PDA

View Full Version : i went for a short spirited drive



rammsteinmatt
08-29-2005, 10:12 AM
so i went driving with a friend (who had never been in an evo before)

so he was scared to death, but i was far more relaxed and cool about the situation. i noticed that it rides pretty well except on decreasing radius turns where it understeers, quite bad may i add (i didnt cross the line, bad, but it wasnt good)

so i was wondering if i put it in snow or gravel will more torque go to the rear, and hopefully remove some/most/all of this understeer, and if changing to this setting will have adverse effects while driving on tarmac?

i know i need to take it down to RRE for alignment and rear swaybar/bushings, but thats $500 that i cant really afford to spend right now

my friend asked if i have ever drifted the evo.............test ride over. there are supposedly no stupid questions, but this one was pretty close

inline4g63
08-29-2005, 10:33 AM
well that is a stupid question on a stock or slightly modded evo. But with enough hp, it is posssible to drift.

SSwest
08-29-2005, 11:06 AM
BS, I have friends that can vouch, even three deep at times in an open parking lot...around the pole several times...flash and Tback is all I got

Macky
08-29-2005, 11:12 AM
BS, I have friends that can vouch, even three deep at times in an open parking lot...around the pole several times...flash and Tback is all I got

+1

ultraflip
08-29-2005, 11:31 AM
what's flash and tback?

Macky
08-29-2005, 11:48 AM
what's flash and tback?

flash

http://images.google.com/images?q=tbn:E-qLa1o77jcJ:www.cyberphoto.se/blixtar/3600hs.jpg


tback

http://images.google.com/images?q=tbn:wd0LHbugAN4J:nagoyajin.blogzine.jp/weblog/images/tback.jpg

ultraflip
08-29-2005, 11:50 AM
lol.. shank

earlyapex
08-29-2005, 06:14 PM
so i was wondering if i put it in snow or gravel will more torque go to the rear, and hopefully remove some/most/all of this understeer, and if changing to this setting will have adverse effects while driving on tarmac?

There is never more than 50% power going to the rear wheels. From what I have *heard*, snow has most of the power going to the front in good conditions, and the car figures it out from there.

Overall, the ACD is constantly changing power to every wheel depending on conditions, no matter what the setting, the settings, I *heard*, only change the algorithms used.

SSwest
08-30-2005, 12:28 PM
what's flash and tback?

flash

http://images.google.com/images?q=tbn:E-qLa1o77jcJ:www.cyberphoto.se/blixtar/3600hs.jpg


tback

http://images.google.com/images?q=tbn:wd0LHbugAN4J:nagoyajin.blogzine.jp/weblog/images/tback.jpg



BONG!! thats awesome

rammsteinmatt
08-30-2005, 07:14 PM
so i was wondering if i put it in snow or gravel will more torque go to the rear, and hopefully remove some/most/all of this understeer, and if changing to this setting will have adverse effects while driving on tarmac?

There is never more than 50% power going to the rear wheels. From what I have *heard*, snow has most of the power going to the front in good conditions, and the car figures it out from there.

Overall, the ACD is constantly changing power to every wheel depending on conditions, no matter what the setting, the settings, I *heard*, only change the algorithms used.


then why is it easier to *drift* in snow mode?

earlyapex
08-30-2005, 10:53 PM
then why is it easier to *drift* in snow mode?


Mitsubishi ACD - “active centre differential system” ACD is the new major technical feature that distinguishes the previous Evo 4-6 models from the new Evo 7 ACD is an extension of the technology used in for the anti yaw control systems (AYC) employed in various previous Mitsubishi models in the rear axle position. The ACD system comprises an electric motor, driving an oil pump which pressures an oil reservoir to a peak 16-bar pressure. This reserve of “SYSTEM PRESSURE” is fed to the piston of the ACD plate pack via a modulation (proportion) valve. The modulation valve is software controlled by the “ACD ECU (electronic control unit).

