Gear Set choice for Voigt 5 speed

[1owner69Elan]

Just to fill in a bit more information on Option #3

1. The 5th gear ratio can be specified as 0.82 instead of 0.84. I’m choosing 0.82

2. The gear set is the BGH “ E7 Pro Sporting Close”

3. A completely new set of BGH E7 gears is used as opposed to reconditioned original T9 gears. Also, the uprated bearing is included. Thus, explains the hefty premium, which is largely a BGH cost, for this option.

Dave Vegher (the engine builder and racer) has also weighed in. He agrees with most everybody on here and recommends that the close ratio box is the way to go.

[My72Sprint]

I've been considering a Voigts Type 9 for my sprint (Kelvedon recently sold 2 with 1 remaining 1/31)

Lot of good information in this post BGH ratios etc.

My new twincam (install in progress) has a slightly different power cure. Dyno Sheet Attached
The 2.8 SPORTING CLOSE seem ok but I'm not sure. Thoughts anyone?
Tim

[1owner69Elan]

Your general dyno curves are similar to mine but translated upwards by about 10% tracking with your +10% increase in engine displacement. You have a nice, relatively flat torque curve (some dip (10%) in the vicinity of 5000 rpm) with a lot of horsepower as well. Looks like a representative "monster" McCoy engine. It's going to be fantastic I expect.

I would say the same E7 BGH gear set would work quite nicely for your engine as for mine. What diff ratio do you have? Is your car for the road or track or both?

The breakthrough in my thinking was realizing that the close ratio would allow you to operate the engine in a narrower rpm range, depending on your driving style. Specifically, one can run the engine in a band closer to redline or alternatively at a lower, more comfortable, and with less engine stress, rpm range for the road. Shifting through the gears 2-5 with smaller rpm changes (upshifts and downshifts) undoubtedly should provide for smoother transitions and a more fluid (pleasurable) driving experience. There is no need with the broad torque curve to keep the engine in a narrow band where the peak torque occurs. But, the broad torque, in conjunction with the close ratio box, allows you to select the rpm band where you want to drive.

The trade-off is perhaps a longer first gear that could decrease peak launch acceleration. But, the good news is that both of our engines with powerful, flat torque should minimize this issue. I also already have an effective 3.9+ diff as well as an overall weight reduction of ~80 lbs from stock (added lightness).

Until I install the new gear box and drive the car I guess I won't know for sure about the close ratio choice. But, the consensus of those that weighed in here seem to echo that the close ratio is preferred. What is John McCoy's, your engine builder's, opinion?

[My72Sprint]

Geese I had the Elan since 1982 but never has time or resources to get it up & running. Everything was broken one way or another.

My Elan is most "stock" layout except 1950 cc, 3:54 rear, Quaile, CV rear shafts, Koni adjustable f/r ,panasport wheels, Waiting, Rear 2.5 coil over, updated spring rates, rear diff mounts.

Hadn't planned for "Track Day", 5 speed was about freeway speed & RPM (3:54 minor help)
Since I'm not track driving the 3:54 might be ok ? Still have stock 3:77 though.

For outright acceleration & freeway I have another car arriving late spring (2020 Corvette )
The Elan should be more fun to drive, more directly connected.

McCoy is too tall for Elan's he's mostly a Cortina/Escort person. He did recommend 3.54 & Quaile but wan't enthusiastic about converted type 9 5 speeds, various reason's.
As a racer himself is concerned about durability. ex: Stock gear box aluminum update parts "stock cast iron engineered dimensions" tend to fail in competition ,didn't last in a Mallock with 250hp Twin cam
Tim

[Davidb]

Can somebody who has driven both tell us what difference, if any, there is between the feel of the original, close ratio box and the Voight T9-or any T9? The original gearbox is one of the appealing aspects of Elans.

Why are we stuck with just one option for the T9 conversion-I would have thought that one of you Aussies would have come up with something? Nudge, nudge, wink, wink...

[JohnCh]

My Westfield has a BGH E2 HD w/ the BGH gear lever. It's a great gearbox, but I slightly prefer the gear change in the Elan. Throw lengths are nearly the same, and they share a similar mechanical feel, but the Elan change is a little lighter. A little more delicate. As further comparison, I also have a first generation Miata/MX5. The Miata changes are closer in weight to the Elan, but not as mechanical as either the BGH or the Lotus and is my least favorite of the three.

-John

[stugilmour]

Tim, I think we have the same McCoy engines. You will love it!

Mine is installed in a Plus 2 with a Lotus 3.55 diff running stock sized 165/80R13 tires. I also have a Spyder supplied Ford MT75 five speed (originally from a Ford Scorpio I believe). I think my ratios are

1 - 3.61
2 - 2.08
3 - 1.44
4 - 1.00
5 - 0.83

For comparing to your diff and tire combination I am pretty much dead on 80 mph at 3500 rpm, which is perfect for the Interstate. Think the Plus 2 weight is about 350 lbs higher. The proses fifth looks very close.

