User avatar
junglejustice
Verde
Verde
Posts: 624
Joined: Fri Nov 26, 2004 1:19 am
Location: Granolaville, WA

Transaxle Fix!!!???

Post by junglejustice »

Anyone? I mean this is the Achilles’' heel of this car. Jes and I are spending all of this money to make these things FAST; this is the last thing that we NEED to address...

Poor shifts make this so NOT a sprinter - WHAT A SHAME with that 3.7 in there and the light weight...

And, the sloppy linkage... What CAN be done?

Besides a new shifter kit and then simply lightening gears say, 1 - 4 and replacing all of the syncros and shot-peening all of the gears and now using the correct fluid and letting it warm up properly first before racing it hard and making a smooth shift up and down between 1-2-3.... Fine!

All of that aside....
What can REALLY be done to the existing setup?

Dawie de Villiers and I BOTH lit up the other day when we realized that we had both FOR YEARS toyed with the same thoughts! Can a 924/944/928 transaxle be made to fit back there...?

Those cars WERE going to have their clutches in the back a la Alfa Romeo transaxle, but "reliability problems with the perpetually rotating driveshaft and weak rubber connections to offset vibration..." compelled them to move their clutch assembly forward on the final production design...

What other options are there besides what Dawie has already done with a Getrag 6 speed German box mounted up front...?

I want to keep the current setup, but I want a direct shifter! I also WANT to be able to shift this thing FAST between 1, 2 and 3 UP and DOWN...

Michael! Paging Michael Harris...! You are closer than any of us (what with owning both a 944 AND a GTV6...) - Sorry to blow your cover like this Michael...
Last edited by junglejustice on Fri Dec 03, 2004 9:27 am, edited 1 time in total.
...to Alfa, or not to Alfa? That is the question...
User avatar
Mats
Verde
Verde
Posts: 4059
Joined: Mon Nov 29, 2004 12:26 am
Location: Gothenburg, Sweden
Contact:

Post by Mats »

AFAIK the Porsche boxes are quite a bit longer behind the driveshafts/halfshafts and this will make them quite difficult to fit the std de-Dion setup...
Had a quick look at a 928 box and discarded the idea, cant remember the reason right now but I think it was the above geometrical problem.

Ah, there it is:
Image[/url]
Mats Strandberg
-Scuderia Rosso- Now burned to the ground...
-onemanracing.com-
-Strandberg.photography-

GTV 2000 -77 - Died in the fire.
155 V6 Sport -96 - Sold!
User avatar
Steve R
Platinum
Platinum
Posts: 237
Joined: Wed Nov 24, 2004 1:06 pm
Location: Dorset UK

Post by Steve R »

So the Porsche uses a torque tube then ! links the engine rigidly with the gearbox & the clutch is at the engine end... and the gearstick is mounted on top of the torque tube with the selector just running straight back into the tranaxle (ours has to navigate "around" the clutch), hence the gearchange is more direct.

Ok I'm thinking 164 engine from a manual boxed car would be the best V6 to start with having clutch in the right place. You'd have to be pretty good at fabricating to make a custom bell housing adaptor to mate with the P propshaft, but it's no doubt "do-able" and probably no harder than fitting a front mount g/box ? (way beyond my abilities though!)

Can't see how anything other than major surgery on the Dedion & watts linkage mounting points would make the P box fit though.

Are there any other combined gearbox/diffs suitable for RWD out there? Volvo did one, but only in a low powered car, so probably too weak. Ferrari & Maserati have transaxle models now - too pricey ! Renault had a gearbox like that in FWD cars (the 25 & 30), but I recal the driveshafts were also near the front, ala Porsche. Same problem with Audi hardware...

I guess what you're looking for as a combined torque tube/gearbox/diff where the drive shafts come out at right angles near the back of the unit, that way you can leave the Alfa's rear suspension alone. Anyone know of such a donor vehicle?
User avatar
Mats
Verde
Verde
Posts: 4059
Joined: Mon Nov 29, 2004 12:26 am
Location: Gothenburg, Sweden
Contact:

Post by Mats »

I believe you mean DAF did a transaxle car... :wink:
Mats Strandberg
-Scuderia Rosso- Now burned to the ground...
-onemanracing.com-
-Strandberg.photography-

GTV 2000 -77 - Died in the fire.
155 V6 Sport -96 - Sold!
User avatar
Andrew.b
Platinum
Platinum
Posts: 205
Joined: Sun Nov 28, 2004 3:21 pm

Post by Andrew.b »

JJ

In a word - Nothing!

