Shaftless Throttle bodies

[michaelmount123]

This particular manifold was originally made for the ATPower ITB's. I've sent you (Gruhsy) the detail and specs for what I used. They are also suitable for a plenum which could bolt to the intake runners and use a single TB. It will be interesting to see what you and Fidelity come up with. Will you send me drawings? A plenum would need to incorporate some sort of radius entry to the runners. The plenum also needs engineering/design considerations to ensure equal airflow into each runner. I'd be happy to assist with a final design if you like. You might want to use a 951 manifold to determine the available real estate to avoid the brake booster, turbo compressor housing and such. It can also show you an approximate location of the throttle body which may be helpful. BTW, the original manifold was made from one piece. I got a little smarter when I realized three runners were identical, and one had a different bolt pattern. That's why you have two 3D printed pieces. One would be duplicated three times, the other once. Perhaps you should talk with Tom to discuss duplicating them with 3D printing suitable for intakes. If an insulating plate is made (see Pg. 2 again) perhaps heat wont' be a problem.

I put enough effort in this project (many years ago), that I'd like to see some out there. I'll help anyone else who is genuinely interested. This would involve several people: Tom (3D printing), Gruhsy (machined pieces), me if I can help. The manifold are properly designed, the ATPower throttles are awesome. Expect to help defray costs involved, but what's not to like? Gruhsy also mentioned he was considering a 2V iteration.

[Tom]

Happy to print anything helpful. Best to test fit in cheaper plastic, but once you are sure of the fit I can print on the resin printer in fiberglass filled plastic that is very strong and rated to over 400F.... Size is the only limitation, but it those are individual runners, it should be fine.

[gruhsy]

https://spingold-atpower.s3.eu-west-1.a ... 416f54.pdf

Michael I see that the universal 52mm oval drawing is the same dimensions as the 3D piece you sent me. Thoughts on using this universal size for 968 head?
I am just emailing back and forth with Andy Lake from AT Power right now.

[michaelmount123]

I looked back at the paperwork from ATPower that I sent to you, and the throttles I used are listed at 55mm oval. This should be the size of the prototype pieces, and is appropriate for a 3L or larger. The cylinder head size on the prototype pieces is S2, and would need to be opened a bit for the larger 968 intake port. There was no need to do different pieces for S2 vs 968.

[michaelmount123]

ATPower provided a package with 4 throttles spaced correctly, lovely throttle linkage, and very nice fuel rail. This is the way to go because it's easy for them, and time consuming to do afterwards. All they need is the throttle body spacing for them to do their magic.

[michaelmount123]

Here you go. TB spacing is 122mm center to center.

ITB's-2.jpg (37.14 KiB) Viewed 1054 times

[gruhsy]

Interesting thing is the 55mm have a different flange as it looks like it is 3 bolt not 4.

[gruhsy]

Here is the 52mm

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[michaelmount123]

Yep, they're 3 bolt due to the larger ID. Go back and look at my photo on Pg. 2 of this thread.

[gruhsy]

Also which Bosch injector model?
My Mtunes are Bosch 80# but we all have different sizes sort of.
Not home right now to check.
I was not familiar with these different “EV” designations.
Did some internet searches but haven’t found a good explanation.
I can contact Performance Fuel Injection locally for some technical help.
The drop has these choices.

I did give the 122mm spacing to them as that’s what I saw on your drawing also

AT Power is also 8hrs ahead of me so they are currently closed.

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