History of a Lola T492 Sports 2000 chassis?

[911thillclimber]

Thank you for your reply!

There are two other discussions running on other sites about this direction on my 3200cc engine.

An answer is slowly coming together!
I'll detail it when the dust has settled...

[JasperClan]

I've run Weber Alpha mapped ignition with carbs on my Clan for years. Need Weber agent to map but if done correctly I've found that there is no need to change the map.

Pete Richards

[911thillclimber]

Current thinking is a simple 36-1 wheel on the crank pulley, sensor to count it a ford 6 coil pack and a DTA ecu for ignition only.

I have the wheel and pack, and an offer of a good DTA ecu for £350.
Could do all this for £600 or less with the option to go back to a dist if it is a load of trouble!

What benefit to you was ignition control over a simple dist/points?

The Weber alpha system was the pioneer I think of a lot of this technology and I remember it on several flat 6 Porsches in the late 80's.

I seem to recall the crank counter was a bit 'crude' by todays ways, but still effective.

[JasperClan]

Crank counter is a trigger wheel as described by you. Benefits are that I'm able to use hotter cams along with the power at the top end but still retain driveability at the low end of the rev range. Also fit and forget.

Pete Richards

[911thillclimber]

Forgive my obvious ignorance: If the ignition-only conversion follows the dist bob weight curve of advance, the only benefit is it is more repeatable than weights and springs and sticky pivot pins in the dist, and no points to move/bounce etc (but surely not at 6500rpm).

If I simply fitted a £40 hall-effect instead of the points and the dist is in good condition then I am gaining very little by going 36-1 etc.

I might be better off spending the money on some track instruction instead!

[911thillclimber]

Just been sent this:

The advantage of mapped injection is accuracy, precision and mixed load optimisation.

At part throttle you need more advance as the less dense air/fuel mix takes longer to burn (so needs ignited earlier, to give the piston a well timed kick down the bore. Too early slaps the piston in the face and too late means the piston is already left the party so the burn energy can't convert to kinetic energy so turns into wasted excess heat). Optimising the part throttle timing improves the torque output and therefore improves efficiency (ie better MPG because you need less throttle to get the same output).

You can also cope with highly tuned intakes where there may be a bump in the intake efficiency if/when the cam timing coincides with the resonant frequency of the manifold/air box. In certain engines you might need a small 'dip' in the advance at the most efficient point in the rev range (distributors only advance with revs and cannot retard in the middle).

However, if all you driving is done at WOT then the timing needs are fairly simple. The motto for timing is the minimum advance to achieve peak output at each rev point & load.

[911thillclimber]

Well: sorted the injection 'thing' yesterday. sold the lot to a fellow Porsche 911 nut!
That has removed the prolonged Shall-I, Shall I not messing.

I've bought instead an Accuspark hall effect conversion for the distributor and one of their new Black box mappable ignition control units.

This allows tweeking of the timing at 1000rpm increments to 8K. The 911 red lines at 6500.
It has a soft ignition cut out that is programmable for the chosen red-line, all this via a simple laptop /usb link.

The bob weights have to be screwed down so there is no movement and then you can map the timing.

Starter map is to take where I am today, using a strobe find the timing at each rpm point (tick-over/1K/2K/3K/ etc) and put those values in.
Lock the bob weights and the timing will be repeatable to those readings.
To a rolling Road for some tweeks to optimise things.

Cost is £138 and 30 mins to fit.

Should be interesting. I can keep the coil I have and the unit has 4 wires.
The Carbs will need another balance and Colour-tune tweek in the spring at the same time.

The body is on order, but no news to an ETA.

Best bit is that the hall and landing are all but finished and a skip has been ordered for friday.

I need the skip to hold all the brownie points!
Mrs Hillclimber never believed I would do it let alone in October as promised.

This means I can press-on with the changes to the rear suspension to get drive shaft float increased and then the engine out for a clean and the chassis re-painted, satin black as before.

It will be ready to race by Xmas!

