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Old 04-17-2003, 09:26 PM   #1
shirokuma
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Default JDM STi drive part II

Review, Part Deuce

Why part II, didn't you go on long enough already? you are asking. BECAUSE!

No no, there are valid reasons. I want to talk handling now, just handling. And I'm going to start off with some explanations from my point of view on understeer, oversteer and the mythical neutral handling.

Now, we're going to start with one constant radius corner with apex speeds around 50mph when driving well. I'll stick with "around", because you really, really shouldn't be looking down at your speedometer while driving around a corner at speed. Learn to gauge your speed by engine note so that you continue to be a member of the somewhat human species.

The bone of contention with understeer in all it forms has more to do with corner entry than anywhere else. When you are hammering it hard up to the corner and manage to brake correctly and then turn in, the first thing that happens is - nothing. It doesn't turn in and continues straight towards the Pine Tree Of Doom. Time here isn't being measured in seconds, thankfully (except for Corolla's), instead this happens in milliseconds (the amount of time that pucker starts in). Of course, you start easing off the damn throttle a bit, the front end starts grabbing and you manage to wrestle it into the proper line. Once you've apexed correctly (hey, I'm optimistic) you get back on the gas - and of course, the smaller Fir Tree Of Doom at the end of the apex before the straight starts cackling in glee. So you modulate the throttle a bit and finally get straight. The good part of understeer is that if you are way too hot going into the corner, the car is essentially very stable - it just goes straight. So you are given a lot of recovery room to save yourself from a date with bark. Get off the throttle, get on the brakes and you should be able to either stop, or regain control of the front and steer your way out of the turn. This really is a good thing, even if understeer is annoying.

Oversteer is held up to the light and pronounced as part of All That Is Holy but that's not necessarily true. First on the bright points. Upon that same entry to the corner, you turn the wheel and, wow, it turns. No hesitation. No manhandling the car into the correct line, instead you can finesse it to the apex, and even keep the throttle going. Whoops. Now the rear end has decided that it would like to give the PTOD a big smack on the woody lips. So once again, you end up modulating the throttle and also have to throw in a dose of countersteer. Slide through that apex a bit sideways and continue to modulate that throttle till you've passed the FTOD, then once you are straight, hello Houston we have launch! Sounds great, right? But that rear end wanting to move has it's dark points also. While you have more control over the front with oversteer, the rear is a pendulum that does need a certain amount of restraint when you are dealing with it. And if it does go too far, either the PTOD or FTOD gets the last laugh.

Ahh, but we are talking Subaru here, and that means AWD with something a little different. A Sort Of Bad Habit of (past) Subaru's is the counterintuitive oversteer handling. You don't want to countersteer, no matter how much that has been hardwired in your brain for whatever reason. You just carefully modulate the throttle and keep the front pointed in the direction that you want to go. That's because the semi-trick centre differential is going to try and save your ass for you, and it's pointless arguing with it. That is a bright and dark point for Subaru's in general, because once you learn how to use it correctly, it gives them a huge chuckability that's hard to match. So once you learn it, you get quite a few of the benefits of understeer, but also a measure of oversteer control if you learn the ropes. One of the reasons so many people love Subaru's - but they still wish for just a little more...

Now on to Neutral. Now, I hate to say this, but there probably exists no such beast in automobiledom, at least not a perfect definition of it. Neutral is more accurately defined as a car whose handling is in the grey area between mild oversteer and mild understeer. It's simple, you turn in, your front goes where you want it to, and your rear end doesn't play any games with that person you met at the bar.

And this is where we get back to the subject that started this little exercise in creative typing. The JDM STi ver. 8 that I've driven now on a couple of occasions. Now, unlike the Spec C RA, it doesn't belong in the Oversteer column. And, thank god, not the Understeer column either. It's in that grey area. It has just a touch of understeer upon entry, and enough throttle-controlled oversteer upon exit to make things interesting.

On entry to the corner I don't have to fight with the steering. While it doesn't have NSX type R levels of turn in, it does turn in very well. There is just a touch of wash and then it's in the groove with no correction needed. Hold on through the apex, and you can literally feel all four tyres dancing on the tarmac, all four patches shifting around slightly depending on the surface they are on at any millisecond, but never fumbling the ball at any point. It's a lovely feeling for control freaks, all input to steering wheel, brakes and throttle have instant, defineable feedback. It's also not harsh in any manner, actually feeling quite good. You not only get to have incredible fun driving the corners, but you can do it as long as you want without feeling like a linebacker's practice dummy. One aspect of this control is the way the engine responds to throttle inputs, of course. The pedal is just firm and linear enough that you know exactly where you are with it. Modulation is a snap, with no bouncy feel to inputs while at the limit mid corner.

Now, the initial feeling is that this is due to the DCCD-A differential, but that's not entirely true. The differential comes into play when it's got something to work with - power. It does a lovely job when you are under power in mid-corner, but the turn-in at corner entry has to do with something else. That's the basic setup of the suspension, and that is indeed different from before. While the standard STi does not have the front end geometry of the Spec C RA, I do suspect that it has been modified from previous models. But the major modification in suspension is in the rear end geometry. It's been revised to cure the mild toe problems under compression in the rear. The result is that the rear tyres keep in contact with the road much better when under load/unload (inside rear/outside rear mid corner). This added control in the rear not only increases overall traction, but it also allows Subaru to move the front end handling far closer to neutral. The overall package ends up being very well balanced. I can say this because I drove a B4 Legacy with many suspension upgrades, including the ALK modification which does increase turn-in and control by a large amount. However, it still has the older-style rear end, and you do have to work the steering a bit more on corner entry to get where you want to go.

The new STi is a supercar for the masses, really. There are very few cars where you can get up to the limits so easily and in such comfort, without being smacked around for your boldness when you do mess it up. I can only wish the more manufacturers would step up to the plate with such a package at such an attractive price.

Paul Hansen
www.apexjapan.com
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Old 04-17-2003, 10:28 PM   #2
944 turbo guy
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Default As always,...Dr. Paul has spoken...

Thank you Paul for not only making me count down the weeks before the Sti is released, but the DAYS. !!

Great writing !!

944 turbo guy
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Old 04-17-2003, 11:26 PM   #3
P2x
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Default

Paul, I wish you'd update apexjapan as often as you bestow us these great messages! I can't help but browse your site once a day on the off chance of an update despite them being too few and far between IMHO...

Keep it coming!
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Old 04-18-2003, 01:15 AM   #4
shirokuma
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Default

Sorry about that, but I'm stuck in a strange cycle of day job work, and selling out to The Man (well, some aussies) on a lot of the articles that would have gone up. Of course, if they don't speak up soon, there will be a huge library of photos from the STi vs. Evo (and Legacy) Hypermeet up!

Cheers,

Paul Hansen
www.apexjapan.com
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Old 04-18-2003, 08:39 AM   #5
mike of pa
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Default JDM STi drive part II

Paul,

Thanks for another great bit of info and writing.

One thing I haven't seen-- what does Shirokuma mean?

Thanks,

Mike
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Old 04-18-2003, 12:28 PM   #6
kage
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That would be white guy, wouldn't it?
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Old 04-18-2003, 01:08 PM   #7
robmarch
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Default

nice writeup. I'm also counting the days.
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