View Full Version : Gearbox.

15-08-2007, 10:12 AM
What gearbox are people running? You still running the gearbox from the Bug, or have you replaced it with a gear box from something else??

Myself, I'm running the Bug 'box. I'd like to get a 5 or even 6 speed 'box down the track, one day...

15-08-2007, 12:48 PM
The watercooled guys generally run different transmissions, since the torque and rpm range usually don't match the Bug tranny. The rest of us heathens still use the 'Bug box! You could always upgrade to a Porsche 901 5 speed if so inclined, but be prepared to do some surgery on the chassis to accomplish that. Gene Berg Enterprises sells a 5-speed kit for the Bug transaxle that is a fairly straightforward bolt-in affair, but they do tend to be a bit pricey!


16-08-2007, 07:55 AM
There's also the problem over here: if you're running on a 'historic vehicle' registration (FREE ROAD TAX and cheap insurance :clapping: ) The gear box is counted as a major component of the original car, they're much more fussed about that than the engine........... 5 gears with slightly longer top end legs would be nice though!

16-08-2007, 08:04 AM
Should note I'm running a ea82t (1.8 turbo) from a Subaru Vortex. I missed out on a cheap Porsche 901 'box a couple of years ago. But cash was a bit tight.

What 'boxes do the water cooled guys tend to run? I've been thinking that something from TR series Triumph, and I know of a V8 (Rover) combi that was running... think it was an Alfa box (maybe).

16-08-2007, 12:56 PM
Hi Cyco - I'm not sure what kind of Triumph gearbox you are thinking of, the only FWD box that I am aware of is the old (66-71) Triumph 1500, which used an in-line A-series on a special 4-speed transaxle. Rare and unsuitable, methinks. No TR series gearbox is appropriate in this case.

Rover V8's can be mated to the standard Beetle box or Porsche 901 using readily available adapter plates. Because the Beetle has a rear engine, gearbox availability is limited. Old Skodas? FIAT 500? What's the point?

Alfa transaxles like the Alfetta are not suitable - the gear cluster is located between the clutch housing and the diff, so if connected directly to the engine (and with the diff turned around, if that is possible), the latter would hang a long way out the back.

I'm using a mid-mount Alfasud, so I can use not only the engine, but the 5-speed transaxle as well, although it's not a particularly strong gearbox.

Many GT40 replicas, Ultimas and Noble/Foreman Fezza P4 replicas use the Renault 30 transaxle. This was designed to place a 3-litre PRV V6 in-line ahead of the front wheels and still provide FWD. I don't know if anyone has ever looked at the feasibility of turning over the CWP assembly for rear engined use, but it's a good strong 5-speed box that has proved reliable with SB Ford and Chevy V8's.

Rubbish ratios are one of the main drawbacks when high-winding engines are used in Novas/Eurekas; the Beetle box is designed to exploit all the engine performance below 4000 rpm, which is nowhere these days. I helped Giles Briggs with an Alfa engine conversion many years ago, and the engine came off-cam at every gearchange, making for very slow progress. My identical engine, with a more sensible spread of ratios, feels considerably faster in comparison :D


16-08-2007, 04:33 PM

I'm using the Renault NG-3 in mine - may suit your chassis :wink:

It wouldn't take a big V, but supposed to be good for at least 250bhp.


16-08-2007, 08:46 PM

I think you will find that the Delorean used the PRV V6& gear box. The Delorean is a rear (as opposed to mid) engined car.

(PRV Peugeot Renault Volvo if memory serves correct)

Cyco, Simon of eureka car club fame has fitted the porche box in a Eureka. Quite a bit of work involved but apparently worth it.

From what I have read you are best to steer clear of the berg 5 speed conversions. make the gear box even weaker apparently.

I am using the std vw transaxle for the 2.5l v6 With its present diff ratio its calculated top speed at 7200 is 140mph

I have a 5 speed transaxle from a Subaru coupe front wheel drive. was attached to the EA82 I was originally going to use. I have held onto it just in case. The diff would have to be reversed or the whole unit turned upsidedown. Engine would sit much lower.

