Is there something wrong?

[kenny.]

I think this may come out a bit long winded, but please don't give up....I'm struggling. To cut a long story short, I posted a thread a couple of months back "Grip or controllability" in which I was stating that my HPC in track trim performed like a dog and that I felt there were plenty of vehicles that would out corner it........a lot of people dissagreed with me.

Don't get me wrong, in the 2 seasons I sprinted it , I improved to the point where I did actually get some results and silverware, but I felt I was working a lot harder in car to achieve this, opposed to mates who in 7's were doing similar times. I swapped cars in practice a couple of times with guys and on each occasion they'd walk away disgusted mine and it's manners.......I just put this down to it being a heavy fronted VX......I did a a good few laps in Julians lower powered Zetec car and immediatly equalled my best in HPC with very little effort or trauma or fighting.

 

To help with any advice you may be kind enough to offer, here is the final suspension set-up car had....and still has.......................

 

Orange AVO 24 click dampers,

250 lb front (10 coil) black...with 7 or 8 mm between coils at nearest spot.

160 lb rear (red) with 50mm spacer blocks.

3/8" front ARB.....rear ARB disconected

1/8" toe out and 2 degrees neg. on front........standard HPC on rear?

Juno castor kit fitted i.e. spacer/ half nut on ball joint on front.

Ran 13"/6" wheels on list 1A tyres. I will add to this for the record, that the car was flat floored and corner weighted with fuel and myself, figures were spot bollock, camber, toe out was done at same place. They are really professinal people and I just trust what they do..........but car from front end did not "look" right to me so I asked them to re-check everything........it still looked pissed to me but figures checked out, so I left it at that.

 

Symptoms......................................

 

Totally twitchy at any speed.......better in fast sweeping corners but loads and loads of correction needed. Slower corners cost me the real time, the car just will not turn in even at 40mph or less .........it just pushes out to the kerb and will not think about "driving round"..I have to turn a not to tight hairpin into a series of blips and lift offs and christ knows what to get it round.......please believe me it's bad.

 

Anyway, a fellow blatchatter was round at our house last night and I told him what I've tried to relay here......he has a VX and reckons it's a pussy cat.

He then picked up on my point regarding the car looking wrong at the front and we did some quick measurements.....................

 

1) My passenger side front spring platform is screwed an inch higher up than drivers one.

2)On the top wishbone/balljoints, the drivers one has 9 threads exposed as opposed to 4 on passenger side...........I picked up on these points at flat floor shop but was assured that this was "quite normal" to get settings right...............is it?....I'm wondering now.

 

I never sprinted car last year as I'd basically given up hope with it and was going to sell it for something else..........but I've got renewed hope now.........i must have a serious problem somewhere, and I feel that my times were ok in evil car, so I'd like a go in one that corners.

 

Sorry for dragging this out and possibly not explaining things fully and correctly.......I'm ok with engines but rubbish with set-ups that's why I trust people do do it for me.

 

Would love to hear from anyone in North West who may be able to give me a lift with this one, or anyone in the world really.........free pints at local and a paid for testing session with me on offer...........many thanks.

 

Kenny HPC

 

PS I would add that small changes like swapping ARB's etc., that seem to transform other peoples cars, make no difference to this animal.......it's always naughty.

PPS The other thing noticable is that if you try to rock car by FIA bar it feels harder than an F1 car......no movement at all apart from its tyres.......is this pukka for springs of this poundage?. By the way the car is like new and has never been bent so I'm assuming chassis and everything are perfect.

 

 

Edited by - kenny on 12 Oct 2001 13:06:21

 

Edited by - kenny on 12 Oct 2001 13:13:11

[deanteam]

It may not be totally related but we received a new lower front wishbone that had the lugs holding the trunnion, welded on the wrong way round. The 'set-up' was also very strange similar to what you describe. If you have the ball type trunnion this will not apply, but it maybe worth a look if your wishbones are the same (handed).

[kenny.]

Thanks for that....just had a quick look and wishbones etc. seem perfect........but something is amiss.

 

Thanks anyway,

 

Kenny HPC

 

 

 

Edited by - kenny on 12 Oct 2001 14:33:59

[AMMO]

Kenny

 

When you say twitchy at any speed what do you mean exactly? Will the car go in a straight line at speed with your hands off the steering wheel? How much castor do you have?

