Hillclimb A35 Build

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Dave Clark
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Re: Hillclimb A35 Build

Post by Dave Clark »

LSD makes such a difference ! (Either kind)

I don,t trust Peter May half shafts after I saw what happened to them on a friends turbo Midget - the splines looked like sticks of barley sugar.

Impressive car control in a relatively small space !
Dave Clark
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Re: Hillclimb A35 Build

Post by Dave Clark »

Also forgot to comment re axle tramp and Panhard rods.

TMT has never had axle tramp, even on the drag strip, and has only leaf springs for location. Once the wheels are spinning there is no chance of tramp !

My experience of Panhard rods on the road is that they tend to make the rear end hop on hard cornering -again TMT does without and managed Cadwell Park OK (ish)

For racing an A35 does need a Panhard rod, rigidly mounted ,with Rose joints, and the noise that transmits into the car is irrelevant. On a road car it would be very intrusive and make the suspension even harsher.
Most racers will have some other form of additional location, or even 5 links,if class regs allow.

I made one from an A35 steering cross rod, with the steering joint on one end and a large rubber and steel bush on the other, to introduce some compliance.(Tends to defeat the object, a bit !) Finding space to mount it as close as possible to the axle and parallel to the ground was difficult with the exhaust and dampers, as well as the brake cross rod in the way, so compromises were necessary,making it less than satisfactory. It is probably still lying around with lots of other discarded A35 stuff in my storage loft above the workshop.

Lastly I am really anxious to see this car, as it has been put together with such care and looks absolutely superb.
fsmlittler
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Re: Hillclimb A35 Build

Post by fsmlittler »

Dave thanks very much for the kind words about the car and our build. Hope it doesn't disappoint in the flesh

Interestingly a very close friend who competes with a Mk1 BDA escort wins his class all over the place with nothing more than updated leaf springs-no 4 link no additional axle control just good socks and springs. Likewise even with substantial slicks on the rear he doesn't get any tramping.

Not only is the traction out of bends infinitely better as you'd expect with the diff but the car is now much more steerable on the throttle than with the open diff and generally far more fun to drive. I believe it is less harmful to the halfshafts too as you don't get the sudden on off power that the open diff created. We'll still be taking spares whenever we're competing as there is no indestructible option yet!

We still have some way to go to improve the front end but our next step is to get the tracking checked as we have set the toe with bits of wood and string so could be miles off.
After that I am considering removing the lowering spacers from the front wishbones as the bump steer is ok an inch either side of standard ride height. Beyond that I am interested in trying the telescopic front shock conversion to get a little more control.

I guess if you ever finish it all gets boring!
Hurtzberg
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Re: Hillclimb A35 Build

Post by Hurtzberg »

Are you popping along to the Thames valley meet in this car anytime soon?
Andrew

1957 A35
fsmlittler
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Re: Hillclimb A35 Build

Post by fsmlittler »

I would really like to get to one of the meetings but the car is down in Devon for a few months whilst we try and resolve the handling issues.
Should be back in Windsor in the spring so will really try and get along
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gazza82
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Re: Hillclimb A35 Build

Post by gazza82 »

How is the A35 coming along?
"If you're driving on the edge ... you're leaving too much room!"

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Cars: "Project 757" '59 A35 2-door bought in 1971 & Subaru BRZ SE LUX Auto plus "family fleet": Alfa MiTo, Peugeot 206, (Ex '98 Alfa Romeo 156 2.0 TS)
fsmlittler
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Re: Hillclimb A35 Build

Post by fsmlittler »

I've just come back from a weekend down in Cornwall running the A35 in a local hillclimb. Apart from bring a bit smokey and fouling a plug, the car ran brilliantly and got steadily quicker to end within 1 second of my full race Clan Crusader. Best of all the bump steer is far less noticeable since we adjusted the steering arms and the limited slip diff meant it is so much quicker off the line and out of corners. The high speed turn in is quite poor with it feeling like big under steer so I may try negative camber trunnions and also a tiny slackening on the steering box. I spend most of my time talking to people who's mum dad uncle auntie etc had one plus met an Academy competitor.
According to the 'coming next month' section of the latest Practical Performance Car magazine there should be a full feature on the car next month.
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gazza82
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Re: Hillclimb A35 Build

Post by gazza82 »

That's great news! Both that the car is performing but also the article .. add that to my "what to buy next month" list!