Forger the Porsche box - if you go to that much trouble, just go with a tried and tested M3 box in front. Easy, stronger, better shift, and cheaper.

Also, where are you going with this car?? will it be dual purpose street and track??? if so, there are so many thing you can do to make the car faster, and gain more than the shifter looses.

How often are you in 1st and 2nd on track?? not much if at all! if you're running 4.1 diff you'll spend most of the time in 3,4,5. There are many things one can do to quicken the change, but like i said, is this a full race car??

Let me know.


Andrew
User avatar
junglejustice
Verde
Verde
Posts: 624
Joined: Fri Nov 26, 2004 1:19 am
Location: Granolaville, WA

Box Issues;

Post by junglejustice »

Well, “race car” would imply race as in race-race... There aren't any points for what we are doing here and certainly NO money in it...!

With my budget I can't go and race wheel to wheel any way. This will be a dedicated track car, but I will probably try to register it and do limited street driving like to and from the track...

That aside, I still WANT a better shift setup, WITHOUT going with the German box up front for now.... Eventually, maybe... For now - just looking to improve the stock setup sufficiently, so both Jes and I are first looking at options including the existing box…

Arguably, I have taken the power as far as I can (with NA...) and it's not as much about being "faster" for me as it is just being able to SHIFT faster AND NOT HAVING TO THINK ABOUT IT.... With the Milano pedal positions and my big shoes, blipping the throttle, braking while navigating a technical course is a pain in the arse!

I want to focus on the line at this point and having better shifting would make it easier on me...

Also, to date, in my Verde (with the long 3.55 ratios) on some of the tighter tracks with slower turns, we go down to 1st often, but second gear gets used ALL of the time at Laguna as well as at PIR and at PR.... I suspect that the 4.1 ratio box is going to alleviate some of this.... (In the Verde 1 is just too high and 2 is just too low...

What are my options aside from what I outlined in the original post? We hear about straight cut gears and whatever-dog boxes and "race kits" but nothing jumps out at me right now.

What can you suggest Andrew?
By the by; what did the IMSA and DTM cars run?
...to Alfa, or not to Alfa? That is the question...
User avatar
Andrew.b
Platinum
Platinum
Posts: 205
Joined: Sun Nov 28, 2004 3:21 pm

Post by Andrew.b »

>Well, “race car” would imply race as in race-race... There aren't >any points for what we are doing here and certainly NO money in >it...!

>With my budget I can't go and race wheel to wheel any way. This >will be a dedicated track car, but I will probably try to register it >and do limited street driving like to and from the track...

>That aside, I still WANT a better shift setup, WITHOUT going with >the German box up front for now.... Eventually, maybe... For now >- just looking to improve the stock setup sufficiently, so both Jes >and I are first looking at options including the existing box…

>Arguably, I have taken the power as far as I can (with NA...) and >it's not as much about being "faster" for me as it is just being >able to SHIFT faster AND NOT HAVING TO THINK ABOUT IT.... >With the Milano pedal positions and my big shoes, blipping the >throttle, braking while navigating a technical course is a pain in >the arse!

>I want to focus on the line at this point and having better shifting >would make it easier on me...

>Also, to date, in my Verde (with the long 3.55 ratios) on some of >the tighter tracks with slower turns, we go down to 1st often, >but second gear gets used ALL of the time at Laguna as well as >at PIR and at PR.... I suspect that the 4.1 ratio box is going to >alleviate some of this.... (In the Verde 1 is just too high and 2 is >just too low...

>What are my options aside from what I outlined in the original >post? We hear about straight cut gears and whatever-dog boxes >and "race kits" but nothing jumps out at me right now.

>What can you suggest Andrew?
>By the by; what did the IMSA and DTM cars run

Well JJ


As the car is 'fast road' and you are looking to drive to and from events, you are kinda limited....

