Special getting closer...

911hillclimber · Post by **911hillclimber** » Tue Aug 11, 2009 12:36 pm

Ian:

Shelsley is this weekend coming, practice on Sat, race on Sunday. Meeting is jam packed full of great cars, not to be missed.

Gary:

The layout is typical of all the racers in '78, and nothing is unusual.
Flex will be everywhere. These cars have run 130 bhp normally and 9'' rims at the rear, 7's at the front.
This particular car once had 350 bhp and even a 500 bhp turbo Cossie in the back on this suspension/ chassis.

Long way to go yet, but a pro job is pre arranged if I fail. Racing is a hard way to do this kind of development...

911hillclimber · Post by **911hillclimber** » Wed Aug 12, 2009 9:27 pm

Sorted the root problem out at last after nearly throwing in the towel for 2009 last night.

The rear bump steer was horrendous, all 3.5 degrees toe OUT of it on one side and a bit less on the other.
Little wonder this car self steered into the weeds.

Found the solution and now I have 20 mins toe in change and zero change on the other so quite close.

The front is done and all that is left is the body tomorrow and some tarting-up for Shelsley in the Rain over the weekend.

Mind you, the tyres are very bad too....

How it should not be:

How it should be:

MikeB · Post by **MikeB** » Wed Aug 12, 2009 10:47 pm

Wow !!

You would also have had severe anti-squat at the rear, the bottom wishbone having been raked down towards its leading edge. That would have left the back brakes prone to locking, as the rear suspension would have unloaded when the pedal was pressed.

I'd much prefer to take it to a nice flat wide airfield and play about with it there, that a Worcestershire goat track

And errr it's not quite how it should be Graham,.......do the top radius arm lock nut up on the rose joint , please

911hillclimber · Post by **911hillclimber** » Thu Aug 13, 2009 6:21 am

No, they do have a surprising amount of freedom. Checked that as they look awful!
The whole suspension is free to go though the 3'' full travel afforded by the damper travel by hand with rotational freedom of the top link all the way.

I did find one Koni body was 'just' fouling on the upright, so that is spaced better.
I fell into this assembly trap trying to get the drive shafts as straight as possible. They are at an angle but OK I hope.

Never heard Shelsley called a Goat Track before!

The car was very very nervey to drive, especially with power on.
The Goat Track is very narrow so it had better be better or I'm doomed.

MikeB · Post by **MikeB** » Thu Aug 13, 2009 6:21 pm

Always worth using the good old "string computer" to check alignment, as per the much missed Mr Staniforth's Race & Rally Car Source Book.

I found that my Vision was very sensitive to rear toe in adjustments, a change of 6mm across the axle could make it understeer or swag it's tail like a happy labrador

Did you get Ian Dyson to do the new alignment?

911hillclimber · Post by **911hillclimber** » Thu Aug 13, 2009 8:53 pm

I have Shelsley this weekend, just polished the bodywork, so ready to trailer tomorrow afternoon.

I've spoken to Ian in the week, and he will come for a looksee this weekend, but there are 3 weeks 'rest' till the end of my season at Prescott in Sept, so it will go to Ian (assuming he wants to do it) in the rest time.

I am really surprised just how good the sting method is. I used high tensile fishing line for the Lola. The Lola has location points already in the front bulkhead for a front cross bar smack on the C/L of the wheel at ride height.
The rear was more awkward!

It might be if interest that the rear width is 8'' wider than the front overall width.

I have not found the late AS's book, but the American book 'How to make your car Handle' has been great.

I think the Visions have a bit of a reputation for being very sensitive, or an I mixing that up with Splinters?
Maybe the Lola should be in the same 'club'!

911hillclimber · Post by **911hillclimber** » Sun Aug 16, 2009 7:28 pm

Great result from Shelsley, not in speed terms but it works!

The rear suspension changes have transformed the drivability no end, and I can get 1/2/3rd gears 'easy' albeit with a super heavy clutch.

The webers continue to dissapoint, but only in thier set-up (I think).

