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+2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Thu Dec 04, 2014 9:01 am
by piple
Hi all

I have +2 basket, now my Duratec engine is back from the rebuild. I want to put a 5 speed gearbox in the car. My problem is, I am not allowed to modify the chassis.

searching through the forum I found a lot of infos, but now I am a little confused.
- Voigt is not possible, alteration to the chassis seems to be necessary
- the state version is basing on the voigt gearbox
- NM stopp to produce their 6-speed conversion


My options as far as I see is a MCT75 conversion , or go originaly 4-speed (CR) (lay alread in the garge, bellhousing??? ).

I would prefer a kit, where all modifications are included. Is there something on the market?

Regards,
Arion

Re: +2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Thu Dec 04, 2014 9:36 am
by Mazzini
There are still a few original Lotus 5 speed boxes out there, not sure if they'll cope with the extra power though?

Re: +2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Thu Dec 04, 2014 11:10 am
by rgh0
They coped with a 160 hp 2 litre 907 engine and a considerably heavier car in the Elite OK

cheers
Rohan

Re: +2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Thu Dec 04, 2014 8:27 pm
by CBUEB1771
rgh0 wrote:They coped with a 160 hp 2 litre 907 engine and a considerably heavier car in the Elite OK

cheers
Rohan


I thought the Lotus Maxi-derived gearbox did not fare too well in the Elite and Eclat. A neighbor of mine went through a couple of these gearboxes in an Eclat. It wasn't too far into the production run that Lotus switched to a Getrag box. I could be wrong.

Re: +2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Fri Dec 05, 2014 3:00 am
by rgh0
CBUEB1771 wrote:
rgh0 wrote:They coped with a 160 hp 2 litre 907 engine and a considerably heavier car in the Elite OK

cheers
Rohan


I thought the Lotus Maxi-derived gearbox did not fare too well in the Elite and Eclat. A neighbor of mine went through a couple of these gearboxes in an Eclat. It wasn't too far into the production run that Lotus switched to a Getrag box. I could be wrong.



I have seen enough of the boxes live a long life in Elites and Eclats to believe they were "OK" in these cars. There are certainly some design issues with them but I suspect Lotus changed more for issues around availability of the Maxi 5 speed internals and cost for a bespoke box rather than the fundamental suitability of the box itself.

Has anyone ever looked at the suitability of the Gertrag box in an Elan or Plus 2. Did Lotus change the chassis in the Elite to fit it in so it would not fit in the Elan chassis like the Lotus 5 speed did. I never see the Gertrag come up on Ebay either do they exist in the second hand market?. The same question on suitability in an Elan could also apply to the Toyota Supra box used in the later Excel

cheers
Rohan

Re: +2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Fri Dec 05, 2014 5:18 am
by Vic
Here is a picture of three different transmissions:
Olympus car photos 002.JPG and


At the top is a 5-speed from my Eclat (similar to an Elan 5-speed). Middle transmission is what I'm installing in my resto-mod Elan S2 (26R clone) along with a 2.0 Duratec and the bottom transmission is an Elan 4-speed. The middle transmission is a Borg-Warner T5 form a Ford Mustang. The tail housing is what makes this an option in an Elan. It is from a Chevrolet S10 pickup (that also uses a T5). The bell housing to mate the Duratec to T5 is from quad4rods.com. It does fit an Elan chassis (TTR 26R chassis), but is tight at the bell housing, the Duratec is wide at that point.

Vic

Re: +2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Fri Dec 05, 2014 8:31 am
by john.p.clegg
Nice photo Vic,but are you sure you can fit the tail housing from the middle box into the frame...I tried with the top tailhousing "Eclat" ( gearlever moved to the front ) and it just wouldn't fit...

John :wink:

Re: +2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Fri Dec 05, 2014 8:54 am
by piple
Hi Vic

Can I see some pics of the installation?

Thank you
Arion

Re: +2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Fri Dec 05, 2014 9:55 am
by 18treacle
A Voigt's gearbox will not fit in an Elan without alterations to the standard Elan chassis ?
I was advised that the Voigt's gearbox with its own cast bell housing went into the Elan chassis without any alteration's , I hope so because I've just bought one on this pretext.

Is there anyone out there who has fitted / owns an Elan with the a Voigt's gearbox who can advise me please?
Some time ago there was a person in Merseyside who was running an Elan with this conversion in it are you still out there?

I'm fitting a Voigt's 5 speed gearbox to a TC engine in a 2 seater Elan not Zetec or Duratec.
Thanks.

