ALFAGTV6.COM

[gatouille]

Hi,

Let me show you a way to fix a bad point of our transaxles, the gear box !

Most of time, they are slow and 2nd or/and 3rd ratio are not easy to use.
One my trackdays'car I decides to change things

I had 3 "targets", first of course rebuilding and fixing all the box, second a 45% "sleeper" and third a shorter ratio. I had 10 X43 (4,3) and I wanted a 9 X 41 (4,55).
I found the 9 X 41 in a Giuletta 1600's box (from eighties)

What a mess !!!


Light is right said Colin Chapman and in our case it's REALLY right, in gear box too much weight mean a slow box, hard work .
Here are gear ratio number 1 2 and 3, before and after.

We also changed rear ration,and 4 and 5 th with ones lighter.

Cleaning and after we "glassblasted" (I hope it's the right word)

After glassblast :


Please don't make a mistake sir !




For example the 1rst gear ratio is about 300 gram lighter than genuine one.


Weight is the public enemy !
Here is the rear ratio


Guess which one is the lighter one ?!





The deal is to machine the gears without hurting the harder "skin" that need specifics machines and how to use it !

The link og the garage who propose this work :
http://autopassion63.e-monsite.com/page ... legee.html

Note you can mix gear from alfetta and 75 and make a sort of "close ratio"
Alfetta have short gear box ratio with a long final ratio , 75 have long gear ratio with shorter final ratio.
So you can take 1st gear from 75, then 2,3,4 from Alfetta...

It's enough with wrong-right CLOSE ration let's CLOSE the gear box !







Gatouile

[gatouille]

The gear box is ready !

[75evo]

I'm very interested in a 4.3 or 4.56 ring/pinion combo. If you find an Alfetta 1.6 or Giulietta 1.3 please let me know.

Btw is it possible to have custom ring gear made for 41/10 combo, make a 43 ring or just fit a 43 ring. Something tells me it is not possible as the pitch for the gears are different. And the wear on the ring and pinion combo will cause random ring and pinion mix and match to cause unwanted whining noise. Just seems like a lot of work to swap out all the gears onto the shaft.

[gatouille]

Dear 75evo, 10 X 43 (4,3) is easier to find and more reliable for powerfull cars like yours, beacause the pinion 's got 10 teeth.
If you want 9 X 41 (4,55) I can look for, give me your email by private message. They were using on Giulietta 1600 for example.
9X43 (4,77) is very very rare and use only for Giulietta 1300 in Italy, or sometimes if your are lucky you can find a race combo 9X43.

The garage which in charge of my box can mix a lot of things, because he know how to deal with.
He always use light gear because they are more reliable.
In my box I have ring gear from a box (75 Twin spark) from alfetta and combo from Giuletta 1600.
They are many things to check or keep if you want a "mix" of 2 or 3 gear boxes.

[Mats]

I have both 4.3:1 and 4.56:1 boxes in my garage, the 4.56:1 is currently on the car. Moves shift points slightly but the only gain will be if you have bad shift points somewhere on a specific track and need to move it to after a fast corner or similar.
The difference in acceleration is next to nothing and compared to a teeny-tiny mistake in a corner it doesn't matter at all.

[gatouille]

4,56 is good for 4 cylinders atmo (trackday use I mean) which have less torque and power than turbo or V6.

Mats, my wife and me are fan of Sweden, we often go to Göteborg
We have friends who are living near Gôteborg.

Very nice place

Here is a link ok my last visit in Sweden (2009)
Of course we visited Volvo museum

http://alfaromeotransaxales.forumactif. ... an-sverige

[75evo]

I have a 4.1 and with 225/45/17 tires, I think it is more like a 3.9+.

Do you guys think it is worth going with a 4.3?

Zamani

[gatouille]

75evo, which car and road use only or trackdays only...

More than 200 HP 9X41 are not reliable at all, many friends broke it during trackdays.

Under 160 hp they are very reliable even using trackdays.

10X43 is the shorter possible and stil reliable with powerfull motor.

[Mats]

Good Info!

Means my 4.56:1 is coming off the car and the 4.3:1 goes on...
I have a 4.1: as well, maybe for Anderstorp. Depend on the redline I guess.

Next time you come here gatouille, let me know and I'll give you the grand tour.
I live a short drive from the Volvo museum bu I've never been inside. Strange.
Where sre you from? France I'm guessing but whereabouts?

Z: I have a spreadsheet somewhere that will plot speed vs. revs. What's your redline?

