Just an FYI for anyone wanting to add to their a-stock setup; my double-adjustable koni shocks are up for sale, see here: https://www.evolutionm.net/forums/sh...d.php?t=239080


Devin

 

- any exhaust AFTER the cat is allowed (90db noise restriction)
- any brake pad and rotor of STOCK SIZE is allowed.
- any alignment settings within the range of adjustment capable of the stock parts.
- any FRONT sway bar (or removal of) is allowed. all other must be stock.
- aftermarket shocks of STOCK SIZE AND TYPE are allowed. This allows adjustable shocks, but not edfc or the like.
- any tire that fits properly on STOCK SIZE AND OFFSET rim is allowed, and must be DOT approved
- any rim that is the SAME SIZE AND OFFSET as stock (+/- .25") is allowed.


That mean drilled or slit rotors are ok for stock?

 

The original poster misstated the rule.

The wording for Stock class which covers brake rotors:

Drilled or slotted rotors would not be "essentially identical" to the standard parts unless the standard parts are drilled or slotted.

 

Now that my A046s are almost done I've been giving some serious thought to what tires I should use this year. Last year I ran the car completely stock in AS and plan to do the same this year except for tires. I still have a lot to improve, but towards the end of last year I found myself sometimes about 0.5 - 1 seconds on a 35 second course behind some of the competitive S2000s on R-compounds. So I've been tempted to see what I'm capable of with better rubber.

Due to price, treadwear, and reviews such as the following I can't think of anything else other than the Toyo RA1s.
From https://www.evolutionm.net/forums/sh...ght=A046+toyo:
But is it worth it? Will moving to R-compounds hide my mistakes? How much faster would they be compared to the A046s on a 35 or 45 second course? Would I be better off investing in a lighter set of wheels for around the same price?

 

RA1s are an interesting tire, because they behave differently from street tires while also behaving very differently from Hoosiers. (Can't speak for Kumhos personally.)

You may find that RA1s are fastest when you "drive it like you stole it"... Even before you start sliding the tires, they'll outgrip a street tire, but they really shine when you start pushing the tires beyond that point. Among all of the various tires I've autoXed an Evo on, the RA1s were the only tires which just got faster and faster the harder you pushed. (As long as you don't push beyond the driver's ability.)

As a result, I've found that RA1s are really fun tires for autoX, even though they may not be the fastest R compounds.

I wouldn't worry about "hiding your mistakes" on RA1s. What I would worry about is that once you've gotten used to RA1s, virtually any other tire that you switch to in the future will probably demand a bit more conservative style of driving.

 

I think you'd be better off getting a set of cheap wheels like Rotas or Enkei take-offs and putting real autox rubber on them. A set will last you all season, and you can wear less agressive rubber on the street--like Advan take-offs, for example. RA1's won't last long in daily use, and they'll probably only gain you half as much autox time as V710s or Hoosiers.

The right rubber can easily get you a second on 35-second course.

 

I second the suggestion to get real R-compound tires (and a separate set of wheels). Unless you have a sponsership with Hoosier, and can ignore the price, the best autocross tires are Kumho V710's. They reduced my times by almost 2 seconds on our 65-75 second courses here at Devens, MA. You can't drive them on the street, so you have to change wheels at the event, but that's not a big deal if you buy a cordless impact wrench (highly recommended: the Goodyear Racing Impact Wrench at Pep Boys. Comes with a 20mm socket, by the way.).

 

Regarding the cordless impact wrench... The cheap way out is to get a square-drive bit for a cordless drill. Use a lug wrench to break the nuts loose, spin them on and off quickly with the drill, and torque with a torque wrench.

If you've already got a cordless drill, you can avoid buying a cordless impact wrench if you're willing to break the nuts manually. Torquing should be done manually, whether you use a drill or an impact wrench--don't trust an impact wrench to get it right.

 

Everything you said is true, but the Goodyear Racing impact wrench at PepBoys was only $79 last X-mas, about the same as a good electric drill, and it is able to break loose lug nuts torqued to over 110 ft-lbs., while you have the wheel in the air -- this is a great time savings when you have to change wheels twice at an event.

