Voights 5 speed conversion

[englishmaninwales]

I can see there is loads on this in the archives, but what is the experience of people who have done this conversion?
Seems, on paper and speaking to them, to be a straight forward swap in a LR chassis. Any problems in practice?

[jimj]

I`ve run the Voight 5 speed for a few years now and maybe 30,000 miles. Yes, I prefer it which is what matters. On the down side it doesn`t replicate the fabulous snickety change of the original and, with hindsight, I would have paid extra for a higher first gear. On the upside, with a 3.55 diff. 80pmh is only just over 3000rpm which on motorways is much appreciated. The other big advantage which I`ve never seen mentioned is that the clutch is really light, so much so that the first time I pressed it I remember thinking it wasn`t connected, yet there`s plenty of feel.
A separate matter concerning modifications from the original; as our cars appreciate in value originality will become ever more valued so do be sure everything is reversible. A good example is that Sprint for sale on here in Canada. A huge amount has spent on "improvements" which, clearly, has reduced its desirability (and $s).
Jim

[englishmaninwales]

Thanks Jim. The gear set I have available is a BGH T9 for the conversion, ratios are 2.66 1.75 1.26 1.0 and 0.84. The diff is 3.9 and this would give through the gears 41mph ,57, 84, 109, 130 with cruising 70 at a more relaxed 3500 rpm, 5th 20mph/1000rpm on 145 80 13 tyres.

[Keith Scarfe]

Mmmm Interesting. I would love one of these. I too have a BGH box sitting in my garage with the intention of doing this one day... maybe... I emailed Voights a while back for some info but they didn't reply. Either not good with email or have so much work they don't want new customers. Anyway do please report back how it goes if you do it, (I will be interested) and how much things cost. Cheers.

[englishmaninwales]

Keith
I spoke with them this morning. I suspect their lack of email reply is that they have loads of work already!!

They use the standard T9 ratios with the rather short 1st gear. (3.65,1.9 1.3 1.0 and 0.81). The main casing is significantly modified to a two rail selector mechanism, along with a bespoke tail shaft and bellhousing. They supply the clutch pressure plate and hydraulic CRB. The gear lever (it is different from the one illustrated on their website and is more vertical) is in the exact same place as the 4 speed but not chrome plated.There is a small modification needed for a Lotus chassis with a grinder to allow room for the speedo angle drive. A Spyder chassis requires much more modification due to the type of tubes used. 4 bolt crank/flywheel may require a modified spigot bearing to accommodate a larger first motion shaft spigot. Otherwise it is a direct swap for the 4 speeder.

Cost is ?2000 + VAT. 10 month waiting time.

No problem if one wishes to supply a different T9 gear set, but don't expect any significant saving.

It would be nice to know (thanks Jim) a bit more about how the gearbox stands up to use over time.

Malcolm

[CBUEB1771]

The modifications required to a Lotus chassis are more involved than what is suggested. The top of the Voight-special tail housing fouls the chassis significantly. To do the job correctly involves cutting at least 1/4 inch wide strip out of the plunged panel that forms the front of the backbone section, material should be welded back in to restore stiffness lost when cutting the plunged section out. The "lug" for attaching the gearbox mount was also cast in the wrong location of the most recent Voight box and is something 3/4 inch too far back, meaning more chassis hacking and fabrication of a new gearbox mount bracket. My Voight box is still on the floor of the basement waiting for me to figure out how to install it with minimum chassis hacking. Nowhere near as easy as advertised.

[englishmaninwales]

Thanks, that's just the sort of information that is really helpful. It was described to me as simple and minor but I'd prefer to rely on customer's experience.
Any information on reliability in service?

[Keith Scarfe]

Oh blimey. 2k +vat + chassis mods. Well that's killed that idea then. It's not for me. I thought it was supposed to be just a straight swap with prop and clutch mod. Oh well, nothing wrong with a high revving 4 speed at 70mph. I have got used to it now.
Ta.

[gordont]

For 2000GBP +++ why not look at a plus 2 5 speed box, harder to find but maybe a better option?

[Mazzini]

I have a Voight 5 speed box with GBH gears awaiting installation into my S2. I'm doing a ground up on the car. I gave Gartrac the chassis modification diagram from Voights and they built it into the new chassis.

