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Discussion Starter #1
well the auto club from my school and a local autocross chapter are putting on an autocross and i'm considering running the 'trep. Can anyone think of some quick and cheap ways to maybe lose some weight or get more power? I am consider pulling the back seat, but i don't want to make the car too flexable. I am running a 3.5 sport w/ autostick. If anyone else has everauto crossed an intrepid or anything else for that matter i am open for advice. Tire pressure up/down any little tricks would help. My main goal is to have a good time w/ some freinds play'n w/ cars, but still i don't wanna come in last.
 

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The back seat doesn't really offer any support. Your tire pressure should be at about what it says on the sidewalls. Too flat and you won't get the response you need, too hard and you won't get enough traction. I would roll in with under a half tank and just fill up when you leave. That will save you a lot of weight considering fuel is roughly 6 pounds per gallon. If you have subs take them out. That's my 2 cents!
 

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When I autocrossed my t-bird I did it with about a quarter tank, took out the spare tire and jack and that was about it. Of course I’d done more to the t-bird than I’ve done with the Intrepid because its engine was kind of restricted to start with. Of course like Rplate said there are few things that will have a bigger affect on how the car handles then the tires and tire pressure. Also since you’ll really be giving those front breaks a workout make sure that the pads aren’t getting old.
 

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front tire pressure: lower (understeer higher (oversteer)
rear tire pressure: higher (understeer) lower (oversteer)
front tire section: smaller (understeer) larger (oversteer)
rear tire section: larger (understeer) smaller (oversteer)
front wheel camber: more positive (understeer) more negative (oversteer)
rear wheel camber: more negative (understeer) more positive (oversteer)
front springs: stiffer (understeer) softer (oversteer)
rear springs: softer (understeer) stiffer (oversteer)
front anti-sway bar: thicker-stiffer (understeer) thinner-softer (oversteer
rear anti-sway bar: thinner-softer (understeer) thicker-stiffer (oversteer)
weight distribution: more forward (understeer) more rearward (oversteer)

Aim for the theoretical ideal, neutral steer.
Neutral steer is matched front and rear traction.
Understeer is a plowing or pushing effect when cornering.
Oversteer is the rear sliding outward on turns.
 

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About the only things I know of are: run good tires and brakes, take everything out of the car you can (subs, junk in trunk, spare & jack), run as little gas as possible, maybe do a few simple mods like CAI etc.

I tried to get info on autocrossing my trep about a year ago, the only two replies I got were 1) treps are not good for autocrossing and 2) why don't you buy a neon to use just for autocross instead of your trep. Pretty dissapointing responses considering I thought everyone here was a trep fan.

Anyway good luck, and don't forget to pass on any tips or tricks you pick up along theway.
 

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I have no idea if this is the same with all of you guys since all sorts of little things like the front shocks maybe being changed by the previous owner when the back weren’t, and the different brand of tires I have on the front and back. But what I’ve found is that my Intrepid seems to have a very sweet balance between under and oversteer, that when you get into a turn too quick the back starts to slide out a little (oversteer) but with a little feathering of the throttle you can balance it out very well, and of course plow it into understeer if you gas it too much. I’m kind of surprised that more people don’t do the autocross thing. After all it’s a legal and safe way of pushing some of the limits of your car, even if you know you’re not going to win your category. This year I plan to run the Intrepid in the autocross and see how it does. After having a little fun with it last fall on a very windy closed residential road for a new development I think it could do pretty well…for being a large front wheel drive family sedan.
 

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rplate said:
I would roll in with under a half tank and just fill up when you leave. That will save you a lot of weight considering fuel is roughly 6 pounds per gallon.
there's 8 pounds in a gallon
 

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Never tried autocross, but if your 'Trep is like mine, cranking the wheel suddenly may outrun the power steering. Watch for that first time out.
 

