Feeling "Pushy"

Use this forum to dicuss driving techniques, how to approach certain turns, etc.

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Ken Jones
Posts: 249
Joined: Tue Jun 21, 2005 3:07 pm
Location: Pleasant Hill

Feeling "Pushy"

Post by Ken Jones » Wed May 10, 2006 8:10 am

I've been trying out a bigger bar up FRONT, because that's all SCCA will allow for suspension mods in AStock. Theoretically, you also need to get less rear 'toe-in' to help with rotation. The offset, by the way, is a gain in transitional speed and maneuverability - but many (AX) courses simply don't have enough of that variety. I think most people would simply try to eliminate the push and work with the other end of the car - but, assume we can't (to stay in class). Also, the front will not accommodate any more than -.7 front camber, so the car is going to push even more in the slow stuff unless we change some lines.

This is what I'm soliciting comments/help for. What, if given ADDED push in the slow stuff, would you change to mitigate that added push? I'm hearing - change lines, but what specifically do you suggest?

1) Just slow down (hate loosing momentum)
2) Use wider lines when available in the tight stuff
3) brake earlier and be earlier on the throttle
4) push/scrub around the apex cone
5)?
6)?

If you can help me get some speed back, I'll buy you a cheeseburger.

kj

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Dan Thompson
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Post by Dan Thompson » Wed May 10, 2006 4:57 pm

Ken,
I would lean more towards #2 and 3 also when I was AXing my Boxster I would try to use what little HP I had to steer the rear a bit with the throttle.

something has to give in the equation and for me it was either the wider line or using more throttle and drop throttle to get the rear to rotate like in the Carrera. :D :lol:
Dan Thompson
GGR DE/TT/CR Racecontrol

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David Leong
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Post by David Leong » Wed May 10, 2006 8:17 pm

How about this?

Don't slow down, but enter the corners with a big lift to rotate the car
David Leong

cdepuy
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Joined: Sun Jan 21, 2007 8:15 pm

Pushy

Post by cdepuy » Mon May 07, 2007 4:27 pm

I just spent some time at Roger Kraus Tires/Racing last week (great service) and also spent some time on the website. I found this on the web site:

http://www.rogerkrausracing.com/TechShe ... nder.shtml

There are 31 different "understeer corrections" that he has and only 1 of them is "drive a different line." There's likely to be some tweaks that would fit in spec, I would expect.

Ken Jones
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Joined: Tue Jun 21, 2005 3:07 pm
Location: Pleasant Hill

Post by Ken Jones » Mon May 07, 2007 8:04 pm

cdepuy,

Thanks... that query was done last year and I've since given up on the front bar only idea. I hated it. As much as I wanted to stay in a stock class with SCCA - it wasn't worth the aggravation I had with trying to make it work (Dave Leong's good suggestion on basically playing "pitch and catch" with the car works for some national level AXers). IF you can change lines, it could help - but far too often (as in last week at the Oakland Coliseum), the average persons lines were not what I wanted. After a few run groups, I was in the "left-overs" or marbles and couldn't get any traction outside of the lines most were taking. If you're a student of the sport, you'll notice that Hank Watts points that out in one the the chapters about driving a course.

As far as Roger Kraus Racing, I've started going back to them also - but I tend to tell them what I want and experiment from there. The sheet you're refering to is a great resource and is part of my 'library'.

I've since changed a bunch of stuff and really, really like how the car handles now (it was very good as a stock car, but after several years in the Boxster, I'm looking for more) - but, it puts me in a much higher class in both PCA and SCCA.

thanks again,

kj

Zone7Rep(Larry Sharp)
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Location: Livermore Ca

Post by Zone7Rep(Larry Sharp) » Tue May 08, 2007 2:20 pm

you seem to have the hang of it now Ken .. are you going to do Stockton this weekend?
1993 RS America
Grand Prix White
Car #6

1974 911 Carrera (resides in Australia)
Light Yellow

1974 914-6 GT (resides in San Luis obispo)

1987 944 turbo (location unknown)

1979 911SC(Hummers have it)

1972 911T (location unknown)

Ken Jones
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Joined: Tue Jun 21, 2005 3:07 pm
Location: Pleasant Hill

Post by Ken Jones » Tue May 08, 2007 8:33 pm

didn't realize SVR was having one 'till your note.... I'll try and make it.

kj

dtfastbear
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Post by dtfastbear » Wed May 09, 2007 11:18 am

How could no one bring up trail braking? Dave gets an Honorable Mention for "lift to rotate" which will also work in most instances...

Given that the car is what the car is, adjusting how and when you transfer weight front to back and side to side to is your primary tool for balancing the car. Two ways for you to transfer weight - throttle/brake and steering. You'll need to use both to get it right :)

Cheers,

Dean
Faster than the average bear...

Ken Jones
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Location: Pleasant Hill

Post by Ken Jones » Wed May 09, 2007 4:07 pm

Yes... that's part of the mix all right and it worked so much better in the old Carerra. When I first got the Boxster and it was stock, I had alot of trouble trail braking - it seems so much more 'centric' in it's rotation and doesn't telegraph the tail coming out nearly as much as the 911s do. When pushing hard, I often couldn't "catch" it or adjust quickly enough on the street tires.

