Lotus Elan

My Voigt 5-speed conversion

PostPost by: 1owner69Elan » Thu Jun 11, 2020 11:19 pm

Steve, would be interested to see what kind of clearance you have between the exhaust pipe and the bottom of the plate gearbox mount.

The mount supplied by Voigt is essentially a flat plate that bolts into the existing mount holes. The stock Elan gearbox mount is a "bridge" affair allowing clearance for a central exhaust pipe. The Voigt flat plate reduces the available clearance by ~1.5 inches (substantial) requiring the pipe to be under a plate that is bolted flush with the body/frame.Voigt on left:
IMG_5502.jpeg and


My large bore TTR pipe definitely will not fit under the plate (further exacerbated by the end folds extending downward). I would have to modify the exhaust and drop it down to clear. With the car already lower than stock, and further reducing ground clearance, I'm not sure that is the direction I want to go.

I'm inclined to look into adapting the stock gearbox bracket to the proper height for the Voigt T9 and thus regain some of the clearance that the flat plate removes. And thus, allow the exhaust pipe be tucked up in the central tunnel as in a stock configuration, and not causing a low hanging obstacle. Note that both the stock 4-speed and the Voigt 5-speed use the same gearbox saddle. The issue is to get the proper height of the gearbox saddle and in the right axial position.

It appears that I can achieve the proper positioning by turning the stock mount around and then using 3/4 inch spacers where it bolts to the frame to achieve the same gearbox saddle height as the Voigt plate (with its spacer). The two different mount plates already use the same mounting hole positions as well the same axial position for the saddle (if turned around). I have dry-fitted this solution and it appears to work. One can fine tune the height of the gearbox by the size of the spacers, later, but 3/4 inch appears to be very close.
Voigt plate on top of stock plate for comparison. Dramatic difference in clearance to an exhaust pipe. The two mounts align except for saddle height:
IMG_5512.jpeg and


Spacer to place saddle at correct height:
IMG_5517.jpeg and


I guess with a stock, small bore exhaust one can get by with the Voigt flat plate but the clearance really becomes problematic with a large bore setup.

So after all the machinations with modifying the Voigt mount plate with a leading edge fold (me) or making a cutout to clear the casting (Steve), I may not be using the Voigt plate after all. But, simply adapting the original mount.
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PostPost by: Mazzini » Fri Jun 12, 2020 5:59 am

The Voigt bracket is similar to the Lotus made 5-speed bracket for their own 5-speed gearbox. The rubber mount is the same for 4-speed and 5-speed.

I have a friend that owns a genuine Sprint 5, it was probably the first car of it's type and it has a 4-speed bracket attached to the 5-speed box. It's done many thousands of miles without any issue from the box or associated brackets/mount.

The only significant difference between the Voigt box and the Lotus box is the weight, the Voigt box is significantly heavier. If you do decide to go down the 4-speed bracket route it might be worth regularly inspecting the bracket.

I had a TTR fast road exhaust system, Voigt box and TTR fast road suspension on my S2. I used the Voigt bracket. The exhaust was modified to fit by making a cut along one of the welds in the exhaust Y piece, this allowed the tail/straight end of the pipe to be bent downward slightly allowing the central pipe to pass under the gearbox.
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PostPost by: 1owner69Elan » Fri Jun 12, 2020 6:59 am

Mazzini wrote:The Voigt bracket is similar to the Lotus made 5-speed bracket for their own 5-speed gearbox. The rubber mount is the same for 4-speed and 5-speed.

I have a friend that owns a genuine Sprint 5, it was probably the first car of it's type and it has a 4-speed bracket attached to the 5-speed box. It's done many thousands of miles without any issue from the box or associated brackets/mount.

The only significant difference between the Voigt box and the Lotus box is the weight, the Voigt box is significantly heavier. If you do decide to go down the 4-speed bracket route it might be worth regularly inspecting the bracket.

I had a TTR fast road exhaust system, Voigt box and TTR fast road suspension on my S2. I used the Voigt bracket. The exhaust was modified to fit by making a cut along one of the welds in the exhaust Y piece, this allowed the tail/straight end of the pipe to be bent downward slightly allowing the central pipe to pass under the gearbox.

Useful input.
I’m going to be using the TTR competition spec 4-speed bracket which looks to be more robust than the stock one. That should alleviate concerns about the strength of the bracket for the heavier 5 speed.
If for some reason this adaptation doesn’t work I can always revert to modifying the exhaust and use the Voigt bracket.
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PostPost by: Mazzini » Fri Jun 12, 2020 7:19 am

Do you already have the TTR bracket? I have new one kicking about.
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PostPost by: 1owner69Elan » Fri Jun 12, 2020 3:52 pm

Mazzini wrote:Do you already have the TTR bracket? I have new one kicking about.

Oops! Just saw your post after I placed the order.