I can only suggest making up some nylon rings for the rear g'box mount, and sticking a bolt through the front mounts. this will 'tighten up' the box, and help with more precise shifts.

I would also revert to the earlier linkage system at the 'box end, as there is less to wear and get sloppy.

Unless you get more 'race' with the setup you are gonna be stuck.

The 'box in road trim has generic problems that can only be solved with 'race only' mods. You will always suffer with a slow shift unless you get rid of rotating mass, race clutch, dog rings, solid lightweight prop, and lever pivot points. But as I said, you could not drive this on the street!

Regarding the other points, I would recommend the following:

Take the 3.55 box and launch into outer space! with all the engine mods you have spent mucho cash, you'll see hardly any benefit with this final drive. How often have you reached 7000rpm in 4th - let alone 5th???

Find a 75 twinspark/milano 4.1 with LSD. Lock this up to around 50% - no mone screwing around with 1st gear on tighter tracks, and the engine will rev properly.

As for your big feet.... use some proper 'race boots' these are very slim, and help with feel. If you have problems with the pedal box spacing..... bend the pedals!!! very easy. If you are looking to change faster, blipping is a must, period.

Maybe think about some expert tuition - seriously, this is time well spent! I have training all the time.

IMSA - full race dogbox with s/c gears. 75/80%lsd solid props modified shifters ect.

DTM=alfa 155.

Cheers


Andrew
User avatar
junglejustice
Verde
Verde
Posts: 624
Joined: Fri Nov 26, 2004 1:19 am
Location: Granolaville, WA

Post by junglejustice »

Yeah, you see with pedals and shoes and instruction (of which I have had PLENTY) - and with plenty MORE to come - but even so, with all of these things we are just talking about a "fix" on my side WITHOUT addressing the issues on the other side (read: gearbox)

Why are these mods, "race only mods"...? (Apart from the obvious, like a grippy clutch...)?

Where can I get a lightweight prop made up (say carbon fibre/kevlar?)

The 3.55 box stays on the Verde - I love it on the long roads.... Running the stock Verde 12 valve 3.0 with the 3.55 on the track was a temporary thing.... (I don't want to rip it up anymore...)

Now the track car on the other hand gets a 4.1 and I have a choice at this point of going with a non-LSD 4.1 from a Silver or Gold box that I have and adding Quiafe??? or Phantom Grip or whatever...
OR, going with an LSD from the US Platinum model and increasing the lockup to 48-50%...

As far as 'hardly ever reaching 4h and 5th"...! ALL OF THE TIME! Going down the main straight here at Pacific Raceways I hit the dogleg (call it turn 10) in 4th and I sometimes upshift to 5th not to long after that - running at about 135 mph by turn 1 (another dogleg) just before going into turn 2 (high RPM 2nd gear - or a low RPM 3rd gear...) That's the problem with the long leg 3.55...

With the 4.1 I will ALWAYS be in 5th all the way down the main straight here... Laguna is similar - Chip and Larry ALWAYS hit 5th before turns 1 and 2 with their 24 Valver 4.1 LSD Milano and GTV6 cars...
...to Alfa, or not to Alfa? That is the question...
User avatar
Mats
Verde
Verde
Posts: 4059
Joined: Mon Nov 29, 2004 12:26 am
Location: Gothenburg, Sweden
Contact:

Post by Mats »

My feet are size 11 (US), 45 Euro... No problems with pedals, blipping or anything. The real key here for me was getting the bloody steering wheel out of the way (far back enough) so I don't hit my knees on it while doing my Chopin impersonation.
I made my gear stick about 20cm longer above the rotation point and as long as possible under it. Old style linkage, tight bolt up front (will do a ball-bearing thingy for the front mount during the winter..).

I got some slop of course, you can't get around that because of the design of the selectors in the box but I don't get why you even care, just shift the thing! :)
As long as it doesn't mis-shift on you it's all good...

