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Old 10-02-2007, 06:39 PM   #1
Element Tuning
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Default Redline Time Attack Summit Point Video Air Time Baby!

All I can say is yikes as most of us in the unlimited class were airborne just after the bridge. Itís hard to tell in the video but wait until the pictures from the event come out. The JIC suspension seemed to handle it well however and the car was in great control without bottoming out.

http://elementtuning.com/Videos/Elem... 2007 Web2.wmv

We recently upgraded to a Cusco 1.5 way rear diff (Thank you GearboxTech.com for getting that setup for Element Tuning) after blowing the OEM STi unit. Without any track time to break in the rear differential I showed up Sunday to race to a big surprise. The lockup was so aggressive that I had people coming up to me asking if we had converted our car to rear wheel drive as I was drifting huge all over the place. Man this was unexpected but definitely a step in the right direction to get rid of corner exit understeer. This was definitely exacerbated by my inability to build any heat into our rear Hoosiers as temps never broke much above 160F given the short race format. The aggressive lock up also had the front pushing on entry and massive oversteer on exit, really making the car very uncomfortable for me to drive. The tire temps played a big role here but also the track is very slow and our downforce really wasnít working to our advantage at these speeds. Once we get the car set up for the new diff I think it's going to be a huge improvement.

I have also been running the new 6 Gun Ball Joints and Tie Rod Ends and I think this was the ultimate test of durability. From my quick visual inspection they appear to have held up perfectly but we'll give them a much closer look as we prep for VIR.

This was our first true ďUnlimitedĒ race and itís extremely competitive with most teams +100 whp and 300-400 lbs less. This was the first time I ran our STI here and the second time Iíve run this track but I just searched for traction where I could find it which had me very slow in, hugging the inside line, and then doing my best to power out cleanly. Itís definitely not the fastest way around the track but it was the only way I could stay comfortable and consistent. Congratulations to all the winning teams and drivers!

Weíre off to VIR next week for GT Live where the car has been tested and setup so Iím looking forward to being in my element. Iíll be sharing driving duties with Tarzan Yamada that weekend, with me driving only for setup and him for racing. It will be nice to compare our times in the same car at the same track. Since this track is much higher speed with long sweepers we havenít had any issues getting the tires up to temp so for the most part Iíve decided not to change much on the setup. We will add some limited slip additive to reduce initial lockup on the Cusco differential which should help on both corner entry and exit. Weíll play with the formula until it feels just right.

Thanks,
Phil Grabow
Element Tuning
http://www.elementtuning.com
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Old 10-02-2007, 07:26 PM   #2
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That looks fast. Note for future videos, though: it'd be really nice if you could get a more centrally mounted camera position that points straight forward. It's hard to get a clear idea of your speed and lines and stuff with it skewed like that.

-Mike
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Old 10-02-2007, 09:04 PM   #3
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Nice video phil! i wonder if you have any pictures of your car flying

good luck at VIR, you should be able to do a lot better there. Being you know the track better and you should be able to get your tires up to temp better. I know when i TA or race the first lap I'm all over the wheel and on the brakes to get everything warmed up.
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Old 10-02-2007, 09:12 PM   #4
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This was at Shen right?

What are you running for times out there?

I think Skip won his class in the dark S2k running 1:39's....
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Old 10-03-2007, 12:02 AM   #5
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Interstingly the JIC 911 had bottoming out issues coming over the crest after the bridge. After the 2nd timed session on Sunday, he bottomed out HARD, and then couldn't get all-4 into the carosel, which caused him to do a chassis-grind along the top rim of the carousel, then spun in the carousel. He was also seeing the highest speed over the crest, and had the most downforce.

Last edited by eclip5e; 10-03-2007 at 01:10 AM.
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Old 10-03-2007, 08:44 AM   #6
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As far as the camera angle I'm really limited due to the mount and the available space on the cage. I would like to move the camera back but I would have to purchase a different mount.

Spazegun,

Thanks and we'll be more in our element at VIR and the car should shine but the competition won't be any easier. I know DSport Magazine took some incredible pics of the car flying through the air.

Eclip5e,

The JIC 911's chassis was extremely low to the ground, probably too low for this track, but who am I to judge the owned it!

I was scraping my front air dam on the carousel eventually grounding the nut off and you can hear the splitter scraping and flapping on my last session. This track is definitely rough on the cars!

Thanks,
Phil
www.elementtuning.com
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Old 10-03-2007, 09:16 AM   #7
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Looks good to me, just different.

Are you planning on making suspension adjustments to reduce some of the oversteer, or are you just going to focus on adjusting your driving style for a bit?
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Old 10-03-2007, 09:33 AM   #8
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Quote:
Originally Posted by jblaine View Post
Looks good to me, just different.

Are you planning on making suspension adjustments to reduce some of the oversteer, or are you just going to focus on adjusting your driving style for a bit?
Thanks! It looks good because I'm really holding back. If you saw how the car looked in my first two practice sessions when I tried to drive it how I normally would it was just wild and tail happy. To help control this I had to just about lock up the diff 50/50 which made the car more controllable on corner exit but it exacerbated the push coming into the turn. Ideally I need the diff to be open on corner entry and lock up on exit. I have a center differential controller from a board member that is programmed with a 3D PWM Map in my Hydra that I am going to try to take advantage of at GT Live.