Oh well, should be here in a few days.
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PostPost by: steve lyle » Sun Jun 14, 2020 9:08 pm

1owner69Elan wrote:Steve, would be interested to see what kind of clearance you have between the exhaust pipe and the bottom of the plate gearbox mount.


1Owner -

Sorry for the delay in responding, no excuses. I just wasn't paying attention,

Belatedly, here's a pic of the clearance. I roughly measured it at 3/8". With my exhaust setup I have a bit of control to increase/decrease that - I've got 12" of pipe connecting the header outlet with the tailpipe inlet, and depending on how I rotate it I can vary this gap a little. So my exhaust isn't stock (who's is?), but should be roughly representative.

Here's another lesson learned. If you've got the original nylon clutch line, and it gets too close to the header, it'll melt, resulting in a negative impact on clutch performance. Or so I've been told.

Before any most recent lessons learned, however, I did get out on the turnpike. 75 mph (my GPS app and speedo agreed) was just about 3500 rpm, maybe a few more. Very nice.

Still working on modifying the console and shift gaiter. More to come on that, but the MGB rubber boot is definitely a good option. The stock Elan one just isn't flexible enough to handle the longer throws of the T9.

IMG_0395 (2).JPG and
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PostPost by: steve lyle » Tue Jun 16, 2020 4:05 am

More test drives, this time with the console modified to fit the MGB gaiter that elanner (Nick) suggested. It can handle the additional movement of the T9 shifter that the stock gaiter can't. At some point this car is going for a refreshed interior, when that happens in a year or so, I'll have a leather cover made for the rubber bellows. But for now, this keeps the hot air out of the cockpit, and doesn't look bad, imho.

IMG_0400 (2).JPG and
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PostPost by: 1owner69Elan » Wed Jun 24, 2020 2:19 am

Finally underway in installing the Voigt box.

I now have the engine out and have removed the clutch cover (pressure plate). It is a Borg & Beck with an orange dot on the diaphragm fingers.
CCF93506-11BE-4F9F-8517-8512F92CDCD9.jpeg and

Dave Bean was the source for this just a few years
back. The Bean catalog only refers to green (standard-120 lb-ft), white (140 lb-ft), and grey (170 lb-ft). No orange.

Can anyone shed any light on the spec (lb-ft torque) that the orange dot would indicate?
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PostPost by: 1owner69Elan » Fri Jun 26, 2020 6:16 pm

So, no response from anyone on the torque rating for the clutch cover, but I determined through measurement that the “orange” pressure plate has a ~165 ft-lb rating. For more details see, viewtopic.php?f=37&t=47015

I also determined that the Voigt supplied clutch cover is indeed standard @ 120 lb-ft. So, if you are installing the Voigt kit and you have an uprated engine the Voigt cover will not be suitable.

Using a non-Voigt supplied cover, one should check the installed dimension of the the thrust pad to ensure that the concentric slave cylinder travel will be in spec. This is information that Voigt does not now supply with his current kits, relying on installers to use the supplied cover.

Thanks to Mazzini, who had an earlier model Voigt kit, here are the additional instructions to check if a non-Voigt installed cover is positioned correctly for the 5-speed concentric slave cylinder.
Voigt clutch plate dimension.jpg and


Thankfully, my cover measured at 98mm, within the 97-99 mm Voigt specified range. No shims required.
Thrust pad height.jpg and
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PostPost by: 1owner69Elan » Tue Jun 30, 2020 10:22 pm

Continuing my Voigt installation at a glacial (but careful) pace. No speed records here.

I have the engine and 4-speed gearbox out. Did them separately and found it pretty easy as a one person job. I do have a couple of advantages in the removal process:

1. Removable cross piece
2. Max Jack, allowing me to easily adjust the height of the car. Suspend it with no wheels to allow easy access for the engine hoist. Etc.

I was troubled by maneuvering the new 5-speed box into position. I tried to fashion various cradles using a floor jack but not happy with the stability and control. Finally opted for a low-profile transmission jack that provides a solid solution. Easy to control and position. All for $USD 80.
IMG_5628.jpeg and
IMG_5638.jpeg and



Having run into issues with things not exactly fitting properly with the as-supplied Voigt kit, such as the metal mounting bracket, I figured I would check the 5-speed for fit prior to doing any cutting on the frame.

Lo and behold, with the fact that I am using a GPS speedo and not the usual speedo fixture, the needed cutout is much reduced. In fact reduced much more than I originally thought. The height of the Voigt specified cut is wholly dictated by the height of the speedo unit. Without this, the height of cutout to accommodate the gearbox tail spine is much reduced. One can see the difference in height from Steve's earlier picture.
Voigt speedo connection height.jpg and


Below shows the larger hatched area (Voigt original), Cut A: What I had thought was needed if using a GPS speedo, and Cut B: Reduced height cut, only need to accommodate the gearbox tail spine, and evidenced by a dry fit of the gearbox (to be double checked).
Voigt cutout modified.jpg and

Thus, I am going to be able to reduce the notch by at least half, if not more. Just enough to allow some clearance all around. For those of you squeamish (like me) of making any alterations to the frame, this is good news. Much less impact on the original frame (allowed by using a GPS speedo).
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PostPost by: My72Sprint » Tue Jun 30, 2020 10:59 pm

Future 5 Speed planning..
If you removed the Speedo Drive and installed speedo drive plug would this reduce modification needed for clearance ?

