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I made about 6 runs in late March at Lonestar Raceway west of Houston. The temperature that day was 87 deg F. My lowest ET was 12.68 and my top speed was 114.86 mph. My slowest run was a 13.09 and that was because I power braked to about 1800 rpm and totally lost traction at launch. These times were all on the original Bridgstone tires. I had a set of drag radials with me but forgot to bring the key to the wheel locks so I couldn't change to the BFG drag radials.

The same day Peter Blach ran a 12.52 at about 113.9. Multiple F owners have run in the middle 12's. The best time so far has been about 12.35 sec.

Pat R
 

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- As far as the fuel: I was running on Shell 101 octane and my fuel level was aprx. about 1/2-1 gallon @ the track most of the night. ( I drove it to the track on E, and then added close to 2 gallons of 101 octane before making the 6 runs ). I shed as much "gas" weight as possible,, without running out of gas while on my way home or down the track for the fact.. lol
Here is a good portion of your problem. You're running too much octane for what the car is tuned for. The factory ECU is tuned around 91-93 octane and you're running blended 101 which is probably averaging in the upper 90's for octane. Running too much octane harms the performance because you're not actually getting a complete combustion process.

Don't throw parts at the car until you get the car performing where it should be. Try running pure 91-93 octane and re-test at the track and see what you get.
 

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Discussion Starter · #23 ·
Thanks for all the reply's. Should the paddle shifts be utilized and the traction control off, for optimal times??

Next time I go it will be much cooler (not 100 F +) , and I will run it on Shell, 91 or 93 Octane. Probably just use 91 octane to start. I figured something had to be WAAAY wrong as I know the Borla axle-backs shouldn't have affected the numbers that drastically.

Good point Viper TT -- The 101 Octane could have messed up the ECU factory tune. The only part I've put on the car is the Borla. Still have the K&N put up in the garage in the box. I will wait until my next run at the track

thanks to all the help and hopefully I can at least dip into the low 13's or even high 12's. The combination of the heat / air density / humidity / the HIGH 101 octane and the launch could have made the times "slow". Too slow compared to all the other IS F's.

This F should easily be in the high 12's or low, low 13's. -- I will keep everyone updated as I'm going to wait about another 3 weeks before I go next and give it some time for these temperatures to cool off... (yes, the A/C was turned off too)...
 

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The F is definitely capable of hitting Mid 12's to under 12.9..Especially anyone with little bit of mods..I.E.Exhaust and intake..:)
 

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I use 97 octane and I hope my air to fuel ratio is not messed up. I've been using 97 octane ever since the car was bran new though and i'm currently running with a Joe Z intake and Tom's drop in. Any thoughts on that? the lowest octane I can get is 95. Power seems to be more than satisfactory to me though.
Also wanted to correct one of the posts that you don't actually need to keep holding the trac button for 15 seconds, 3 seconds will do
 
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