6 speed gearbox for the Elan

[bill308]

Thanks David. I was especially looking at the end column and the numbers made no sense to me.

Bill

[msd1107]

Bill,

On the right column, the first number is the gearbox Figure of Merit, which is a calculation as to how well the gear ratios are staged. 100 is the max, there is no min. Anything over 80 or so you will perceive as well staged.

The next number is the nominal speed difference between gears. The next number is the speed difference increment between gears. Starting with 1st gear, add the speed difference to get to the speed in the next gear. For higher gears, add the speed difference increment also.

The following numbers are the error term in the actual gear ratio speed and its calculated value from the speed difference and inc. 0 is good, small digits is ok, larger digits and double digits are symptomatic of a problem in the staging of the ratio set around the error term.

The individual error terms are mathematically combined to produce the Figure of Merit. One large error term has more of an effect on the FoM than several small terms.

You can look at the % diff between gears, the speed difference between gears, and the error term to determine where there may be awkward ratio gaps.

By the way, what is the latest from Vincent?

David
1968 36/7988

[CBUEB1771]

I hope their business plan includes some means of shipping the kit to customers, rather than requiring customers to come to them. The roads between the US and UK are in poor repair...

I wonder if there is a US market for the Mazda conversion box now that Quantumechanics, Voights and BGH seem to have done a deal with a developed product and at a manageable price? The T-9 conversion is arguably a good continuation of the Lotus lineage, meaning a cheap Ford development on the Cortina 4-speed, not too many years later. How many road vehicles had six speed boxes from the mid sixties to early seventies? (My apologies to the Zetec crowd, especially Sir Pelly) I know it has been done to death with various spreadsheets but my experience with modern 6 speed manuals is that the ratios are far too close. I bought my Acura TL because it has a 6 speed manual but in practice the ratios are ridiculously close and 6th is still too short for US highway driving. I am changing up every few seconds with a 3.2 litre V6, give me a break! I did put my money where my mouth is and placed a deposit on a Quantum/Voight/BGH box.

[msd1107]

Russ Newton wrote

I wonder if there is a US market for the Mazda conversion box now that Quantumechanics, Voights and BGH seem to have done a deal with a developed product and at a manageable price?

Actually, the question is, is there a market anywhere? John says shipping will be calculated from the US or UK, which ever is less. From this I interpret the gearbox can be assembled in the UK, like the T9 conversion for the Elite was. If John had had the T9 gearcase drilled for the Cortina bolt pattern, he could have saved the cost and shipping for the custom bellhousing. But these are just quibbles at this late date. At least there is a viable product. If you select the options of the BGH gearset and aluminum gearcase, the project is very desirable.

And don't quibble about the cost. This is a one time purchase, with a life time of enjoyment. As Brian Buckland quoted Dennis Jenkinson "Sell the television set, Sell the washing machine, Sell the wife's car, Give up smoking, Give up drinking, Scrimp and save and buy an Elan, You will not be disappointed"

As far as 6-speeds go, Vincent's project suffered from attempting to use a stock wide ratio gearbox. 1st was useless and 6th was too low. If they had designed in a differential ratio in the range of 3.0-3.1, then it would have been better. 1st would have been more useful, top speed would be achieved in the 1:1 5th, and 6th would be a true overdrive.

But this is speculation. If John is able to deliver, we should all rally behind one project for the economic benefits of higher volumes and eschew other competing products. Of course, if Vincent comes up with a truly superior product at a more than competitive, the situation changes.

David
1968 36/7988

[CBUEB1771]

And don't quibble about the cost.

I am not quibbling about the cost of the kit that John Esposito is bringing in. It is less than I was expecting.

[GrUmPyBoDgEr]

Hi,

it's most likely an age thing but I have to admit that with the thread now stretching to 7 pages, I've now lost track of who's (or will be) supplying what g/box at what price.
I still have an interest in the initially proposed 6 speeder with 2 overdrive ratios.
To those of you that have been following the developments more closely; is it possible to now provide a summary of the present situation please?

