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Lotus Europa Forums => The Paddock => Topic started by: StephenH on Monday,April 14, 2014, 03:10:21 AM

Title: Turn-in oversteer
Post by: StephenH on Monday,April 14, 2014, 03:10:21 AM
Now that I am settling into the Europa I want to start thinking about some setup tweaks and closing the gap on the competition.

One thing I have noticed is that on initial turn-in there is a feel of light roll oversteer, then the car settles nicely.
Not scary, just slightly disconcerting at times.
Car is on adjustable springs and dampers with adjustable rod ends, so plenty of scope for simple tweaks.
No rear roll bar.

Before I get too carried away I am looking for a baseline setting for rear wheel alignment if anyone can provide a known (good) reference.
Tread face is wearing pretty evenly so nothing wildly out of the envelope.

Thanks in advance.


Title: Re: Turn-in oversteer
Post by: jbcollier on Monday,April 14, 2014, 03:14:30 PM
Baseline? Start with the factory settings.

S1/S2:

http://www.lotus-europa.com/manuals/s2work/tech/index.htm#k

TC/S:

http://www.lotus-europa.com/manuals/tcwork/tech/index.htm#k

Title: Re: Turn-in oversteer
Post by: StephenH on Monday,April 14, 2014, 05:56:57 PM
 :beerchug:

However, I will revise slightly.
Before I get too carried away I am looking for a baseline setting for rear wheel alignment if anyone can provide a known (good for track use) reference.

Maybe the standard factory (road use, standard suspension) setting is fine, but happy to explore some direction from others pain :)
Title: Re: Turn-in oversteer
Post by: Mecky on Monday,April 14, 2014, 08:06:03 PM
Hi Stephen,

I never experienced any oversteer while turning in to a bend. Maybe because our car has 9" rear rims. Sometimes I had a tiny bit of oversteer at the exit of the corner. But thinking about correcting that was enough as long it was dry. Our wet tyres were not the best. Softer ones are necessary.

We set up our suspension like it was recommended by Jensens competition manual.

Best regards

Stefan
Title: Re: Turn-in oversteer
Post by: jbcollier on Monday,April 14, 2014, 09:02:12 PM
http://www.lotus-europa.com/manuals/misc/jensen.pdf
Title: Re: Turn-in oversteer
Post by: StephenH on Tuesday,April 15, 2014, 04:19:40 AM
Thanks, I'll check a few things against the Jensen manual.

When I say 'roll oversteer', it is fairly mild and hasn't led to anything scary, just 'feels' a bit loose as you turn in.
Car is currently fairly supple on suspension as it is used mainly on public roads and road courses, not smooth racetracks.
might be able to tune out with damper adjustment. Will stick the car on the alignment table near work and have it measured up accurately first.

Actually Stefan I was going to contact you as it was planned for me to be in Belgium next week, but that has been put off for a while, next time maybe.
Title: Re: Turn-in oversteer
Post by: Valerio Leone on Tuesday,April 15, 2014, 06:16:12 AM
I had the same problem and then it turned out I was losing a wheel...
I had to replace the hubs and stub axles.
 
Title: Re: Turn-in oversteer
Post by: StephenH on Tuesday,April 15, 2014, 07:43:05 PM
That bit I have checked, several times :)
The wheels are still firmly attached to the suspension.
Actually I replaced the axle nuts and checked for float only last week.
Title: Re: Turn-in oversteer
Post by: jbcollier on Tuesday,April 15, 2014, 08:49:02 PM
Interesting reading in the comp manual: " It is recommended that the stub axles be replaced after three practice and race sessions as a precautionary measure."
Title: Re: Turn-in oversteer
Post by: Serge on Wednesday,April 16, 2014, 01:13:59 AM
I have talked this over with Richard at Banks and he recons if you install them properly they will stay on. He races with them regularly and says that it isn't a problem for him.

He installs everything, torques it all down without loctite to seat it properly. Then takes the nut off and then loctites the nut on. But you have to make sure that your spacers, hubs and stub-axles are in good condition, if there is any play in there, you are going to get problems.

Serge
Title: Re: Turn-in oversteer
Post by: Valerio Leone on Wednesday,April 16, 2014, 01:47:53 AM
I would recommend to buy a well done American stub axles and hubs alligment conversion.
It is for sale on e-bay.
It's pricely but it works damn good!
It's a litte investment on safety, we should bear in mind we are driving a kind of plastic torpedo after all.
Serge, this is even more important if we will have 160hp on our back...
Title: Re: Turn-in oversteer
Post by: Serge on Wednesday,April 16, 2014, 02:18:54 AM
Valerio,

I've seen the kits on ebay, they look nice! Do you have these? If so, did you have to send your stub axles to them?

Serge
Title: Re: Turn-in oversteer
Post by: Valerio Leone on Wednesday,April 16, 2014, 02:26:26 AM
Of course I have that kit.
I really recommend to buy it for competition cars!!
you have to send to them your stub axels and the alluminim hub carriers.
They will give you back the conversion ready to fit with new bearings.
ciao
V

Title: Re: Turn-in oversteer
Post by: Mecky on Friday,April 25, 2014, 03:03:26 AM
Sometimes I had a tiny bit of oversteer at the exit of the corner. But thinking about correcting that was enough as long it was dry.
I experienced it yesterday again. I don't even have to think about correcting. It straightens out by just staying on the throttle.
Title: Re: Turn-in oversteer
Post by: Valerio Leone on Sunday,April 27, 2014, 10:35:29 AM
I am wearing dunlop racing.
With those tyres I ve experienced many times what it was called "four wheels drift".

 8)
Title: Re: Turn-in oversteer
Post by: StephenH on Sunday,April 27, 2014, 05:53:32 PM
Having some fun yesterday I found the car quite sensitive to rear rebound damping on the short Rob Roy hillclimb circuit.
There is a section that will heavily compress the suspension just before a sweeping uphill (with crest) left hand bend.

With 5 extra clicks of rebound the driver (me) ran out of talent and rotated onto the grass.
With that reduced to only 2 extra clicks I took more than 1 second from my previous best on a short 650metre run.
Unfortunately I didn't have the video running for the half spin but looking at other runs I suspect the suspension wasn't recovering from the compression before being loaded up again on the bend (with some bumps).

I spoke with the Group S class record holder (very quick S2) and he recommended running the rear quite soft at the rear with minimal rebound (which is actually where I started).
He also suggested a heavy front roll bar (but himself didn't run a rear roll bar).
Basically has that setup on his new Europa T/C (or might be a Special) that is already running quicker than his old S2.