Unfortunately they use the '08 dog WRX ... but still looks like a good article. Effect on AX times after each of these "mods," adjusting tire pressures, adding coilovers, alignment, rear sway bar, adjusting front shocks, front sway bar, Nitto NT05 tires, stiffening rear bar, adjusting tire pressures and shocks again, switching to Nitto NT01's ... with a bunch of interesting side bars.

Like the Oct. 2007 article where they essentially did the same with an earlier WRX wagon.

anyone want to post her up - or am I gonna have to run out and find one (nearest store that carries it is 30 miles away :( )

Go to their website and order your free first copy ...

Got my GRM issue earlier this week. It's definitely a good read.

anyone want to post her up - or am I gonna have to run out and find one (nearest store that carries it is 30 miles away :( )It would end up getting taken down. Just spend the $5 (or less)

An interesting article.

I thought it was funny that they pushed the camber plates out to 3 degrees, but kept 1/4" of toe out for "better turn in". I think they were too lazy to adjust the tie rods. I mean 1/4"?

I'm also surprised they didn't bring the toe into zero for the skidpad test. Once the "turn-in" phase is complete, the toe out is not helping the car get around the pad. Could be a reason why they burned through the first set of tires so quickly too.....

Maybe one of the guys from GRM will chime in with more background info.

Jay

Interesting. I'll have to run out and pick one up.

When I did the EVO Set-Up school a few years ago, we spent the morning setting up the car for fastest lap and even tire temps on a skid pad (insides about 10 degrees warmer). We would do three runs in each direction, and then make adjustments. I had custom Tein Flex's, 12K/10K springs, Hotchkis bars, adjustable lateral links, camber/caster plates, sub-frame bolts, racing bushings - a SM set-up. With the '03 WRX set-up nicely for the skid pad, it was way too loose on the autocross course in the afternoon, especially in transition/slaloms. We had to go back and soften the rear and if I recall correctly we added some rear camber, perhaps took away some of the toe out in the rear. I'm sure a better driver would have been able to use some of that looseness, but both my co-drive and I had to dial some of it out.

It would end up getting taken down. Just spend the $5 (or less)

no prob, i will get one i next time in town - didn't know if it would be an issue

Uh ... copyright laws. There are people that earn a living producing magazines. They don't when they're given away.

The article was lame. Don't bother.

Uh ... copyright laws. There are people that earn a living producing magazines. They don't when they're given away.

and they are members here too.

The article was lame. Don't bother.

I thought the article was fine if you take it for what it is. The relative improvements of each change are still educational even if their alignment was unorthodox. Plus their skid pad numbers seemed reasonable. I did email them asking to do a follow-up showing the data from the WL ALK and RCK kits, and the rear camber bushings, as well as from adding more caster and maxing the camber bolts while minimizing the camber addition from the camber plates. We'll see if they step up...

Frank

What was the actual G number, and by street tires do they mean the Nitto?

I did a sustained at 1.02g average (one lap in each direction) in a 2006 STI - Ohlin's and Continental Sport Contact 3's - -3.5' front camber, 1/8th total toe out, 0 toe in rear, -1.5' camber in rear...


Jon

it was pretty good overall

few pieces of info were off- the 08 has a 15mm rear sway bar, not a 19mm one

they wanted to "retain the stock alignment of -1.5 up front"- you'd be very lucky to get that w/ stock hardware- the oe spec front camber is only -0.1

the side bar discussion on the WL roll center kit missed the mark IMO- they talked a bunch about bump steer and nata about roll center, the tie rod end is simply along for the ride to counter the longer ball joint needed to raise the roll center

I'm not going to complain too much though, the WRX even made the cover :)

Picked it up yesterday, finally read it today. Are NT01's really considered street tires?

The article was okay, but when it said "Street tires" I thought it actually meant "street tires" and not R-Compounds.

They achieved an indicated 1+ g's with streets, ie. the Nitto NT05, after adjusting the sway bar and tire pressures ... and THEN went on to the NT01.

A properly set-up STX/WRX or STU/STI will easily corner at more then 1 G with street tires.

1g on the Traqmate, but not the real calculated number... unless I'm reading the number wrong. If you really want to get down to it, they got 1g on the traqmate with RE92s, even, but I thought only the calculated value counted.

They achieved an indicated 1+ g's with streets, ie. the Nitto NT05, after adjusting the sway bar and tire pressures ... and THEN went on to the NT01.

A properly set-up STX/WRX or STU/STI will easily corner at more then 1 G with street tires.

so what were they doing wrong? Inquiring minds want to know...

STX/STU prep:

Higher end coilovers with MUCH stiffer springs ... 10k/12k

possibly a much bigger front sway bar, ie. 27 mm.

smaller rear bar

less weight through sport seat, light weight exhaust/downpipe, light weight wheels

wider wheels, shaved tires

lowered (our tests, with National Championship winning STX WRX's, show that the benefits of lowering outweigh optimal suspension geometry) Not sure where the GRM WRX was, but typically a STX car is at around 13.5" ride height

more aggressive alignment, ie. -4 or more camber, +6 caster, more toe out front and back

stiffer bushings

... but as I pointed out above, an optimal skid pad set-up might not work in a transition rich auto cross environment

I ran some numbers. The difference between indicated and calculated Gs was about 1.1 (= traqmate/calculated) for every test they did. They stated that the difference between the 2 was because of body roll - the meter rolled, so gravity became a factor. Based on this the body roll would have been 12 degrees. Seems wrong.