Re: +2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Fri Dec 05, 2014 12:42 pm
by jimj
Yes I have a Voight gearbox in an S3 with a "Lotus" chassis, though I`m not from Merseyside. I didn`t fit it but I don`t recall the mechanic having to cut anything. I seem to think I`ve seen on here someone who removed a little from the Vee where the gear lever sits. I can`t believe that the authorities in Lichtenstein would know or care if you did. It`s hardly a significant alteration to the chassis.
The Voight is definitely the most straightforward way of fitting a 5 speed and I`d recommend it but, if I was doing it again I would pay a bit more and have a higher first gear.
Jim

Re: +2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Fri Dec 05, 2014 1:48 pm
by CBUEB1771
18treacle wrote:A Voigt's gearbox will not fit in an Elan without alterations to the standard Elan chassis ?


No, the frame must be modified to accept the Voights conversion. The problem is the tail housing, not the bell housing. The installation instructions are attached. I have not finished the installation of my Voights box so I can't verify that the instructions are entirely correct, but they look reasonable based on my preliminary fit-up.

Re: +2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Fri Dec 05, 2014 2:06 pm
by Mazzini
I have a Voigt box in my S2, the chassis does have to be modified slightly, it works well. Go for the uprated gear set, it's well worth the extra.

Re: +2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Fri Dec 05, 2014 4:17 pm
by CBUEB1771
rgh0 wrote:I suspect Lotus changed more for issues around availability of the Maxi 5 speed internals and cost for a bespoke box rather than the fundamental suitability of the box itself.

Has anyone ever looked at the suitability of the Gertrag box in an Elan or Plus 2. Did Lotus change the chassis in the Elite to fit it in so it would not fit in the Elan chassis like the Lotus 5 speed did. I never see the Gertrag come up on Ebay either do they exist in the second hand market?. The same question on suitability in an Elan could also apply to the Toyota Supra box used in the later Excel

cheers
Rohan


I am sure you are correct about the availability of the Maxi internals and the cost of the bespoke gearbox, not to mention ensuing displacement and power increases for the 907 engine and inevitable weight increases for the Elie and Eclat. You raise an interesting question about the Getrag box for an Elan or +2. The gear lever location in the Elite and Eclat is much further back than in the Elan or +2 so the entire tail section of the original Maxi-derived box for the Elite and Eclat differs from that for the Elan/+2 application. So the Getrag box would also have to be modified and I have never looked into how difficult that might be.

Re: +2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Fri Dec 05, 2014 6:25 pm
by Vic
Here are some more pictures. This is in my rotisserie (rusty frame) and 65 Elan GTS body.
PC050306.JPG and

PC050307.JPG and


PC050309.JPG and

As you can see there is clearance for the tail housing to slip into the tunnel. For the transmission mount I will first bolt a plate to the tail housing, then fabricate a mount further forward. The gear lever hole needs to be opened up. A Duratec in a folded Elan chassis needs frame clearance for one block to bell housing bolt, or trim off this one ear. Bell housing flange in these pictures is 17.25 inches back from the front cross member. With a small diameter front crank pulley, the pulley fits the recess on the cross member.
Vic

Re: +2 Gearbox 5/6-Speed Lotus Chassis

PostPosted: Sat Dec 06, 2014 12:34 pm
by worzel
Hi Arion

Only my personal experience- I've run a home brewed T9 conversion for the last 15 years using a modded box from a 2.8i Capri with a 5th ratio of 0.75 as opposed to the usual 0.825. Mine fits straight in but then again isn't quite the same as the AV box. Works fine, slick change but can suffer from slight obstruction 1st to 2nd if change is taken slowly (surprisingly). Winding up the revs definitely improves matters but I'm baffled why this should be.

As for the MCT75- I have one that waits for me to get fired up enough to fit it. Pricey though- new ones are around ?1700, 2nd hand about ?500 minimum (and they don't seem to come onto the market very often). I was lucky to get a brand new one for ?350 a few years back (although I might know where there is another unused one, still in the maker's packing case at a heavily discounted price).

MCT box has some advantages- no fiddling around moving the lever (although it's not exactly where the 4 speed lever is). Rated to 300hp and has a drain plug (type 9 boxes don't). Ratios not ideal for some (3.61 in first). Std Lotus chassis will take the box unmodified as will the Spyder "Stressed Skin" unit. Don't know about the other frames. Fitting almost certainly involves modifying the exhaust around the "Y" pipe area but nothing too disastrous. Requires an expensive bellhousing (a Rocket to BDA unit from the likes of Lotus Cortina Spares- about ?400), plus a new prop plus a new friction disc. Also requires a few other things like a custom rose jointed linkage and a modified speedo right angle drive.
However- principal advantages are no chassis cutting, retains original starter, clutch cover, release system, spigot bearing. Very slick change.

Hope the info interests.

John