A 3.2 which will run 8,000 rpm?

[smallspeed]

I do think if you rebuild then go efi - fuel and spark, with a camsync so you can ditch the dizzy
It needn’t be mega costly and I think the driveabdrivability gain you’ll get will be very noticeable, potentially enough to avoid the odd gearshift depending on the track..

[911hillclimber]

The transmission is a very big bag of worms.

I originally had a very very simple connection to the gearbox shift shaft, a copy off an Ultima with a G50 box.
It was terrible, but very simple.
The box came to me with a nice guidance mechanism engineered by Crispin Manners for when Terry Davidson had this drive train in his Nomad sports race car, Jonathan drove that car so has direct understanding of this thing! (small world isn't it?)

I had the box rebuilt by Mike as it was really done for and I had to use my 1973 Mag case 911 box as a donor, so the guts of the box were good.
I re-fitted the 'Manners' mechanism and there was a marked improvement in terms of precision, the gate was a real H rather than a V with 2nd and 4th almost in the same spot at the gear lever.

Come to the gear lever now. It is on the rh side of me (RHD car) and is about 4" long from pivot bolt to top of the knob. This is about 3 times shorter than the stock 911 design, thus to change a gear the effort is 3 times that of the road car.
From the base of the gear lever is a round ball which runs in a slot in a long shaft that runs from my right hand down to the rear bulkhead, about 800mm to a bearing sleeve and a precision UJ, motorsport size so small but precise. This is almost new.
Another shaft runs from this UJ to another slide bearing and another UJ down to the 'Manners' mechanism bolted to the gearbox.
None of these shafts are in a straight line, so there is a lot of side load and hence sliding friction, all adding to the effort.

The gear lever is adjacent to the steering wheel so the width of the H gate has to be squeezed between the roll cage of the car and the wheel, this is not too bad and I've made the H as wide as I can for the 4 gears, but have to allow extra room to engage reverse.....

All of these ergonomics (?) are a compromise and the adjustment is very precise.

All this thinking has come from some recent chat with fellow hill climbers asking what I was doing the the Lola for 2019, but the restoration og the 911 has taken the time and money for this winter, so all this is about next winter.
Thank you for your offer Paul, it will have to wait until this time next year...

Another dis-incentive is that I have almost stopped going faster!
Age for sure is a problem but also there is almost nobody in the class close to me, others are miles ahead! There is almost no point in spending a lot because I will not gain much, motorsport is always difficult to justify changes v time reduction on the track.

My first linkage to the box:



The Crispin Manners device, much better



The gear lever

[fetuhoe]

How many times do you change gear during a typical hill climb and how long do you think it takes per gear change?

'Miles Ahead' is relative and how much time do you need to save to catch up?

Could you imagine saving a second on each hill and how much would this help?

Some years ago Renault F1 invested a huge amount of money on a Gearbox test rig (Sequential Shift Era) and set a target to save around 5 milliseconds per gearchange by improving gearshift management.

The V10 engine cars changed gear, on average, once every 2 seconds and during a 2 hour race this adds up to around 20 seconds.

The test rig was used to measure and monitor and control the dog to dog speeds and to find a way to make the shift more efficient.

The rig was very tricky to engineer due to the extreme speed changes of the engine during down shifts but was reasonably successful in meeting the teams objective.

The shift system that resulted was used on a car that won F1 World Championships in 2005 and 2006.

If you can shift efficiently and very quickly the impact on times could well be significant and I still tend to believe that a sequential box with paddles is a good solution.

The 270Nm rating of the Elite transmission is probably adequate for your needs as AGMA gear charts tend to assume infinite gear life and this leads to very conservative ratings.

[Brookesy]

I’ve not used it in anger yet as you know Graham but the “cable shift” system I have fitted to my 914 box in the Nike is a revalation and there is one off the shelf for the 915 box.
May not solve all the issues but I’m sure would be move in the right direction.

[911hillclimber]

Chris,
At Shelsley Walsh I change gear 6 times in 30 seconds.
My usual class mate will be 4 seconds quicker over the line, he uses a sequential changer on a H pattern box.
At the much loner Loton Park hill, the car needs 7 changes, 55 sec run.
Same class mate is 6 seconds faster....

Brooks, we have discussed this, and it is still an option in my mind.

