Springs/Brakes/Spin

Wess-RA · #1 12-09-2008, 03:28 PM

Hey guys. I am experiencing a problem with my brake positioning. I have wide feet-haven't bought racing shoes yet. All too often, while braking hard I end up also depressing the edge of the throttle. I recognize this when the car isn't slowing properly and I subsequently push through harder causing the wheels to lock up. This result necessitates getting off the brakes to regain steering authority which has on rare occasion caused me to miss the turn in point. Hence check out the link to the world famous corkscrew at Laguna Seca. The damage was done (passing the turn in point) before the photo sequence starts but it does show the aftermath of being "significantly off line in the dirt". http://gotbluemilk.com/web081208/69/index.html

This car was once part of the women's racing series which may explain the narrow pedal positions. My first solution is to buy narrow shoes-any recommendations?-if that doesn't mitigate the problem I believe the solution would be to cut/reposition/re-weld the pedals. Any other suggestions?

If you take time to look at the photos you can see significant body roll. (non-spin shots) These are the stock springs. I have a set of 550# springs to put in the front and switch the existing fronts to the rear. From all the feedback I have heard this should be a good solution.

Craig245 · #2 12-09-2008, 05:11 PM

An easy alternative is to lower the throttle pedal buy adjusting the cable/linkage. You may also have to adjust the stop to ensure that you still get full throttle...wouldn't want to leave any of that 250 hp on the table.

Craig

PRO SYSTEMS · #3 12-09-2008, 05:17 PM

Get yourself a set of snug racing shoes and practice in the shop. You need to brake with your the most sensitive part of your foot so you can feel the limits of the brakes (I use my toes and the ball of my foot to make the tires squeak at me). You can't do that with a thick shoe.

If you do have racing shoes and wide feet like I do. Then you may need to move the pedals. But I just practice foot placement in the shop and then at the track when its time to brake I'm good.

But heres my trick... I KEEP THE BACK HALF OF MY FOOT AWAY FROM THE PEDALS.

Shape your foot like you have on high heels (during braking and acceleration) and feel through your shoe the pedal so you are aware of where you are on the pedal and you have the distance memorized and can compensate and tweak when you change fomr pedal to pedal.

You need to memorize this distance as in order to be fast you have to go from wide open throttle to absolutely slamming on the brakes. DO NOT TAKE that car settling breather in between wide open and braking, it will cost you a half a second every time you do it.

When I am doing an outbraking maneuver I almost overlap them and brake with my left foot and then switch back at the apex of the corner so I can downshift and come out in the correct gear. There is time..it just takes practice.

Also left foot trail braking to turn the car and then already have your right foot hovering or lightly resting on the accelerator to get away from the apex is awesome in the rain.

Patrick James
PRO SYSTEMS

AIMidwest27 · #4 12-09-2008, 05:50 PM

Racing shoes will make a big difference in your pedal feel. I buy simple G-Force shoes and replace them every year. Adjusting the throttle may also help as suggested, but don't lower it too much or your toe/heel will suffer.

Wess-RA · #5 12-09-2008, 10:45 PM

Thanks for the input-all very good information. My tennies have to go regardless.

eric1h · #6 12-10-2008, 09:50 AM

Yes Tennies have to go, I have a size 12 and VERY wide feet as well, and racing shoes make all the difference in the world. This car has been pretty easy to heal/toe and modulate the brakes.

As for springs, panoz26 just upgraded to 950/800 and the car feels great. I will be changing over to 850-750

Bumping up a few hundred pounds on the springs will eliminate the body roll but will also change the speed at which the car transitions weight, so be aware the car will change.

panoz used such low spring rates to make the cars easy to drive...

eric1h · #7 12-10-2008, 09:52 AM

Yes Tennies have to go, I have a size 12 and VERY wide feet as well, and racing shoes make all the difference in the world. This car has been pretty easy to heal/toe and modulate the brakes. As for springs, panoz26 just upgraded to 950/800 and the car feels great. I will be changing over to 850-750 Bumping up a few hundred pounds on the springs will eliminate the body roll but will also change the speed at which the car transitions weight, so be aware the car will change. panoz used such low spring rates to make the cars easy to drive...

Wess-RA · #8 12-10-2008, 10:20 PM

Those are super high spring rates. Let me now how that works out. No rear stabilizer I assume.

