[race_prep] Guernsey Hillclimb 205 Build

[petert 588]

Wow! For a supersprint, and depending on the circuit, I'll typically start with 25 in the fronts and 31/30 on the rears (depending on track direction), aiming to finish with 33 all round. Kumho V70A.

[wardy18 33 1 Cars]

Again different tyres suit different pressures as with different suspension set ups, these Avon Hillclimb tyres have no option for hard or soft wall either.

 

New springs and torsion bars will be fitted this afty so will be able to have a proper play at my next hillclimb tomorrow.

 

Will also try to get the gauges of a mate today to properly set the caster, i want my adjustable top mounts to give me a range from 5 to 7 deg +ve

[wardy18 33 1 Cars]

So had the last hillclimb of the year yesterday and had managed to fit the new springs and torsion bars, reset the ride height, measure the caster which was 3deg +ve both sides and match the camber to a shade under 1deg -ve on both sides

 

To be honest the handling characteristics of the car didn't really change that much and I was pretty disappointed with it, could only get within 0.14s of my pb which was set with the old suspension so you can probably understand my fristration.

 

I was getting much less tire roll and found the optimal tire pressures before the tire roll increased was 23-24 rear and 25-26 front.

 

Rebound/bump settings I found setting about midway front and rear seemed ok but was hard to test along with pressures with only having 5 runs

 

My biggest issue still is understeer

[Cameron 16]

Where is your understeer most pronounced - corner entry, mid corner, or exit?

[wardy18 33 1 Cars]

Mid corner and corner exit, tried increasing the front rebound but didn't help, was considering disconnecting the from ARB buy ran out of time

[Cameron 16]

Sounds like you could really do with a track day to tune your setup as a run up the hills just isn't enough time to figure out what's working and what isn't. Your basic setup is pretty good (although I still think you're a bit soft at the rear) so it should just be a case of fine tuning.

 

Try setting front camber to 1.5Deg first and see how that changes things, if you still have problems then un-bolt the ARB and try that. I'd spend some time on a track (or any set course that you can drive round over and over) changing one setting at a time and seeing how it affects the balance and grip.

[wardy18 33 1 Cars]

I was thinkin of reducing camber to 0.5-ve or even trying 0deg as from what I have read and wht you or others have said here crossply are very sensitive to camber

 

I am also thinking of looking at radials for the next set of tyres??

 

Track time would be great, might see if I can get onto our little kart track :0)

[Tesstuff 222]

Multiple changes, no testing or professional set up and you expect instant results?

 

Take a step back.

[Batfink 201]

The problem is so much has changed. I would revert the front to what it was before then evaluate the effect of changing the rear ride height and stiffening up the rear has done. My thought is that you may have reduced body roll considerably which in turn is not building heat into the front tyres. You need to get the car right within a corner or two max and don't have the luxury of a warm up lap...

Edited September 2, 2012 by Batfink

[welshpug 1,661]

or is it plain and simple you are putting the boot down just too early?

[wardy18 33 1 Cars]

Certainly not puttin the boot in too much as I can judge engine rpm round the corners and was struggling to stay on cam.

 

I only have one more hillclimb to go and that's our annual Alderney event so no more running at Le Val De Terres this year. The surface at this event is much more abrasive.

 

I was checkin tyre surface temps when finished a run just by touching my wrist against the surface and when I had the fronts up to 27-28psi the centre I the tyre was much hotter that outer edges so dropped back down, other than that run it was always felt that that inner edge was hotter so maybe a little too much camber at 1-ve which with a 3+ve caster increases the outside wheels camber considerably if I understand correctly!!

 

I know I have changed alot at once but with minimal running in a season I tried to set a base setup based on what everyone had advised they have tried and tested as front and rear needed upgrading from what I had.

 

So would you recommend stick to what I have and just adjust camber or swap back in the 300lb front springs to test with the stiffer rear?

[EdCherry 34 1 Cars]

You need to be measuring carcass temperature not surface temperature of the tyres to get consistent and useful data.

 

Too much advice from too many different people, I think you need to sit down and sift out the s*it as a lot has been flung.

[Cameron 16]

How about you contribute some ideas then Ed, as opposed to the usual "I'd have done it differently" spiel?

 

I'm with Daz, unless you're an unfound F1 star you'll need more time to adapt to the changes and figure out what's really going on, where the grip is, where it isn't and how the car responds to your inputs. You've changed a lot of things, so you need to fine-tune now and figure out how much of an improvement (or not!) has been made. Expecting miracles right out of the box is a bit too much to ask, people are rarely that lucky!

 

My suggestion is to do an open pit track day or get access to a course and try and tune your setup to improve your times. Take a proper tyre probe that has a spike to measure carcass temp and see how your tyres are working. I would certainly start by increasing negative camber at the front, if you have it set at 1Deg, go up to 1.5Deg, then up to 2 and see how it affects the balance of cornering and braking.. me saying that crossplies are sensitive to camber may have thrown you slightly, as they will run 1.5Deg-2Deg all day long depending on the vehicle, whereas radials can run up to 5 or 6!