I'm moving my 4 speed Elan to electronic Smiths w/GPS and installed speedo drive plug. Easy with body off.
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PostPost by: 1owner69Elan » Wed Jul 01, 2020 12:27 am

My72Sprint wrote:Future 5 Speed planning..
If you removed the Speedo Drive and installed speedo drive plug would this reduce modification needed for clearance ?

I'm moving my 4 speed Elan to electronic Smiths w/GPS and installed speedo drive plug. Easy with body off.
Tim


If you are referring to the Voigt 5-speed conversion, the point of my previous post was that not using the standard speedo gear unit and using a GPS speedo instead and just putting a blanking plug in the 5-speed gearbox does indeed reduce the amount of material to be cut from the frame.
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PostPost by: My72Sprint » Wed Jul 01, 2020 2:08 am

I saw the photo with the drive installed but missed the text..
"One can see the difference in height from Steve's earlier picture"
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PostPost by: 1owner69Elan » Sat Jul 04, 2020 7:36 pm

So, I test fitted my Voigt gearbox into position. It actually fits through the bulkhead plate without any cutting! This is with the Voigt mounting bracket in place and a proper, small upward angle to mate with the engine. Again, this is with no speedo angle gear.

But, while the gearbox slides into position the clearance to the plate is all of 0.035 inches. A bit too close for comfort with engine vibrations and potential movement of rubber engine/gearbox mounts. Thus, while I like the idea of no cutting I will be obliged to be making the slight frame alteration along the lines shown as Cut B in my previous post. Still much less of a cut than that of the original instructions.

I can also report that, in a recent correspondence with Alan Voigt, he said that he still could not "fathom" what went wrong with Steve Lyle's fifth gear non-engagement problem. Alan says he is waiting for the faulty parts to be returned to the UK for a post-mortem.
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PostPost by: 1owner69Elan » Sun Jul 05, 2020 10:47 pm

Next step in my installation. I fashioned a new gearbox mount configuration using the original Elan gearbox bracket for the 4-speed instead of the Voigt supplied bracket.

The motive behind this was ostensibly to create more room for my large bore exhaust, and to avoid having to modify the exhaust system by dropping the exhaust further down and thereby reduce ground clearance.

As noted in previous posts, the new Voigt bracket is a flat plate with a fold-down at the back end and, in my case, a modification to also create another fold-down in the front of the plate. If you recall, without modification, the front of the Voigt bracket fouled the gearbox and required either a cut-out (see Steve) or a front fold-down to shorten the bracket plate.

The problem is that in either form of the folded Voigt bracket, the fold(s) descend downward and restrict the clearance for the exhaust pipe that is hung under the gearbox and runs along the center of the car. I suppose one could grind out passages for the exhaust pipe in each fold but that results in a rather inelegant solution (bodge) and also weakens the bracket. If you don't have a large bore exhaust or already have a lower slung pipe, the whole clearance issue may be moot.

My thought was to use the original gearbox bracket, which is a bridge type and raised in the center to allow for more clearance. After careful measurement I ascertained that reversing the original bracket front to back (180 deg rotation) and using the existing bracket holes, in both the chassis and the bracket, would place the Voigt gearbox saddle in the exact same place as the Voigt mount, but now with more clearance for the exhaust. The change in configuration would require positioning the original bracket 3/4" lower with spacers. While the bracket is lower it will still be higher than the exhaust pipe at that location - so no net effect on existing ground clearance.

As shown below I have carried out my theoretical exercise, and it does succeed in its objective. The gearbox is positioned the same location, axially and vertically, compared to the Voigt bracket. After the engine is installed one can further fine-tune the position if needed. I'll also be painting the spacers to have them blend in with the bracket.

Here is the Voigt bracket "in-situ":
IMG_5633.jpeg and


Here is the "reversed" and lowered original bracket positioned for the Voigt 5-speed, now with better clearance in the center.
IMG_5660.jpeg and

IMG_5663.jpeg and



I have further utilized a new "uprated" gearbox bracket from TTR, instead of my original, for more strength as the T9 is heavier than the 4-speed. I would say that this TTR bracket gives nothing away to the Voigt bracket in terms of strength and may in fact be stronger.

So, as this shows, there is another, relatively simple, way to utilize the existing gearbox bracket if desired for more clearance for the exhaust. Also this avoids having to modify the Voigt bracket for gearbox casing clearances, until Alan Voigt fixes this issue himself in future production.
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