Yesterday I was nearly stopped from racing due to the noise levels of the pops and bangs @ 118dB!
I changed the plugs to a set of 3.2 injection plugs I had which were new.
On start-up the pops and bangs had subsided considerably and as the day went on the pops n bangs came back.
Could this be a simple case of plug fowling?

The ones that came out were not black, but were dark so I think the mixture is very rich. It also has a hint of mis-fire about it.

I started the hill on 44 secs and finished with 38 sec and I really was taking it easy. When the car is sorted it will be quite fast.

The winter's list is now growing:

Go onto injection/management (wide open to suggestions!)
Balance the brakes
Repair the front body
Get a lighter clutch and throttle pedal (adapt G50 hydraulics?)
Nickel plate a lot of parts
Fresh real hillclimb slicks
Raise the front roll cage cross bar as it is uncomfortably close to my knees.

Next and last meeting is Prescott in early Sept when I hope to have a reverse gear and 5 forwards, plus I hope Ian Dayson can sweeten the chassis a touch more.

I am making progress!

Lightweight_911 · Post by **Lightweight_911** » Sun Aug 16, 2009 7:57 pm

Excellent news Graham !

Gary71 · Post by **Gary71** » Sun Aug 16, 2009 9:19 pm

Fantastic, I couldn't be there today as I'm down in Devon, but good to see it coming together.

MikeB · Post by **MikeB** » Sun Aug 16, 2009 10:23 pm

When does it pop and bang, Graham? On idle, over-run, or on power?

911hillclimber · Post by **911hillclimber** » Mon Aug 17, 2009 7:12 am

Idle when cold is ridiculous, sounds like rapid anti-lag.

Warmed up is much the same.

Half throttle under no load is is less but there, full throttle under load makes the commentators say it's missing/ 5 cylinder.

All connections are sound, but I have not changed the leads yet.

It was so noticable that the pops all but stopped immediatly the fresh plugs went in.

When the old plugs came out they were dark but not at all sooty, but certainly a universe away from light grey.

I have a new Aldon automotive electronic ignition system instead of the points, but this was in the car when Bob tuned the carbs.

I have a lot of time for mapable injection, just another £2000!

MikeB · Post by **MikeB** » Mon Aug 17, 2009 12:42 pm

As it's across the rev range, on the fuelling side I'd check that your are not putting too much fuel, check the pressure into the carbs (about 3 - 5 psi should be about right) and check the float levels. That might account for the sooted plugs

I assume the engine was fine at Loton, you didn't mention any problem, so something has changed sine your Off.

911hillclimber · Post by **911hillclimber** » Mon Aug 17, 2009 12:54 pm

Car has always had this problem!
Pressure reg (which I'm told is a bad design) is set at 3 psi right from the start.
Bob had to change the float levels significantly from where I set them (I followed the Weber manual before taking the car down)

The back-fires are embarrasingly loud, and they should be quiet and smooth.

Still does not explain why the clean plugs stopped the problem except they were not fouled.

Must be the mixture (all plugs are the came colour, so not just one cylinder)

MikeB · Post by **MikeB** » Mon Aug 17, 2009 1:14 pm

If there is unburnt fuel getting into the exhaust system, it will backfire. So if one or more of the sooted up plugs wasn't working properly, then a new set of plugs would cure it.....until they become sooted up / dud

I assume you were using std plugs, nothing too trick.

It only backfires , it doesn't spit back through the carbs?

Well atleast if the new plugs cleared the problem, it's not mechanical - cam timing, leaky exhaust etc. So hopefully easier to fix.

Now I know why you don't like the Webers. I assumed it was OK on the rolling road session, but from what you say it wasn't.

PMOs are the other alternative ofcourse, but if 2k will sort some EFI then it's the better course.

MrPerkles · Post by **MrPerkles** » Mon Aug 17, 2009 2:50 pm

NGK iridium plugs are good for carbs as they are less likely to foul,1 spec of debris and carbs will always backfire and pop have you adequate fuel filters ?