The Plus 2 five speed box isn't a bad box, but the change isn't great, though it can be improved and the ratios are better suited to the original family saloon for which they were designed.

[CBUEB1771]

[quote="Mazzini"]I gave Gartrac the chassis modification diagram from Voights and they built it into the new chassis./quote]

The sketch I got from Voight does not mention the chassis modifications needed to make the clear the gearbox mount. This is why I think he doesn't realize he put the lug for attaching the gearbox mount in the wrong location in his new casting.

[CBUEB1771]

I thought I had better post some images to illustrate the source of my rant. Sorry for the double posting of one image, I can't seem to remove it. It is hard to see in the last image but with the block mounted normally the gearbox mount is hard up against the front of the backbone section of the chassis.

Marker shows point where tail housing fouls the backbone.

Material to by removed to clear gearbox with block mounted normally.

With gearbox mounted without modification this is how far the block needs to go forward.

Marker shows point where tail housing fouls the backbone.

[Mazzini]

Thanks Russ! That's good to know, I'll be starting on my S2 very soon and after it's done I'll be working on EB 1575...well that's the plan for this evening...

[worzel]

Hi

I've used a T9 for the last13 years or so in my sprint. It's not a Voight's modded box so not directly comparable in some respects but I'll give you my input anyway.

Mine is ex 2.8 Capri so 1st is 3.35 with higher intermediates than the box Voights normally use. Mine is also higher in 5th- 24.9mph/1000 revs as opposed to around 23mph on their conversion.

Since my gearbox doesn't have an internal spring bias to push the lever over to the 3rd/4th plane but uses an external one I don't have the problem of any chassis fouling as per the ones illustrated and as I don't use a right angle drive for the speedo (I use the original Ford circlip method to secure the modified cable) again I don't have similar chassis fouling problems.

The lever on my gearbox is slightly aft of the Voights conversion (more upright rather than backward sloping) but the gearknob ends up where the 4 speed one would anyway so not much different.

In use- there seems to be pretty varied opinions on the change quality of these T9's. All I can report is that in use the shift movement on mine is very short, mechanical in feel and very precise (but remember that mine is internally std ie there are no modified selectors unlike the Voights box) so maybe not directly comparable. When cold I don't have any problems with fast changes from 1st to 2nd but then again I've never driven any other type of car with one of these boxes fitted. Changing into 5th on my box involves overcoming a spring loaded internal cam rather than just strong spring resistance so slightly different. Changing from 5th to 4th on a Voights box would, I imagine, simply involve pulling back the lever and the springing would automatically slot the lever into 4th. In my case this move involves pulling back from 5th which invariably means slightly "overchanging" so I need to relax slightly my hold on the lever and allow the springing to locate the lever in the 3rd/4th plane.

In practice 5th to 4th is immediate only involving a very slight additional movement as described.

A case of swings and roundabouts- converting a box to the one I use is pretty straightforward (and a lot cheaper) and involves no chassis mods with a std Lotus frame. By using a Rocket to BDA bellhousing you can also keep the car pretty much std- eg this bellhousing permits the retention of the std flywheel, ring gear, starter, external clutch slave cylinder and the std release bearing and the std gearbox rubber mounting. A T9 also permits the use of a std spigot bearing and the 4 speed clutch cover- only the friction plate differs (23 splines on a T9).

Price- if you do it yourself- allow ?400 for a new bellhousing, ?140 for a new prop (adviseable), ?80 for the clutch disc (a racing spec GB item from DemonTweeks) plus ?30 for a new gearbox metal support bracket, ?30 or so for a modified speedo cable, ?30 for a custom stainless gearlever plus whatever it costs to alter and alloy weld the tailhousing.

All-in say around ?900 or so plus a precautionary change of gearbox bearings, seals etc.

Hope the info helps.

Regards

John

[Mazzini]

I have a Voight 5 speed box with GBH gears awaiting installation into my S2. I'm doing a ground up on the car. I gave Gartrac the chassis modification diagram from Voights and they built it into the new chassis.

The Plus 2 five speed box isn't a bad box, but the change isn't great, though it can be improved and the ratios are better suited to the original family saloon for which they were designed.

My S2 is now finished and I can say that I didn't have any issues fitting the box and I can agree with what Jimj wrote previously in this thread - I'm a happy customer