You seem to have som weird tracks in the US, I don't EVER hit fifth with my 4.1 and we have som friggin' loong straights here, never down to first either.
Mats Strandberg
-Scuderia Rosso- Now burned to the ground...
-onemanracing.com-
-Strandberg.photography-

GTV 2000 -77 - Died in the fire.
155 V6 Sport -96 - Sold!
User avatar
MD
Verde
Verde
Posts: 2420
Joined: Mon Nov 22, 2004 2:37 am
Location: Brisbane, Australia

Tranaxle Fix

Post by MD »

Just a small suggestion amongst the many quality tips provided already by others. Try going to "Our Cars"> Featured>Scroll to bottom of page. Select Blue Image of GTV. Check out the shifter conversion. You may get some ideas that you can use for your purposes. I can assure you the set up works very efficicently with short shift patterns and a narrow gate. For left hand drive configurations in a race car, the set up need not be placed on top of the transmission tunnel, it could be located on the drivers side. The key is reducing the length of the crank. Cheers, MD
Transaxle Alfas Haul More Arse
User avatar
Mats
Verde
Verde
Posts: 4059
Joined: Mon Nov 29, 2004 12:26 am
Location: Gothenburg, Sweden
Contact:

Post by Mats »

Wow, that looks...incredibly complicated... :shock:

You did all that to shorten the throw?
So how much does that weigh you think?
Mats Strandberg
-Scuderia Rosso- Now burned to the ground...
-onemanracing.com-
-Strandberg.photography-

GTV 2000 -77 - Died in the fire.
155 V6 Sport -96 - Sold!
User avatar
MD
Verde
Verde
Posts: 2420
Joined: Mon Nov 22, 2004 2:37 am
Location: Brisbane, Australia

Post by MD »

Hi Mats,

The weight is something I never anticipated anyone would ask me so I didn't plan for a reply!

However, I would say that the selection mechanism itself would weigh approximately 50% more than the original set up but in real figures this would amount to no more than 0.5-1 Kg.

In practical terms, this is irrelevant because the benefits in precise and quick shifting are so good. In a race car you would not fabricate the dress covers etc so as I say, the weight increase is zip.

The characteristic of the changes is that it works better than a 105 series "stick-in-the-box" change. (to give you some idea.)

Mats, the reasons I did it are much more than just short changes. For a right hand drive vehicle, the location of the shifter is not optimum so the whole thing started from there and the quest to get it right just kept getting bigger. You know how it is, while we are at it ....

MD
Transaxle Alfas Haul More Arse
User avatar
junglejustice
Verde
Verde
Posts: 624
Joined: Fri Nov 26, 2004 1:19 am
Location: Granolaville, WA

Hhmmm...

Post by junglejustice »

Still looks complicated....

Need someone to build this... It'll cure one of my problems....

Moving the steering sounds good too - I bought a steering extender....

What about this kit:

shift mechanisme in aluminium with direct link to the gearbox
Attachments
Aluminium Shifter.jpg
Aluminium Shifter.jpg (45.44 KiB) Viewed 11994 times
...to Alfa, or not to Alfa? That is the question...
User avatar
ar4me
Verde
Verde
Posts: 645
Joined: Fri Dec 03, 2004 9:55 am
Location: Southern California

Post by ar4me »

JJ,

Is that from those DK guys? I never got a reply out of them. Did you get a price quote on the shifter kit?

Did you get the steering extender from RSRacing?

Jes
87 Milano Verde - daily driver - Juliet
87 Milano 3.0 Motronic - budget race car - Roxanne
87 Milano 3.7 24v - race car
(Repeat or do as I say at your own risk - be critical)
User avatar
Micke
Verde
Verde
Posts: 810
Joined: Sun Dec 05, 2004 11:33 pm
Location: Finland
Contact:

Post by Micke »

Some thoughts:

- very few rear mount gearboxes will fit as they usually are behing the rear axle. The DeDion is in the way.

- lightening the prop shaft does not make almost any difference in gearchange (it is like lighening the flywheels but much less inertia in there)

- the new milano style shift is not bad if everything is OK. Worn out parts must be replaced ASAP.

- there are several diff ratios (3.55-4.78) of which some must be suitable for almost any application.

- gear ratios can be changed. Good idea but only worthwhile for real racing.

- moving the gear lever (just bend the damn thing) to a suitable place for the driver makes a real difference in shifting.

- IMHO the 4.1 TS box is a good starting point for most application.

- I don't know how much torque these boxes can take. Any ideas?

- I use a TS box with modified gear ratios and shift time is not a problem.
Post Reply