DRIVETRAIN WEAKNESS'S & ANSWERS

[PETROLHEAD]

Gearboxes, Clutch, Driveshafts?

the limiting factor of many of my own "Design Lounge" plans always comes back to the fact that the clutch and gearboxes etc simply won't stand a much stronger engine power and torque delivery.

What can be done? what options are there?


Is the 16v/145 box a notably stronger casing? or is it just younger and less fatigued?

Why is it better and can we improve things further?

Lets try and get some info on the forum about the real world options of coping with what is now a 40 year old drivetrain design!

How can we best care for them, modify them for more performance and power capabilities etc etc

Chocks away....




(Chris, i don't want to know that you have a 16 speed and 5 reverse Scania tiptronic box attached to a scaffold bar prop shaft just to air your laundered undies round at speed! )

[ricky ricardo]

I read about it somewhere and considering cutting a 5 to 10mm alloy sump plate with longer bolts to match. It apparently stiffens the casing.

[PETROLHEAD]

would that tie in with the last of the 145 boxer gearboxes sump perhaps?

rather than a tin plate they have an alloy cast plate, much thicker for starters, but are mainly fitted in preference to the tin plate version because it has air cooling fins cast into it.

could there be a stiffening benefit to it aswell?


good one? i like it!

[KevJTD]

i have heard it said before (maybe by tom?) that the alloy bottom plate does add a degree of tortional rigidity.


driveshafts though i have heard are able to withstand power hikes without issue

[ricky ricardo]

I thought I read about a aussie racing a Sprint with a thicker sump plate but also just found a thread over here where a guy has super charged "and" turbo charged a 16v 33 . He made a 25mm plate claiming it stiffens the box. No word on power figures and says the box is handling it. Another advantage is stopping oil leaks for good.

[Johnboy]

Good info so far guys ! Is the turboed car a sprint ? As there's a guy on utube with one. Looks quick

[ricky ricardo]

Here's 2 vids, he doesn't post much on the aussie forum "nether do I" It's pretty sick.

https://www.youtube.com/watch?v=K9UbaETeDgs

https://www.youtube.com/watch?v=I_baep2m53I

[PETROLHEAD]

WHOA! very interesting.

Nice to see Buzzed get a mention in his video too!


I'd love to know more about his drivetrain experience over time, and his engine spec for that matter?

I wonder what he did crank/rod/piston wise, and what compression he was running before charging it?

Any chance you could get him over here Ricky?

[Johnboy]

holy poo

[ricky ricardo]

I've sent him a invitation to have a browse here and join. Neither of us post much on the aussie forum so I hope he see's it.

[PETROLHEAD]

Thanks Ricky, much appreciated.

[Alfasixnut]

Nicely sorted 33!

[Spacenut]

i have heard it said before (maybe by tom?) that the alloy bottom plate does add a degree of tortional rigidity.

driveshafts though i have heard are able to withstand power hikes without issue

AHM sell a machined alloy sump plate to stop the gearbox casing distorting under load. The plate is dowelled into the casing. The 145 sump does the same thing, but isn't anywhere near as strong, and really needs to be dowelled in too, but if you use it without a gasket (like I have done) it is supposed to help a bit.

The input shaft is supposed to be susceptible to snapping if you try and feed a lot of power through a competition clutch. AHM sell uprated versions of this too. The other thing I have read is that the backplate can be modified to take a stronger bearing (can't remember if this is for the input shaft or the main gear), otherwise the gears squirm about in there!

The other thing I have overheard in the hillclimb paddock (where rules are somewhat more relaxed than they are in circuit racing) is that the VW gearbox is inherently stronger than the Alfa unit. I know, I shouldn't have said it, but there you are. Obviously the VW box was the basis for the Hewland Mk9 and others, 5-speed conversions are available, a wide selection of aftermarket tuning parts... and adapter plates

Lauren

[BS25]

We did all the above (and a few other tricks) to our race box way back in 2002, Adie has also modified his transmissions along the same lines and produced some very nice kits for folks to buy. Since we did this, we've had no issues. It should be noted that on the track this was much to do with wide slicks - but also the fact that the majority of components are dating back to at best the mid-90's in the case of 145/6 sourced parts - and of course, rarely new.

Forced induction race cars have struggled with transmission reliability - even with all he above, those that have gone down the supercharged route have pretty much been forced into bespoke racing transmissions.