dc2R track setup: lets share some info?

[freakie]

Hi guys,

I would love to hear what you guys have to say about setting up a car which has adjustable suspensions/sways/ties etc.

I speak to many people, and a few of my tuners guys run surprisingly soft spring rates and settings. I've always been soft myself in terms of suspensions, but spoke to one guy who runs 22kgs at the rear of his car! Im surprised because i run a maximum of 6 kgs....

Any ideas/hints to share? Ive found that running lower tyre pressure with more bump and less rebound and soft suspension springs gets me alot more traction of the zebra zones and therefore earlier acceleration.

Dan

[T-BaGGeR]

I tend to stay off the ripples. Hitting them hard messes the alignment and I think it will only shave off a few 10th's of a second. It also upsets my car big time.

Turn 3 at Wakie is a killer if you hit it in the wrong place. Smashes my bumpstops.

[mofo]

i guess it all depends on what track ur on..
like i would use a softer setting if i was at wakies due to the layout of the tight corners and the bumpiness.
and as for eastern creek i would tend to go for a med/hard setting as the track is smooth and a few fast corners.

then again, it all depends on the driver and how they like the feel of the car.

[freakie]

yeah that is exactly the information I'd love to hear mofo.

I've only done 2 tracks ever and I'd like to get a feel for other tracks. If I can get to Eastern Creek, Id love a hand setting up the car!

[tinkerbell]

i just put my 12k springs back on the front and moved my previous front 8k's to the rear to replace the 6k's

this is becuase i am going to Eastern Creek, whereas i usually race at Wakefield which is bumpier...

[euGeR]

I have the following theories which by no means is a professional opinion and is information/behaviour that I have recorded from my own testing:-
(feel free to correct me if I have mis-perceived anything)

-------------------------------------------------
One end of the spectrum - think of this as a bell curve.

- Soft side Spring Rate + roll bars to stop pitching
--> better for bumpy conditions keeps the tyre on the road better in bad conditions
--> comfort
--> depends on desired ride height -- with soft, you can't go to low
Some will say use an absorber that has a higher damper rate, but I think if you use a softer spring, it increases the chance of blowing the shock.

--> Braking - the Front will tend to dip and the Rear will tend to lift, so the car will pitch forward and down. This is good and bad. You need the dip but you can do without the lift as it increase the chance of locking the brakes..

This could be desired for those who like to trail brake. You can get a nice turn-flick under brakes.

This may not be desired as you may get squirmy under brakes (confidence of the driver)

--> Acceleration - more weight shifting to rear - could lose traction on acceleration/exits (take into account Rake)


- Stiffer spring rate
--> better for good road conditions. You can gain stability and control

--> The lower the car the stiffer springs and possibly a shorter stroked damper - you should go stiffer because you dont want to be hitting the bump stops

--> one thing I would recommend is that the stiffer you go, you should look into adding additional camber/castor.
--> this can decrease braking distance or increase the need for better brakes
--> keeps set up more consistent on acceleration deceleration -> less movement when weight shifts.

You get more stability but if you dont negate the higher rate with camber/caster, my feel is that may lose traction for the gain in stability. I see the difference in tyre wear.

Example:
I've used 3 set ups on my DC2R
OEM
12kgF/8kgR
14kgF/12kgR

On track

OEM set up --> tyre wears approximately 3-4 inches of the outside. This indicates good tyre contact patch

Each time I have gone up in rates (sussy change only) the wear has gone closer and closer to the outside edge.

With the 14kg F and 12kg R - my tyre wears about 1inch from the outside edge. I believe this is the contact patch. It has decreased but the car is extremely stable. This has been good and bad. Good that my lap times are consistent lap after lap, bad because I was expecting a decrease in lap time but I didn't get it (frustrated) - However, the two things I need is a change in driving style and an improvement in the contact patch.

The max camber I can get by lowering is around -2.5 to -2.8 degrees at the Front and about -2 at the rear. From my tyre wear, I'd need to go to about - 4degrees, which is about what BlackDC2 runs. This would be spot on

RAKE and Ride height
- are important factors in selecting the desired characteristics.

