De Deon versus IRS?

[Matt Seabrook]

out of interest - on track how consistent are your laps times ??

On a good day lap times can be within 1/100s normally 3/10ths is more normal looking at the data logs.

[gixermark]

sorry mark - my questions were aimed at Carl..

Good consistency by the way - I am now normally within 0.2 or 0.3 in any session on clear track....  consistency i think is the key when you are setting up or making changes...

[Matt Seabrook]

sorry mark - my questions were aimed at Carl..

Mark

[gixermark]

oops  

sorry mate.....

[stu999]

The live axle supplied by Westfield generally comes with a touch toe out due to the brackets being welded on to the rear of the of the axle for the trailing arms. This can give a problem with power on oversteer out of a corner. My race car now runs a touch toe in and about a 1/4 deg neg camber. This makes the rear end planted but given the choice I would have had IRS. The De Doin has advantages over the live axle but given the three its got to be IRS

But would you be any faster?    

[Matt Seabrook]

Good question only way to know would be to convert what I have. My gut feeling would be yes at my local sprint as its mostly broken tarmac and it should put the power down better than I already can with live axle. On a smooth race track may be not. But with not being able to give the car more neg camber the tyres may start to tuck under a little and this will reduce tyre contact patch thus reducing grip.

[Carl]

The main issue is the light weight and small dimension of the car means that with IRS accuarate camber control is impossible to achieve.

With De-deion / live axle the camber (and therefore grip levels and break away characteristics are fixed) regardless of vehicle weight / load.

[Matt Seabrook]

As has been said perfection will never be possible but owning both a live axle and IRS car the IRS car is more planted when the surface is less than perfect.

[salexander]

A de-dion setup is simply a live axle with the diff seperately mounted to save weight.  Weight and ease of adjustment aside, I can't imagine there is much overall difference in performance between the two.

[nikpro]

Tere is really no debate here:

A well designed IRS will always be better than a well designed de-dion - FACT

The debate is:

Is 'X's' IRS better than 'Y's' de-dion?

[stephenh]

There is another potential disadvantage of de dion compared with unequal length wishbones; the roll centre is generally higher than ideal with the de dion tube, whereas much easier to get it where the chassis designer wants using wishbones.

[conibear]

The debate is:

Is 'X's' IRS better than 'Y's' de-dion?

And the answer is  

[iiyama]

X+Y=Z!

[pistonbroke]

here's me thinking de IRS is de Tax man and de Dion Warwick is de singer  

[opelgt73]

This is a very old thread but it's the only thread I can find that has to do with what I need to know about.

 

The caterhams is very close to weight and power to what my opel gt will be when I'm done.  It has a solid axle right now.

 

It's getting a Ford 1.5 3 cylinder Ecoboost.  I'm either going to use a t5 with a 7.5 or 8.8.

 

The radical option is using a Volvo 360 m47r transaxle or a Porsche 928 g31 transaxle.  If I do that, I would either use a Volvo 240 dedion suspension but very heavy or I could use the IRS from the Porsche 928.

 

I know generally an IRS is better but as discussed in the thread already, the dedion is very good if not better in a much lighter vehicle.  It also seems the caterhams setup might be easier to adapt to my car and it it might be lighter compared to ones in production cars.

 

The car is a daily driver but I'll be taking it to car shows as well.  I'm on the West Coast of Canada.

 

I'm not 100% on which would be best to go with.  There are so many options for big engines with heavy parts for lots of power but not really anything for fast cars that prioritize lower power and low weight.

 

I would really appreciate your advice on irs or dedion.  Ive read there are kits available for both for caterhams but I haven't found anything I could buy close by to me that comes with everything I need.

 

Thanks and merry Christmas