Many thanks in advance.
John

[msd1107]

A Summary? Here's a slanted take.

20090608. STEVEWW had seen a brochure for a 6-speed gearbox for the Elan at Castle Combe Track day and wanted details.

20090609. Vincent Haydon responded. He together with Neil Meyers and engineers looked at the market and decided that a modern aluminum 6-speed converted for the Elan was the way forward.

Other musings.

20090624. Steveww confirmed the transmission is from the Mazda Miata.

Other musings.

20090629. steveww posted he had seen the work in progress and it was wonderful.

Much more musings

20090801. There was a reference to a Club Lotus announcement of the 6-speed.

More musings.

20090802. JJDraper made an extensive post on the progress of the project. It is a Mazda Miata gearbox. It has been installed in an Elan and test driven. The shift lever is in the Lotus position. Various details remain to be sorted. There are 12 pre-orders.

More musings.

20090803. JJDraper made another post in response to some questions. From the engineering point, little tooling is required which minimizes the up-front development costs. The conversion requires skilled welding and machining. The compatibility with the Spyder chassis is not known (Why didn't they use a Spyder chassis to start with, since this is the most difficult?)

More musings.

20090803. elanfan1 said he is one of the 12 pre-orders and gave second hand report on the progress of testing (fantastic). He reminded us of the background and qualifications of the principals and engineers on the project.

More musings.

20090813. Then a post referencing the announcement by Quantum Mechanics of a 5-speed conversion for the Elan using the T9 gearbox, Allan Voight tailpiece and centre plate, BGH gearsets, and aluminum gearcase. There was an enclosed spec sheet and price list and orders were being accepted with a supposed 30 day delivery.

More musings.

Hope this helps.

David
1968 36/7988

[GrUmPyBoDgEr]

Thanks David,

so we're still talking about the original 6 speed Miata 7 MX-5 based box with the Quantum mechanics box being thrown in towards the end.
I won't be doing any pre-ordering unless someone can confirm the situation with the Spyder space frame chassis.
I would have thought that Spyder themselves would have a vested interest & could try out the fit & bracketry. You out there Wiggy?
By the way, "The shift lever is in the Lotus position". made me chuckle.
Must do something about my wild imagination.

Cheers
John

[mikealdren]

Russ,
I agree with your comment about close ratios. My Alfa 166 has a six speed box. With a 150mph top speed I would have expected it to have a wide ratio spread so allow relaxed cruising. Instead, being italian, it's got a close ratio box for acceleration and top is only 23mph/1000. The engine pulls like a train and I never use 5th gear!

Give me an engine with a wide rev band and a wide ratio box any day for road use.

Mike

[CBUEB1771]

Quantum mechanics box being thrown in towards the end.

John - The kit from Quantumechanics is the Alan Voights T-9 conversion. The only thing that John Esposito (owner of Quantumechanics) has added is the option of several of the BGH gearsets, something that Alan Voights had never done. I don't mean to belittle John Esposito's contribution. Alan Voights has been resolute about not selling his T-9 conversion to US customers. It has taken John a very long time to negotiate a deal but now the US Elan and +2 owners have something to look forward to.

ps - Quantumechanics is also talking about an alloy main case option. I can only assume this is the bit that has been available from Quaife for many years.

[msd1107]

Russ,

Yes, let's not belittle John's contribution. Quantum has a leg up in that they offer T9 kits for MG TF, A, B, TRx, A-H etc already. So John has the infra-structure and recipe to bring out new kits.

Anybody who has attempted to interface with Alan or Brian know the drill. No email. Maybe they answer the phone, especially if they don't know of you.

And Alan's kit has perpetually been waiting for cases, machining, you name it. The stock reply seems to be "call back in 3 months". And, of course, is the problem of out of UK delivery.

