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Posted by: edgetoo Nov 4 2003, 08:49 AM

Has anyone used an annular clutch release bearing assembly?

Also, has anyone installed a Hewland MK 8 (or MK 9) in a 914.

(we are looking for an easier way to change gear sets in a track car.)

Ed

Posted by: John Jentz Nov 4 2003, 09:37 AM

No direct experience and approx 25 years since I last fooled around with formula cars, so here goes. Assuming the Mk8 is the Formula Ford style gearbox and the Mk9 is the Formula Super Vee gearbox, you need to fabricate new hangers forward of the stock ones on the chassis over the axle centerlines to mount the box. The S/V box is built in the correct direction of trans section lower than the differential and bellhousing. The F/F is flipped over and the trunk floor would need to be cut away for clearence. Clutch, T/O bearing, and linkage need to be fabed to suit.

Really, not to hard if you can fabricate and weld. Very expensive if you need to have someone else do it!

Posted by: Brad Roberts Nov 4 2003, 12:09 PM

Hey Ed,

I have pics:

Here is a hyd. throwout bearing assembly from WEVO that we use.


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Posted by: Brad Roberts Nov 4 2003, 12:13 PM

I have pics of a hewland in a 9146 somewhere. Its a Brumos car.

FYI: PCA club racing doesnt allow it and SCCA ads something like 80-100lbs to the EP and FP cars.


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Posted by: Dave_Darling Nov 4 2003, 05:38 PM

I believe that someone puts the guts from a Hewland box into a Porsche transaxle case, and that gets around the PCA restriction. Not sure if it avoids the weight penalty in SCCA or not.

Sadly, I do not remember who does this. I do recall hearing that it was not anywhere near to "cheap"...

--DD

Posted by: ArtechnikA Nov 4 2003, 07:05 PM

Dennis Sherman was doing this back in 1975; it works because - quelle amazement the shaft centerline in a 901 box is exactly the same as the Hewland. probably because the original Hewland was (IIRC) basically a hotrodded VW case...

i don't know how much easier it would be to change the gear stack over a 901 gears - but you do get the straight-cut gears (less drag, cool sound...) and lightning-quick (but harsh) dog-ring synchros.

i've seen pros change the gear stack in a 901 over a lunch break, so probably it's a matter of practice ...

Posted by: Racer Chris Nov 5 2003, 12:00 AM

There is currently no weight penalty for running an alternate gearbox in a 914 in SCCA Production. However it must be a 5 speed box.

Posted by: Brad Roberts Nov 5 2003, 01:16 AM

Chris,

did this change when they went to the different FP cars ?? (full prep/mild prep) ??

Or is this rule still in effect for the EP cars ??

I went over this back in 2000 but havent read the rules recently.

I have a local guy running Hewland gears in a 901 (in a 911). He had a custom mainshaft built.


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Posted by: 914Timo Nov 5 2003, 01:19 AM

Sorry, I am not going to steal this thread, but may I ask if WEVO have same kind of hyd. throwout bearing assembly to the 901 boxes ??

If they do, how much ?? I want one.

Posted by: Brad Roberts Nov 5 2003, 01:35 AM

I have spoken to them about making a version for the 901, but I dont know if they are moving forward on the project or not.


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Posted by: 914Timo Nov 5 2003, 01:46 AM

Oh, damn......

That is absolutely beautiful part. Piece of art

BTW, anybody know the webb address of WEVO. It is not www.WEVO.com ??

Posted by: Brad Roberts Nov 5 2003, 01:54 AM

Its is:

http://www.wevo.com/

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Posted by: 914Timo Nov 5 2003, 02:25 AM

Oh, sorry. I tried that, but didnt scroll the page down enough. When I saw something about housebouts, I thought that can not be the right page and address.

Posted by: Brad Roberts Nov 5 2003, 02:39 AM

Haydens brother builds carbon composite boats in Australia.

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Posted by: Racer Chris Nov 5 2003, 06:46 AM

I checked the '98 GCR and the only difference back then was the allowance of sequential shift boxes with a 50 lb penalty.
Certain cars have weight penalties for alternate gearboxes listed on their spec line, but not the 914.
Another thing I noticed is the 1.7/1.8 cars (formerly in EP) are allowed 4 or 5 speeds, while the 2 liter currently in EP and the limited prep 1.8 in GP are required to have 5.
The whole full prep/limited prep thing is complicated since some of the new EP cars classified a just few years ago have their limitations on the spec line for their car (they are not truly limited prep). Most of the limited prep cars are subject to a list of special rules in the body of the rulebook. At this point the only 914 that is classified as limited prep is the GP 1.8 liter that has to run on the factory L-Jet FI in addition to having suspension limitations.

Posted by: edgetoo Nov 5 2003, 09:42 AM

Thanks Chris,
Only a sequential box gets the WT penalty.

The issue is technical:
Finding a slave cyl and TO bearing that is low enough to fit.
Finding a clutch pack small enough to fit.
Flywheel must be orig. dia.(starter ring gear)
While box must be mounted upright (FSV, FMazda, VW, Porsche),
with Ring gear on left side, shift linkage could be FF, FSV, or FM.

Thanks for the Pix. Are there any dimentions available?

(Need all the help I can get to catch up to Chris.)

Ed

Posted by: John Jentz Nov 5 2003, 12:18 PM

Please post the pictures here.

Posted by: TMorr Nov 8 2003, 05:27 PM

914Timo,

Yes, we have a 901 annular hydraulic release mechansim.
The mechanism is for a push center clutch - not pull center, be aware of this for your application (?).

The kit with all hardware and lines out of the bellhousing is $725.

This does not include the actual bearing, as that might be specific to your application too.

Our kit is designed for the Tilton 5.5" flywheel mounted on our XT_057 flywheel, once again it might need spacing or something else for a different application.

Regards

Hayden

Posted by: Brad Roberts Nov 9 2003, 03:46 AM

Duh. I held one at the German Autofest. WEVO sells a kit for the 901 (like Hayden said above).



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