[gridgway]

Surely you just need more oomph. As has been mentioned... High compression, twin plugged 3.6?
Graham

[Gary71]

Well as you already have the flat fan you just need that little something in the exhaust system...

[911hillclimber]

Ha!
I remember Bob Watson saying it needed twin turbos!
He was not joking, but the chassis let alone me could never cope.

Graham, you cannot find an air cooled big capacity 911 engine anymore, all priced out of reach,
A 3.8 would be good.

I'm retired now so funds are not as abundant as they were...so things have to be tailored to fit.

I may well have to resign myself to eeking an odd 0.1 sec from the car on a good day and be braver as I get older.
It is a special car to me after a lot of grief, but it has won me 3 Class championships in the last 3 years, so not too bad, but as you know Graham, you always want to go faster....

[gridgway]

Ha!
... but as you know Graham, you always want to go faster....

Ahh yes. I had a really crap race season, having started with a car that should have been absolutely on it. Loads of winter works including a new motor.
Great pre-season testing, awesome test day at the first meeting. Then all downhill from the first race. Slower everywhere this year over last year along with some problems getting off the line. Of the 6 double headers, I got punted off in race 1 and DNF'd then started from the back in race 2 and I missed one entirely with another wrist op after the breakage last year!!

We sorted the starting issue halfway through the season. Hopefully we now know what went wrong with the handling through a process of elimination and can get sorted for next season. I was around 0.5s a lap off the pace I had the previous season with the wheezy motor!

Graham

[911hillclimber]

I can see how you feel!
Maybe leggy Gt3s are a very good idea!

For suspension I can really recommend Sean at McClurg Motorsport, he understands the circuits as he races them himself, and the older suspension systems.
He has done lots of FFs I know of.

The Lola has/is going well, but I would like a bit of tech challenge and some better personal bests.

[rhd racer]

Hi Graham

Have you ever tried mounting the gear-lever to your left? This would allow a much straighter linkage set up.

Having tried lots of configurations on the 914, those with no friction are the straightest - IMHO the angle of the linkage from driver's sill to the centre of the car is probably the point at which the friction is being introduced. The for aft movement of the gear-lever is trying to change the angle of that diagonal rod (sorry if this teaching you to suck eggs)!

Going up the centre does require sufficient engine clearance to do it. My gearbox end is similar to yours, but in my case a Rennshift linkage which is all brass bushed and like a rifle shot. It has a single UJ and then one mildly kinked shift road to the bulkhead where it meats another UJ. From here it is through a spherical bearing in the bulkhead via a straight shift rod up to the standard 901 shifter, located closer to me than it would be in a standard road car. Essentially this means fixed points at each end, tow UJs and too shift rods, mounted in a virtually straight line for / aft, so there is very little to go wrong, absolutely no play or slop.

It is not without challenges, engine height is crucial to get a nice straight run at your rear link rod, but apart from that it should be an afternoon's work for you!

HTH
Wayne

[911hillclimber]

You are bang on Wayne and fully understand my position.
The short connecting rod from the rod coming off the gear lever is at a horrible 45 degrees with the 'Manners' device.
I tried to ease this to about 30 deg when I first tried to do the linkage years back.

The force I apply on the short lever comes to the start of the 45 deg link from a near straight line of action, but there is consequently a high side thrust close to equal to my effort.
This thrust is passed to the rose joint on the plate bolted to the box so a lot of friction at that point and much less at the similar rose joint close to the box gear input shaft.

I'm sitting here at home with a light pass of man flue ( running nose and cold, close to death of course) and your post has just made me think of a way to give a guide to the 45 deg shaft but remove 80% say of the sliding friction.
Thank you! This is why I post these little probs so others can solve them for me!

To make the path far less than 45 degrees will need serious mods to the silencer, and not easy, been there already this time last year.
Also, moving the shifter to the middle of the car, my left hand, is difficult too as the fuel tank is in the way, but also the engine itself, again, been there.

Brooksie and I have similar cars and we have discussed this at long length at various hill climbs.
His cable shift should be the bee's knees.

When he starts competing next year I need an excuse for being beaten, a slick gearchange will do me nicely.

[rhd racer]

Glad it helped, get well soon!

Cheers

[dragonfly]

Could a 3.4 + G50 solve your problems? viewtopic.php?f=5&t=63910

[911hillclimber]

Seen it!