Wonder if the magazine will let us put it up on the main web site?? :?:

Thanks for the update!!
"If you're driving on the edge ... you're leaving too much room!"

Club WebEditor.

Cars: "Project 757" '59 A35 2-door bought in 1971 & Subaru BRZ SE LUX Auto plus "family fleet": Alfa MiTo, Peugeot 206, (Ex '98 Alfa Romeo 156 2.0 TS)
Dave Clark
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Re: Hillclimb A35 Build

Post by Dave Clark »

Definitely must see the magazine article.

The LSD may tend to "push" the car in corners and initiate some understeer.

I,m sure that you have considered it, but now that you have the LSD have you considered a rear anti roll bar ?
This might reduce the understeer and with the extra roll stiffness it might also be possible to reduce the size of the front ARB, for a similar effect.

Playing with tyre pressures may also be illuminating.
Big Daddy
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Re: Hillclimb A35 Build

Post by Big Daddy »

Dave Clark wrote:My experience of Panhard rods on the road is that they tend to make the rear end hop on hard cornering...
:?: :?: :?:
Dave Clark wrote:The LSD may tend to "push" the car in corners and initiate some understeer.
Depends upon ramp angles in the diff (assuming conventional plate-ramp LSD). We run 30 and 45 deg drive angles without experiencing any reluctance to turn-in (clamp load is proportional to cosine of ramp angle)... :thumbs:
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Countryboy
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Re: Hillclimb A35 Build

Post by Countryboy »

Big Daddy wrote:
Dave Clark wrote:My experience of Panhard rods on the road is that they tend to make the rear end hop on hard cornering...
:?: :?: :?:
Dave Clark wrote:The LSD may tend to "push" the car in corners and initiate some understeer.
Depends upon ramp angles in the diff (assuming conventional plate-ramp LSD). We run 30 and 45 deg drive angles without experiencing any reluctance to turn-in (clamp load is proportional to cosine of ramp angle)... :thumbs:

I knew that !! :rol: :rol: :rol:
Rest Home for rusty vehicles
Big Daddy
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Re: Hillclimb A35 Build

Post by Big Daddy »

Countryboy wrote:I knew that !! :rol: :rol: :rol:
Is all hope lost :?: ... :mrgreen:

Excess clamp load on decel can make the car very unstable under braking and prone to spinning on turn-in. Adjusted by changing over-run ramp angle, which should not be confused with pre-load across the clutch pack.
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Countryboy
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Re: Hillclimb A35 Build

Post by Countryboy »

Big Daddy wrote:
Countryboy wrote:I knew that !! :rol: :rol: :rol:
Is all hope lost :?: ... :mrgreen:

Excess clamp load on decel can make the car very unstable under braking and prone to spinning on turn-in. Adjusted by changing over-run ramp angle, which should not be confused with pre-load across the clutch pack.

I find I can detect all of this happening earlier if I drive commando :shock:
Rest Home for rusty vehicles
Big Daddy
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Re: Hillclimb A35 Build

Post by Big Daddy »

Countryboy wrote:I find I can detect all of this happening earlier if I drive commando :shock:
Don't your dangly bits get cold :?:

Just thinking back to your facial expression after a few quick laps around Goodwood. Attention to detail kept you safe... :thumbs:
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fsmlittler
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Re: Hillclimb A35 Build

Post by fsmlittler »

I'm not convinced I'm getting much turn in under steer and it was much the same before we fitted the diff. It just doesn't have much feel and you get the feeling you need to wind more lock on. I'm definitely inclined to try negative camber trunnions and hope to get some testing done so I can play with tyre pressures.
The academy competitor I spoke to described the handling of his car as 'bloody awful'!
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