Oversteer on corners

PostPost by: pauljones » Sat Mar 10, 2018 1:40 pm

Jon

Happy your on your 4 wheels. Looks like it will make life soo much easier for you.

However, i now have garage envey. If mine was as big as yours id be happy.
Kick the tyres and light them fires...!!!!!!!
pauljones
Fourth Gear
Fourth Gear
 
Posts: 825
Joined: 09 Feb 2008

PostPost by: Bigbaldybloke » Sat Mar 10, 2018 2:01 pm

Looking good Jon.

It?s amazing how a broken car can hang together. Many years ago I used to go as mechanic with a friend banger racing. Started many a race with the suspension strapped together with ratchet straps, chains or u-bolts and clamps, even finished some races like that too!

Only thing to be aware of is tight turns or going up kerbs.

What is the next chapter going to be called?
Change is inevitable, except from a vending machine!
Bigbaldybloke
Fourth Gear
Fourth Gear
 
Posts: 889
Joined: 16 May 2017

PostPost by: JonB » Sat Mar 10, 2018 2:21 pm

Oh alright then, BBB. Since you ask so nicely...

lotuselan-plus2-f51/2018-peterborough-odyssey-t41443.html
User avatar
JonB
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2371
Joined: 14 Nov 2017

PostPost by: JonB » Wed Mar 28, 2018 10:08 am

So, following the successful conclusion of "The Peterborough Trip", I am to report on whether or not my steering issues are resolved.

I need a nice dry day so I can test drive it properly, but initially it seems that the straight ahead vagueness is much improved. The steering into corners (roll steer) I am not sure about yet, but as noted on the Peterborough thread, the car is rolling too fast and I think this is unsettling it. It feels like the rear end (opposite the direction of turn) is lifting up dramatically, most odd. The car needs new front shock absorbers, probably springs, and probably rears as well.

Let's take up the story once I've had a chance to drive it on familiar roads in the dry!
User avatar
JonB
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2371
Joined: 14 Nov 2017

PostPost by: Foxie » Wed Mar 28, 2018 11:47 am

JonB wrote:How can they be toed out when there is no adjustment?

It's a Spyder chassis that has no visible damage and the wishbones have new bushes.


Because they make them that way !

Both my Spyder rear arms had significant toe-out when I eventually had them checked. The expensive solution was a set of Spyder adjustable rear wishbones, but they transformed the car ! :)

I had them set up to the correct basic spec, and then tried equal minor adjustments to fine tune the feel of the car.
68 Elan +2, 70 Elan +2s
User avatar
Foxie
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1210
Joined: 20 Sep 2003

PostPost by: 661 » Wed Mar 28, 2018 7:29 pm

Foxie wrote:
JonB wrote:How can they be toed out when there is no adjustment?

It's a Spyder chassis that has no visible damage and the wishbones have new bushes.


Because they make them that way !

Both my Spyder rear arms had significant toe-out when I eventually had them checked. The expensive solution was a set of Spyder adjustable rear wishbones, but they transformed the car ! :)

I had them set up to the correct basic spec, and then tried equal minor adjustments to fine tune the feel of the car.

I measured my spyder rear toe in recently and I have zero. As they are the 'upgraded' oval profile it would be difficult to weld an adjuster to them, and frankly for the fuss I'd like to do camber too. So it looks like a trip to Mr Wallet.
Graeme
S4 SE
S2 GTS
Caterham 420R
Sold - Peterson JPS Exige
User avatar
661
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1192
Joined: 29 Mar 2012

PostPost by: Foxie » Thu Mar 29, 2018 12:59 am

661 wrote:I measured my spyder rear toe in recently and I have zero. As they are the 'upgraded' oval profile it would be difficult to weld an adjuster to them, and frankly for the fuss I'd like to do camber too. So it looks like a trip to Mr Wallet.


Forgot to mention, the rear camber was mad wrong also, but the Spyder adjustable top arm fixed that.

Have to say that the rose joint was not up to resisting accelerating/ braking forces and I had to fit brass collars (Conex Instantor !) to prevent the rose joint outer rings from coming out of the end eye. The original rubber bush was ok. I contacted Spyder about this but never heard back. :(
Attachments
p4260177a.jpg and
p7030002a.jpg and
68 Elan +2, 70 Elan +2s
User avatar
Foxie
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1210
Joined: 20 Sep 2003

PostPost by: JonB » Thu Mar 29, 2018 12:10 pm

That all looks very expensive - I'm not going to spend that much, though the idea of the extra adjustability is tempting. On the other hand, I'm not too impressed with the rose joint bushing failing, or the lack of response when queried.

