# Lift throttle oversteer - good or bad (ax)?



## ·clyde· (Dec 26, 2001)

So, is lift throttle oversteer a good or bad thing in autocrossing?

The RX-8 had a bunch when the rear rebound was at full soft. Slaloms were a handful, but throttle steering in sweepers was more fun than you could shake a piston at. Increasing the rear rebound has made getting through slaloms without drama a lot easier, but in sweepers, the nose doesn't tuck in like it used to when breathing the throttle (I know...duh).

The ideal solution would probably be to set the rebound to the right place after seeing the course. Unfortunately, that's not always feasible when it takes an hour to make an adjustment. Beyond changing air pressures, I'm not sure what else I can do. or am I walking down the wrong path entirely?


----------



## TeamM3 (Dec 24, 2002)

Handling in Stock is always a compromise, was it faster with or without it?

fwiw, it will probably be worse with 275's ...

you can also try to lighten up the rear alignment; less toe-in and less camber


----------



## ·clyde· (Dec 26, 2001)

I was faster on that one course but I also had the benefit of about 8,000 extra mental runs. Still, it did feel like it let me drive faster through much of the course. Then, last week (on street tires), the course was almost all right hand turns of near constant radii and while turn in was still real sharp, mid turn corrections felt like they were slowing me down because they took more effort and time to complete (than the last event on street tires before adjusting the rebound). It was the same feeling that I had in the event on r comps right after making the change, but amplified about 400%.

Alignment...hmm...Anyone notice where clyde left his brain? :dunno:

It should be a lot easier to put 275s out of my mind when I know they won't help through experience.


----------



## TeamM3 (Dec 24, 2002)

you can try increasing the rear tire pressure too

but don't make the mistake of trying to evaluate and adjust the handling on street tires or worn race tires, you have to be sure you're on "good" race rubber to make a correct evaluation otherwise you'll steer yourself in the wrong direction, been there done that


----------



## ·clyde· (Dec 26, 2001)

I'm not planning on trying to make adjustments for r comps based on street tire experience (or the other way around) I'm trying to find what works best for me for each. It was just that what happened on the street tires last week was so pronounced it helped me isolate something that was much more subtle on r comps the week before.

The point about good versus worn race tires is well taken, but I'm not sure that I'm sensitive enough to them to know the difference. I don't know if my 245s were still in their sweet spot at the last event or have started falling off yet. I think it was their sixth heat cycle and runs 31-35. They sure felt good...and I was at least as fast on them as I've ever been...but still, I don't know.

There's still a lot to learn...


----------



## racerdave (Sep 15, 2003)

That was a good point Mark made about *worn* Hohos, because the characteristics between worn tires and new ones (whenever you get them) can vary quite a bit.

Like he also said, which way was it faster? Fast does not always = feels good. Why not go halfway between where you started (full soft) and where you are now? :dunno:

And hey, the fun is in the journey, not the destination... 

(Personally, I like TTO and think it can be quite useful on an ax course... and it sort of looked liked you needed it to rotate a little better from that cone-cam vid, but it's tough to say from that angle and from a video)


----------



## ·clyde· (Dec 26, 2001)

racerdave said:


> That was a good point Mark made about *worn* Hohos, because the characteristics between worn tires and new ones (whenever you get them) can vary quite a bit.
> 
> Like he also said, which way was it faster? Fast does not always = feels good.


"Felt good" was code for "able to keep my foot on the gas where I would have to take it off in the past." Which way was faster should be clear.  Still, it was a course that I had run ~6 weeks before and had mentally driven many, many times in between, which makes it harder to draw conclusions that I'm comfortable with. While I don't doubt the new setup is faster, how much faster is something that I can't begin to quantify.



> Why not go halfway between where you started (full soft) and where you are now? :dunno:


Well, now that I know what I'm looking for I want to do an event with the r comps where I can pay attention to it and try a couple different ways to deal with it. The car was SO much better in transitions that I'd like to deal with the sweepers be adjusting the driver if possible.