 

AMMO

[kenny.]

Ammo,

 

I was a bit vague there......I mean it's twitchy whenever any sort of conering forces are applied.......as I said the main time sapper on a lap is the very slow corners.....the car feels a if it's on ski's, It won't even attempt to go the way its wheels are pointing!!!!.........as for castor as far as I know it's standard as per factory, but with that Juno spacer bit I've added.......cheers.

 

Kenny HPC

 

 

[FH]

Get your edges sharpened, apply the correct wax for conditions and bend ze 'nees wink.gif

 

 

 

Edited by - fullharness on 12 Oct 2001 15:22:01

[AMMO]

Kenny

 

I would measure the castor or get it measured by someone who has the kit. My Mini was doing strange stuff, it turned out I had different castor figures on each side. It can't hurt to find out what you are running. At least you can eliminate it as a source of trouble if the castor is correct.

 

Is the steering really heavy?

 

AMMO

[Peter Carmichael]

Well spring rates look OK. Dampers could be anywhere with adjustables. Start full soft and be very careful stepping up a click at a time.

 

But it does sound like something is not right fundamentally. The threads on the top wishbone can be misleading, but that is easy to check with as simple a tool as a spirit level.

 

That pushing symptom you describe sounds like too much rear roll-steer *with* the front steering. Raise the ride height at the rear.

 

The twitchiness you describe could be too much toe out or too much castor without matching camber. I usually set toe to straight ahead until I have fixed all the other problems and adjust toe as a last resort.

 

The only other thing that springs to mind is the possibility that your de Dion tube is wildly out, with mismatched rear camber and toe. Worth checking with a four-wheel alignment check.

 

The suspension should move on those spring rates. Friction in the shocks could be poor. Mine has 250lb/in springs and standing on the front wishbone flexes the suspension enough to see it bounce and settle. To get the rear to move I have to stand on the boot edge and bounce it a bit.

[kenny.]

Thanks very much for comments, they are very welcome. I feel a bit out on a limb up here in the North West as I 'd really like to take it somewhere who a) knows what they're doing, and b) has the equipment.....I feel as though there is little mileage in me pratting about with it at home.

The castor theory for sure needs checking.....and the comment about the de-dion tube has given me more worries. Is there anyone in this area who may be able to sort this, as the little 3 sisters track is on the doorstep and very cheap to use for Friday testing sessions after tweaks,.....I'd be over the moon if could get someone to say......"ahh that's the problem", after looking at it. I'd love another season in it....I've missed it.

 

Many thanks,

 

Kenny HPC

 

 

[millsn]

Cn you try someone elses Bilsteins on your car - I suspect they'll make one hell of a difference. There's so much to go wrong with replacement dampers.

 

Nigel Mills - 2.0 Zetec carbs

[CHRIS CLARK]

I have very little experience with 2litre V/X's, but Phil Stewarts car (Road & Race) feels very well sorted whenever I've driven it.

 

He has a 22% quickrack but of greater interest is the fact that there is a 35mm difference between the front and rear ride heights measured at the Caterham suggested positions. Caterham themselves say there should be 10mm. It makes the car look down at the front, but it works!

 

I know there are untold other variables, but here's another to ponder thumbsup.gif

[Jason Plato]

Kenny ,

You could consider taking the car to a company called Terrapin Services , a company run by Alan Staniforth which has a huge reputation in sprinting and Hillclimb for suspension analysis and modifications .

They are in Harrogte ( Hey - at least its in the north ? ) on 01423 711228 .

 

Dave

[John E]

I have first hand experience of Alan and if you can tie him down and are prepared to leave the car then he will sort it for you. Probably the best suspension guru in the country.

[kenny.]

Thanks for the last 4 replies....I will give Alan a call...especially if he has experience with 7's.......I'd leave it there as long as is needed.

Interesting point about setting rear up a lot higher.....a couple of people have mentioned that. A further thought I have is that my Avo's were purchased from a non 7 but race specialist..........could the valving be a mile out and suitable only for cars weighing a great deal more than mine.....thus creating the skateboard feel I'm suffering.

 

Thank you again

 

Kenny HPC