I've never driven on this track or setup our STI here but I have lots of time at VIR where the car feels good so I am going into the event with the current setup and then make adjustments from there since I should have no problem getting the tires up to temperature.

Thanks,
Phil
www.elementtuning.com
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Old 10-03-2007, 12:41 PM   #9
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Quote:
Originally Posted by Element Tuning View Post
We recently upgraded to a Cusco 1.5 way rear diff (Thank you GearboxTech.com for getting that setup for Element Tuning) after blowing the OEM STi unit. Without any track time to break in the rear differential I showed up Sunday to race to a big surprise. The lockup was so aggressive that I had people coming up to me asking if we had converted our car to rear wheel drive as I was drifting huge all over the place. Man this was unexpected but definitely a step in the right direction to get rid of corner exit understeer. This was definitely exacerbated by my inability to build any heat into our rear Hoosiers as temps never broke much above 160F given the short race format. The aggressive lock up also had the front pushing on entry and massive oversteer on exit...
I'm trying to wrap my brain around this one. It seems to me that a very tight rear diff would cause power-on understeer, not oversteer. In the worst case scenario, RWD drag cars use a spool (which keeps both rear wheels locked together). Road racers generally don't use spools because the car will understeer like a pig under power as both rear wheels have to spin the same speed. Similarly, a very tight rear LSD is trying to make both rear wheels spin at the same speed, so the rear of the car is trying to push the car straight.

I think in your case, Phil, you've got enough power to spin the rear tires, so when you tromp on the gas the inside rear tire tries to spin as fast as the outside rear tire (due to the tight diff) and goes up in smoke, causing the power-on oversteer. In my car, which has probably 1/4 the power of yours , when I get on the gas I can feel a decided shift to understeer because of the tight Cusco rear LSD I've got.

I'm heading to Shenandoah this coming weekend. I don't think I'll be running 1:34s.

Pat Olsen
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Old 10-03-2007, 12:49 PM   #10
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Why not the cusco 2 way for the rear?
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Old 10-03-2007, 03:37 PM   #11
Element Tuning
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Quote:
Originally Posted by Patrick Olsen View Post
I'm trying to wrap my brain around this one. It seems to me that a very tight rear diff would cause power-on understeer, not oversteer. In the worst case scenario, RWD drag cars use a spool (which keeps both rear wheels locked together). Road racers generally don't use spools because the car will understeer like a pig under power as both rear wheels have to spin the same speed. Similarly, a very tight rear LSD is trying to make both rear wheels spin at the same speed, so the rear of the car is trying to push the car straight.

I think in your case, Phil, you've got enough power to spin the rear tires, so when you tromp on the gas the inside rear tire tries to spin as fast as the outside rear tire (due to the tight diff) and goes up in smoke, causing the power-on oversteer. In my car, which has probably 1/4 the power of yours , when I get on the gas I can feel a decided shift to understeer because of the tight Cusco rear LSD I've got.

I'm heading to Shenandoah this coming weekend. I don't think I'll be running 1:34s.

Pat Olsen
Have fun and catch some air!
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Old 10-03-2007, 03:39 PM   #12
Element Tuning
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Quote:
Originally Posted by STi-MAN View Post
Why not the cusco 2 way for the rear?
You should get better turn in with a 1.5 way. We can arrange the plates how we like to alter it to a 2 way if required.
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Old 10-03-2007, 03:42 PM   #13
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Ive got a nice one of you in the air. I'll oost it tonight.
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Old 10-03-2007, 06:24 PM   #14
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Quote:
Originally Posted by Element Tuning View Post
You should get better turn in with a 1.5 way. We can arrange the plates how we like to alter it to a 2 way if required.
I think you should re-arrange to a 1-way instead of a 1.5-way. This will help corner entry understeer and give you the ability to increase center diff lock to put more of the power down during corner exit.
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Old 10-03-2007, 06:43 PM   #15
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As promised.
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Old 10-03-2007, 06:58 PM   #16
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Sweeeet jebus!
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Old 10-03-2007, 07:07 PM   #17
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Haha! Nice air!
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Old 10-03-2007, 07:09 PM   #18
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Quote:
Originally Posted by Patrick Olsen View Post
I'm trying to wrap my brain around this one. It seems to me that a very tight rear diff would cause power-on understeer, not oversteer.
Most people don't experience this. If I were to venture a guess as to the mechanics behind it, it would be that because the unladen wheel must spin at the same rate as the outside wheel, the slip angle on the unladen wheel is increased to a point where it is not contributing very much to the cornering force, causing a net reduction in rear grip.

Think of your 3 wheeler going on a circle in dirt. Inside rear just spins at the rate of the outside wheel.

Any way you slice it, it would make sense for wheels sharing an axle that maximum grip will only be achieved if that axle is traveling straight, since to turn that axle is to ask one or the other to turn slower or faster than the pavement is moving by them.

Chris Lock
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Old 10-04-2007, 09:31 AM   #19
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Nice pics!

Thanks,
Phil
www.elementtuning.com
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