Mary Pozzi at Atwater autoX

[David Pozzi]

Here is a link to video of Mary autocrossing her 73 Camaro in CPL. She won by .4 second over other cars weighing 500 lbs less.
http://www.nastyz28.com/forum/showth...830#post751830
David

[Steve Chryssos]

Awesome.

[CraigMBA]

Watching Mary drive and from the lap time she cut, it's obvious that package is very well sorted.

Nice job on the car and nice job holding the hammer down Mary!

What size Kuhmos are those?

[David Pozzi]

She's very smooth and seldom over drives the car. This site is on concrete and if you overcook a corner it takes forever to recover and get going again.
Front are 275 40 17's on 8 inch rim which isn't ideal but we just moved up from a 245.
Rear is a 295 40? 17 on 9.5 which is a bit narrow too but we just increased width there too. We used to run the 275's on the rear, 245's front.

We are still developing the car, but the last mods were Alston G braces, GW cat5 rear springs, and I modified the rear anti-roll bar for adjustability, we have around 6 or 7 adjustment holes now. This car is teaching me a lot! FYI, - The G braces increased torsional rigidity by a third!

The car weighs almost 3600 lbs without driver, it seems everything we do to it adds weight.

We haven't done rear subframe connectors yet, saving that for last because I don't believe it will help much for an autocross car.

[MrQuick]

Congrates Mary, thats great. Nice to see the car is doing you good. I'd like to see a full run down on mods and other specs. Sweet job you two.

[David Pozzi]

FRONT:
Vintage wheels 17X8
Kuhmo V710 275X40X17
Springs, Hotchkis 600
Antiroll bar Hotchkis tubular
A arm bushings, all GW del-A-Lum
Stock lower arms, GW tubular upper
Upper Balljoint is 1/2" taller SC&C "Howe" unit.
Alignment -1 deg camber, 7 deg caster, 1/16" toe-in.
Steering, 12 to 1 AGR, Sweet late model pump and tank with return modified in tank, PS cooler
Brakes, Baer "Track" 13" vac power booster stock type. Cooling ducts for open track.
Alston "G" Braces
Global West solid aluminum stock height subframe mounts.
Shocks, QA1's Aluminum Stocker Star double adjust. Started with Hotchkis/Bilsteins, too soft.

REAR
Vintage Wheels 17X9.5
Tires, Kumho V710 295 40 17.
Brakes, Baer Serious Street.
Started with Hotchkis leafs 175 lbs/in measured, now have GW Cat5 L2 240 lb/in measured.
Hotchkis antiroll bar, modified to make it adjustable via several holes in welded on arm ends.
No leaf pads in perches
Herb Adams mod, raise front spring eye 3/4" increased anti-squat.
QA1 Stocker Star single adj shocks, started with Hotchkis/Bilsteins, too soft.

OTHER STUFF:
No subframe connectors yet,
Autopower roll bar
Corbeau seats
GM crate motor with 15lb flywheel
Speed Demon carb 750 double pump
Dual plane manifold
Hooker headers poor fit to pan/ground.
Summit X pipe with Walker mufflers, 2.5" and 2.5" Flowmaster mandrel bent tail pipes
Canton wide sump Road Race pan.
Richmond 5 speed
3.08 Gears
battery in trunk

Car is almost 3600 lbs WO driver, 54% front weight.

[zbugger]

Heh.... I think I'll be doing a little copying of that car on mine. I still want to go for a ride in it.

[Orngcrush69]

Dave,
You got Mary hooked up! Now it's time to put your toy together! No more sharing the second gen!

Thanks for the CD of Buttonwillow, we spend a lot of time looking at it!!!!

[David Pozzi]

It seems there's always something on the "list" for Mary's car. But I told her we are getting close to making it a race car with the stiffer rear springs and shocks, etc so we need to back off and get the 69 racer running instead. However she is going to be doing most of the work on that car and I've set my Camaro as a priority for me.

She's begun work on the 69 Vintage car, and I'm finally clearing out the area around my 67 to begin work on it!!! My shop is large enough that I had the luxury of just leaving stuff here and there on the floor and just moved to a new area for the next project, but I'm finally fed up with it and clearing it.

