In short it means you applied too much throttle in this corner.

Nice. So we have again rear bias car.
So my sentencewas right.

I know it was not you Mr AWD disagreeing with me. I just mixed my replies in one post.

You guys need to seperated the corner into sections: entry (trail brake), mid-corner(steady state) and exit (acceleration). Now talk about types of differentials and there effects on cornering! A Torsen type for instance (in the front) will increase understeer on the way in then it will reduce understeer on the way out. The advantage (as Mr.AWD stated) of a 1-way or 1.5-way (or active) diff is that it is freer on entry (less understeer) then directs power to the outside front tire (buy increasing locking) during acceleration to reduce understeer mid-corner to exit.
If you are using a Torsen you can adjust the suspension (toe-out in rear etc.) or change your driving style to compensate (more trail brake or maybe a Scandinavian flick!) to get the thing to turn in.
A 1 or 1.5 way (better still a Cusco 35/65r) center diff will go along way to curing understeer by "freeing" the car up on the way into the corner, it may make a bigger difference than changing the front (I guess that's for our "Post EVO Arrivial Discussion"!).

P.S. I know there is no active front diff avaliable (to you and I!) just using it for the sake of discussion

The best part of this one is that you didn't!! Because of this kind of behavior, you can use it for additional rotation of the rear end and help your front with the cornering effort. That gives you lower slip angles, which goes back to more traction as well. Also, it points your car into the direction where you (supposedly) want to go, so you can accelerate quicker out of the turn!

Fedja

Hmm, this comment looks so familiar... oh it is you chronohunter!!

Have a or


Fedja

This is why the Suretrac front diff on the subaru STi is so good. When your car is under brake or you are cornering, the suretrac acts like an open diff. When you apply throttle, its acts as lsd. The slip is proportional to the torque input.

The Subaru guys get it right again!

Agree here. But it rather means you need something like DCCD to send less torque to front and still change a slip angle on rears under power. And if you lift a wheel with Suretrac you have no drive at all. This is how it works.

If you are talking about a little helpful oversteer from mid-corner on I'm with you 100% however...if you are (still) talking about "powering" all they way through the corner you are cornering slower than you could be. Remember your front tires are relatively light meaning your max cornering g is limited by the low vertical load on the front tires. Your front and rear tires may be at perfect slip angles (lets say ~7deg rear and ~5deg front for nice mild oversteer) but your cornering g is overly dependent on the only loaded tire on the car, the outside rear. If the car were balanced (equal vertical load front to rear on a car w/ 50/50 weight distribution) and the tires (both outside) were at peak slip angle your car would now be at true peak cornering g.

Bottom line: you cannot corner at true max and accelerate at the same time

That still remain to be seen!!

Fedja

Exactly.
Where are all this comparos!!!!

Well this would be true for the perfectly balanced car. But for the EVO and most of those with a very heavy front end, it is not completely accurate. If you are careful with the throttle application, you can still maintain the balance between the weights on the two outside wheels and make it work.

I think we are on the same page here. Still due to the imperfect weight distribution on our cars (hey, at least on the one I drive every day), we can actually push thing on one side more than 50/50 cars could. We both know that the goal here is to be the fastest through the whole thing. We are also on the same page regarding the traction circle as well. So, if I say that what is important here is not to have max cornering nor max acceleration, rather then the combination of those two so the result of the two together stays bellow the max available, I believe we both should agree as well.

The point is that you don't have to have the max cornering for the fastest time around the turn. You can surely sacrifice a bit here and there and compensate it with an extra acceleration that you can get. That way, you can follow the traction circle the closes and have the best results over all!!


Fedja

Is it a moment where front LSD helps to put power down better?

I think that extra acceleration should happen in the rear, not in the front (kind of like the RWD cars do). That would rotate the car even more (more than what would front wheels do by them self), so less steering angles are required in the front, which makes car to earlier gets into the position to use all four wheels and get out of the hole! That is where the front LSD would help!

Also, by having an extra rotation in the rear, you are kind of getting over the traction limits too. The good thing is that having that happen in the rear, helps car to turn better, while the same thing in the front would just push the car out. That is why you can't have any extra power on that outside front wheel, but it is OK for the rear (of course, if you get too much in the rear, car will loop around you, so... )!

Fedja

According to the press information . It has a viscous coupling and bevel gear design that splits torque equally 50:50 between the front and rear wheels.

The balance is the key. Because the car has a front weight bias it requires more vertical load on the front than a car that is more evenly balanced (BMW) or rear biased (MR-2, Porsche). that means more trail brake (therefore later throttle) than the balanced car. To get max cornering the vertical load on each tire should match the weight distribution. This is up untill the point of acceleration when we have started to unwind the wheel (therefore less cornering force=grip avaliable for acceleration). Yes I get on the gas a little later but the exit speed is actually higher because I started accelerating from a higher speed and remember I had to brake less because my entry speed was higher and my apex speed was higher as well. Make sense?

In general terms: The more the front weight bias the more trail braking is needed and the later you car accelerate. That is why race cars (purpose built have a ~40/60r bias, awsome braking as well!) have more weight in the back. We need to drive an EVO into a corner like a front wheel drive car because it has similar weight distribution! But we can rocket off the corner like nothing else!

As far a the sacrifice you make to get on the gas sooner that is done with the line through the corner. In slow to medium (up to about 3rd gear) we use a latter turn in and apex so we can get the wheel straighter sooner (and therefore accelerate sooner). about two thirds of the turning is done in the first half of the corner to maximize acceleration off the corner (if it leads onto any sort of straight). Top of 3rd and above you use more of the maximum constant radius and you do indeed pick up the throttle nearer the turn in point (depending on balance of car and actual speed of corner, generally the faster the corner the earlier you pick up the throttle). Your turn

Well hey, this is the most interesting thread in some time! Good job, people. Mr. AWD, what you are saying makes a certain amount of sense to me as far as outside-front tire needing less power in order to put all its traction towards turning, hence less understeer, however, it is conceivable that adding power to the wheel with the most traction (being obviously the outside-front) in a turn actually helps pull the car in that direction. This is precisely how the front active differential in my Prelude works (called active torque transfer system or ATTS, only on the Type SH model). It's a system basically designed to remove understeer from a frontwheel-drive car, and it works wonderfully. Breaking down its complicated processes into simpler terms, it basically increases power to the outside front wheel (how much so determined by the ECU) during cornering, in effect pulling the rest of the car in that direction, something along the lines of (admittedly a pretty thin analogy) a tracked vehicle (ie tank, whatever). Now I can tell you that with 4 years of owning my car and pretty much driving it to the limits, this system works near perfectly. Going around a corner very quickly, you can start to feel the front slide out very slightly, but as you increase the throttle (which is very unnatural feeling at that point in the turn), the front actually tightens up dramatically virtually eliminating all hints of understeer, doing basically the same thing you stated would actually CREATE understeer. Now if I were to have no experience either way, what you are describing makes more physical sense, but I KNOW that it works the other way through experience, so the details regarding these different characteristics are somewhat of a grey area to me. Anyways, just wanted to say that. By the way, to all the people skeptical of active differential reliability, I have driven mine HARD (many times at the track and pretty much highly agressive cornering on a day-to-day basis) for 75,000mi with a clutch-type active front differential and not a problem in sight; not even any maintanence required on it thus far, and I don't think that is all simply because of Honda quality or whatever, but who knows.