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Lobux... thanks for the heads up on the 1 wheel peel.

I'll try the first session with just the 'long hold' of the VSC... and see how it goes... When your car spun the inside tire... was it with Race tires, or Street tires?

I test fit the RPF1's as well... the nice thing about the PF01 is another 1/2" of Caliper Clearance inside the wheel 'drum'... and more than 1" of caliper clearance from the face of the wheel. The RPF1's were VERY CLOSE to 'wiping off' the 'LEXUS' letters off the brake caliper.

Thanks again guys! I'll give some updates tonight!

Dave

Joe Z

iTrader: (10)

I am seriously debating the 2010 OEM Torsen unit.. But I have a long list of other "to do's" at the moment..

I might have to add "Lift in Garage" to that list too... LoL

Joe Z

ming15237

iTrader: (3)

Yes as long as the track is COMPLETELY dry, and you are VERY confident in your abilities! (Ask me how I know...) In sport mode the stability control is not as intrusive as the regular setting., But as someone else already stated you can overheat the front brakes after a short time on a dry, fast track with a few kinks/chicanes in it. I have tracked my F through 2 sets of ps2's, and this last set of RE050's, and without the system on you will not overheat the brakes unless you are REALLY pushing the hell out of it for quite some time. One thing to remember guys NEVER leave your plate on when you track your car and ALWAYS cover your VIN #!

PurduePete

Why? Because of CarFax spies all over the place?.....

SCCAForums

Thanks Guys... well I didn't have time to 'attempt' to the Pedal dance... as the 'electronic lsd' wasn't too bad, if you were VERY VERY Smooth.

Here at Auto Club Speedway (Formally California Motor Speedway)... the IS-F is at HOME! I'm hundredths off the TTB track record... so they are 'wondering' of the car classification is accurate!

I'm running 285/30/18 Race tires... and Carbotech XP12 / XP8 brakes... and the car is Just FLAT OUT HOOKED UP!!! I let my dad take it for the last session and he said 'What Understeer'... The car handles like it is on RAILS!!!

The problem is the Oval... at 150+ in the middle of Nascar 1 - 2... the rear diff starts to freak out... or something 'electronic' is NOT happy... and it cuts the power... not horribly... but it doesn't continue to accelerate until I 'lift' completely out of the throttle... and then get back on it... Not fun at 140+ mid corner. I've tried multiple different entry points... and smoother inputs to 'try' to fool it... and it seems like at 140... it's ok... but 145ish... and it's a very fine line.

Today I was 3 seconds ahead of the 2nd place car... (2nd & 3rd are good friends of mine... so they 'weren't too mad'. )

Tomorrow... once I get Fast time again... I'll do the pedal dance... and see if that removes all the 'electronic' gremlims completely.

However... I can FEEL the rear is 'light' and wants to 'unload' the inside tire in the tighter stuff, and I can imagine it may just 1 leg my 285's... like nothing... but I'll at least 'Try' and find out!

These cars are TRULY amazing... I have video of out braking just about EVERYTHING!

Thanks Carbotech! and Thanks LEXUS IS-F!

Dave

trackdood

iTrader: (1)

I got to see this... I am going there tomorrow now.... I am interested...

lobuxracer

iTrader: (2)

I was on street tires, and exiting the turn the engine revved like I had a bad clutch. Of course that's not possible...

Curious - why 285/30, when 285/35 is only 0.4% off stock and 285/30 is 4.2% smaller? Were they tires you already had for something else?

infinus

post 10 said 2 of them were from the Z06.

Maybe thats what was causing his gremlins he mentioned earlier?

lobuxracer

iTrader: (2)

Good point. Not sure how the nannies, even turned off, will behave at high speed with smaller tires. Sounds like it's time for mechanical LSD and pedal dance to be sure.

t0e

iTrader: (1)

Met dave at the track.

