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Drag strip humor (Vishnu/FFTEC single turbo content)
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03-08-2012, 01:38 PM | #1 |
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Drag strip humor (Vishnu/FFTEC single turbo content)
Here are some funny stats for last night drag strip testing. Maybe you drag strip junkies can visualize what we were doing. The person who can describe the run most accurately (i.e., closest to the video that I'll post later today), will prove their time slip analysis skills!
Reaction time: 2.059s 60' time: 2.559s 1/8 mile ET: 8.650s 1/8 mile trap: 100.095mph 1/4 mile ET: 12.573 1/4 mile ET: 125.189 UPDATE ANSWER: Answer: Last week, we took the car to Sac raceway to do some testing. During the very first pass, the driver's side axle snapped, completely disabling the car. Luckily, i only got 20-30' before it happened so it didn't take much work to push it backwards into the paddock. Towed it back to the shop and found that it snapped right at the CV joint. These are ORIGINAL axles with 83k miles and 100+ drag launches on slicks. So it was about time I suppose. New axle: There was only 1 new axle in the US according to the dealership so i had that overnighted to me. A couple days later the car was back up and running. Doing the usual nonsense that the car has been doing for the last month since the project was completed. So we took the car back to the strip last night. This time, we had to comply to the following rules. 1) No launches 2) No WOT in 1st gear 3) No trapping over 135mph due to track safety regulations Judging by our on-road vboxing, we know the car is able of trapping over 131mph with just a rolling start. So to play it safe we decided to take it a step further and ease out in 2st and not even get on it hard until 2nd gear. Which would effectively turn a 1/4 mile pass something more like a shorter 1/5 mile pass. Something that would keep our traps and ETS slow/low enough to not get kicked off for not having a roll cage. Yet give us the info we need just as long as I keep running past the 1/4 mile mark to make up for the effectively shorter late-started run. With the vbox data, we could construct a virtual 1/4 mile pass to see if we are were we expect to be. With all the acceleration data, we could figure out the 60' time necessary to hit our target. And then we can go back and work out what is required to make this car launch without any axle hop (which is what broke our axle in the first place). And then go back, run the car and get a result representative of what it can do before finally get kicked off the track forever Or at least until we put a cage in it and make it into an embarrassingly prepped daily driver. We have some ideas on what to do with regards to curing hop during hard launches (i'll post a video of our axle breaking launch later today). And in the near future, we will be sending our axles to DSS to get upgraded. Here's the vid of the run: Couple of things we learned during these two trips to the dragstrip: 1) The car has incredible acceleration potential in the 1/8 mile. Something that we didn't expect from a big turbo. To get a late and casual start and still trap over 100mph in the 1/8th is just absurd. With an actual launch, the car should easily see 104-106mph. Boost hits HARD and post-shift torque is disgusting. I was running fully warmed MT drag tires at only 16psi just so that it would get halfway decent traction in 2nd gear. And it still spun going into 3rd (clearly audible in video). 2) Two step rev limit works incredibly well with this single turbo. Above 4000rpm, it builds more boost in neutral than the stock or upgraded twins. It make more off-the-line torque than I've ever seen before with twins. Even with the super light Spec flywheel, launching with a 2-step at anything over 4500rpm just resulted in wheelspin with fully warm 275mm Micky Thompson drag radials. Hoosier slicks will be used next time. The sidewall crinkle should soften the stock to the drivetrain nicely. I used to run them and I wish I never made the change. The MTs are nice because they can be driven on the street. But they sidewall is too stiff which beats the hell out of 6MT drivetrains. 3) NLS works beautifully. So well that when running 20psi of boost, the throttle blade stays perfectly open between gears with mid-shift boost dropping to 14psi. That is one of the advantages of running large singles with high rotational inertia. They don't de-spool as quickly during ignition cuts. Same reason why they build so much boost during 2-step rev limiting. 4) Wheel hop is evil. I've had it in the past when running stock and upgraded twins. And still cut 1.6x 60' times easily. But the car never made this much power. Nothing to really worry about on the road with street tires. But on a sticky drag strip with wide and sticky drag tires, it will be a problem as we found out during our first and only drag strip launch. You 6AT guys have it so easy. 6MT drag racers will need DSS axles. And an LSD. 5) Sac raceway trap speed and ETs are much slower than what is shown on the VBOX. Consistently. My runs are about 3mph/0.5s off. The days when Sac was a fast track are long gone. It's a heartbreaker track now. Or perhaps the VBOX is optimistic. Who knows. More testing/videos to come! Cheers, shiv Last edited by OpenFlash; 03-08-2012 at 11:31 PM.. |
03-08-2012, 01:41 PM | #2 |
Agent Smith
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You drove in reverse.
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The i8 needs a V8 amirite?
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03-08-2012, 01:42 PM | #4 |
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Unfortunately, I suck at reading time slips so i'll wait for others to chime in
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03-08-2012, 01:45 PM | #7 |
Major General
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You rolled out slowly instead of properly launching and floored it in 2nd gear. Would need to see the 330' to properly see.
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03-08-2012, 01:46 PM | #8 |
Mad Linux Guru On The Loose
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Attempted launch in 2-nd gear resulting in a 2-second wheel spin without any forward movement?
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03-08-2012, 01:49 PM | #10 |
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Waited 2 seconds after the lights went, then went all out and proved to us that this car is a 10.5 second car at the moment
tis only a guess though
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03-08-2012, 01:53 PM | #14 |
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You gave them a 2 second head start, then you did a .5 60'.
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03-08-2012, 02:07 PM | #20 |
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oh I like this
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