 

If you have no other chance to drive it between now and the next race, make your first run on the current setup then change the camber to 1.5Deg and do another.

Edited September 2, 2012 by Cameron

[wardy18 33 1 Cars]

I will look into getting it onto our kart track as I know he allows it at a price so won't be able to go massive speed but has some good flowing corners!!

 

I was inspecting my tyres before and my god they need a very good rasping or one of them heat guns and a scraper to remove the old layer, the inside of the front left and rear right have a lot of build up from rubber moving across the surface from the outside of the tyre to the inside, if you know what i mean

Edited September 2, 2012 by wardy18

[EdCherry 34 1 Cars]

You mean they are graining? You wont be removing that with a heatgun.

 

Im happy to offer advice, but it takes a bit longer than a paragraph to truly understand the situation and get enough feedback to make a decision based upon it. Your advice is pretty sound cameron and goes in the right direction, theres no point giving too much advice as I said in my previous post, just have to weed out the s*it then.

 

There is no reason why a clubman with some thinking and understanding cant make big changes and reap the rewards... instantly.

Edited September 2, 2012 by EdCherry

[Cameron 16]

There is no reason why a clubman with some thinking and understanding cant make big changes and reap the rewards... instantly.

 

Agree 100%, but the level of understanding needed to get things right from the word go is pretty high! No offence to Simon but he's only just starting to learn about tuning suspension so getting things right from the word go either requires a great deal of luck or some outside help and advice. That's why I reckon he'd learn a huge amount by having a track day dedicated to making adjustments and figure out what works and what doesn't.

[Tom Fenton 1,542]

camber to a shade under 1deg -ve on both sides

 

I don't claim to be any kind of suspension setup guru but this does not sound like anywhere near enough front negative to me.

 

I also think that you need to try and take some tyre temperature measurements across the tyre width to get a feel for which part of the tyre you are using the most.

 

If you are getting heavy build up on the inner edge this suggests to me you are using the outer edge hard and it is shifting rubber to the inner edge. In turn this suggests more negative camber could help by getting the tyre contact patch to sit flat when cornering hard. This will also help the tendency you mention for it to roll onto the outer sidewall.

[Cameron 16]

+1 on the above.

 

I'd recommend one of these:

 

http://www.demon-tweeks.co.uk/motorsport/pyrometers-temperature-indicators/anton-digital-pyrometer

 

And one of these:

 

http://www.demon-tweeks.co.uk/motorsport/pyrometers-temperature-indicators/anton-tyre-temperature-probe

 

You need the proper spiked tyre probe so you can measure the carcass temps, surface temp will tell you very little!

[wardy18 33 1 Cars]

Thanks guys, would love to buy one of the tyre pyrometer but funds are a little tight with our Alderney events coming up and then my lads week in Vegas at the end of this month.

 

I will reset the front cambers with the adjustable top mounts so i can go from 0.5 to 2.5 -ve, i know i used to run 2 - 2.5-ve in my past 205 and that was with the 8j on the front and 9j on the rear (not sure why i used to stick the wider rims on the rear of a fwd???) those days i used to run pressure of 20 - 22psi and had none of this tyre roll issue however that was with a 1.9 ally block, not the heavier iron block up front i have now

 

I have been doing A LOT of reading outside of this forum too so dont worry i am not just taking 1 or 2 persons opinions and applying to mine, i am reading a lot of proper race set up and general car geometry to understand how it all works, most of which does reflect what i am being told in here.

[Baz 421]

I concur, more seat-time, trackdays etc for example is very beneficial to development, not just for the car but you too, works for me.

[welshpug 1,661]

The material of the block is almost insignificant, but the power youre getting from it is somewhat of a large factor!

[wardy18 33 1 Cars]

Does anyone run radials??

 

In doing research into tyres and compounds etc it seems that Radials are used as much if not more than Crossplys and have much more development to the tyre and compounds, it seems (as someone said earlier in the thread) Crossplys are old school and radials are more for modern vehicle use and have as much going for them as crossplys.

 

Anyone wish to discuss??

[Cameron 16]

Don't buy in to the "crossplies are old fashioned" crap!

 

They're a different type of tyre for a different type of car, that's all. Crossplies are more suited to lightweight single-seaters as they're more sensitive to pressure and changes in negative camber, and seeing as most single seaters will have SLA suspension with good camber control they work very very well. You'll find radials on saloons a lot more as A they're heavier and B they generally have poor camber control (lots of body roll and little or no camber compensation) so need to run a lot of static camber - 3Deg and upwards - and need a tyre that can cope.

 

You were probably recommended to use crossplies as they come in the Avon A15 compound for hillclimbs whereas radials don't, and the advantage you gain from this outweighs the disadvantage of not having such a suitable construction - provided your suspension is set up to make the most of them!

Edited September 3, 2012 by Cameron

[wardy18 33 1 Cars]

Thanks, i was actually looking at Avon's compounds and they do a softer version of the A15 called the A92 but with being softer they dont quite last as long, i am very tempted next season when i replace my tyres to go for A15's on the rear and try out some A92's on the front!!

[wardy18 33 1 Cars]

Some pics from Saturdays hillclimb to show how it was handling