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"Valentino" and his MEGA! IRS Tranny

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dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 ·

#638315
The side covers are a custom made part.
They were not new when I fitted them but had a history from back in the eighties(rally car) as far as I can tell.
The BAKAHAG is, I am guessing, the company who made the conversion to IRS.
Sounds like you have done a search Mac and come up empty?
If you wanted something similar it would be a custom order I would say.
You could try formula ford guys though.
westi wrote:That's mad Alan.

mactaylor Custom Title Time!

1,005 posts · joined Aug 2007 ·

#638456
yeah they just look soooo good and couldnt find them anywhere !!!
EVERLAST CONCRETE TANKS
1800 552 123

choppa Seriously Crusin Dubber

190 posts · joined Oct 2002 ·

#638761
Nice stuff Dave
Thanks for sharing.
I think I noticed your gonna run the standard coil spring between 3rd and 4th.
Makes for a nice whine, but do u get breakage with that?
I do but I havent so far.

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 ·

#638772
Never had a problem with using the spring spacer.
I use a solid one now because, on my own tranny, I use 4th gear as a thrust face and it needs to be constant.
Pinions with a nut on the end get a solid spacer like stock.
At least with the spring it will not lose its pressure against 4th, and helps keep the circlip under thrust and therefore, in place.

Even my blown combo used the stock sprung spacer ,
and I DID break a 3rd gear once, but it was a stock VW third and had suffered oil starvation.
I was also using third gear for skids back then.

Nothing should whine.
I have heard whine when the crownwheel and pinion is set weird under coast conditions, to get a better load pattern.

I recal Bergs saying that with a bigger engine they had once the tranny began to whine under a coast situation,
but Gene's explanation never made sense to me.
Despite my respect for the Bergs,
there were(are) a lot of things they say and do that don't ring true with logic.
Suspension advice was one of a few.

.....but without proper analysis, taking their advice will, in general, be a satisfactory path to take.
westi wrote:That's mad Alan.

choppa Seriously Crusin Dubber

190 posts · joined Oct 2002 ·

#639159
Interesting. Yep all my boxes whine. I did have a go at blueing a crown and pinion once, but I got a bit bored, now I just use the OG shim that came out, maybe thats my problem.
I think your right, I remember reading that bit of Genes about cocking of 3rd and 4th , looked believable to me, maybe it wasnt the gospel.
Now ive got your info, ill blue the next one i do.

Cheers

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 ·

#726390
Actually Valentino recently sent this trans back to be for an upgrade of gear ratios and inspection.

The 1.333 fourth gear was not much fun with 4500rpm at 100km/hr,
and the previously "reconditioned" ZF was a little noisy, so these things were addressed this time.

After a recent taste of circuit racing, he thought he would change a few things.

I have some pictures and will post them up soon.
westi wrote:That's mad Alan.

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 ·

#726708
After some discussion about budget and available used ratios,
we settled on the following ratios.

3.875 crownwheel and pinion
Original FTC 3.778, and 2.357 mainshaft,
1.524 third gear
1.125 fourth

This will give him a 'bearable' 3600rpm.
westi wrote:That's mad Alan.

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 ·

#726710
One of the reasons for changing the crownwheel and pinion was this:





If you saw Steveys driving style at Valla,(and probably Wakefield) you can under stand why the poor old R&P
westi wrote:That's mad Alan.

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 ·

#726711
The other thing I found was that the sides of the trans were not flat.
I think this was from an over eager removal of excess powder coating.

I made up a big flycutter and this worked well.







westi wrote:That's mad Alan.

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 ·

#726712
The other area that needed addressing was with the ZF limited slip.
The break away torque was measured and found to be well avove the factory settings
of 108 to 144 ft.lbs.

Someone had added some shims in there from "who knows what"? ,
so these were removed,
and the casing machined to acquire the correct preload.

westi wrote:That's mad Alan.

Stanley I guess the reward is in the doing of it

4,523 posts · joined Mar 2003 ·

#726715
Top stuff Dave....imagine what you'll be able to do with a mill

Flintstones Custom Title Time!

1,077 posts · joined Aug 2002 ·

#726818
Great work as always Dave.

Cheers
D

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 ·

#726991
Here is the insides of the ZF limited slip diff.
Note the tiny spiders and fine 18 tooth side gears.
This is the reason I am not a fan of the ZF.
If clutch packs are kept tight within spec they tend to hold up pretty well.





westi wrote:That's mad Alan.

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 ·

#726992


You will note that these side gears have 18 teeth.
Stock VW is 17 and later swing axle and IRS bugs had 15, making them even stronger.



Here is the NEW Brazilian 3.875 crown wheel and pinion.
I set it up for factory pinon depth and the pattern is where it has been lapped at the VW factory.
I normally like the pattern to be closer to the nose,
but being a Klingelnberg tooth form in this case, the tooth is a little thicker toward the heel anyhow.



Also the pinion pattern location is where I like it in both 'drive' and 'coast', so I was happy to comprimise a little.

westi wrote:That's mad Alan.

Sick68VW Officially Full-On Dubber

303 posts · joined Mar 2003 ·

#727037
looks nice dave keep up the great work...