Suspension Tuning for AutoX

[TurboNeon568]

I am building a Neon Autocross car with a 2.4 turbo in it. I would like some hints as to how to set it up and get a good weight balance and handling for a tight autocross course.

Anyone got any good advice, links to threads or websites or product information that could help?

[Rattlesnake]

For a tight course you want a set up with minimal or no understeer. Basically loose in the front and tight in the rear. The loose front will help you put and aim the front of the car were you want it to go and the tight rear will help you with the rotation of the rear of the vehicle. How thight or loose depends how thight the course is. Loosen the front and thighten the rear and test and tune to you driving style and your laptime.
-loose front= soft strut, springs and swaybar
-thight rear= stiffer struts springs and thight swaybar(if applicable)

[TurboNeon568]

For a tight course you want a set up with minimal or no understeer. Basically loose in the front and tight in the rear. The loose front will help you put and aim the front of the car were you want it to go and the tight rear will help you with the rotation of the rear of the vehicle. How thight or loose depends how thight the course is. Loosen the front and thighten the rear and test and tune to you driving style and your laptime.
-loose front= soft strut, springs and swaybar
-thight rear= stiffer struts springs and thight swaybar(if applicable)

Sounds like yo've done this before. Is there a different style to it than road racing? With the road racing, you use the whole track but would you do that with the autoX course?

On another note, do you have a video on StreetFire.net? Because I saw a video of a sprit R/T said had a title somewhat similar to your username and had a lip spoiler on the front bumper like the one in your pic.

[Rattlesnake]

It's basically the same, go through the course at the least amount of time. The only difference is that in the autox is shorter so you have to be quick, not fast. There are no straights only tricky turns and you have to go through them as straight and fast as possiblewithout sliding the car, everytime you slide you scrub speed and add time to your lap time. The key elements are driver imput and vehicle suspension tunning specially the alignment.
Yes, I have a couple of videos at streetfire.

[TurboNeon568]

It's basically the same, go through the course at the least amount of time. The only difference is that in the autox is shorter so you have to be quick, not fast. There are no straights only tricky turns and you have to go through them as straight and fast as possiblewithout sliding the car, everytime you slide you scrub speed and add time to your lap time. The key elements are driver imput and vehicle suspension tunning specially the alignment.
Yes, I have a couple of videos at streetfire.

So instead of using things like trail-braking you gotta do a lot of down-shifting? Control of your entry angle sounds important, should I pull out wide and then enter the corner from the outside,steer sharp towards center or should I try to just keep as much of an inside line as possible?

[Rattlesnake]

So instead of using things like trail-braking you gotta do a lot of down-shifting? Control of your entry angle sounds important, should I pull out wide and then enter the corner from the outside,steer sharp towards center or should I try to just keep as much of an inside line as possible?
That depends on the configuration of the circuit. Trail braking for autox makes you very fast, specially on a turbo car where you can go throgh the corner applying throttle and brake to keep the turbo spooled and right before the apex just let off the brake and you will have rocket-like exiting speed. In some sections you can stay on the inside of the line and that'll be the fastest way around but in some other turns it will be better to get the wider angle as possible to go in and out at a higher speed. Like I just said in the other thread, feel what your car is telling you and were it wants to be, try different lines and techniques on entering and exiting angles, wide and narrow turn radius. Just remember that in autox you will not be fast on the straights because there is none, so the way you go through the turns is what is going to make you fast. Try also looking ahead further up the course, by doing that things will look much slower and you will be able to plan your next execution.
Good luck:thumb:

[TurboNeon568]

That depends on the configuration of the circuit. Trail braking for autox makes you very fast, specially on a turbo car where you can go throgh the corner applying throttle and brake to keep the turbo spooled and right before the apex just let off the brake and you will have rocket-like exiting speed. In some sections you can stay on the inside of the line and that'll be the fastest way around but in some other turns it will be better to get the wider angle as possible to go in and out at a higher speed. Like I just said in the other thread, feel what your car is telling you and were it wants to be, try different lines and techniques on entering and exiting angles, wide and narrow turn radius. Just remember that in autox you will not be fast on the straights because there is none, so the way you go through the turns is what is going to make you fast. Try also looking ahead further up the course, by doing that things will look much slower and you will be able to plan your next execution.
Good luck:thumb:

Okay so what about steering components? Like quick-ratio steering rack-and-pinions or 1:1 steering? Can you recommend anything?

[Rattlesnake]

Okay so what about steering components? Like quick-ratio steering rack-and-pinions or 1:1 steering? Can you recommend anything?

If you can get a quick turning ratio rack it'll help you a lot. My advice is, don't go too crazy now, just do it and then when you get more experience improve your equipment.

