Westfield Elevens

Did my corner weighting this morning using my Sainsbury's scales. You need to be careful how the tyre lands on them or they do stick. But a bit of plywood here and there to even the load and they were free moving and giving repeatable results. After half an hour of tweaking I got left to right and front to rear %'s within 0.2%. Good enough, I think. Weight of the car ready to race but without driver is 510kg. Tally's well with Westfields 500kg claim, as I've got maybe 15kg of roll bar in there and the extinguisher, but no carpets or passenger seat. That gives me a ceiling of 127Hp to stay in Class D (250 hp / ton limit). As you'd expect it's quite right hand heavy given the fuel and driver are on that side - and 70kg of driver is a lot of mass to stick off to one side in a 500 kg car. To do the setting up I used 4 wheels & tyres, two batteries and a large extinguishers to represent the weight of the driver!
Fitted the nice new MED 1.5 roller rockers in place of my old Mini Spares 1.3's and went out for an hours drive around the back roads. The engine initially felt strong - using full throttle on the road was not something you can do for long. The new rear springs & dampers (120lb springs, 13.5" open length ProTech dampers) transform the ride on typical British roads. No more crashing and banging about with a skittish rear end. It rides the bumps and undulations much better. I'd recommend the mod to anyone with a road Eleven.
However the engine started to feel less great as the miles went on. When I got home I checked the valve clearances to find they had opened up to 030" to 040" on most rockers. Suspected the balls on the adjustment screws were not hardened correctly and had worn away, but on closer inspection what was happening is that the pushrod was sitting in the rocker body and not the adjusting screw. The pushrod then wears away the aluminium of the rocker arm opening up the clearance. Ouch! The rockers are slightly different geometry to my old ones and clearly need rocker pedestal spacers fitting, so that the adjustment screws can be further out from the rocker, ensuring the pushrod sit on the ball and not the rocker. Annoying. Spacers ordered, along with a larger diameter water pump and alternator pulley (couldn't resist them - clearly not essential, but can only help when the engine is spinning at 7000 rpm).

Loving how you created your body mass in the car!!
You might find 120lb springs still too stiff, i thought we ran 100's but uncle thinks they might be 90's. Comes down to driver preference though - what works for one might not for another.

We used to run a huge pulley on the old alternator (electric water pump so dont need one there), the new one runs a tiny one as its happy to spin at up to 18k!!
Just finished putting the sump back on today after lengthening the pick up pipe a smidge, repacked the silencer, had the FE serviced and refitted that, just a couple more tweaks and it'll be ready for Spa

Speaking of Spa, did you know that for this year ou need to contact the licencing department at the MSA and ask for an approval letter to be issued allowing you to race on th continent?? I only found out this yesterday, call them and they emailed me a copy and the hard copy arrived today!

Thanks for the heads up on Spa. It seems a long way off but sounds like another thing to get sorted. No doubt the MSA letter costs a bomb...? I'll see how he 120's work out. I know Ken ran really soft rears - 80 lbs or so. But I alos know that at Rockingham even with the stock 200lb springs I could get the seat pans grounding into the turn 1 hairpin. But I may go to flat floors as your has...we'll see.

My uncle fitted a lowered floor (was originally flat) due to his height for racing - hurts when you ground on a corner kerb, impact straight up the spine!

Letter is free which is good, you wont be allowed to race if you dont have it at Spa - it's a new FIA reg, bound to catchmany people out i think

The one thing I dislike most about the late chassis is that stupid, lowered, steel floor. It's just wrong. That it cuts the already low ground clearance is ridiculous. You can't run a low ride height, as 3" have been lost just to start. You know, back in the old days, when Lotus 11s were new, if a driver didn't fit, he found a larger car, or had one made with a longer wheel base. Taller roll bars were built, if required.

I have decided to make a few changes to my early car, reflecting the improvements of the late chassis. That would be the addition of the shear plates for the rear suspension arm pickup points at the chassis. That about covers it. Oh, and rear battery mounting.

Note that rear spring rates and the results may vary due to spring height and preload. My early car has 55 lb springs, but with 4" of preload, as they are 11" long on an 8" damper.

If you are going to discuss spring rates, note the rate and length of the spring, and the damper length to accommodate that spring.

Dragging floor pans with a 200 lb spring? Easy, if you have the car set up low enough.

Anybody running Protech double adjustable 400 series (1.9") dampers? I just tried a set, and found them very stiff even at the lightest compression damping setting. Just about no compliance at all.

I am sure that this is correctable (I have an inquiry in at Protech), but I am wondering if anyone else has had this problem with the initial setup, and if they bothered to correct it.

Here, we set up the cars with some compliance and suspension travel. We need the compliance and damper control.

Thanks for your input!

The new rears I've fitted are single adjustable Pro Techs, but I asked them valve them as they do for their Locost racers. A very similar vehicle to the Eleven in terms of suspension and weight, and they blitz me in the corners at present. No more grip - they can just drive right at and beyond the limit and easily catch any wayward slides. Something I couldn't do previously in the Eleven. They feel a bit soft set at No. 2 but plenty more to go at.

Dont forget though that Locosts are ~4inches wider on the rear - at least mine was compared to the eleven.

We contacted Protech, and the dampers can be adjusted softer, by changing the center point of the damping curve. This is pretty easy, repositioning the adjustment knobs.

The dampers were ordered for an 1100 lb chassis. However the softest setting is still WAY too stiff. Hopefully, the change in the controls will fix our problem.

I was able to increase the track width of the wire wheel equipped XI using center laced rear wheels. The increase is about 2". Plenty of space in the bodywork for the 5.5" Triumph TR6 wheels with the 5.00X15 Dunlops. This setup only works with a wire wheel axle.

I take your point about the Locost having a wider track Adam - but it's not so much their ultimate grip I'm after. More the controllable break away. In case you were wondering it looks as if any testing before April 1 is out of the window. I've got to go to the US on Saturday for almost two weeks, so a quick rolling road session on the 30th and out racing (hopefully) on the 1st. If I feel the need for any testing after that first race I'll let you know. On Saturday I fly to Chicago, and spend Saturday night downtown. Someting I've done many times but not on St Patricks day before! Should be good...