I also have the Lola entered in the Monterey HIstorics this year so need to prep that in a few months.
David

P.S.
The 600 lb front coils allow a fair amount of suspension travel on the street, the rate at the wheel is only 129 lbs/inch due to leverage ratios, and the low hanging Hooker headers have scraped from dips in the road when we drive it on rural roads. I'm not saying the front springs are way too soft, -they are twice what stock coils are, but they are not as stiff as we may imagine. I think they are a good compromise, I just wouldn't recommend using a lower ride height with these springs.

I think that for a street driven car, the 175 rear leafs with rubber front bushings is a better choice. I haven't driven the Cat5's except around the block, but they ride a lot rougher than the Hotchkis leafs we started with. I first rod in it with the GW leafs and race tires, it was TERRIBLE riding. I told Mary I no longer wanted to ride in it if she went on a club cruse out of town. The street tires were much better and tolearable but the Hotchkis leaf rate and rubber bushings are more ideal for a street car.

The Hotchkis leafs allowed some squat, but mainly I saw more front end rise. We couldn't do the Adams mod because the rear was already a bit too low compared to the front, and the front couldn't be lowered more because of header scraping. I had to use double 4 deg shim wedges between axle and leaf to adjust pinion angle down to a proper setting.

The GW Cat5 rear springs and Adams mod stiffened the rear to the point where I don't see any movement up or down when power is applied, the rear is very stable vertically now, also the front does not rise as much as before. I think preventing the rear from squatting helps keep the front down. This may be great on a race car but you sacrifice ride for it on the street, and with street rubber the G forces are lower anyway.

Suspension frequencies are:
F 1.24 CPS
R 1.42 CPS

[David Pozzi]

News Flash!
Mary won again today! by over 1 second!
The Kumho tire guy was there and said he'd never seen anything like it.

Some NastyZ/28 members took videos again and will post them later.
David

[Chad-1stGen]

sweet!

[67Sally]

cool!

[CraigMBA]

Are you guys that far "in the zone" or is everyone else that slow?

1 second on an autocross is an eternity!

[Merlin]

A big CONGRATULATION for Mary. Most people don't realize that Mary won with a street car. Her competitors were in fully built, tube frame car with optimize suspension, and race tires
(aka pure racecar). I watched her runs as she pulled down faster time lap after laps. The most truly amazing thing I 've seen in auto-xing. Mary, you are very special person, not the driving part, we all know that, but the part where you help my co-driver with driving advice. With your help, she won her class by a large margin and her first National Tour trophy. Thank you again!

Cliff
p.s. you are welcome to drive our car anytime.

[Zedzag]

Way to go Mary! You give all us 2nd gen guys proof that we can one day beat these newer "superior" performing cars. I can't wait until my 81Z is ready to take to the local auto-x where I can slowly start to better my car and driving skills.

[David Pozzi]

Are you guys that far "in the zone" or is everyone else that slow?

1 second on an autocross is an eternity!

Remember she's running in Ladies class, CPL, the men's CP ran 4 or 5 seconds faster than her on sunday, she beat them Sat but it rained during their runs. She's still beating women who drive well and have faster cars, she's just out-driving them. At the time she quit autocrossing 16 years ago, she had more national wins (10) than almost any other woman, if I recall correctly.

I was told one of the hot cars in CP is a late model Camaro with V6, they have 500 hp and are very light with close to 50/50 weight bias. They are allowed 10X16" wheels with 12" wide slicks.

All I can say about her car is it's pretty well balanced now, with no major flaws, we just got it that way this event, so it's not like we are so far above everyone else, just a great driver in a good car but we are really in the wrong class, but with the mods we have, it's not legal to run any class lower than CP.

[CarlC]

WOW! That's great Mary!

[David Pozzi]

Carl,
The G braces were a very good addition, stiffened the car in torsion by a third! Give or take, my method of measuring was not all that accurate.

Mary bought a photo from a guy at the event that shows the car cornering with the LF wheel about 2" off the pavement! This was taken two weeks prior to when we hooked up the rear anti-roll bar and the car was understeering and rolling a LOT! I'll post it when we get it copied, it looks cool even if it doesn't represent our current setup.
David

[Bow Tie 67]

Great job Mary.

Did anyone else notice the 69's hood fly up and block the windshield. I loved the expression in Marys voice, you could here the adrenaline. It has me jonesing for our first track event.

Matt

[IDLZRUF]

Yea several cars had hood problems this weekend