[MGDavid]

Originally Posted by 911thillclimber

....... and a skip has been ordered for friday..........

good job we don't know where you live, it would be full of old tyres by Sunday night

[911thillclimber]

18 months ago the Lola would have been in it!

[JasperClan]

Have Stealth BlackBox ignition control unit on one of my Clans. Works fine.

Pete Richards

[911thillclimber]

good to hear!

did you map the ignition curve different to the dist bob-weight advance curve/ rpm?
They do a 'starter' map for 4 pot engines only, but not for 6 or 8 cylinder engines.

[PeterMorley]

Originally Posted by 911thillclimber

good to hear!

did you map the ignition curve different to the dist bob-weight advance curve/ rpm?
They do a 'starter' map for 4 pot engines only, but not for 6 or 8 cylinder engines.

I've just got a 123 distributor for an Alfa. A bit of searching on the internet finds plots of all 16 advance curves.

They do make them for 911s so it might be possible to find a plot of the 911 curves.
Failing that you could ask (as a prospective customer!) 123 what curves they use.

[JasperClan]

Originally Posted by 911thillclimber

good to hear!

did you map the ignition curve different to the dist bob-weight advance curve/ rpm?
They do a 'starter' map for 4 pot engines only, but not for 6 or 8 cylinder engines.

I used a combination of a known curve for a distributor suitable for my use along with the information from the Weber Alpha system on my other car. Not helpful to you I know but probably worth starting with the known curve for the distributor you have.

Pete Richards

[911thillclimber]

Thanks both:

It has been suggested to use an modern timing light to plot the curve ar 1K rpm intervals off the engine as it is.
Thus the timing at tick-over (deliberately set to a fast 1200), then 2K then 3K etc to say 6K. (red-line is 6400) and then load these settings into the Black box.
At least that sets the way the engine runs today.

You then lock the bob weights solid with a screw somewhere/somehow and the engine is running off the map.
There is a soft cut for the red line which will be nice as I visit it regularly and rely on the cut-out in the rotor arm (Porsche/Bosch design) which is a bit abrupt and bouncy.

Then I can leave alone free of points and tweek the curve on the rollers or simply tweek the balance/mixture of the carbs in the garage.
I know where a Porsche indi have a dist machine which can plot the mechanical curve and do it that way for a few £££.

This should be an interesting half-way house at a very low cost, £140 landed in my garage.
The box is on its way today.

I really want to get the chassis done and the drive pegs/wheels/tyre thing asap before it is so cold the paint won't set in the garage.

No heated garage here!

In the beginning! This story has been a very very long one hasn't it?

[Clive Brown]

Luxury.... pure luxury. When I were young it were so cold.... and we didn't have a garage.... we had it tough then.

[911thillclimber]

I've always had access to a single garage!
Only in the last 15 have I had this double width and short length garage but the central heating boiler in in there so luxury indeed!

My early snaps remind me of all the work this car has taken to build let alone finding the 'Number', the very best bit of the whole saga!

Over on Sports 2000 web site I was castigated by many as the "butcher" with this modified Lola which has only a few parts unmolested from the original.

Amusingly to me it is still the biggest most visited thread on that site by a few light years.

It has been a challenge to do let alone for those of you who visit this 'blog' (if that is what you call this?).

First ever run at Loton Hillclimb before the scrutineers refused the log book because the tyres protruded past the bodywork.

[Andy Clegg]

Still following you. This is the first thread I check.

[911thillclimber]

Thanks Andy, there must be quite a few who drop in regularly.
Never did I think this little car and it's tales would score so many hits.

I feel quite chuffed that this story is the second largest thread on 10 Tenths.
Catching those SD1 boys will be tricky!

It is good to see the older snaps taken of the project to remind me how much work and toil has gone into it.

Despite all the troubles, i just love the shape of the car!

[MGDavid]

Originally Posted by 911thillclimber

......... i just love the shape of the car!

that's certainly what caught my eye, never tire of it.