Also, if you stop the wrench about 1 sec after the nuts stop spinning, you will find that they're torqued almost perfectly to 80 ft-lbs. You should still check them with a torque wrench, and I do, but I usually find that the torque wrench has no work to do on most of the nuts.

With this wrench I've got my wheel-changing time down to 15 minutes each at the beginning and end of the event (that includes getting the wheels out and packing them up in the back seat).

Oh, I also should have mentioned that the US General portable racing jack from Harbor Freight is indispensable, as well. Much higher quality than the stamped steel things from China that you find at places like the AutoZone.

 

So what you're saying is that you're overtorquing the lug nuts using the impact wrench. That's not good, and can lead to weakening/breaking the studs, especially if you're doing it often.

 

Thanks for the info guys. A friend of mine also suggested the Kumho VR 700s. Tirerack sells them in 245/45/17 for $157 whereas the cheapest I've found for the Toyos are $168 in 235/45/17 at bmwwheels.com.

I live about 75 miles from my two favorite autox courses, so I think driving to them on these shouldn't be a problem. But I'm still undecided if I should go for R-comps yet. There are a few experienced guys who are faster than me on stock A046s, so it wouldn't satisfy my ego if I can't beat them without going to R-comps

So do you think that's a big problem when you eventually want to move onto really good tires?

That seems to be the best plan.

Exactly what I wanted to hear.

 

No I'm not overtorquing them. I'm torquing them to 80 ft-lbs, which is within the spec of 73 +/- 7 ft-lbs. I used to use 75 ft-lbs, but the front wheels kept loosening up during autocross competition. 80 ft-lbs is the minimum that keeps them from doing that, at least for me.

And I said that the torque wrench takes them right about to 80 ft-lbs, as proven by the fact that I get a a little more tightening on some of the nuts when I check with the torque wrench.

Look, you can't be too **** about the tightening specs. One trip to the tire shop to have your snow tires put on, and you're going to find your wheels torqued to over 100 ft-lbs (unless you specifically warn them and they have good customer service). I've had lug nuts put on so tight that I had to jump on the breaker bar to get them loose, and they didn't fail.

The quickest way to have your lug nuts fail, and it has happened to me at least 5 times, is to have them loosen up while you're racing. Then they're going to be badly stressed. That was happening to me all the time before I upped the torque to 80 ft-lbs. I now carry at least two spare lug nuts and wheel bolts with me for any racing event.

 

You're torquing to approximately 80 ft-lbs, maybe. Unless your impact wrench has been calibrated--and checking lug nuts with a torque wrench afterwards isn't calibration--you don't really know how much torque it's applying. Sure, I'm being a little ****. What you're doing is OK if you're aware of the risks. I'm just trying to make sure that newbies are aware of the risks.

The ones that get a little tightening are undertorqued. The ones that don't budge are either perfectly torqued (unlikely) or overtorqued (more likely). This just proves that your stop-a-second-after-it-stops-turning method results in variable torque. The only way to get known, consistent torque is with a torque wrench.

I know... But when you're torquing each nut twice per autocross event, that can really add up.

Yeah, that's a good point.

 

To get the performance advantage from most R-compound tires you have to be conservative with them. If you're breaking the tires loose and sliding at all, you will quickly overheat them and reduce their traction to street-tire level. So, yes, if you get used to tires that like to be squealed and abused, you'll have some learning to do with real R-compound tires. This happened to me last season, which was my first season on R-compound (Kumho V710s). I discovered the hard way that it's easy to reduce the performance of your R-compound tires down to street-tire levels in the first 30 seconds of an autocross. Not good for your performance in the second half of the course!

The good news is that it only took me half a season to learn how to drive on R-compound, and now I'm getting the full performance advantage from them. (Now if I can only learn the right racing line for autocross...)

 

Yikes! 80 ft-lbs is my minimum (usually I do at least 85). I don't know why the manual says 73 +/- 7.

The specs for a DSM and 3000gt/Stealth are 87-101 ft. lbs. So I wouldn't be afraid to crank it up a little.