Ultima Group C

[Racingroj]

Martin
Have you posted any info already on the changes you have made? Did Steve Smith do any work on your car?
Thanks
Roj

[V8Dom]

a truely fantastic car

http://www.pistonheads.com/GASSING/topic.asp?h=0&a...

Edited by V8Dom on Monday 23 February 19:38

[Racingroj]

Thanks Dom
I would like to know what changes were made to the standard car to make it handle that much better without spending an arm and a leg.

[CJulian]

I would also be interested in understanding what suspension changes might improve handling but retain street-ability in the GTR. Were the wishbones extended and repositioned? This is one are that I have been hesitant to toy with.

Thanks, Chris

[macgtech]

CJulian said:

I would also be interested in understanding what suspension changes might improve handling but retain street-ability in the GTR. Were the wishbones extended and repositioned? This is one are that I have been hesitant to toy with.

Thanks, Chris

We redesigned the frontend of the car at the beginning of 2014 and addressed the steering geometry with our race specification wishbones and uprights and saw an 8kph cornering speed increase in mid speed corners in back to back testing. Next step is the chassis which is in progress which will further improve the response of the handling and the level of overall grip.

[ultimass]

Hi,

Steve Smith built this car from scratch.

here are just a few of the mods which have improved the handling:

chassis is far stronger and a lot stiffer than the standard one.

the front wishbones are longer and runs with 295 wheels on the front.

the fuel tank is behind the seats (where is should be for safety and balance of the car).

it has a completely flat floor with a diffuser at the rear.

the front and rear clip have been lightened and hinged so can be removed in seconds.

the rear wing is custom made and active, controlled from the steering wheel (also has the capability to be programmed).

the damping is Nitron adjustable for bounce and rebound.

the ride height is lower than standard (front suspension can be raised hydraulically for speed bumps etc.).

Anti-roll bar on the front - there is hardly any body roll around the corners.


I can go on and on and will post a more detailed description in the ad.

Martin.

[Racingroj]

Thanks for the info guys, a lot to think about there. I'm thinking my cheque book isn't going cope with my wish list.

[CJulian]

Could someone here post the contact info the outfit that offers the revised front wishbone setup?

Thanks, Chris

[UltimaCH]

Chris,

If you are talking of "macgtech" just above, then try contacting Jonny at the site: http://www.macgracing.co.uk/

[macgtech]

UltimaCH said:

Chris,

If you are talking of "macgtech" just above, then try contacting Jonny at the site: http://www.macgracing.co.uk/

Best to contact me on email at jonny(at)macgracing.co.uk

[The Italian]

CJulian said:

I would also be interested in understanding what suspension changes might improve handling but retain street-ability in the GTR. Were the wishbones extended and repositioned? This is one are that I have been hesitant to toy with.

Thanks, Chris

If I am not mistaken, the factory tried this and they said it was no improvement over stock design

[macgtech]

The Italian said:

If I am not mistaken, the factory tried this and they said it was no improvement over stock design

It is worth reviewing our previous post...(7 posts up)

[V8Dom]

ive been in Martins car, and the front grip is 100% better,

the factory car runs standard width front tyres with long arms

. Martins car has massive front tyres... the longer longer wishbones allow the tyre/wheel to pivit in the centre rather than on the inside of the wheel like the standard car, this means even with massive front tyres, the steering doesnt feel heavy

ive promised Martin some photos of the car for when he advertises it, so ill post a few soon

[anonymous-user]

Kingpin offset and tyre coneicity is just one factor though. Most racecars these days run large amounts of static castor (to give camber gain during turning) and hence need power steering! Once you have power steering, you can move to a steering geometery that is optimised for grip. One downside, is that often this results in significantly non linear steering weighting changes with lock and lateral load & tyre deformation/slip etc. For a race car, where the driver will learn the circuit by doing multiple laps this is less of a problem than for a road car, which needs to give the driver good and repeatable feedback about front end grip under very changeable and often unique conditions (you don't often go round the same corner twice after all)

[macgtech]

V8Dom said:

the longer longer wishbones allow the tyre/wheel to pivit in the centre rather than on the inside of the wheel like the standard car, this means even with massive front tyres, the steering doesnt feel heavy

And crucially, keeps a far more consistent tyre contact patch.

[Ult-Jim]

V8Dom said:

ive promised Martin some photos of the car for when he advertises it, so ill post a few soon

Photos - yes please Dom. Even though I have seen Macgtech's race car I've always struggled getting my head round the physics & engineering thought of this set up.

[GT40LS7]

Hi Chris,

I like very much the way how you approach the problem, meaning where you are and where you would to be and the way to use Solids work.

Please keep documenting your project as it is so sounding to the whole Ultima community.

If i was enough lucky, i would dive in solids works and modelize the whole structure of my Ultima as soon as possible and would be glad to share our experience in MP.

Live strong and with passion.

Jérôme

[CJulian]

Here's a few recent images of the GTR. Mostly cardboard, wood, and plastic. Your constructive comments would be appreciated.

Thanks for all the support.

Chris

BTW- that's my neighbor that's been carving most of the wood...

[macgtech]

CJulian said:

Here's a few recent images of the GTR. Mostly cardboard, wood, and plastic. Your constructive comments would be appreciated.

Thanks for all the support.

Chris

BTW- that's my neighbor that's been carving most of the wood...

Looks great! I know how difficult this kind of thing can be. I think with some clever design around the rear lights this is going to look really good.

[deadscoob]

Agreed. Proper group c, looks great.