Okay, here's a deep question for whoever styles themselves the board wheel/tire/handling guru. The ultimate question is about how to get the best handling out of our cars with the way our AWD system is setup. But first, a few pieces of evidence:
We've seen this car posted quite a few times, but mostly because it looks great. But not a peep about the funky wheelspecs: Rims are apparently both 17x9 +38 with a PCD changer. But note the tires, 245/40F, 225/45R. And Hideki told us that the owner had previously run the more conventional 255/40 Front and Rear. So he presumably thought this setup handled better.
Exhibit 2: From our own Handling FAQ http://www.alltrac.net/phpBB2/viewtopic.php?t=8799&postdays=0&postorder=asc&start=15
Note the first two pages discussing front and rear track and esp. CMS-GT4's observations about how keeping a wider front track seemed to improve his handling. Also related is how the article from whiteline mentions that the AWD design of the GT4 is basically adapted from a FWD design. In other words, the GT4 is more or less a FWD car with a differential putting power to the rears as well.
With that in mind check out the specs of this Integra Type R from the "Touge Showdown 2" video (It laps Tsukuba circuit at 1:04 with an almost stock engine):
http://video.google.com/videoplay?docid=-6277203205548987907&q=touge+showdown+2&hl=en
Hows this for odd wheel/tire specs: 225/45 R16 Front, 195/55 R15 Rear
If you then compare a road race car with an advanced AWD system like the Mine's or MCR Skyline GTR, you will notice they run the same size wheels/tires front and rear.
So what does all this tell us? My theory is that, because of our primitive AWD system, our cars behave much more like a FWD car handling wise and should probaby be set up like one. That is, wider up front, skinnier in back. I have no clue what effect different sidewall sizes have, but it must play a role as well. Problem is, Im just making an argument based on what I have observed. I know jack about handling and what makes a car handle better or worse. And thus have no real way to suggest specific setups for our cars that might work. But I thought I would throw this out there and see what you all think. Maybe some of the board autocrossers might be willing to experiment and let us know the results?
J.
We've seen this car posted quite a few times, but mostly because it looks great. But not a peep about the funky wheelspecs: Rims are apparently both 17x9 +38 with a PCD changer. But note the tires, 245/40F, 225/45R. And Hideki told us that the owner had previously run the more conventional 255/40 Front and Rear. So he presumably thought this setup handled better.
Exhibit 2: From our own Handling FAQ http://www.alltrac.net/phpBB2/viewtopic.php?t=8799&postdays=0&postorder=asc&start=15
Note the first two pages discussing front and rear track and esp. CMS-GT4's observations about how keeping a wider front track seemed to improve his handling. Also related is how the article from whiteline mentions that the AWD design of the GT4 is basically adapted from a FWD design. In other words, the GT4 is more or less a FWD car with a differential putting power to the rears as well.
With that in mind check out the specs of this Integra Type R from the "Touge Showdown 2" video (It laps Tsukuba circuit at 1:04 with an almost stock engine):
http://video.google.com/videoplay?docid=-6277203205548987907&q=touge+showdown+2&hl=en
Hows this for odd wheel/tire specs: 225/45 R16 Front, 195/55 R15 Rear
If you then compare a road race car with an advanced AWD system like the Mine's or MCR Skyline GTR, you will notice they run the same size wheels/tires front and rear.
So what does all this tell us? My theory is that, because of our primitive AWD system, our cars behave much more like a FWD car handling wise and should probaby be set up like one. That is, wider up front, skinnier in back. I have no clue what effect different sidewall sizes have, but it must play a role as well. Problem is, Im just making an argument based on what I have observed. I know jack about handling and what makes a car handle better or worse. And thus have no real way to suggest specific setups for our cars that might work. But I thought I would throw this out there and see what you all think. Maybe some of the board autocrossers might be willing to experiment and let us know the results?
J.