Rake is defined as the R to F slope.

Theories:
Generally with FF, you need to keep some weight on the Front. To high at the Front and you could get good turn in and better rear stability but shit traction when exiting the corner because there's no weight on the front.

The higher the rear means more weight at the front - this can create understeer because the more weight you have, with the same factors, you have reduced your traction limit - to which when you break, the car may not steer - creating understeer or oversteer.

Ride height determines the centre of gravity and roll centre - these can determine the cornering speeds and contact patch of the tyre. Sways can alter the roll centre which in turns affects the "change" in suspension geometry. Basically the less movement, the more accurate the geometry.

You may increase the "capability" of your cars traction by lowering the centre of gravity. Remember, by lowering, you only increase the capability and not the actual traction and there's other things you need to take into account and modify.

Example
OEM - traction point limit 1G
Lowered - capacity 1.3G but actual is still 1G


------------------------------------------

From the experience, the trick is to find what you like then measure whether it makes you fast or faster. To be honest, if you slap on sussy without setting it up, you'd probably gain 2 seconds. It's those little microsteps after that are frustrating

It is a pain in the arse to play around with. Simply because you need track time or some way of consistently measuring for changes and monitoring for improvements. This is why people often want something that is proven, but where's the fun in that?

In summary, it is about finding a set up that suits your level and driving style. The stiffer you go, there may be other changes that should be done that we often miss. The main benefits of a simple "stiff" change are stability and control. One thing with the stiffer chassis/sussy set up is that it is less accomodating to mistakes.

- question for the mods - is there a rep point system?

[T-BaGGeR]

tb

[T-BaGGeR]

The higher the rear means more weight at the front

Hey Euge, I was under the impression that raising one side increases the weight on that corner. This doesn't apply if you raise one end evenly?

I saw that nihon video about tuning sussy that you posted ages ago and it did say that lowering the front increases the weight on the nose but from doing corner weighting, that theory doesn't work?

[euGeR]

Hey Euge, I was under the impression that raising one side increases the weight on that corner. This doesn't apply if you raise one end evenly?

I saw that nihon video about tuning sussy that you posted ages ago and it did say that lowering the front increases the weight on the nose but from doing corner weighting, that theory doesn't work?

Hey TB,
If I understand what you are asking, it would like the following:

If you raise FL , then the FR-RL cross corner would have the increase in the proportion of weight.

Corner weighting is to ensure that the cross-corner weight of the car is balanced and so it will turn left and right evenly.

That is. FR-RL weight to FL-RR weight.

You can be "corner balanced" at different heights and rakes.

I'll add corner weighting in, but usually you'll do it after you've found the settings you want because at about $280 a pop, you probably don't want to be changing it after.

I've had my set up corner weighted twice. Then second time (after I re-adjusted), I almost had it spot on - 3kgs out with me in the drivers seat - which isn't considered much.

[tinkerbell]

to euGeR

[euGeR]

to euGeR

haha ... i think I may be off topic for freakies post ..

[freakie]

I think the info is great! but does anyone want to share tyre pressure in relation to say bump and rebound.

also height to turn in relations?

[dc2rrrr]

Whats the best wheel alignment settings to use? One guy told me to toe the front out 2mm and have rear at 0? At the moment im all at 0. What will give me more track grip??? Thanks

[rG`]

With my front at 2mm and rear at 1mm the car corners great, but loses max speed down the straights (plus its a garage queen).

Toe-in creates more understeer and toe-out increases oversteer.

Toe-in = the front of the tyres are closer together than the rear.
Toe-out = the rear of the tyres are closer than the front.

Bear in mind that a vehicle with too much toe will generate excessive friction and use up tyres and fuel much faster.

[T-BaGGeR]

Toe doesn't affect track grip so much, toe controls more of the rotation of the car/turn in.

I haev toe out at the front -2mm total

and toe in at the rear- 1mm total