I now have 245/285s and at first blush, you'd think it would be worse with the rotation - but with the Kumho V710s, I can still toss it, but it seems to have a more predictable rotation (if that makes sense) and I can rely more on the sticky nature of those tires to provide enough grip without the 'surprising' consequences of the earlier days. The Boxster can be quick to come around - I've just not been quick enough to consistantly catch it.


kj

Zone7Rep(Larry Sharp)
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Location: Livermore Ca

Post by Zone7Rep(Larry Sharp) » Thu May 10, 2007 7:09 am

the quick coming around part is what a mid engine car is all about
1993 RS America
Grand Prix White
Car #6

1974 911 Carrera (resides in Australia)
Light Yellow

1974 914-6 GT (resides in San Luis obispo)

1987 944 turbo (location unknown)

1979 911SC(Hummers have it)

1972 911T (location unknown)

Ken Jones
Posts: 249
Joined: Tue Jun 21, 2005 3:07 pm
Location: Pleasant Hill

Post by Ken Jones » Thu May 10, 2007 8:11 am

Then, it's back to the basics for me. I gladly invite any/all of you to come teach this old horse how to take real advantage of this "momentum" car.

I think this is a good time for some semi-pro help. Larry, Dean, Dan, Dave, Dave, Tim, Andrew, Boris?....and that's just the short list - any others want to volunteer? :)

I'm still buying you a cheeseburger.

kj

Zone7Rep(Larry Sharp)
Posts: 389
Joined: Thu May 12, 2005 7:49 am
Location: Livermore Ca

Post by Zone7Rep(Larry Sharp) » Thu May 10, 2007 8:16 am

sounds like we have a date ....... No fries with that?
1993 RS America
Grand Prix White
Car #6

1974 911 Carrera (resides in Australia)
Light Yellow

1974 914-6 GT (resides in San Luis obispo)

1987 944 turbo (location unknown)

1979 911SC(Hummers have it)

1972 911T (location unknown)

Ken Jones
Posts: 249
Joined: Tue Jun 21, 2005 3:07 pm
Location: Pleasant Hill

Post by Ken Jones » Thu May 10, 2007 4:16 pm

Hey - nobody calls me cheap... doesn't the 'Happy Meal' include the works?


kj

Zone7Rep(Larry Sharp)
Posts: 389
Joined: Thu May 12, 2005 7:49 am
Location: Livermore Ca

Post by Zone7Rep(Larry Sharp) » Fri May 11, 2007 7:46 am

I dont know does it? Just as a siode note,, I was pleasantly surprised drivng the RSA at Santa Rosa how little it does push. It has a nice balance between the front and rear that gives me a option on how to approach the corners. I am glad I dont have to deal with the understeer like you have to
1993 RS America
Grand Prix White
Car #6

1974 911 Carrera (resides in Australia)
Light Yellow

1974 914-6 GT (resides in San Luis obispo)

1987 944 turbo (location unknown)

1979 911SC(Hummers have it)

1972 911T (location unknown)

Ken Mack
Posts: 39
Joined: Tue Aug 23, 2005 2:53 pm
Location: Almaden Valley

Post by Ken Mack » Fri May 11, 2007 1:15 pm

Larry congratulations on the first place finishes at the last 2 autocrosses. I am glad you like the handling of the RS. I quess the set up I put on it is working. 8)
Ken...(still looking for a new toy)
PCA member since 1970 (SPAF) Silver Porsches are FASTEST

Zone7Rep(Larry Sharp)
Posts: 389
Joined: Thu May 12, 2005 7:49 am
Location: Livermore Ca

Post by Zone7Rep(Larry Sharp) » Fri May 11, 2007 1:21 pm

yup ken the only issue seems that the steering is not centered .. but that i can fix..
1993 RS America
Grand Prix White
Car #6

1974 911 Carrera (resides in Australia)
Light Yellow

1974 914-6 GT (resides in San Luis obispo)

1987 944 turbo (location unknown)

1979 911SC(Hummers have it)

1972 911T (location unknown)

Ken Mack
Posts: 39
Joined: Tue Aug 23, 2005 2:53 pm
Location: Almaden Valley

Post by Ken Mack » Fri May 11, 2007 1:34 pm

That's interesting, did that happen after you put the new tires on it?
Ken...
PCA member since 1970 (SPAF) Silver Porsches are FASTEST

Zone7Rep(Larry Sharp)
Posts: 389
Joined: Thu May 12, 2005 7:49 am
Location: Livermore Ca

Post by Zone7Rep(Larry Sharp) » Fri May 11, 2007 1:43 pm

yup so maybe they are different
1993 RS America
Grand Prix White
Car #6

1974 911 Carrera (resides in Australia)
Light Yellow

1974 914-6 GT (resides in San Luis obispo)

1987 944 turbo (location unknown)

1979 911SC(Hummers have it)

1972 911T (location unknown)

Ken Mack
Posts: 39
Joined: Tue Aug 23, 2005 2:53 pm
Location: Almaden Valley

Post by Ken Mack » Fri May 11, 2007 2:01 pm

I have seen that many times at my old shop. No real scientific explanation except that tires are manufactured differently and sometimes your steering wheel does not end up perfectly centered. If the wheel is off one spline you could pull the wheel and re-center it. Or a slight "tweak" of the toe-in might be necessary. It all depends how much it bothers you.
Ken...
PCA member since 1970 (SPAF) Silver Porsches are FASTEST

Zone7Rep(Larry Sharp)
Posts: 389
Joined: Thu May 12, 2005 7:49 am
Location: Livermore Ca

Post by Zone7Rep(Larry Sharp) » Fri May 11, 2007 2:03 pm

It is just slightly off .. Ill just do the toe adjustment myself
1993 RS America
Grand Prix White
Car #6

1974 911 Carrera (resides in Australia)
Light Yellow

1974 914-6 GT (resides in San Luis obispo)

1987 944 turbo (location unknown)

1979 911SC(Hummers have it)

1972 911T (location unknown)

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