4396 replies to this topic

[CHILL Gone DUTCH]

Time to get prepped ready for the next round of croft and i actually feel like i have recovered from a very long winter (work wise )  

 

I wanted to do a lot of work over the winter but it just didn't happen. 

 

ok croft ive decided to remove all my carpet from the inside of the car and also the passenger seat as i attempt to improve on last years sprint time 

J6 class is a lot closer this year 

 

the car is now off the road no mot etc and don't  plan on putting it back on until after the sprint season is over (maybe i will get through the season on one set of tires and pads ) or not.

 

i also have changed the rear wishbone bolts as they came lose 

 

so hopefully monday i can make a start on the car and try and make it better (well lighter )

Edited by CHILL Gone DUTCH, 28 April 2018 - 02:58 PM.

[Captain Vimes]

Easiest place to lose weight is probably fuel. Do you know how much fuel you need in the tank to avoid starvation and how much fuel youll use over a lap?

[CHILL Gone DUTCH]

No the exactly but I do keep it around 10 litres maximum per flying lap

[CHILL Gone DUTCH]

Not the best result over the weekend, we'll beaten by Dale dale in exige v6 I new from Saturday that he was going to be hard to beat as had really improved from last year going 4 seconds quicker One of much middle laps

[jonnyboy]

Looks a bit wet in places there too. What V6 model is it? Not sure a LSD will help much. They like to go sideways even more with LSD which is why I like having them just for hoonage reasons  

[CHILL Gone DUTCH]

Ive got excellent grip from the loaded rear wheel but the inside is just spinning rediculasly I've got to get this sorted Already have 800 springs ( do I go higher ) go for a rear anti roll bar Or look at getting a lsd Anyone has any expierience of this and idea should to solve it I'm also taking thevweight of the passenger seat out of the car And a few other things

[CHILL Gone DUTCH]

Looks a bit wet in places there too. What V6 model is it? Not sure a LSD will help much. They like to go sideways even more with LSD which is why I like having them just for hoonage reasons  

The car is a 350 model But he has really improved his driving or modded the car He does have a huge BGW and front splitter It has a plastic engine cover ( don't think it's a cup )

[CHILL Gone DUTCH]

@ Jon There was a dry line but did hit water in video in sunny in and sunny out

[MAXR]

What Dampers are fitted to your car? I had similar issues with my old Nitron's. I used to have excessive initial wheel spin coming out of some corners. Now sorted.

[Pidgeon]

If you need more traction, soften not harden, the rear.  Try tender springs if you have the travel.

[CHILL Gone DUTCH]

What Dampers are fitted to your car? I had similar issues with my old Nitron's. I used to have excessive initial wheel spin coming out of some corners. Now sorted.

Im on quantums Max, ive got loads of grip on the loaded tires but as soon as i get on the throttle balancing the car the inside is just spinning for fun 

 

@pidgeon its just the inside wheel giving me issue so would say there is to much role at the rear of the car 

[Rosssco]

The chap has obviously improved since you previous meetings, but the Exige S3 will have an advantage in mixed conditions - they have a fairly advanced Bosch variable traction and stability system which helps them optimise both traction and slip, which I'm sure must give the driver more confidence in pushing on..

 

Whether he uses it or not..

[Nev]

Ive got excellent grip from the loaded rear wheel but the inside is just spinning rediculasly I've got to get this sorted Already have 800 springs ( do I go higher ) go for a rear anti roll bar Or look at getting a lsd Anyone has any expierience of this and idea should to solve it I'm also taking thevweight of the passenger seat out of the car And a few other things

If one powered wheel is spinning and one has traction when cornering then a LSD is the way forward - that's what they're specifically designed for after all, though it is a pain to fit them. Also, as Pidgeon says, getting harder springs will make your problem worse. You need softer springs as they will correctly allow the car to roll and dynamically change your camber so that the tyres stay on the tarmac better. Also softer springs can help with absorbing the ripples and bumps (providing your dampers are moderately set) to improve the break away point in the first place.

 

Bear in mind that by over springing a car you are partially eliminating the very benefit that double wishbone geometry trys to give you. They actually need to flex up and change the camber (ie lateral grip) and to change the toe as your corner. Basically if your car isn't rolling enough it can't grip as much.

 

Yes, you have to compromise and offset your spring Lb setup with issues like dive (under braking) and squat (under acceleration), but when I see poundages of 800+ being mentioned I have to wonder if you've gone too far, particularly if it happens to be wet or damp. 800 Lb is roughly 2.5 times the OEM setup, I find it hard to believe that without slicks that your tyres can muster up 2.5 times as much lateral grip as a road car to make the car heel over. GL.

Edited by Nev, 14 May 2018 - 11:29 AM.

[jonnyboy]

I would deffo swap springs 800 lb is Aero car level poundage. It's a low cost easy thing to try before fitting a LSD. Don't forget that with a LSD you outer wheel will want to spin up as soon as it locks with the power you have and your ultimate break away point with a LSD will be lower overall than with the open diff. I love cars with LSD just because they like going sideways and car control is something that's pretty satisfying and you can enjoy a little on the road but over a lap I really think it would slow down all but the very best drivers (which I certainly don't claim to be) Lotus have only just started putting LSD into cars probably just to inflate the spec sheet as they were always adamant that the platform doesn't need one. 

 

As with all problems like this start with the simple stuff. I think throwing an LSD in right now would probably make it worse. 

[CHILL Gone DUTCH]

THere is nothing up with the loaded rear wheel there plenty of grip there and I'm able to control that with my right foot what I'm saying is the unloaded wheel is spinning/smoking etc it's not causing a issue with the loaded one it's just spinning making lits of smoke and probably pulling rubber of the surface of my tire Other thing to remember is this is on very cold tires in a sprinting scenario

[CHILL Gone DUTCH]

Surely a softer spring will have more give and the inside tire is more likely to spin up Which is why I was thinking Rear ARB Where scuffers when you need him

[jonnyboy]

You'll be maximising the opportunity the inner wheel has to be in contact with the tarmac 

[jonnyboy]

800 lb its just skimming the surface 

[Nev]

Surely a softer spring will have more give and the inside tire is more likely to spin up Which is why I was thinking Rear ARB  

 

Yep, I think a rear ARB would help with this by squatting the inside wheel (and indirectly changing it's camber too). But I've only driven 1 VX220 with a rear ARB  in and although it handled very well indeed there were other major mods to it's geometry, so I don't know what mod was affecting what...

 

On the other hand I can say for sure (subjectively) that my Quiafe ARB really does allow me to get the power down earlier when exiting a corner. I've driven Nipper back to back at Landow with another OEM diff'ed VX220, as well as back to back on the road and there is no doubt in my mind I can accelerate harder out of the corners with the ATB.

 

Open diffs are fine for cruising round corners with neutral power input, but if you want to put power down then some sort of torque biasing diff will help stop the inside wheel spinning up. I suppose this is also evidenced by the number of factory performance/drivers cars that now come with mechanical torque biasing and clever electronic diffs, with the aim to help the driver get the power down in the corners.

Edited by Nev, 14 May 2018 - 12:49 PM.

[Rosssco]

Surely a softer spring will have more give and the inside tire is more likely to spin up Which is why I was thinking Rear ARB Where scuffers when you need him

  Maybe you need to look at different spec dampers - the spring (while important) does not control the car / suspension loads, the damper does that. I thought a very general rule was to run as soft a spring as possible (allows suspension compliance = more grip), and use a properly spec'ed damper to control it all..

 

An LSD is ultimately a sticking plaster for suspension that is working out with its range (i.e. when you lift a wheel)