The control inputs for the ACD electronic control unit are

4 wheel speeds
G force both lateral and longitudinal
Throttle position – a variable value
Braking state - on or off
Steering angle – neutral position (straight ahead) and off centre position provided by 3 optical inputs generated by rotation of the steering wheel.
Handbrake state – on or off
System pressure – Hydraulic pressure state
Mode switch state – to select Gravel, Snow or Asphalt software strategy (maps)

The “Gravel” and “Snow” software strategies are similar; Gravel has the highest ultimate locking value of the two. In “Asphalt” mode a unique software strategy is employed
The system is technically far superior to the preceding Evo models VC centre differential systems. The centre differential performing well and able to limit front to rear axle “slip” on full throttle to a mean of around 0.6% on a slippery gravel surface. To put this in perspective, a good condition VC unit on a Evo 4,5 or 6 would struggle to be better than 30% aggregate slip value, which is traction going out of the window.
Pressure can be introduced and lost within the ACD system at speeds surprisingly close to WRC car standards, which has allowed Mitsubishi engineers to use a complex and sophisticated software control strategy.

Using sensors, ACD regulates slippage in the 50:50 torque-split diff from free to lock-up according to speed and load. So under hard acceleration the ACD moves towards lock-up to put more torque down on the road for stronger traction, but with rapid steering inputs it operates virtually like an open differential to improve steering feel and response.


Another advantage of ACD is that it is adaptive to road conditions. Choose "Tarmac" mode and it will allow more clutch slippage, hence torque transmit freely from one end to another. "Gravel" mode tends to limit the difference between front and rear torque split so to minimize tyre slip. "Snow" mode nearly lock up all wheels to prevent from any wheel spin.

trinydex
08-31-2005, 03:52 PM
that means that acd give you a certain amount of lock up in 50 50 mode depending on which setting you give it. where in gravel you lock up the soonest and on tarmac it lets you play around with the accel and shit before it throws the 4wd on you.

rammsteinmatt
08-31-2005, 04:23 PM
but the simple fact remains:

when in snow mode, it is easier to get the back end out. it has been physically proved

earlyapex
08-31-2005, 04:39 PM
but the simple fact remains:

when in snow mode, it is easier to get the back end out.* it has been physically proved


probably because more power is going to the rear than normal, but not more than 50%. So if in Tarmac, lets say (and i am pulling this out of my ass) it's usually 60f/40r, in snow, from above , it sounds like full 50/50 lock, so you have more power going to the rear than usual.

evomrguy
08-31-2005, 05:48 PM
It is easier to fling the ass end around with the snow mode on, but in my experience it feels like you have less control over whats happening than when in tarmac.

Tofurky
09-07-2005, 06:52 PM
well that is a stupid question on a stock or slightly modded evo. But with enough hp, it is posssible to drift.


or some hefty trail braking

gt40
09-07-2005, 07:24 PM
I like my 03' and my quaife :twisted:

nj1266
09-08-2005, 12:19 AM
i know i need to take it down to RRE for alignment and rear swaybar/bushings, but thats $500 that i cant really afford to spend right now

You do not have to spend that kind of money on an Alignment and rear sway bar. RRE has a special on their sway bar for $145 and you can get a race alignment for $80. I know a shop in Gardena owned by Darin Nashimura called West End Alignment. He does the race alignment on my SE-R Cup Car. The guy is great to work with and he knows what he is doing. He used to work at a very famous alignment shop, Johnson's I believe, and a few years ago he openned his own shop. He can either give you the alignment that you want or he will suggest alignment specs based on your needs.

Evolution.VIII
09-08-2005, 04:04 PM
Thanks for the info earlyapex, very informative!

trinydex
09-11-2005, 04:37 PM
I like my 03' and my quaife :twisted:


word... cept mine is an 04 which is better :P

trinydex
09-11-2005, 04:40 PM
but the simple fact remains:

when in snow mode, it is easier to get the back end out. it has been physically proved


btw how was this physically proven?