Not saying the values were wrong, but I wonder why the calculated vs. measured G was so big. I'll run some more numbers at work when I am more sober.

I'm not familiar w/ the Nitto's they ran, but would wager that any of the top tier ST tires (especially shaved) would have yielded better numbers

There were definitely some wierd moments in the test, where they did something that you'd think would really help and it made the car slower around the skidpad - just another reminder of the gap between theory and reality - and between different versions of reality (i.e. autox vs track vs skidpad vs rallyx etc etc)

In the test they did a couple of years ago with the same car, Oct. '07 ... 10 mods with new lap times after each mod ... adding the coilovers did almost nothing ... except make the car easier to drive consistently at the limit ... if I recall correctly. But it doesn't seem they're really taking the time to find the best settings with the shocks.

STX/STU prep:

Higher end coilovers with MUCH stiffer springs ... 10k/12k

possibly a much bigger front sway bar, ie. 27 mm.

smaller rear bar

less weight through sport seat, light weight exhaust/downpipe, light weight wheels

wider wheels, shaved tires

lowered (our tests, with National Championship winning STX WRX's, show that the benefits of lowering outweigh optimal suspension geometry) Not sure where the GRM WRX was, but typically a STX car is at around 13.5" ride height

more aggressive alignment, ie. -4 or more camber, +6 caster, more toe out front and back

stiffer bushings

... but as I pointed out above, an optimal skid pad set-up might not work in a transition rich auto cross environment

I wonder which of these things would transition well to a track car. Obviously weight savings would help, but probably also the stiffer springs, better dampers, lower ride height (I'm lowering my track car and adding stiffer springs for this season), perhaps the stiffer front bar and softer rear bar, and perhaps a little more camber. My sti already has ~6.5 caster and -3 camber and my tire temps are pretty close to even. I have no toe out, but I doubt that you would want as much toe out on a track car as on an autocross car. I already have an ALK and RCK. Anything else for the track?

Frank

they shoulda consulted steven rankins and racerjon. they hold the subaru street tire "actual" g world record, that i know of.

luke

Frank ... I would definitely have a good racing/sport seat in a track car ... and SERIOUSLY consider a roll bar/cage. Last year a driver (police officer actually) balled up his STI at Buttonwillow/track day ... at the Talladega portion, ie. 100 mph+ section. Witnesses said he and his passenger would not have survived if they hadn't had a cage. But that's always the dilemma. Accidents happen. Are you going to keep taking a chance doing track days without maxing out your safety gear first? I was pretty uncomfortable getting 7 laps at Willow Springs in a Solo ASP C6 Z-06 as a passenger without safety gear ... accelerating through Turn 8 at 145 mph ... even though the driver was a very smooth and capable Instructor ... accidents happen ... especially with other drivers of unknown capability on the track with you.

To those who havent seen the article: I think anybody that frequents this forum should consider a grm subscription. Easily the most enjoyable car magazine to read imho and catered exactly to people like us collectively (cheapskates who wanna drive fast).

To those who havent seen the article: I think anybody that frequents this forum should consider a grm subscription. Easily the most enjoyable car magazine to read imho and catered exactly to people like us collectively (cheapskates who wanna drive fast).
+12345 My awesome wife signed me up for a 2 year subscription as a b'day present earlier this year. Best magazine subscription I've ever had! :banana:

... and if you go to their website you can get a free sample issue.

You can also get a "free" subscription when you join NASA

...Once the "turn-in" phase is complete, the toe out is not helping the car get around the pad...
Jay
On a skid pad the inside wheel's radius around the pad is smaller and a wheel with more turn dialed in will match it better.
See: ackerman
http://www.rctek.com/technical/handling/ackerman_steering_principle.html

Frank ... I would definitely have a good racing/sport seat in a track car ... and SERIOUSLY consider a roll bar/cage. Last year a driver (police officer actually) balled up his STI at Buttonwillow/track day ... at the Talladega portion, ie. 100 mph+ section. Witnesses said he and his passenger would not have survived if they hadn't had a cage. But that's always the dilemma. Accidents happen. Are you going to keep taking a chance doing track days without maxing out your safety gear first? I was pretty uncomfortable getting 7 laps at Willow Springs in a Solo ASP C6 Z-06 as a passenger without safety gear ... accelerating through Turn 8 at 145 mph ... even though the driver was a very smooth and capable Instructor ... accidents happen ... especially with other drivers of unknown capability on the track with you.

not really the thread for it, but thanks- I've seen cars blow a rod, dump oil on the track, and cause the next 2 cars through to spin and nearly total one another. Almost every time I've driven at the track there has been at least one significant accident. I've seen everything from porsche's to S2000's be totaled. Arrangements for a cage are being worked out. I already have one seat, but need to buy a 2nd. back to max traction talk!