F23- HTOB question (Page 1/1)
cam-a-lot JUN 28, 07:24 AM
Good morning

Can anyone please point me to a link that describes the dimensions needed for the spacer ring that prevents the HTOB from over extending? I can't seem to find it . I have access to a CNC lathe and can make a few of these if anyone else needs one.

When ordering a new clutch from SPEC, what "car" should I tell them it is going into? It is a Series III 3800 block and F23 transmission, so there is really nothing "Fiero" about the driveline. Can anyone advise on how to order the clutch or what part # to use?

thanks!
Will JUN 29, 04:29 PM
The issue arises from the stack heights of the Fiero and Cavalier clutches being different. If Spec can set you up with a flywheel and clutch package that duplicates the setup height of the 2.2 Cavalier clutch, then you won't need the spacer.
ignorant prodigy JUL 01, 08:40 AM
I found this thread helpful
https://www.fiero.nl/forum/Forum2/HTML/138464.html

Supposedly there's two different versions of HTOB's - a green and an orange. There's slight size difference between the two, so some people need a spacer and some don't. To be safe, you should measure.

I went with a Camaro flywheel cut down to .840"
Spec stage 3+ SC883F
Spec HTOB 1/4 N1774-.250 (spacer - which had to be slightly honed out to fit over the HTOB)
ACDelco 386521 Professional Clutch Slave Cylinder (green one)

Honestly, pushing the clutch in the first time was one of the most nerve racking things about my swap.
cam-a-lot JUL 02, 06:59 AM
Thanks... enough info to make my head spin. Hopefully I can get it to work.
V8Steve JUL 02, 01:21 PM
I ran into a similar situation with my F40 swap. First I put 3-4 washers behind the clutch master cylinder. I put as many washers as I could fit. I had several bags of convenient size shim washers from McMaster Carr so I began by removing one flat washer and replacing it with a set of the precision McMaster Carr washers. I used a vernier to check the thickness reduction as I went along. Eventually I was able to creep up on the sweet spot carefully. Hope this helps. These washers are cheap via McMaster Carr.

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88GT 355 CI Sequential Holley HP Multiport EFI, AFR milled 180, Dyno'd at 427 HP, 360 WHP, F40 6-Spd
anderson@gdsconsulting.com

[This message has been edited by V8Steve (edited 07-02-2021).]