> And hey, the fun is in the journey, not the destination...


It doesn't end, does it?


----------



## racerdave (Sep 15, 2003)

Nope! :thumbup:


----------



## TeamM3 (Dec 24, 2002)

I still think stiffer rear rebound is the direction to head in, at least initially to see where it takes you, which I believe will be better rotation in the turns but still stable in the transitions


----------



## ·clyde· (Dec 26, 2001)

TeamZ4 said:


> I still think stiffer rear rebound is the direction to head in, at least initially to see where it takes you, which I believe will be better rotation in the turns but still stable in the transitions


Initial rotation or mid-turn corrections? Both?


----------



## racerdave (Sep 15, 2003)

He's saying... stiffen up the rear rebound to get the best of both worlds.

Correct?


----------



## TeamM3 (Dec 24, 2002)

racerdave said:


> He's saying... stiffen up the rear rebound to get the best of both worlds.
> 
> Correct?


no, only during entry (major) and exit (minor), little to no effect during steady-state cornering (generally speaking, not true in extremely high valve stiffness settings on very rough surfaces)

go for the higher rear pressures, I should have thought of that earlier, maybe some rear bump valving too


----------



## ·clyde· (Dec 26, 2001)

TeamZ4 said:


> I still think stiffer rear rebound is the direction to head in, at least initially to see where it takes you, which I believe will be better rotation in the turns but still stable in the transitions


No rebound changes yesterday, but higher rear pressures initially (35 vs 31). Every time I turned the wheel, I had more rotation than I knew what to do with. It was like the fronts were on a sandpaper-glue combination and the rears were on ice. Dropped a couple pounds for run 2, same thing, just not *quite* as bad. Dropped back to 31 for the third run, but had other issues that made it a wasted run. Fourth and final run at 31 felt very, very good...maybe too good since I kept having more speed than expected (based on the earlier slippier runs) entering the slower sections. Braking and turning late for a turn at the end of a long slalom cost me nearly a full second as best I can tell. It was an ugly day yesterday, but I think I learned something.


----------



## FSelekler (Jan 15, 2002)

Sorry to bud-in to the discussion, but just wanted to share a thought.

I am of course not sure exactly how high of pressures Team Z4 has suggested when he mentioned to use _higher_ rear pressures; but going from 31 to 35 on Hoosiers is not that healthy of a test IMHO.

When we make adjustments to our tire pressures that are within 0.7 psi range. It may sound silly at first, but that range makes very significant difference. It took us a while to nail that range down however during the last two weeks. When we were on Toyo's that range was 1.5 psi.

Granted the above is on our Street Prepared car. With the AS car that range is more within 2 psi. However, suddenly making changes within a 4 psi range, I don't think, can generate good test data for evaluation.


----------



## Nick325xiT 5spd (Dec 24, 2001)

Well hey, I upped my rear pressures 10 PSI.


----------



## ·clyde· (Dec 26, 2001)

FSelekler said:


> Sorry to bud-in to the discussion, but just wanted to share a thought.
> 
> I am of course not sure exactly how high of pressures Team Z4 has suggested when he mentioned to use _higher_ rear pressures; but going from 31 to 35 on Hoosiers is not that healthy of a test IMHO.
> 
> ...


 FT, if you haven't figured me out by now, I'll stop beating around the bush...I'm fricking lazy. Really, really lazy. 

Bleeding extra air out between runs is a whole lot simpler than adding air. I didn't expect 35psi to give me what I wanted, but I did expect it to give me easy adjustability...and it did. First run was at 35 and was no good. 33 was better, but still not good enough. Down to 31 and I was happy. Still, I don't know.somewhere between 31 and 33 might be better. Something below 31 may also be better. Had I started at 31 yesterday and moved up in smaller increments, I wouldn't have ended the day with much (if any) more understanding than I went in with.


----------