In this respect, the previous T9 conversion for the Elite was maybe a miracle. But they had both engineering and inside connections. The Elite conversion is, arguably, more straightforward than the Elan conversion, although subtle engineering was necessary to produce the shift action of the result. And, even though the kit used the BGH E7 gearkit, the final price was less than the Quantum kit (primarily because they cut and welded the gearshift rather than cast and machine a new tail housing and centre plate)

The kit uses quite a bit of non-standard pieces. Already I see questions about the compatibility of the kit with this component or other. If John had had BGH machine the input and output shafts with the Lotus splines, the kit would be more compatible, as well as arguably less expensive. And if John had had the T9 case redrilled for the Cortina bell housing, the cost and weight of the kit would have been reduced.

Maybe if there is a flood of orders, some of this can be rectified. Reading between the lines, Quaife is not interested in adapting old gearbox components, and BGH has new projects also, so they can't spring an engineer loose to redo the NC programs.

Well, what we might be getting is better than what we had before.

David
1968 36/7988

[cabc26b]

I have thrown in my lot with Quantum ( my lot and CC#) , I don't need 6 speeds just a highway transit gear to get me from the city to the mountains.

It was certainly no more expensive than a quaife kit with TTR alloy bits .

I also opted for the alloy center piece - ( Quaife part.)
Plus the kit comes with alloy bell housing ( my bet is that this is the already available casting from burton and others that adapts TC/cortina motors to the T9.
I will also have the tranny kitted by John with a tilton clutch disk and Pressure plate so they can look/check that it works with the annular throw out. My completely stock set up will not sit on the shelf for posterity.

George

[bill308]

I want to resserect this thread and suggest that a 6-speed is still desireable despite the availability of some good 5-speed alternatives. The key issue in my mind is the availability of appropriate gear ratios and overall weight. Quantum Mechanic's 5-speed offering is pretty darn good. Still, a similar 6-speed offering with a 6th gear 0.7 ratio would be near ideal for conditions in my area where fast traffic on interstate arteries travels in the 80+ mph range. It would also be especially good for those who have rear end ratios higher numerically than the 3.55 that I have. To summaize, a gear set somewhere between the Lotus close ratio and close ratio gear boxes for the first 4-gears with two overdrive ratios of about 0.82 and 0.7 would be highly desirable.

Bill

[msd1107]

Bill,

I agree - your proposed set based on 2.65, 1.70, 1.27, 1.00, 0.83, and 0.71 would provide 5 nicely staged ratios with a good TC being able to pull peak rpm in 5th, with 6th as a true overdrive. It would be a dream come true.

However, at least two posts here with 6-speed sedans (an Alfa and an Acura TL) complained that 6 speeds were too much. The ratios were too close and they were shifting all the time. To put this in perspective, both are sedan ratios and are what I consider wide ratio, necessary to provide a startup ratio for a heavy sedan up a hill and an OD ratio. So some of our members may not be as anxious for a 6-speed as they would be for a 5-speed.

The other factor is a gearbox with a 1.00 4th, to allow for 2 overdrive ratios. Here, we would have to find a small, lightweight gearbox that would be a suitable candidate to swap into an Elan. And all the other aspects of the conversion (custom gear set, intake splines, output splines, gearshift relocation, gearbox to bellhousing conversion, speedometer drive, etc, etc) would have to be faced.

Another possibility with the Mazda gearbox is a gearset with ratios around 3.205, 2.042, 1.528, 1.208, 1.000, and 0.855 with an 11:33 differential. This would produce the same speeds in gear as the previous 6-speed with 2 OD ratios with a 3.55 differential.

However, until we hear back from Vincent with a wonderful progress report, this may be idle speculation. I don't know about the rest of the readership, but even if Vincent came back with the Mazda gearbox as currently under development and under the price of John Exposito's T-9, I would take the T-9.

And for those of you who are not tired of this talk of gear ratios, there is a downloadable paper over at elan-f15/quantum-mechanics-john-esposito-speed-offering-for-elans-t19015-15.html that discusses the design of gear ratios with references to sedan, F1, formula, and other production cars. Has references to Lotus gearboxes spanning 40+ years. Ideal light bed time reading, sure to put you to sleep.

David
1968 36/7988

[bcmc33]

I've just read in the latest issue 4/2009 of the Club Lotus magazine that the 6 speed is now running. See page 13 for a full page description.