Autocross setup questions...

MrBone

New Member
Mar 10, 2012
18
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1
Parker, CO
Okay, I traded in my 2003 GT for a 2012 V6... on purpose! I sold off all my motorcycles, which I used almost year round for commuting (injuries from racing and wrecking them too many times made it nearly impossible to ride anymore). I couldn't afford the gas mileage on the GT due to a heavy right foot, and I just really really liked the new V6 and the way it handles.

So, since I can't ride anymore and I don't really want to drag race, I'm going to start into the autocross circuit. Having been a former pro road racer on motorcycles, I want to be competitive, but not ridiculous. This is, after all, a daily driver.

What do I need to do to the car to make it fairly competitive without ruining it for the street? I know that suspension is probably the first thing I need to do, but not sure which way or what products to go with. Name brands specifically. There seems to be a ton of different suspensions out there and I have no idea about any of them.

I appreciate any input that anyone has to offer, and not just for suspension.

Thanks in advance.
 
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If you are racing I assume you'll be removing the 113mph speed limiter. If you do this, you will want to upgrade your drive shaft as it has been prone to failure. I'd recommend the Drive Shaft Shop's aluminum unit as it has a cv joint so you don't have to worry about your pinion angle when you drop it. As far as which way to go for suspension, there are a lot of options out there. Some of the more popular choices for people looking to race as well as track their car is the Tokico D spec dampers because they are adjustable. With these dampers you will have to change your strut mounts because they are only built for 05-10 at the moment; the GT500 mounts are the most popular here. You can go with Eibach Springs, Steeda Springs, H&R.. whatever you want really; it just comes down to how low you want to go on a DD. Alternatively, you could go for a full out coil over system. Either way, you will want to replace your lower control arms to reduce wheel hop and you will need an adjustable panhard bar to re-centre your rear end after the drop. BMR is quite popular for LCAs. Depending on how low you go, you may need caster/camber plates (Maximum Motorsports) or caster/camber bolts (Eibach). You can go with a strut brace/ sway bars but I'm skeptical as to their increased performance relative to their price.

When it comes to power, the most common upgrades are an Airaid CAI and a tuner (usually BAMA). Together, these are supposed to be good for ~20hp. There are LT headers out there (BBK and Borla - Bassani has some in to works too) but again, for a DD I don't know how loud you want to go. If you don't want to go all out with the headers but do want more noise and power, Lethal Performance makes O/R X and H pipes which are good for 12-16hp for ~$200. The biggest gains people have seen without going FI is in changing the stock 2.73 rear end gear. The most common ratio change is to 3.55 or 3.73 but some autos are even running 4.10s (brand: FRPP). Once again, with the gear change, you will likely want to change the stock driveshaft.

If you want to go FI, procharger has a supercharger kit out which is good for about 475hp. Also, Central Florida Motorsports is just putting the finishing touches on their turbo kit so it should be out within a couple months. You'll find these engines are able to handle this kind of power and are quite reliable. On another forum there's a guy running 550RWHP with the procharger at 12.5psi with LTs, E85 as well as a few other toys.

Finally, as I'm sure you know, the biggest improvement you can make on the track is new TIRES. Our V6s are sold with low rolling resistance tires so we can achieve that magical 31mpg but they're not very good for grip. Now, everyone has their own preference in tires but I'd say the most popular ones are some of the Nittos as well as the Michelin Pilot Sports.

Welcome to the community and happy modding :nice:
 
On my fox body I really enjoyed being able to adjust the Koni SA's (Single Adjustable's) to dial it in. It was a little learning curve, I'd go with simple stuff to start (Tires, brake pads, and non adjustable stuff) and learn the car before getting adjustable parts.
 
If your going to autocross in order to be competitive you will want to stick to basic suspension mods and a good set of tires. Anything more in depth and you land in a different class, in wich you will not be competitive without turning your car into a purpose built machine. You can look on the SCCA website for the what you can do while staying in a competitive class. Grass Roots Motor Sport also has a wealth of knowledge on the subject of Autocrossing just about anything. To be honest tires are by far the most important part to a decent Autox setup. Don't worry about the speed limiter or the drive shaft, you will never see triple digit speeds or anything close competing in auto x.
 
You do not need to a supercharger for autocross, nor do you need to remove the speed limiter. You will never go that fast in autocross, I have been doing it for three years and have never gone much over 60. The course is small but I don't think you will have any issues with the limiter. I would recommend going a couple times with the car stock, then if you want, get some better shocks and springs. Something like Koni STR.T or Koni Sports, depending on how much you want to spend. They go well with Steeda Sport springs. Then if you want, get some sway bars, like some from stranoparts. You can get tires when you are ready, but they will make an instant improvement.
 
Thanks for all the input. Looking more to keeping it simple at first. I don't want to modify the car to make it a race car, so I think I'll run it stock the first few outings and go from there.

Seems tires is the best option to start out with, and then maybe a suspension upgrade.
 
I wouldn't touch the car at all for the first year. The local SCCA organizers always emphasize that the first nut you should work on is the one behind the wheel. When I first autocrossed my 02 GT I figured it would understeer/snap oversteer all over the place. Instead I reached the limit of my ability (or lack there-of) lol. You'll be surprised at what the stock suspension is capeable of. Tires are a great upgrade, as well as getting a set of dedicated wheels and tires. Certain classes limit you to a certain size so I would pay attention to that. I also wouldn't jump into R-comps immediately. I would also bring a tire pressure guage with a bleeder valve on it so you can keep your tire pressures consistant and adjust tire pressure depending on your sidwall rollover. Don't worry about adding power, at least not at first. Like what ct07gt said, shocks/struts and sway bars will make a good improvement. Most importantly, have a blast. I was able to get a friend of mine to finally try it and he was so worried about doing well in his class and not looking like a novice that he had no fun and probably did worse than he would have if he had just relaxed. The best thing I probably ever did was say, "I'm new to this" and had veterans helping me with stuff like how to adjust my tire pressures, lines to take, where to brake, etc.
 
To get an idea of the speeds you are likely to see, the link in my signature up above is one of my autocross runs. Don't be afraid to have an instructor ride with you, or ride with them; they are available at the Porsche Club of America events that I go to.
 
the v6's have driveshaft problems?

Ya, it usually happens at higher speed (130+mph) but there have been a few that have broken at more normal speeds too (60-70mph). They seem to break most often when letting off the throttle after WOT acceleration. It's the one thing that's holding me back from installing new gears. I don't want to risk get my driveshaft rpm too high and possibly running into a failure