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Discussion Starter #9
well i have picked up 2 bottles of octane booster.....i want to run a tlest most of one tank of it before i run the car.....to get the computer used to it. the winter rubber comes off friday and then i should be all set. The race is the 2nd weekend in april and i'll let you guys know how it goes. and about the neon...my buddy will be running a '00 5-speed with a little work done to it (short throwshifter,CAI, catback) and well have some numbers to compare it to. I just hope to have fun
 

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dualoverhead said:
well i have picked up 2 bottles of octane booster.....i want to run a tlest most of one tank of it before i run the car.....to get the computer used to it. the winter rubber comes off friday and then i should be all set. The race is the 2nd weekend in april and i'll let you guys know how it goes. and about the neon...my buddy will be running a '00 5-speed with a little work done to it (short throwshifter,CAI, catback) and well have some numbers to compare it to. I just hope to have fun
Autocross on street tires. It's a blast... but you need to compete against similarly equipped cars, or it's just an exercise in futility.

I have seen an intrepid do autocross once. It was a rental, on skinny tires, aired up to 45 psi.

It did...so-so. The driver was not in any mood to get nailed for abusing his rental car. :)

If your track designer is any good, the great majority of your time will spent at under 45mph, and quite a bit under 35, too. The biggest key to success is "smooooooth". On street tires, agressive moves result in breaking traction, which scrubs speed and you end up where you don't want to be. You will gain far more by knowing precisely where your tires are and going as narrow as possible through turns and slaloms and cutting gates as close as you can, than ANY other strategy. It's better to take the slalom close and easy and cut it tight and precise, than to get fast and loose. Long sweeping benders are a hoot in a FWD, as you can nearly drift them, if you know how, while acclerating where RWD cars would spin.

Take some chalk, and chalk across the treads of your tires, and up the sidewall. Then, alone in a parking lot, define some points to slalom through, and then start adjusting your air pressure up until you stop rolling badly into the shoulders. Do the same for the back, but try to keep as much rubber planted on the road as possible, without the back being "sloppy" side to side.

As you raise the pressure, the contact area of the tire will decrease slightly, but in the in-turn contact will be more in the tread, and less grinding off of your sidewalls. If you're too low on pressure, the tire can come off the bead, and it's likely to happen in a spin or broadside slide, and if that happens, you're ROLLING your car - with you in it.

I would fill the gas tank full, not run near empty. Some cars have difficulty pulling clean gas flow from the tank when the gas is low and sloshing wildly, which can cause misfire, stalling, or just cat converter overheat and smell. Sloshing in the tank can actually be enough to cause you to lose the back end in a slalom. Not only that, it is in the back, which changes your weight distribution positively when full.

Power is only somewhat useful in autocross. It's nice to have the acceleration and braking to match, but that's worth only a fraction of what having cornering grip, and a smooth, educated hand are good for.

Tire selection is crucial... THe heft of the Intrepid means you need the stiffest sidewalls you can find. That used to mean BF Goodrich, but I haven't kept up with tires in several years now, since i quite autocrossing. Look for a sticky compound, without a lot of sipes on the edge (they'll just shred and you'll be into the cords in NO time, and some very expensive tires could be trash), and very heavy shoulder, sidewall, and bead area build-up.

Tread designs:

Not bad: http://www.tirerack.com/tires/tires.jsp?tireMake=Yokohama&tireModel=AVS+Sport

not good: http://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Potenza+RE92

bad: http://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Turanza+LS-H

good: http://www.tirerack.com/tires/tires.jsp?tireMake=BFGoodrich&tireModel=g-Force+T/A+KD

The REAL thing: http://www.tirerack.com/tires/tires.jsp?tireMake=Kumho&tireModel=ECSTA+V710


now, I'm only talking TREAD DESIGN. Please don't assume I'm rating the tires. I'm just trying to illustrate what's a stronger...and weaker... tread design for harsh, low-speed cornering, like you do in Autocross.

Make sure your engine oil is full, recently changed, and the lightest grades you'd normally run for the temperature, and you might even consider synthetic or running a light oil and something like Power Punch or STP in it, to increase film strength for those moments your oil is sloshed and you pick up foam...

You'll need a helmet... make sure you know what type of "approval" is required. Take tools to change a tire, make sure you've rotated your tires so the best tread is on the outside. Take something to put all your stuff into, like lug nut caps and/or hub caps, spare, jack, etc. Take lots of water (stress really increases your need for water) and avoid excess caffeine. Get LOTS of sleep the night before (gonna be tough).