[TurboNeon568]

If you can get a quick turning ratio rack it'll help you a lot. My advice is, don't go too crazy now, just do it and then when you get more experience improve your equipment.

Does rat-racing count?:lol: Before I quit street racing I used to rat race a lot. I think that is possibly more dangerous than regular street racing. What with the blind corners and traffic and all. Going through neighborhoods and what not. I have to laugh at how stupid I have been.

Anyways....What about sway bars and strut tower braces? With the strut tower brace in an FWD car, is it anything like a RWD car where if you put one in the fron, the back end gets loose?

On another note, I just got a better job at Joe Cooper Ford. More money and comission for upselling repairs.

[travis_k]

For an autox neon, you will need shortened struts, or you cant lower it more than an inch. They have very little travel with the stock length struts, so lowering them is a big job. Expect to pay about $1500-1800 for the kind of struts you will need to go beyond the stock suspension for an autocross car. As far as swaybars, on a bumpy surface, stiff swaybars and softer springs are good, on a smooth surface stiff springs and soft swaybars are good. The main ting though is to not modify the suspension much at all until you drive it stock for a while and get really good at it. If you spend money without seeing what it needs, you will make it slower rather than faster.

[Rattlesnake]

For an autox neon, you will need shortened struts, or you cant lower it more than an inch. They have very little travel with the stock length struts, so lowering them is a big job. Expect to pay about $1500-1800 for the kind of struts you will need to go beyond the stock suspension for an autocross car. As far as swaybars, on a bumpy surface, stiff swaybars and softer springs are good, on a smooth surface stiff springs and soft swaybars are good. The main ting though is to not modify the suspension much at all until you drive it stock for a while and get really good at it. If you spend money without seeing what it needs, you will make it slower rather than faster.

I couldn't have said it better!:thumb:

[Frank]

For my 2.4L Shadow, I add this awesome plan if I just had time and was a better welder. I want a wider stance and more adjustment. I was looking at a 15x8 Kosei with 12mm offset. Problem with wider stance is your steering axis is off because your contact patch moves further out. Well that is easily solved if you can move the top of the strut further in. Well you can't for two reasons. One is the narrow top of the shock tower and secondly their instant enough adjustments from the strut to knucle setup if you are already running max camber of -2.

That is where my plan came in. I was going to cut the top of the shock towers off and weld in a new top about 3 inches further down. I could then run a 1st gen neon coil over for cheap and be able to position the bolt holes to achieve the adjustments nessecary to run the wider stance. Granted its not all that much wider, but steering axis is important outside of autocross. I would also need to weld in the bolt holes on the steering knuckels and redrill to allow for this also.

I was also going to run about 1" taller ball joint to get my angles back to stock even though the car was going to sit about 2-2.5" lower the stock. In the rear, I was going to remove the standard shock spring setup, and put in short coil overs between the axle and the frame rail.

It was going to be sweet with fender flares, etc. We will see how well tax returns go this year. May pay someone to do my fab work... aka my uncles and such since I need to get the chrome molly halo put in.



Frank

[TurboNeon568]

For my 2.4L Shadow, I add this awesome plan if I just had time and was a better welder. I want a wider stance and more adjustment. I was looking at a 15x8 Kosei with 12mm offset. Problem with wider stance is your steering axis is off because your contact patch moves further out. Well that is easily solved if you can move the top of the strut further in. Well you can't for two reasons. One is the narrow top of the shock tower and secondly their instant enough adjustments from the strut to knucle setup if you are already running max camber of -2.

That is where my plan came in. I was going to cut the top of the shock towers off and weld in a new top about 3 inches further down. I could then run a 1st gen neon coil over for cheap and be able to position the bolt holes to achieve the adjustments nessecary to run the wider stance. Granted its not all that much wider, but steering axis is important outside of autocross. I would also need to weld in the bolt holes on the steering knuckels and redrill to allow for this also.

I was also going to run about 1" taller ball joint to get my angles back to stock even though the car was going to sit about 2-2.5" lower the stock. In the rear, I was going to remove the standard shock spring setup, and put in short coil overs between the axle and the frame rail.

It was going to be sweet with fender flares, etc. We will see how well tax returns go this year. May pay someone to do my fab work... aka my uncles and such since I need to get the chrome molly halo put in.



Frank

you wana project the SAI angle out into the center of the tire the switch from a standard MacPherson strut to a MacPherson/SLA combination and then cut the ends off of the control arms and then weld on mounts for 4 ball joints instead of the regular 2. Because of the way the dual upper and dual lower ball joints flex, it will actually cause a projection of an "imaginary" SAI out into the middle of the tire. I think this would be simpler to do, even though it sounds off the wall. Go look at an '04 VW Passat and you'll see what I'm talking aout.