Panoz26 · #9 12-11-2008, 09:22 PM

Quote:

Originally Posted by Wess-RA

Those are super high spring rates. Let me now how that works out. No rear stabilizer I assume.

The car was awesome with the new springs -- body roll is gone - especially in rollercoaster at VIR .... I'm planted now

eric1h · #10 12-11-2008, 09:22 PM

Quote:

Originally Posted by Wess-RA

Those are super high spring rates. Let me now how that works out. No rear stabilizer I assume.

keeping it for now, although with the higher spring rates it won't be doing much!

The spring rates all but eliminated the body roll and devin feels the car is more stable.

I am reinforcing the shock mounts on the cars to make sure they can handle the higher spring rates without worrying about fatigue.

Wess-RA · #11 12-11-2008, 10:26 PM

I just bought 550# springs for the front and am putting the 350's on the rear. I am hoping that will be a nice improvement. I was going to corner weight and align with those new springs. I'm still running the 5.0L Explorer motor. I'm guessing this setup will work for now until the day that I switch out engines and have to reset the suspension again. Would love to hear others weigh in on those high spring rates as well with the larger V8's.
Eric and Devin-what springs were you running before the change?

Panoz26 · #12 12-11-2008, 10:39 PM

Quote:

Originally Posted by Wess-RA

I just bought 550# springs for the front and am putting the 350's on the rear. I am hoping that will be a nice improvement. I was going to corner weight and align with those new springs. I'm still running the 5.0L Explorer motor. I'm guessing this setup will work for now until the day that I switch out engines and have to reset the suspension again. Would love to hear others weigh in on those high spring rates as well with the larger V8's.
Eric and Devin-what springs were you running before the change?

Mine had the 550/350 setup -- and, yes, I have the springs if anyone wants to purchase a good / used set.
Wess, I still need to send those damn windows......

panozracing · #13 12-11-2008, 10:46 PM

Quote:

Originally Posted by Panoz26

Mine had the 550/350 setup -- and, yes, I have the springs if anyone wants to purchase a good / used set.

What data lead you to believe that those springs were incorrect? Too much spring can hurt the performance just as much as not enough. I ran mid ohio with 900 fronts and it was WAY too much (you could feel the tires skipping). Ended up at 500 fronts. We bring about 10 diff. sets with us and tune into the correct one. Its diff just like running diff tire compounds and shocks settings. I dont think there is 1 spring that is the best its setup dependent.

Panoz26 · #14 12-11-2008, 10:58 PM

Quote:

Originally Posted by panozracing

What data lead you to believe that those springs were incorrect? Too much spring can hurt the performance just as much as not enough. I ran mid ohio with 900 fronts and it was WAY too much (you could feel the tires skipping). Ended up at 500 fronts. We bring about 10 diff. sets with us and tune into the correct one. Its diff just like running diff tire compounds and shocks settings. I dont think there is 1 spring that is the best its setup dependent.

Didn't say they were incorrect at all. It was probably more of a personal decision..... I did not experience the skipping effect at VIR, but, I would tend to agree that there is not 1 spring that is the best......but, from what I felt with the car at VIR Full, it was a nice change. I felt tight where I needed and wanted, no bouncy, no body roll causing scraping down rollercoaster.... car just felt solid.

boothkc · #15 12-12-2008, 01:42 AM

Wess,
we should look at your peddles as our 3 cars have pretty wide spacing. I can't heel/toe well when I wear racing "elf" shoes such as Pumas etc. I end up using my Piloti sneakers (with Nomex) to get a wide enough base. I wonder if yours have been narrowed....go by Tom's shop (Competition Autowerks in San Ramon) and look at the 3 cars (2 GTS and 1 GTRA) as they are all the same and pretty wide. I is possible to hit the break and gas at the same time, but practice should allow proper heal toe which is important in a V8.

The 800 or 900# springs seem pretty high as the GTS specs are 550/350 I think. GTRAs use the Koni shocks, not Penske but aren't that different. We put 500/350 in the GTRA to keep it fun/forgiving for friends and it is much better. Almost impossible to drive well with 350/200s that it came with.

Oh BTW the dirt line down the corkscrew has won many a race....nice to see you are practicing it.

Put the 550/350s in and run some Hoosier R6s (275x17 on all 4s) and you will jump up several levels of fun.

Kevin

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