So as I ponder taking my AS EVO to STU, I was looking at pax (yea, I know it's just a number...). On a 60 second course, AS is about a second faster than STU based on 2007 pax. My experience has been that STU prep pretty much makes up for the DOT-R tires.

Does this seem about right with what everyone else has seen? (with the disclaimer that there aren't really any top notch drivers running fully prepped AS EVOs).

If this is right, then can you turn it arround and say that the EVO is about a second off the class leaders in AS that are used to set the pax?



Any other thoughts on what it's like to drive an AS EVO vs a STU EVO? Obviously you've got a lot less body roll and dive in the STU EVO, plus more power. How does this translate to the autocross course... more likely to hit ABS due to less grippy tires and different weight balance, probably better transitionally in the STU EVO with suspension acting faster. Without any direct comparisions, it seems that ultimate grip is actually pretty similar at around 1.1g. Is wheelspin more of a problem on corner exit because of the less grippy tires, or does the flatter attitude of the car make up the difference.

In short, are there any shortcomings to the EVO STU driving experience. In AS, the softer suspension taking time to transition can be frustrating, as can occasionally being off/on boost at just the wrong time. Is it safe to say that the AS and STU EVOs run about the same times, just go at in a slightly different way?


George M

 

Any thoughts on running the EVO in STU vs AS?


George M

 

"Technically" AS is supposed to be faster due to the difference R-compounds make. For me an STU EVO was/is a lot more fun to drive.

 

I would agree here. With the ability to change the handling dynamics of the vehicle, not to mention adding power, it makes STU more fun to run in. For me, it's more about the fun than the overall time.

 

With my limited experience, it would cost quite a bit more money to set up a fast STU car. I think the raw time it would be pretty close between a top AS Evo and a top STU Evo. I also think S2000s and boxsters are faster in AS then the Evos. So if you don't mind spending more money and have more fun driving, STU is the way to go. I just don't think an AS Evo is as competitive as some others in the same class. JMHO.

 

I agree completely.
As said, technically the AS evos should be faster. I have run a few courses where STU was quite a bit faster though. Case in point, SLC ProSolo, very transitional course, the amount of body roll in the AS cars really affects its overall times in comparison to a highly spring STU car. Another situation where STU could be faster is low traction conditions (cold, sandy, think HPT), where race rubber is less of a factor in overall time. In other words course dependancy is a huge factor.
Where you want to go depends on a lot of other things like what your car is used for when not autoxing (AS car is more comfortable daily IMO), wether you want to be competitive nationally (STU or BSP), or locally (locally dependant), money (AS), how bad your mod bug is (STU or BSP).
I personally would go to BSP before STU, thats just because I love fresh race tires.

 

The Evo is definitely out gunned by the Solstice GXP ZOK in AS.

I've run AS for the last 2 years and have decided to switch to STU. I've tried everything under the sun(within AS rules) to try to get the car to under steer less. I also had the problem of over coming the rear LSD on power. When this happens, most of your power goes to the inside rear which spins and you go no where.

If you want to run AS, get some shocks, a big front sway bar, and run the 275 front, 245 rear setup. Keep fresh tires on the front. Also run as much rear toe out as possible. I also ran very high rear tire pressures(in the mid 50s on V710s). Brian might have a few different tweaks, but our setups were fairly close.

Good luck this year Brian. Need any parts?

 

Just wondering: Should the swaybar setup be bigger in the rear instead of the front to help the car to rotate better? I found a bigger rear sway plus slight rear toe out neutralize the understeer tendencies.

 

Thumbs up for a nice rear bar danny, dont let anyone talk you out of it... Assuming you are allowed to add one in whatever class you race in.

 

EDIT: double post

 

With the stock springrates, I would think you want to keep the front bar larger -- even if using a larger rear bar. It doesn't matter in this case though. Stock class does not permit changing the rear bar.

d

EDIT: Also remember that suspension dynamics are not so simple that you can say that a front bar always increases understeer and a rear bar always increases oversteer. If, like a stock evo on race tires, you're getting a lot of roll then a front bar can _decrease_ understeer by limiting roll and associated outside wheel camber loss.

 

Thanks donour. I am still learning...

 

This is absolutely true. I thought putting on a bigger front bar would make the car understeer worse. By limiting front roll you maintain a flatter front tire contact patch. Its simple, more front grip=less understeer.
My first time out with the front bar was our 3rd to the last event of the season and I couldnt believe how much the car changed, I actually spun the car for the first time. I took all of the toe out I had in the rear for the next event and the car still had oversteer tendencies. I even called upon a co-driver to make sure I wasnt crazy and he said there was a bit more oversteer than he would like.
In an AS Evo? no way!.
While outside the car I noticed the inner rear wheel, although still off the ground, was not quite as high, and off the ground a lot less total time. This of course helps with corner exit power delivery but it also helps the understeer problem by not unloading all of the cross weight on to the outside front tire overloading it and causing it to lose grip which will result in more understeer.
Next year I will be out on 275's all the way around guaranteed.

 

Very interesting Brian - thanks for sharing the perspective on the AS EVO. I didn't do the front bar yet, thinking that it couldn't make that much difference to only change to a slightly larger bar. If you don't mine me asking - which bar are you using - the Whiteline?

George M

 

After inquiring a dozen different evo parts vendors for Whiteline, Tanabe, Works, and robispec bars and getting answers that ranged from "they are on the way" to no answer or voice mail when I called to order, I finally went to my local Les Schwab Tire store and ordered an H+R bar. Its a 2 way adjustable 25mm bar with room for an extra set of "stiffer" holes. $259.
Took me about 3.5 hours to install from jack up to jack down.
I have heard a bit about your Koni's George, maybe we should take this to PM's for more discussion, Id like some more info about them, pics?