This afternoon I took the car for a little drive on the now (mostly) dry Sussex roads. Just a few miles to clear the oil fouling in Cylinder 4 and try the handling and other things out.

My findings are:

  • Despite using flowable silicon I can still hear the wind noise at 60mph+. It might be be quieter.
  • Steering is definitely less vague in a straight line. A win.
  • The car is still diving into the bends, but not as bad as before. It can be driven smoothly if I bear this in mind. Win. By process of elimination, and bearing in mind what Spyder said, new dampers/springs should resolve this.
  • I noticed the front end diving under braking - another symptom of worn dampers. Win (on the grounds that it now a known problem and so can be fixed).

So I am not entirely out of the woods yet, but I know what the way forward is.
User avatar
JonB
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2371
Joined: 14 Nov 2017

PostPost by: 69S4 » Thu Mar 29, 2018 12:59 pm

JonB wrote:[*]I noticed the front end diving under braking - another symptom of worn dampers. Win (on the grounds that it now a known problem and so can be fixed).[/list]

So I am not entirely out of the woods yet, but I know what the way forward is.


It does depend on what you've got at the moment and how bad the issue is but the Protech and Spax dampers that I considered recently did most of their damping on the rebound stroke so you'd still experience some front end dive under braking. You could crank all the settings / spring rates up to 11 but that would lead to a pretty harsh ride.
Stuart Holding
Thame UK / Alpe D'Huez France
69 S4 FHC
Honda GoldWing 1800
Honda CBX1000
Kawasaki H1 500
Yamaha XS2
69S4
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1124
Joined: 23 Sep 2004

PostPost by: Bigbaldybloke » Thu Mar 29, 2018 1:12 pm

By design the front brakes do the majority of the stopping, but the rear brakes also do some of the work. If you have a problem with the rear brakes this will throw all of the braking to the front and cause the front to dive more. Just a thought, have you done an emergency stop on a nice empty bit of road and checked all four wheels are locking equally. More likely to be the dampers but worth a check.
Change is inevitable, except from a vending machine!
Bigbaldybloke
Fourth Gear
Fourth Gear
 
Posts: 889
Joined: 16 May 2017

PostPost by: JonB » Thu Mar 29, 2018 3:08 pm

No, I haven't, but I noted earlier (actually mentioned in another thread) that the fronts lock readily in the wet, and my rear disks appear to have some rust on them that won't shift (i.e., is not getting scrubbed off by the rear brakes). Something to investigate in due course - but the car's stopping power is good.
User avatar
JonB
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2371
Joined: 14 Nov 2017

PostPost by: vincereynard » Thu Mar 29, 2018 5:28 pm

The "turning in" problem is probably still more to do with lack of rear toe in than front dampers.
Roll oversteer. I'd sort that out first. And check the front end has been built correctly.

As someone else stated dampers mainly work on rebound anyway.
vincereynard
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1071
Joined: 12 Jan 2015

PostPost by: JonB » Fri Mar 30, 2018 5:50 pm

vincereynard wrote:The "turning in" problem is probably still more to do with lack of rear toe in than front dampers.
Roll oversteer. I'd sort that out first. And check the front end has been built correctly.

As someone else stated dampers mainly work on rebound anyway.


Hmmm. Well I jumped on the front shockers today and the diagonal roll (opposite rear side of the car lifting up) was quite pronounced. I had a look at the front suspension and it looks correct. Now I will have to take the rear arms off again (to fit the turnbuckles). I need to find someone who can weld - that is what's delaying me.
User avatar
JonB
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2371
Joined: 14 Nov 2017

PostPost by: john.p.clegg » Fri Mar 30, 2018 7:40 pm

Fourth gear in four months , must be a record..

John :wink:
User avatar
john.p.clegg
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 4521
Joined: 21 Sep 2003

PostPost by: JonB » Fri Mar 30, 2018 9:04 pm

john.p.clegg wrote:Fourth gear in four months , must be a record..

John :wink:


Enthusiasm. Determination. Love of the car and the marque.

Those are my excuses... :D
User avatar
JonB
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2371
Joined: 14 Nov 2017
PreviousNext

Total Online:

Users browsing this forum: No registered users and 37 guests