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-   -   still confused about a arms.. (http://www.haynes.co.uk/forums/showthread.php?t=7465)

MarkB 29th November 2011 11:27 AM

[quote=Bonzo;68393]
Quote:

Originally Posted by MarkB (Post 68379)
The Sierra based Roadster handles like a shopping trolley and understeers for a past time but that is my opinion and no doubt will be frowned upon[/QUOTE

That is only my personal opinion of that post :p

What a pity that you never took the time to build one & by your own admission, wouldn't even drive a 7 type car ;)

Hey ho, you have to get your kicks somewhere & I guess this forum is as good a place as anywhere :D


There are plenty of 7's that handle, I have built a few but had no interest, time or space to build a Roadster. Sooner make something different....as for being a Troll well that made me laugh........:D

MikeB 29th November 2011 03:57 PM

can't wait to get mine built and on the track to have a look at this understeer problem.

From my understanding it will be the high g corners where theres a lot of body roll. Aparantly there isn't enough camber gain on the front suspension, i.e the camber angle can't keep up with the body roll angle. Thus causing the outside front wheel to camber out under heavy cornering. Thus causing a bit of understeer. The front shock angle is also quite low so effectively you loose stiffness the more wheel travel (or roll) angle you see.

Three things I'll be playing with to solve this (or minimise this)
1. Static camber angles, probably come up with a track and road setting.
2. Limit the body roll with some antiroll bars (or stiffer strings)
3. Weight distribution etc to give a more neutral oversteer charactersitic.

Other than Ash I'm not sure who else has actually experienced the understeer and this could just be down to the basic geo setup.

As said on the road it isn't going to be a big problem, on track you might feel like you not quite getting the most from the tyres. No biggy.

In my opinion a wider chassis would look naff

flyerncle 29th November 2011 07:55 PM

From experience of the Roadster I put together in conjunction with Saturn the total opposite is true and has a lot of oversteer when corner weighted and set up to suit the driver,it is wearing R1R Toyo,s at about 26 psi or there abouts and standard Protech,s and shorter springs.

spud69 30th November 2011 09:33 AM

Quote:

Originally Posted by flyerncle (Post 68473)
From experience of the Roadster I put together in conjunction with Saturn the total opposite is true and has a lot of oversteer when corner weighted and set up to suit the driver,it is wearing R1R Toyo,s at about 26 psi or there abouts and standard Protech,s and shorter springs.

Yes you're right Paul, the roadster can be set up and corner weighted to suit the drivers preference. For the track my setup is the opposite with some understeer that i can balance out with my right foot and get some really nice 4 wheel drifts coming out of the corner, the front can really turn in while coming off the brakes into a corner. Really is good fun - wish it was spring / summer again.....:D

AndyH

ozzy1 30th November 2011 09:43 AM

Quote:

wish it was spring / summer again.
It is :D :D just wish i had my car finished.:mad:

davidimurray 1st December 2011 03:14 PM

Quote:

Originally Posted by spud69 (Post 68481)
Yes you're right Paul, the roadster can be set up and corner weighted to suit the drivers preference. For the track my setup is the opposite with some understeer that i can balance out with my right foot and get some really nice 4 wheel drifts coming out of the corner, the front can really turn in while coming off the brakes into a corner. Really is good fun - wish it was spring / summer again.....:D

AndyH

Spud - any chance you would be kind enough to share your setup with us ????

mark 1st December 2011 07:06 PM

I personally find with my car it would be hard to quantify the setup as it currently is

I did use some inital numbers from locost builders but after driving it i altered things here and there to make it behave how i wanted

Spud has obviously played with these cars more than me so maybe he has some exact settings to start with, but with so many variables such as engine weight, power output, springs/dampers, wheel and tyre choices make everyones car different and behave differently

Im sure you will soon get it feeling "right" once you get it on the road and have a play

spud69 2nd December 2011 10:04 AM

Quote:

Originally Posted by davidimurray (Post 68525)
Spud - any chance you would be kind enough to share your setup with us ????

Mark is right there, a lot of it is just by feel and tweaking it to your own preference and will vary between cars. I've found that a good starting point is:

Front:

Toe in 2deg, camber 3deg (will vary on driving style), castor so that it just starts to self centre

Rear:

Toe in - none, camber 1/2 deg

Corner weighting the car is important with the driver in the car, adjust the springs to get the car even all round then you can balance the car between the front and rear. Adjust the ride height, 100mm front / 125mm rear, to as low as you dare for speed bumps and turn up the bump / rebound to as stiff as our crappy roads will allow. If you go on a track day you can drop the car right down and damper setting as stiff as they go and it will make quite a difference.

Hope that helps.....AndyH

davidimurray 2nd December 2011 10:15 PM

Spud you are a star (and my wife says you're a darling :p ) !!!

Thanks for the setup info - duly recorded and noted!:D

spud69 3rd December 2011 10:55 AM

Quote:

Originally Posted by davidimurray (Post 68564)
Spud you are a star (and my wife says you're a darling :p ) !!!

Thanks for the setup info - duly recorded and noted!:D

Well David i dont know what to say, i'm redder than the post box red of the body we are gelling today.......;) Hope my misses doesn't log on today.

Have a good weekend......AndyH


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