[911thillclimber]

Accuspark parts have arrived and look very neat. Leads on the Black Box may need extending to get it in a dry space (if there is one on this car), but nothing tricky.

No news on the body yet, but progress on painting the hall is all done, but another room to do but smaller.

Expect to be in the garage by end Nov once the 911 is in storage.

The Carcoon I've used twice seemed to accelerate the corrosion on the disks, wrecking all four over last Xmas, and to do the body without damage will need the Lola in the full double width to get the new body in place and even across the front wheels.

Have just 5 months to get this lot done and that will speed by I'm sure.

Memories, the 2nd reason I need a new front end...

[911thillclimber]

We are back in the garage!

i have SO MANY brownie points I have to leave the crowded house and get into the 'man-den' to get away from the piles...
Well, slight exaggeration here and there, but Mrs Hillclimber is impressed now the hall/landing AND Dining room are all freshly decorated.

Thaere has been a glitch on the body side (ie not ordered) but now in hand and i hope collectable before Xmas. Spanners crossed.

So, to the details that need some action on the rear end.

The CV joint bellows steel cover split and came free at the last meeting so needed replacing. Of course, the March drive shaft assembly is not standard CV size so a bit of improvisation and a universal CV boot kit for £7 from ebay had it all clean, fixed and looking good.

CV's now are 94mm dia, this one is 92 of course, but the same size as early VW golfs. all is well now after a bit of a fight last night, but the old dog won!

When I built the rear chassis the new chassis legs were determined by the width of the engine and the mounting of the rear chassis top legs to the rear bulkhead, oddly the same size(!). However add the suspension and the top radius arm are so very very close they kiss the chassis, a fact pointed out to me by McClurge Motorsport.
To sort the drive shaft float (ie to have some) through the full compression/droop of the upright I had to fit a thick 10mm spacer onto the splined end of the drive shaft. this reduced the spline contact length by about 25% which has always left me wondering as i dumped 240 lbft into the transmission.

My goal is to reduce the width of the rear track by 10mm so allowing the spacer to go into the spares bin.
To do this needs a slice out of the rear chassis and a bit of MIG welding to get the strength back.

This way I give clearance to the top radius arms and delete that spacer = a far better set-up.

I should get that all done by sunday night ready for some chassis paint.

The narrowing will be done by winding in the lower wishbone rose joints and the top link ones too as there is plenty of thread to use. The wishbones seem to catch a lot of stone chipping, so these will be stripped, painted and re fitted.

If i feel like it i will then remove the engine/box for clean, check, paint and refit in Dec and then I'll be ready for the new body and re-mounting the pip pin locations to get even front tyre cover over the narrow rims.

That should keep me busy over Xmas.

That then leaves the ignition map Black Box and some cosmetics.

The body is gulf blue and the temptation is to add graphics used on the Targa Florio Porsche 908-3 sports racers...

CV boot looking like it grew there



Cut along the masking tape to get clearance and spacer deleted:





908-3...

http://www.legacydiecast.com/product_images/aa87071.gif

[MGDavid]

Originally Posted by 911thillclimber

..............
The body is gulf blue and the temptation is to add graphics used on the Targa Florio Porsche 908-3 sports racers...

Yes!

[Tim Barry]

That would look great! Didn't they also run with suits of cards graphics as well? ie heart, club, diamond, spade on each front corner?

[911thillclimber]

The idea is warming to me.
I hope to do something using vinyl but the small Lola body is not so smooth as the 908 around the top of the front arches, but it will be a bit of fun for next year.

[911thillclimber]

So much for a Sunday in the garage..
Took the 911 to a storage unit locally to free the garage up on Friday.
Had to reverse the car into a tight slot which is never easy in the 911 as you can't see the wings and the racing seat locks you in place, so Saturday dawned and I could barely get out of bed with a pulled neck muscle, I've had to even watch the F1 coverage sitting very still....

So frustrating and I'll miss work tomorrow for the first time in 32 years.

Next weekend I hope for some metalwork at last.