Sometimes the answers you're looking for already exist. Ford is currently doing something similar on some of their models. Using a MacPherson/SLA combination with dual lower ball joints and a spindle that curves up and around the top center of the tire to a single ball joint. This has the same effect as the VW suspension but is simpler. The downside is that it limits the size and offset of tire you choose.

But then again, I am talking to franks and you probably already know what i am talking about. You probably know more about it than I do, in fact.

[TurboNeon568]

So for the AutoX that I will be doing with my neon, will I need to worry about creating downforce? If so, how extreme should I go at this (front and rear splitters,side-skirts and stupid wing)? Will just lowering the car and making it stiff be enough to make it competitve?

[Frank]

You dont want downforce in the rear.... plus wings and such arent effective until around 75mph. In addition, everything most people sell dont do anything... they are just for ricer looks. The only thing useful is front chin spoilers, however depending on the course, you might not reach it.


Frank

[TurboNeon568]

I would be more inclined to wait patiently while i save the money for good quality, fully adjustable front and rear splitters. But like you said, I may not reach the speeds needed to use those items efficiently.

What about braking, though? What is the best way to reduce nose-dive under braking in a MOPAR? I have seen Fords use rear suspension upgrades that, instead of reducing nose-dive, reduce rear-end climb which has the same effect.

[Frank]

just upgraded to Koni/Eibach and the Mopar sway bars. That car will be dynamite afterwards. Oh and take care of the bushings at the same time.

[GLHS377]

actually there's been no metnion AT ALL of tires. i mean. theyr'e worth more in seconds than anything else. especially if he has a totally awesome suspension and lousy tires. same thing other way around doesn't work so bad though. a bitchtastic ssupension(stock is the worst you can really get, and not THAT bad) with some sweet race rubber. it'll handle way better. lean a lot etc, bumpstop city, but you can get to that later. yeah i propposed a long time ago a bolt on SLA setup which bolts to the upper strut mount on the knuckle and and the framerail. and has a short racing coilover _shock_ working on it. i have cad drawings around here somewhere. i prolly need to convert and/or just make them new. they're like 6 years old in cadkey something or other. so no, you don't need to redesign the knuckle. virtualizing the upper balljoint is cake, you can leave the lower one alone. and incidentally run ridiculously wide tires. no struts to hit. by ridiculously wide i'm talking 275s. on a 2200 lb fwd omni...

i'm gonna sound like an ---, but really, this is how it is:
if you need advice on what to mod for your autox car, then you probably need to learn how to drive an autox course first. so start in the slowest car you can, it gives you time to learn a line, and more importantly, how fast a car on the autoX you can handle!
first thing to mod is GOOD tires. not R compounds, something that'll last a few weekends. i chose RS2 Z212s.
second thing is a SEAT. a nice one. no steel frames or aluminum seats. a nice fiberglass one. dont' worry about harnesses. they're not DOT legal anyway, and a 3 pt is good enough for a streetcar in the autoX. cinch it down you'll be fine.

then buy a gtechproRR and an IR/pyrometer.

you'll then take VERY DETAILED run logs and use things like tire temps and how you feel the car is handling the course and your times vs others, split times etc. use the G tech in your car and ask if you can record other's runs in your class or faster with it too. let other ppl drive your car as well.
study that and set up your camber and tire pressures.
that'll make you a much better driver. well,more track time will. and you don't get a whole lot of in autoX. 10 mins a month really... so do track days. different beast, but the driver is waht eneds to be fast, the car can be slow.

in a mostly stock 55hp metro on the autoX i was able to come in raw time, 31st of 90+ racers. ahead of more than half the modded wrx club. in autoX, it's NOT nescesarrily the car thats fast. a turbo 2.4l neon would be in EM or something ridiculous too... with a good driver a well prepped 2.4l N/A neon could FTD reliably. turbo may slow you down. well good luck!
-jason

[Frank]

Actually tires was mentioned in a different thread, but very true Jason! The great thing about stock class is you can run slicks. ;)


Frank

[Stealth1347]

a turbo 2.4l neon would be in EM or something ridiculous too... with a good driver a well prepped 2.4l N/A neon could FTD reliably.Both cars you mention would be street mod.

Even a stock Highline suspension is pretty good in a neon. With just year old all but worn out 205 A3S04's as my sole handling mod and ~140whp I was able to finish within a tenth or two of a stock STi with a good driver. The track was an outdoor go kart course with a long but uphill straightaway. On other courses, I was near competitive in STS with just Azenis. Keep in mind that the Highline has no rear sway bar, and I still able to 3-wheel it.

To the original poster: check out neons.org. There is a dedicated autox section there.

