a little tuning to do before I get it on the road. Turbos spinning up sounds cool!!! I tried video w/ my digital camera, but the audio is horrible. Unfortunately I've got another commitment this coming weekend, so probably a couple more weeks. Hey, like I said at the beginning this has been a project I started 4 years ago... what's a couple more weeks :)

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Don't know :( I haven't taken it out of the garage yet. I just got the tune set tonite so it will idle good now. When I rev it up, it bucks a little before smoothing out, but the A/F meter shows about 11.5:1, so I know I have a little tuning to do before I get it on the road. Turbos spinning up sounds cool!!! I tried video w/ my digital camera, but the audio is horrible. Unfortunately I've got another commitment this coming weekend, so probably a couple more weeks. Hey, like I said at the beginning this has been a project I started 4 years ago... what's a couple more weeks :)

 

Paul, Your Z is the February Car of the Month in our Newsletter! ;0)

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This install is exactly what this site is about (IMHO). The attention to detail, the use of easily available parts, learning from others, and our opportunity to learn from,(and copy) you. I dig it man! congrats on the great results. You are going to love it as much as we all do if not more...

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Wow, you guys are too kind :-) and not one person asking "Why do you need more power??"

 

This site is great!

 

 

 

Yeah, I wasn't too sure about the fit before I started, so I did a fit check using 3D CAD first. I knew it had been done before, but to be sure... (images from ProE)

 

turbo_CAD_1.jpg

 

turbo_CAD_2.jpg

 

turbo_CAD_3.jpg

 

turbo_CAD_4.jpg

 

 

 

The outside color is close to stock (the engine bay is the original paint) I remember going thru color samples at the paint store looking for a close match. It is actually a mix for an AMC blue. Delstar DAR14025 is the color code. It was painted over 15 years ago (d*mn, I must be getting old )

 

 

Is the small block in your model scale? I have been trying to find a SBC 3D model to go along with the scale 3D S30 I am working on. Do you have any vehicle measurements outside of what is in the service manual? I want to make an accurate 3d model of a V8 Zcar.

 

BTW - great work on the twin turbo... that will be my next build (I have been planning it for a few years now, just trying to get the cash together). One question though, is the paint on your hood discoloring or peeling with the turbos so close?

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Is the small block in your model scale? I have been trying to find a SBC 3D model to go along with the scale 3D S30 I am working on. Do you have any vehicle measurements outside of what is in the service manual? I want to make an accurate 3d model of a V8 Zcar.

 

BTW - great work on the twin turbo... that will be my next build (I have been planning it for a few years now, just trying to get the cash together). One question though, is the paint on your hood discoloring or peeling with the turbos so close?

 

The 3D model is to scale. I found a CAD model on the web and checked it against dimensions that were in a GM book I have. Should be the same as the ones in the sticky at the top of this forum. You're welcome to a copy (ProE or a nuetral format like IGES or STEP). PM me and I'll send it to you. If a moderator wants to add it to the sticky, let me know.

 

I haven't run it hard enough to get real hot. but I do have stainless heat shields over the tubines. ( made from a sauce pan I bought at Value Village for 69 cents :) ). So far, I can put my hand onthe hood and it is comfortably warm. I'll probably glue some insulation on the hood above the turbos before I get on it.

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