View Full Version : 1/4 mile with DCCD


Tasberley
16 June 2004, 14:09
Best setting for a type r in relation to the dccd for quarter miles.....

any help or advice pls..


tas

Simon Lines
16 June 2004, 14:26
50/50 for the launch then as free as possible to cut drag

Cheers

Simon

achad
16 June 2004, 20:40
Simon,
Would this apply to the DCCD-A system? Or is the Auto mode clever enough and quick enough to first maximize grip and then minimize drag?
Apart from the cool/ fun factor of the manual mode. I'd like to know whether you and/ or anyone elce uses the DCCD-A or prefer to manually agust it?
I'm hoping to take some driving tution soon to try to maximize my enjoyment I'm already having with my new WR1:D Oviously I'll have a play with the DCCD while I'm there but if there's an advantage to be had using the manual mode, I can spend more time doing that:)

Thx
Anthony

what would scooby do
16 June 2004, 21:18
yup - I did a few runs at santapod and had 4 wheel spin at the start with DCCD open :D

greasemonkey
16 June 2004, 21:48
Simon,
Would this apply to the DCCD-A system? Or is the Auto mode clever enough and quick enough to first maximize grip and then minimize drag? I doubt the automatic mode was mapped with drag racing in mind. ;)

Provided you keep the car in a straight line and there's good grip under the tyres, it should open up, yeah.

Apart from the cool/ fun factor of the manual mode. I'd like to know whether you and/ or anyone elce uses the DCCD-A or prefer to manually agust it? I've little experience with Subaru's version of automatic control, but, in general terms, you will likely have more luck leaving the computer to sort it out than you will sticking it in manual.

The automatic mode is constantly modulating the locking force applied to the centre diff according to steering wheel position, throttle position, brake pedal pressure, wheel speed, longitudinal and lateral g, road speed and probably other parameters besides. There's no way you could replicate this by twiddling the thumbwheel while trying to drive the car fast!

ScoobySport (SdB)
16 June 2004, 23:09
greasemonkey

I think you may be mistaken on the DCCD-A. As I understand it doesn't minitor steering wheel postition, brake pedal pressure or longitudinal g.

It does however monitor throttle postition, lateral g, wheel speeds (and possibly infers road speed based on the wheel speeds).

---

In terms of dragging, Simon Lines has it spot on.

Lock it up completely for launch then wind it fully open as soon as the car is off the line, stable and not likely to wheelspin.

All the best

Simon

greasemonkey
16 June 2004, 23:54
greasemonkey

I think you may be mistaken on the DCCD-A. As I understand it doesn't minitor steering wheel postition, brake pedal pressure or longitudinal g. I stand corrected then Simon, it's not as clever as I thought it was. Could've sworn someone told me it had a steering pot, at very least, but not to worry.

Point remains though that in a circuit/fast road scenario, no driver (even with a lot of practice/experience) would be able to replicate its responses while actually driving the car.

ScoobySport (SdB)
17 June 2004, 00:22
Agreed on that much, it is impossible to beat a computer for response, but.. if the computer isn't programmed to do what you want it to do, then you're potentially better off on your own.

Not commenting directly on the DCCD-A as I don't have any solid time in the car so can't really comment, more as a general principle.

Cheers

Simon

ALi-B
19 June 2004, 12:27
I wonder if in the future someone will come up with a mappable DCCD-A "chip" for drag racing, track use or hill climbs etc. LOL :D

TonyBurns
19 June 2004, 18:41
Id personally leave it to the computer, you wont have time to do anything with it whilst trying to grab 2nd and 3rd gears as they are so close together, ie your still stuck in 50/50 split, but the computer should compensate for straight line accelleration.

Tony:D

greasemonkey
19 June 2004, 19:40
I wonder if in the future someone will come up with a mappable DCCD-A "chip" for drag racing, track use or hill climbs etc. LOL :DFuture? That's been available for a while. A number of aftermarket ECU's can handle diff control, TEG do a fairly simple one, I've made one, and so, probably, have others.

I believe it's also theoretically possible to remap the Subaru controller.

ScoobySport (SdB)
19 June 2004, 23:05
ROFL @ Ali-B :D - touche!

We are indeed developing a fully mapable active diff ecu based on the latest WRC technology.

Obviously the actual diffs will not be the same as on the WRC car, unless you want to spend about 15K a diff! :D which I doubt.

It's just not necessary for the road, and in-fact would actually be a disadvantage in many ways - including noise, wear, etc.

But.. the logic and the way it behaves / is mapped is based directly on the experience gained at the top levels of WRC so the results are going to be spectacular.

The development version we have now is a whole lot of fun, but it's not there yet - it's.. shall we say, a little bit of a handful :D

Looking forward to showing it to everyone though. :)

All the best

Simon

ScoobySport (SdB)
19 June 2004, 23:08
PS.. and greasemonkey is right.. you can't do anything powerful unless you have a whole lot more inputs.

Daz34
20 June 2004, 23:07
greasemonkey

I think you may be mistaken

:eek:

greasemonkey
21 June 2004, 00:31
Tis true Daz, I am human after all! :D

Having said that, I was going by what someone had told me, not seen the DCCD-A gubbins in bits yet. Always a dodgy deal trusting the word of a Subaru UK staffer! ;)

Simon Lines
21 June 2004, 09:08
Id personally leave it to the computer, you wont have time to do anything with it whilst trying to grab 2nd and 3rd gears as they are so close together, ie your still stuck in 50/50 split, but the computer should compensate for straight line accelleration.

Tony:D

No, sorry but this is not correct, the difference between "auto" and locked 50/50 can be as much as 1200 rpm on your launch speed! In auto it has a marked tendency to "spin-up" the fronts, in 50/50 it "hook's-up" properly and you'll need over 5k to get a bit of slip (depending on surface mu of course)

Just set the wheel to the 50/50 setting and flick the auto/man switch after your in 2nd gear.

Cheers

Simon

No offence intended Tony


LinkBacks Enabled by vBSEO 3.0.0 © 2007, Crawlability, Inc.