Very cool guy, and he was pushing the hell out of the ISF, for sure!

formula0

Thanks for the info. Since you mentioned you have gone through 2 sets of PS2's and one set of RE050's while tracking your car, can you also talk about brakes?

How many sets of pads/rotors have you gone through and what rotors/pads did you use? Any info you can provide on the wear items for track use would be greatly appreciated for those of us that want to track our IS-F's

ming15237

iTrader: (3)

2 sets to front pads now, just using the Hawk pads at this time, rears are still original, Rotors are also still original. Most recently I changed the front tires to 245/35/19's and rears are 265/35/19's Rears are a size down from what I would like, but one of my suppliers got them in on special and I only paid $150.00 each for a ps2, and as we all know "WOW, NOW THAT'S A GOOD PRICE!" before I track the car anymore I am getting a dedicated set of track wheels and tires, the wife (the budget minded one of us two) has been a little uptight about all the tire cost!

Joe Z

iTrader: (10)

Sounds like you had a Great Time Dave!!!


Can't wait to see the Videos..


Question on your speed issue... At what gear were you topping out @ 145-150 mph ish??

Sounds like the speed limiter was cutting into your power..

We have hit the limiter many times during Dyno research and it's just about what you are describing..

Here is the Drivetrain chart for OEM tire sizes.

IS-F Transmission: 8-speed automatic

Gear Ratio | Overall | (Rpm) | Mph
1st 4.60:1 | 13.50:1 (6800rpm) 39 mph
2nd 2.72:1 | 8.00:1 (6800rpm) 66 mph
3rd 1.86:1 | 5.47:1 (6800rpm) 96 mph
4th 1.46:1 | 4.30:1 (6800rpm) 122 mph
5th 1.23:1 | 3.62:1 (6800rpm) 146 mph
6th 1.00:1 | 2.94:1 est(6450rpm) 170* mph MAX
7th 0.82:1 | 2.42:1 est(5300rpm) 170* mph MAX
8th 0.69:1 | 2.01:1 est(4400rpm) 170* mph MAX
Final drive ratio 2.94:1


Regards,

Joe Z

SCCAForums

Thanks guys what an AWESOME weekend! These cars are HONESTLY AMAZING!!! SOO AMAZING!! Wow!! Just did EVERYTHING you could hope for! Insane Brakes! Insane Acceleration! Insane Grip!

Yes, I ran the 285/30's... cuz we already had 2 from the front of my Dad' Z-06... 35's probably would look better... but the gearing, and grip sure seemed perfect! The car was incredibly predictable. Not sure if the 285/35 will fit on the 'inside' of the front... on the 9.5" rim... I'll have to check. It was nice being able to rotate the tires for the following day!

It was great getting to Meet TrackDood & t0e at the track! I was giving some rides, but was unable to connect with them in time. Here are some pics...

I won both days... by more than 3 seconds over 2nd place... wining 2 free Hoosiers.

Joe... yeah... I'm not sure on the Speed Limiter... but it did kick in like that... I was only seeing about 145 to 150 in the oval when it would do it... and was in 6th gear... didn't notice RPM unfortunately... with the small tires... not sure where it was at exactly.

The more I thought about it... it seemed like it could have also been possibly due to running no TPMS... as I want to say it happened 'more often' when the Tire System Warning was displayed in the center console. Possibly it freaks out seeing a car with 'sterring' input over 140mph... and supposedly a 'flat tire'? The reason I don't think it's the rev limiter... is I was hitting 160ish on the front straight entering the oval... and would scrub down to about 150 mid corner in the oval... and pick the throttle back up... it would just go 'flat' like a speed limit, or a fuel starve. I ran more fuel... and it seemed 'better'... but I still want to say, it may have done it a time or two.

I also did the pedal dance... and 'think' it didn't do it... but I only made three laps... and came in... so I can't be sure.

On most other tracks... I don't think 140+ MPH banked corners will be relevant. The car was flawless everywhere else.

Dave

SCCAForums

A few more pics