There, that's my two bobs worth


16-08-2007, 11:02 PM
Hi all

I think the Beetle AS code box is the dogs.

The 5 speed geen burg is weak. You don't need one If you run a stock Beetle box. As you will get the same top end speed.

If I was going to build a midmount Nova I would use. The Audi 2.5 Diesle transaxle as they are built for lowend torke and have a chuffing big diff.


17-08-2007, 10:23 AM
Of course! I am a plonker :D

DeLorean did use the PRV V6 AND the Renault transmission, although I guess the latter could have been from the Alpine A310 (my favourite French GT), and not necessarily the same as the R30 box.

Plus there's the later Renault-Alpine A610 which was rear engined and turbo'd to boot!

Hi Jon - it's mainly the engine torque that kills those 'boxes. Stump-pulling Chevy 350's or Boss 302's aren't what they were designed for (neither was the ZF transaxle used in the GT40). But get a high-winding V6 with a smaller capacity, plus a turbo to f-e-e-d the power in progressively, and you can get a lot of use out of them.

Forgotten the name of the French supercar that used the Alpine turbo engine in a mid-mount... Venturi, that's the one... they were twin-turbo'd in some latter versions I believe. Lightweight body helps of course!

140 mph top speed is one thing BB, but if the engine goes off the boil at each gearchange you won't be getting there so quickly. But there are close-ratio 4-speed gearsets available for VW aren't there? You wouldn't necessarily be losing out on top speed either if you can max out at 7200 rpm. Bring the top speed down to around 115-120 and select well-spaced intermediates (say 1st = 38 mph, 2nd = 58, 3rd = 78 mph etc.) and you'd see off all the opposition at the stop-light GP, before you have to stray into silly-speed territory.

Is that peak power rpm or the red-line, by the way? Sounds like a jewel of an engine if it's the former!


17-08-2007, 01:46 PM
I'll post in the engine section about the V6 or else I'll tangent this thread away from transmissions!!


17-08-2007, 05:48 PM

Agreed - I wouldn't want to put any serious torque through it. Mine's not on the road yet, but the folks who did it (it's the same package they've used many times on their revamped Europa's) guarantee it's good for 130mph top end, and a 0-60 around 5s (on condition I can keep the weight where it's supposed to be). To be honest, that's enough for me at my age :lol:


17-08-2007, 07:57 PM
Hi Jon - as I understand it the original Lotus Europa used the transmission from a Renault 16, so the NG-3 is a distant relative anyway. Also, the all-up weight and torque output from the engine are not going to put the same strain on the internals as a conventional steel body would, so you should be fine.

According to my old "Motor" road test reprints, even the Europa Twin-cam (in that evocative JPS livery :D ) had a strange set of ratios, with a large gulf between 2nd and 3rd gear, which was fairly typical of late 60's gearboxes: 1st and 2nd gears for hillclimbing, 3rd and 4th for relaxed cruising - and b***er all in between. Lotus fitted the 5th gear into the Renault 16 box themselves, but couldn't change the remaining ratios.

Conversely, the Lotus Elan +2 5-speed came from the Austin Maxi, which had a much better spread of ratios. Same gearset was used in the AC3000 ME, which mated the iron-block Ford Essex V6 to the transverse Maxi gearbox via a chain drive. Not many AC3000's around, but they all seem to have survived having a 138 bhp V6 going through instead of a measly 85 bhp!!!

Thanks BB, I'll look out for it (saw a Ford Probe the other day, it had a mean growl to it :D )


17-08-2007, 11:52 PM

Mike K on the Eureka forum has messed around with the Subaru box and without some serious $ and smarts it can't be inverted and you can't flip the C&P. He even went to the trougle of cutting the case.


18-08-2007, 01:49 PM
I have a 1302 gear box on swing axles, (yeh, I know, wrong way around dough! :? )
Instead of going for more gears I just go for more revs, :twisted: (7,500 instead of 5,000) :D

22-08-2007, 01:44 PM
Hi Cyco - I'm not sure what kind of Triumph gearbox you are thinking of, the only FWD box that I am aware of is the old (66-71) Triumph 1500, which used an in-line A-series on a special 4-speed transaxle. Rare and unsuitable, methinks. No TR series gearbox is appropriate in this case.

