RX-8 a little squirley under braking
 

I've noticed that the RX-8 can be a little squirley under heavy braking, for example threshold braking from speeds of 120+ mph, especially in downhill braking zones. It seems the tail end gets a little light, and wants to come around a bit.

I've also noticed during low speed corners that the car likes to rotate a lot (maybe too much) while trail braking. In fact, it rotates so much, that I seldom use this technique on the track just because it is a bit scary at times.

Can something be done with an alignment to the rear wheels to correct this and keep the back end a little more steady during heavy braking?

I bet you're toe'd out a little in the rear. Something like 0 toe will help stabilize it a bit.

Toe out in the rear helps rotation with slow speed transitions, but once you get to high speed, all bets are off. I felt the same way with my 8 with toe out in the rear on a road course (auto-x alignment means having a bit of toe out in the rear). Thing felt all sorts of loose with a tap of the brakes, but great on the turn-in on corners with some really easy rotation.

Or, you could brake in a straight line instead of trail brake (but wheres the fun in that?) ;)


--kC

What's the brake bias on this thing? Feels like there's far more to the front than rear.

what shocks do you have?

good question. the nose may be diving to much and causing the weight of the car to shift to the front loosening up the contact between the back tires and the pavement. Maybe a better rebound on the front shocks? Somebody correct me on this.

more rebound on the rear shocks, some more compression of the front shocks wouldn't hurt either.

but rear alignment may be an issue too, just trying to assess the situation before throwingout suggestions

I tried differant alignments for the squirrely rear end thingy and none of them worked. it wasnt until i got aftermarket springs and shocks did it go away:) As per Team says though fully assess your situation before throwing things at it. Every car and driver is differant.
olddragger

I just read elsewhere that you're on OE shocks, IMO that is the issue.

I noticed this this past weekend, too. I definately makes things more interesting. I thought it was just my driving :cwm27:

the shocks are the weak point of the suspension of this car on the track.
OD

Thanks guys, yes I am on the stock suspension and will likely upgrade it eventually but first want to get every possible second out of the stock set-up before upgrading (i.e mod the driver first).

Sounds like your car is in similar shape to mine. I've been on stock suspension (which is great) until putting sway bars on last weekend. Huge difference. Read about it in the suspension page.

Anyway, there are a couple modifications that you can make to your driving style to counteract they "squirrleyness". First, be as smooth as possible in your brake application. Be sure to progressively add more pressure as the weight transfers to the front and you gain front grip. Make sure that you are properly matching your revs in your heel-toe downshifts. You may want to brake a tad bit earlier (I'm really not one to talk... but anyway,) in order to gain some smoothness and you may actually stop faster when you're able to keep the tires settled. You could also back off of the trail braking a bit. Use just a bit to get the car rotating, but then you have to immediately be back on the gas to settle the rear end. If there is any negative camber to the turn, trailbraking is probably a bad idea to begin with. Also, any mid-corner bumps can kick the tail out under trailbraking.

See: www.scottbarton.net/anthony/mid-ohio/videos/DRIFTS!!!.wmv
right click and save-as!

See why I'm not one to talk? :dunno:

I too am experiencing the 'squirrel' when braking hard from >100. The car feels like it is suddenly on egg shells (very important to be pointed straight...)

My issue, I suspect is as described above, the result of the weight shifting forward and likely best solved by better shocks and springs.

I have not felt this before my recent upgrade from OEM brake pads to Carbotech Panthers brake pads on the front for the track. That probably contributes to this. Better braking = more weight shift???

grippier front pads = harder front braking = more weight transfer to front = squirrely rear end??

btw i also have experienced the 'squirrelly rear end' syndrome while braking from 120+ on front straight of VIR... but i really didn't care much for it, i just make sure i finish my braking before i start turning the steering wheel for turn 2...

EDIT: i had all stock brake pads at that time....

I think it's your alignment in the back, my car is ok but I've been on small tracks where I barely get over 100 mph. Try to straighten out your line while you brake, trail braking with the 8 loosens up the rear quite a bit but still feels really balanced.