[gatouille]

Next time you come here gatouille, let me know and I'll give you the grand tour.
I live a short drive from the Volvo museum bu I've never been inside. Strange.
Where sre you from? France I'm guessing but whereabouts?

Thank you Mats


Z: I have a spreadsheet somewhere that will plot speed vs. revs. What's your redline?

Sorry I'm not sure to understand, many time whithout using english

[gatouille]

Mats I'm living near Clermont Ferrand (Michelin head quarters are based here), this is center of France (Who said ass hole of the world )

Price of the specialist of gear box are, if you bring a old transaxles gear box leaking, with no more 2nd ratio...
He changes every parts for a genuine second hand but in perfect shape.
I will explain why
Put lighter gears
optional combo gear pinion is possible different than yours
25 or 45% limitedsleep
Bearings like Porsche for gears are also optional

Price are between 1000 ans 2000 euros which I find not expensive.

[Mats]

Z: I have a spreadsheet somewhere that will plot speed vs. revs. What's your redline?

Sorry I'm not sure to understand, many time whithout using english

Är det bättre med svenska?
I was directing a comment to Zamani "Z" about his final drive question, offered to do some speed calculations with a spreadsheet I have (somwhere).

Mats I'm living near Clermont Ferrand (Michelin head quarters are based here), this is center of France (Who said ass hole of the world )

Price of the specialist of gear box are, if you bring a old transaxles gear box leaking, with no more 2nd ratio...
He changes every parts for a genuine second hand but in perfect shape.
I will explain why
Put lighter gears
optional combo gear pinion is possible different than yours
25 or 45% limitedsleep
Bearings like Porsche for gears are also optional

Price are between 1000 ans 2000 euros which I find not expensive.

I see, I have spent some time in Marseille and Pornic and thought maybe you lived close to there...

Prices on gearbox refirbishment seem fair if the job is done right. I don't like the look of some of the lightened gears though but that might be just my job that is making me think too much about gear fatigue.

[gatouille]

I (try to) speak a very little swedish

Light gear is a rsult af more than 8 years of working, One of his first customer who use his GTV 2.0 in races have been used this light gear for 8 years.
Of course a 300 HP with 38 NM torque will break it (an everything in fact)
Durind these 8 years he worked to find the more reliable way, first gear wern't enough light, after they were too much and reliability was not enough good.
Now they are reliable for most of our cars.
More than gear, the way you mount everyparts is more important.

Light gear reduce hurt between parts of gear box and the feeling is very good when driving.
On my GTV 2.0 TS I can believe that gearbox is in front of car...

He propose also a "molybdene" or something like this for "synchos" (I don't know the name in english)

He showed me that brand new synchro you can find on internet are not the same as genuine one, wich can provoque failure.
That's why he prefers rebuilt synchros by himself.

For example one of his customer wanted to moint himself the gearbox on a GTV6 rally, he put too much "seal paste" between gear box casing or housing ? (Sorry I'm not sure of the word (I 'm talkink about the aluminium "case")
Some paste went in oil and then in holes spare parts and of course he broke the gear box.


That's the thing I'm calling gear box casing :


Very important when you mix gear box spare parts (gear combo gear pinion...)
You must keep the combo gear pinion for example a 9X41 with his genuine rear gearbox casing ! You keep the genuine combo gear pinion clearance which is very precise.



Sometimes you need a special part to adapt limited sleeper on a combo gear pinion who avn't before.





I hope everything is clear enough

[Mats]

Sure.
I have done exactly the same thing on the 4.3 and 4.56 I have built, the crown gear spacer looks exactly like the one I made about 5 years ago...
I also kept the gearsets (ring/pinion) in the same casings for that exact reason.

Never seen the problem with "heavy" gears and the lightening of them, I can shift my gearbox as fast as I can move my hand and never had problems with wearing down synchros. Maybe if you do endurance racing but for sprint I feel good with my everlasting gears.
New turbo motor will be a torque monster and strong gears are more important then weight. A lot of the lightened gears here in Sweden have had issues with failures and lost races (and money!), seems to work now even on turbo and supercharged cars though but why risk it?

[gatouille]

Of course my friends with 3L 24V (between 260 and 270 hp) or 75 Turbo with serious tuning break EVERY gearbox (standard, light or race gear)
They plan to mount BMW gearbox because they are fed up with this lack of reliability of transaxles boxes

We can say that more than 230/240 hp and heavy duty use, you must think about another gearbox system if you want reliability.