I only mentioned the TR series as someone I was talking to several years ago said that the TR series box should be easily adapted to a rear mounted engine. This was after I told the guy what the car was and what engine/gearbox I was running. Most likely, he was talking out his donkey.

Old Skodas? FIAT 500? What's the point?

How old are we talking about? The Skoda 130/135/136 ran from '84 to '90, and ran a 5 speed 'box. I don't know how durable they are, not many Skoda's down here. But, it's an extra gear. Again, I don't know what the ratios are like.

As for the Fiat 500, we'd screw that 'box right over. lol

22-08-2007, 02:06 PM
Cyco, Simon of eureka car club fame has fitted the porche box in a Eureka. Quite a bit of work involved but apparently worth it.

From what I have read you are best to steer clear of the berg 5 speed conversions. make the gear box even weaker apparently.

The Porsche 'box Simon used was the G50 I believe, not the 901, and required a fair amount of work. The 901, as I understand it, requires some work on the chassis to fit, but not as much as Simon had to do.

I've heard the same about the Gene Berg modded 'box.

22-08-2007, 02:41 PM
I just hit up Wiki about rear engine vehicles (http://en.wikipedia.org/wiki/Category:Rear-engined_vehicles) vehicles.

Maybe something here we could use....

Just more food for thought.


30-10-2007, 10:28 AM
hi, i have looked into gearboxes as i have a water cooled ford pinto which is pushing around 186bhp (hopefully) and i have a 1302 gearbox :shock:
from what i understand is that the beetle gearboxes are really good but if your putting lots of power through it like i am and occasional drag strip starts! then you will need to up grade.
if im wrong please put me right people but the beetle gear box are made to handle approx 100hp comfotably depending what model you have. now lots of people i know have got away with this no problems but some and i mean very few have had a problem where the diff cracked under strain. as a rule of thumb its probable worth looking into a new gearbox if your enging is pushing 130hp or above.

im sure if im wrong then someone will put me right but im getting my box from here http://www.johnmaherracing.co.uk/index.html

its an expensive doo (around the 600 mark) but at least im covered for those drag starts!

oh also i looked into straight cut and helical cut gears! unless your seriously into racing it dont get straight cut gears! they only give you about 10-15 hp extra and there a pig to change gear (revs have to be almost right on each change) i know ive tryed on also there not easy to use for road use and believe it or not they are weaker than helical cut! :shock: as they are only used for track mainly and usually get rebuilt every few thousand miles.

this all i found out but im not sure how correct some of the info is

30-10-2007, 11:29 PM

I'm about to put 165 horses through my IRS trans. Don't intend doing any burn outs though. It was rebuilt back in Oz but don't think it has a "super" diff or welded gears so I'll just drive it till it breaks :nonono:

Can't afford any thing special at the moment any way!!



I'll let you know how it goes

31-10-2007, 12:04 PM
it will be very interesting to see what happens?? as this area seems to be very hazey. good luck anyway i hope all is well, you useage is very diffrent from mine but it would be still nice to know for future questions :clapping:

31-10-2007, 05:13 PM
I have considered a porcshe box as I can get one quite easily and the chap could install, if I asked nicely and promised my daughters hand in marriage I may get it free. some how I think my days may end if I took that option.

31-10-2007, 09:40 PM
sell her it would be worth it really!!! lol only joking we nearly sold my niece when we were in turkey, a man was willing to give us 2 camels for her and i said give us a bag of camel poo for the garden and she's yours! :rofl: needles to say i got thumped for it!

31-10-2007, 10:53 PM
she's doing the second best thing at the moment, going out with a lad whose parents run a pub.

23-06-2008, 10:40 AM
www.ckoon.org/vw/tranny/ (http://www.ckoon.org/vw/tranny/) Just in case anyone is looking for a good walk through on a swing axel.