I am not a cowboy, but I used to wear the biggest, widest cowboy hat I could find, to shield my face from the sun. Use lots of sunscreen to protect your face from the reflected sun. Even if you say "oh, I won't burn much", those things reduce your fatigue, which improves your performance. Wear solid shoes that fit well, and give you feel of the pedals, but are comfortable for standing on hot asphalt for a whole day.

I autocrossed 3 years. Year 1, modified Reliant. Year 2, police pursuit Diplomat, year 3, plymouth Horizon - bone stock. My best success was in the Diplomat, which, on street tires, was a heckova fighter vs the mustangs. It had a serious horsepower deficit, but the cop suspension and brakes outhandled the Mustangs.

The reliant was fun. It had a cam, open exhaust, (carb, not efi), low transfer gears in the auto, and a shift kit. It also had Mopar Performance struts, and some improved springs in the back, as well as KYB shocks. It had wide steel 14 inch rims (stock was 13) and I ran 205/60's as I recall. It had more than 10 inches of rubber on the ground and it would smoke them off the line and then leave two strips when it hit 2nd. Goofing off out in the back roads one day, I ran over a "hump" in the road and got it 4 wheels airborne... It came down on flat ground and it didn't even bottom out. It rode like a little red wagon. Stiff, and very, very positive feeling.

More importantly, BE SAFE, and that'll let you do the most important thing of all... HAVE FUN!
 

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autocross in a trep is a blast. you wont really get rid of the weight you wanna get rid of unless the car goes on the lift for a bit, and you get crazy with some cutting tools. stay in low, and like everyone says have fun with it.a full tank will help a tad on the weight distribution. ok alot. and be safe. ive had a few friends get hurt by tryin to push too hard.
 

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Discussion Starter #12

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Discussion Starter #14
Well the intrepid has been auto-x’d. IT WAS A BLAST. By no means was I the fastest, best looking, or expensive car there, but did I draw some attention.
The weather here in Erie was low 40’s and sunny and we were running on an old asphalt parking lot. When lining up for my first run I was put between a Corvette, and a Mustang (early ‘00’s), man did I fell like I didn’t belong. For the first run I have an instructor ride with me, couldn’t have asked for a nicer guy.
As I come of the starting line I light up both tires…I think the instructor was completely amazed that it could do such things. The first obstacle is a 5 cone fast slalom, followed by a 110 degree, a few tight little corners, turn into another 130 degree turn, through a tighter 5 cone slalom, another 110 degree turn, with a widely spaced slalom, into an insanely tight 90 degree turn, then about a 100ft of pure acceleration to the finish.
The tire spun through every slalom and turn, the weight transfer would make the outside tire bust loose. A LSD would have been nice and without the auto-stick I would have done much poorer. It allowed the car to engine brake to a point, and with the long first gear I never had to shift like some of the 5-speeds did.
My times:
1st run: 45.576
2nd run: 42.430
3rd run: 40.656
4th run: 46.473…..hitting cones has a 2 second penalty I got 4 this run
5th run: 38.994
6th run: 36.938
My buddy’s ‘00 5 speed neon ran a best time of 35.716

With a little more time I could have cut it down more I think. It’s a fine line between, slow and control, and lose and scary and finding the balance took awhile.

If ya ever get a chance to do it, Do It. That’s all I can say.
 

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lose everything in the trunk including the spare tire. Run with only enough gas for the circuit, mogas runs close to 6 lbs/gallon.
 

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Discussion Starter #17
The closest thing to my car there was a chrysler cirrus he ran .2 seconds quicker than me. I beat a Lancer by over a second. the averege in my class was around 35 to 36 seconds for my class. Ther were 11 cars in my class i was 3rd from last. i would have done better had i been able put a little more air in the tires........the free air at sheetz only went to 45lbs max.....and only reads 40 w/ a gauge.
 

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Discussion Starter #19
my tires were rated for 41psi.......there were people there running 55psi in tires like mine.
 

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"keep as much rubber planted on the road as possible"

lighter/wider rims with fatter low profile tires. lowered center of gravity/dropkit. better shocks/struts

everything else is little things like everyone has explained nicely

after i fixed up my 95 3.5 im pulling tread on my walmart tires, but here is my question... how do you pull more lowend torque?? my highend is what pulls my tires off the road. its getting the 4543 lbs moving that is the problem
 
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