Lower differential ratio?

I don't need to go 140. I would like to have the responsiveness from a little lower final drive ratio. Is any lower gear available for a 308 that I wouldn't have to sell a kidney to afford?

 

no

 

The way to do this is probably with the drop gears rather than trying to change the actual final drive.

But most of these things are straight cut/dog gears I think & so pretty noisy (because they are designed for track cars). Maybe enquire of some of the indis who also support some of the race series. Here in the UK the guys at QV London would definitly be able to tell you what was possible & also provide the parts I think.

Your other issue might be that doing this might mean a lot more gear shifting and these gearboxes don't exactly lend themselves to that, they are not the fastest things in the world!

 

Succinct as always

 

Had to move to another computer to get the pic -- here's an example of the straight-cut transfer gear system (where they add another gear on the center shaft to change the overall ratio) that Iain mentioned, but don't see how this would be much different $-wise than a custom differential gear set:
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This type of system would make changes easier (at the track) than having to go inside the gearbox (if you had multiple sets for the racetrack), but I think that you'd still be in the same $ ballpark for a single set like this as Newman's price for the TR ring/pinion set.

How about a 355 or 360

 

Oh well...I knew it was a long shot.

 

if you want to improve low end torque, get a smaller wheels size

 

I was wondering about this as well....guess this answers the question though.





PDG

 

I think they have another gear ratio then the 308 to compensate for the smaller engine (same as 308 in all respects apart from volume). I might be totally wrong in this....

Pero

 

Wasn't there a 208 in the beginning? Did it have the same gearing?

Don't forget a lower ratio will increase your RPM's at driving speed, I am doing nearly 4,000 at 70 now, not sure I want this little engine to turn much faster on highway trips

 

I am trying to remember but didn't the 328 have a different gear set from the 308?

 

I read that also but I belive the 328 had the same gear ratios but one gear was changed. I will check my book tonight and report back which gear that was.

 

The 208Turbo is an Italian Market only vehicle...although some were in other parts of Europe.

The was also a 208GT4 for the same reason...(taxation values)

 

What you need is this. Stratos Group 4 and Michelotto 308 style.
Many ratios available.
You need the clutch shaft, cover and a set of drop gears to suit.
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Here are some specs I pulled off the internet over time. I can't promise the accuracy as I never checked against shop manuals.
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There you go, put in a set of 4V stump puller gears

 

Thats great info but I wonder if all the drop gears are the same?

ETA I found a pic of my 328's dropgears & the cogs are 27,28 & 30 teeth from top to bottom - I think calculates at 0.90:1 (or is that 1.11:1 ? )

 

If I am am looking at this and the information is correct (there is no bad information on the internet) the 328 has a taller first gear and would hinder acceleration. Looking at the final drive ratios, the 308 4 valve has the best accelerating ratios and the 2V only has a minor advantage in first gear only over the 328.

 

On paper, yes, but 1st gear on all these cars is pretty much "blink & you'll miss it" anyway....

 

Where is this kind of stuff available and at what $$$?

 

LOL

 

'Group 4' on these cars is like saying "light the money in the fireplace" man!!

That was custom racing level equipment when new 40 years ago....you be starting from billet to replace it at this point...

Doable, but not cheaply.

 

That's what I have...'85 QV.

 

Okay, the book says "Within the transmission individual gear ratios remain, but there is a change in the overall ratios through the introduction of a 17/63 crown wheel and pinion in place of the 17/65 set used for the Qv cars" This is talking about the changes in the 328 made after the 308 QV. Hope this helps.
Also to confirm:
308 gt4 1st 3.418 2nd 2.353 3rd 1.693 4th 1.244 5th 0.952 rev 3.247 final 3.71:1
308 GTB 5th becomes 0.918
308 GTBi final is 4.06
308 GTS,Si, Qv final is 3.82
Mondial 8 5th becomes .919 final is 4.06
328 final is 3.7:1
very confusing in the book but I think it's right now

 

Interesting note:
In 1986 Enzo himself stated "what the customer really wants now, is instant speed, in other words 0-60 and 0-100 by the fastest possible route." "So while Ferraris will always top out at 160mph, there will be a concerted effort to lower the 0-60 and 0-100 times to a minimum, all coupled with greater traction, better car control and better brakes. Look for 6 speed gearboxes, Torsen type differentials, four wheel drives with variable torque split, electronic suspensions, automatic ride hieghts and ABS brakes. All will be quite common by the end of the decade, and no doubt Ferrari will have high-tech versions of them all"

The guy was really quite a visionary.