My car accelerates easily for passing in fifth now; the stock engine required downshifting. I think the proposed 2.66 first will be fine without Rotaflex stretch. Looks like a nice gearset.

[My72Sprint]

Stu, Great news about McCoy Twin cams

Doesn't a Spyder supplied Ford MT75's also require a Spider space frame, insufficient clearance with standard Lotus ?

I do recall an older posting indicating Spyder was about ready to provide a 6 speed trans for their space frame.
Nothing on the Website.

Guess I could ask but 3.55 & MT75 sounds like a great combo.

Tim

[stugilmour]

I would look at other alternatives to the MT75, particularly our side of the pond. It is an old piece of kit now, and parts are impossible through our NA Ford network. To get rebuild parts I reached out to list members to get stuff from Ford UK, and even then it was getting difficult. We are still having issues after service, and I can’t find much help locally. Note ratio choices are limited, and the bell housing is integral to the gearbox so it is not as flexible a starting point as the T9.

Asking Spyder about the Mazda six speed would be great. I just ran across a supplier tonight (looking at other stuff) that uses the MX-5 five speeds in both MG & Triumph...

https://www.vitesse-ltd.com/pages/mga-m ... rsion-kits

We have been hoping for something for the Elan for a long time; check out the date on this post...

https://www.mx5world.com/forum/miatapow ... ap.239347/

And here is the link to the Mazda transmission data that is mentioned in the kinda disappointing answer Jeff got to his enquiry about ten years ago. Looks like the listed six speed also suffered from a low first gear. Maybe Spyder is focusing on a newer MX-5 six speed?

http://fixjunk.com/solomiata/solomiata/Drivetrain.html

If guys are starting to get T9’s supplied, that sounds like the way to go. The CR gearset shown by the OP looks pretty sweet. If they have actually fully figured out the bell housing, starter, shifter/tail housing, transmission mount, chassis clearance, and prop shaft issues there is a lot of value there. And a guy should be able to source T9 spares all over the world forever.

Is the dyno curve for your actual engine? Don’t want to be caught in a white lie when I show it to the tuner! I think mine was built in last year’s batch, and has the stroked tall block, cassette water pump, Stromberg head conversion with Weber 45’s, oversized airbox, large exhaust, MSD electronic ignition, and John’s signature oil pump conversion, He said he was building several in the batch. Just tuning another batch now I understand.

Stu

[My72Sprint]

Yes, That's the an actual dyno results. McCoy 1950 tall block,Stromberg / Weber

My engine dyno run:
https://www.youtube.com/watch?v=EQ7qg3187UQ

Johns Facebook with current Stromberg head weber conversions + my engine is included

https://www.facebook.com/omnitechengine ... wUoxkGWBxK

Tim

[1owner69Elan]

McCoy is too tall for Elan's he's mostly a Cortina/Escort person. He did recommend 3.54 & Quaile but wan't enthusiastic about converted type 9 5 speeds, various reason's.
As a racer himself is concerned about durability. ex: Stock gear box aluminum update parts "stock cast iron engineered dimensions" tend to fail in competition ,didn't last in a Mallock with 250hp Twin cam
Tim

The Voigt conversion uses the original cast iron case with a newly cast aluminum bell housing and tail piece. So no particular issue with a “weak” aluminum alloy case cast to original iron dimensions.

I should add I wanted Voigt to use the Quaife alloy case but he refused. Feels not necessary and stated that various suppliers are selling “uprated” , and expensive, parts that have no real added value.

I believe that the Quaife case is more than just an aluminum version of the iron one by including strengthening ribs etc so as to not compromise robustness for lighter weight. In any event, not getting one even if I want to pay for it.

[My72Sprint]

The new tail is required for Elan shiftier location, Aluminum bell housing just look nice too.

John has a opinion but I'm not concerned. If this was a 100% effort racing Elan I would establish a fault inspection schedule based on hours and replace components as cracks/defects occur.

That how we maintained sport racer and open wheel formula Atlantic cars in the distant past late 1980's, early 1990's.
Tim

[jonesa62]

Some previous posts about 5 speeds

viewtopic.php?f=37&t=13955&start=

viewtopic.php?p=82911

Follow the links for more.

David
1968 36/7988

Hi David. AKA msd1107

This is a topic of great interest. I have found the previous post with the hyperlink to your spreadsheet - unfortunately now corrupt. Could you repost the link to another version or send to my email address: [email protected]" target="_blank

I have also uploaded a spreadsheet I have been accumulating Re. Gear options, tyre options and camshaft options for the Lotus Twincam. With your background in racing and matching performance, I'd be interested in your thoughts