[TurboNeon568]

I know a thing or three about cornering but autoX is different from a road course. It is tighter. Believe me, I know the importance of tires. What I am wanting to know is what kind of setup would be best for a tighter course like that. With a road course, there are sharp turns and long sweering turns where you hug the inside of thwe turn for what seems like an eternity and then come outside as you hit the straightaway or begin to set up for the next turn.

[Frank]

Both cars you mention would be street mod.

Even a stock Highline suspension is pretty good in a neon. With just year old all but worn out 205 A3S04's as my sole handling mod and ~140whp I was able to finish within a tenth or two of a stock STi with a good driver. The track was an outdoor go kart course with a long but uphill straightaway. On other courses, I was near competitive in STS with just Azenis. Keep in mind that the Highline has no rear sway bar, and I still able to 3-wheel it.

To the original poster: check out neons.org. There is a dedicated autox section there.

The 2.4L Neon in question WONT be in SM because it is an old school neon, and requires a transplat without the ability to completely backdate/update the car since the chassis are of a different generation.


Frank

[Stealth1347]

The 2.4L Neon in question WONT be in SM because it is an old school neon, and requires a transplat without the ability to completely backdate/update the car since the chassis are of a different generation.

FrankUpdate/backdate doesn't apply to SM. As long as the motor is from the same manufacturer, it is legal in SM. If it isn't, it is EM at the least.

EX: SR20DET in a 240SX is SM. LS1 in an FC (2nd gen/late 80's RX7) is EM. Besides, IIRC, Mark Daddio had a turbo 2.4L in a first gen and was SM.

EDIT:

Engine block must be a production unit manufactured and badged as the original standard or optional engine for that model. Badges that exist as marketing aliases for the manufacturer will be recognized as equivalents. Swaps involving mates related only at a corporate level are not recognized as equivalents. Models produced as a joint venture between manufacturers may utilize any engine from any partner in the joint venture, provided that an engine from the desired manufacturer was a factory option in that particular model (e.g. Eagle Talon available with either a Mitubishi or Chrysler engine, may use any motor from Chrysler or Mitsubishi). This allows blocks manufactured as production units for sale in other countries such as Japan or Germany.Examples I gave were still valid. Though maybe Daddio's car was a 2.0L. A close interpretation says that a 2.4 isn't legal at all in SM since it was never offered in a 1st gen neon as an optional engine, but I thought 2.4's were SM legal in neons.

[Frank]

Wow. That is nuts. When did that change? That is awesome.

[Vigo]

I was looking at a 15x8 Kosei with 12mm offset. Problem with wider stance is your steering axis is off because your contact patch moves further out. Well that is easily solved if you can move the top of the strut further in. Well you can't for two reasons.

It seems like moving your scrub radius so far out would be the biggest problem there, and wouldnt be addressed by moving the strut. I would imagine with scrub radius so far out that torque steer would be crazy and the car would want to steer itself a lot more if you locked up one of the front tires.



you wana project the SAI angle out into the center of the tire the switch from a standard MacPherson strut to a MacPherson/SLA combination and then cut the ends off of the control arms and then weld on mounts for 4 ball joints instead of the regular 2. Because of the way the dual upper and dual lower ball joints flex, it will actually cause a projection of an "imaginary" SAI out into the middle of the tire. I think this would be simpler to do, even though it sounds off the wall. Go look at an '04 VW Passat and you'll see what I'm talking aout.

Sometimes the answers you're looking for already exist. Ford is currently doing something similar on some of their models. Using a MacPherson/SLA combination with dual lower ball joints and a spindle that curves up and around the top center of the tire to a single ball joint. This has the same effect as the VW suspension but is simpler. The downside is that it limits the size and offset of tire you choose.

I havent seen a passat but it sounds like the 2nd gen DSM suspension is similar to what you're describing. Our Avenger handled better than any k-car stock for stock. the limited tire size thing does suck, but imo people make it out to be worse than it is. I have 245/40/17s on 17x8 with 35mm offset on my dynasty, bolted right on. I would like to try 275/40 next, but i will need mods for sure.

[TurboNeon568]

It seems like moving your scrub radius so far out would be the biggest problem there, and wouldnt be addressed by moving the strut. I would imagine with scrub radius so far out that torque steer would be crazy and the car would want to steer itself a lot more if you locked up one of the front tires.




I havent seen a passat but it sounds like the 2nd gen DSM suspension is similar to what you're describing. Our Avenger handled better than any k-car stock for stock. the limited tire size thing does suck, but imo people make it out to be worse than it is. I have 245/40/17s on 17x8 with 35mm offset on my dynasty, bolted right on. I would like to try 275/40 next, but i will need mods for sure.


It is similar to 2nd gen and some 3rd gen DSM suspensions. I can't remember which models it was but i used to see them when i worked @ cable Kia-Mitsubishi in OKC,OK. It works well, too.