BS ISF

dv8, was that with I/H/E, weight reduction and a tire only? Don't recall a full built on is cutting under a 1.8

ISFPOWER

iTrader: (20)

nice times. like others said, raise the psi. if you said you were getting too much traction, it's most likely why you are bogging as well.

Dv8tion388

iTrader: (2)

I hit a high 1.7 on the DRs once, just gotta launch at above 1k with full track. It was hot day so I only came in at 115 12.2.

Consistent 1.7s on nitrous injecting at 1500rpms


~Dv8

darbs242

iTrader: (5)

humm. after reading this I think i have figured out whats keeping me from lower 11s. Im not doing 2nd gear burn outs and I'm running my tire psi way to low in my slicks... I have one of the fastest trap speed to date im pretty sure but haven't been able to lay down a solid 60'. One of the reasons I bought a lsd over the winter. Il be at the track as soon as i get my car back hoping for a good season

MRxSLAYx

60' and DA are what its all about IMO. If I were to take my car to one of the "fast" tracks, im pretty sure it would run some amazing numbers. I've never run my car when the DA was under 1500, so I think I definitely could have hit 10s with the 125 shot.

Do you know what the DA was for your last set of runs?

My best 60' ( a 1.68x) was with a 1st gear burnout and tires at 14psi. With the updated nitrous controller and tire setup, im looking for a low 1.5 when the cars ready.

SeanGTS

iTrader: (1)

Guys, I appreciate all the of the input. I know some like to keep their secrets secrets, but really we all represent the ISF community and I think its important for all of us to put out a good showing on the drag strip.

DV8- So your left foot braking, giving it a little throttle, dumping the brake and smashing the gas on the 3rd yellow right? This is what I was trying to do, brake to the floor, throttle up. I did it so aggressively one time I was burning out at the start line before I took off, I got yelled at lol. As soon as I let off the brake she just gripped and goes, I just feel like 1st gear is longgggg. The only thing I can think of is I'm not transitioning off the brake pedal to gas pedal fast enough, or my car is low on power. Next time I will leave the tire pressure at 35 or so, if traction isn't an issue just leave it to help trap speeds? I blame the mustang guys, telling me I was crazy for running such high tire pressure. Its not like the ISF is a torque monster.

Also, do you go as far as turning the VSC off?

Should I reset the ECU prior to my drive to the track?


I will be back at it on the 14th, different track though.

Dv8tion388

iTrader: (2)

You can have all my secrets, I wont be dragging the IS-F anymore to that level.

DO NOT reset the ecu!

I found these cars do better on learned driving. Takes several drive cycles to get there. Only reset after a big mod. Never reset before a dyno unless the dyno is planned ahead of time or you can get several drive cycles out of it on the dyno.

Doing a brake stand, the idea is to know where the tires spinning point is and practice. If you hold the brake and tq it for too long it will bog. You can try the last method; hold at 800rpm then at the last yellow give it a bit more and simultaneously let go. That's worked too. Grip is key however.

Traction control should be off all the way! Press and hold the traction key for double yellows lights at idle.

~Dv8

SeanGTS

iTrader: (1)

Thanks man! More practice! It was your advice on the tire size, I appreciate the help!

Dv8tion388

iTrader: (2)

Yes, just regular weight reduction, spare, jack, mats. 17" 275 MT ET streets DR's

I recall cayman was rolling on 245 18 DRs N/A


No prob! Who knows, squeezing in some wider DRs could help launch higher without a burnout on the brake stand launch.

Remember street traction is typically worse than the strip! where you break loose on the street will typically not occur at the track(more rpm).

~Dv8

Roffles

This has always been a theory in my head, but may as well voice it to get feedback. The open differential model years ('08 and '09) seem to be a few ticks quicker in the quarter mile compared to the 2010+ models based on Internet research. Perhaps the rear locks up differently on launch. There are several reviews from the typical sources such as MotorTrend, Edmunds, and Car and Driver that show the newer models being a few tenths slower through the trap. Slower to the point of it being noteworthy in their reviews. I would provide sources but I'm lazy and it's easy enough to look up. They blame it on a green engine but I'm not so sure. It's something to think about. Maybe the limited slip models require a rethink on launching technique. Maybe it's just a slightly slower car, all things being equal.

lobuxracer

iTrader: (2)

The other factor at play here is the cars the magazines test are usually either pre-production models or have been through "special" preparation for the motoring press (usually both) and as the model gets older, the less importance this has. If you look at reviews of the MkIV Supra, there never was a quicker or faster Supra than the red hardtop C&D, Motor Trend, and Road & Track tested in 1993. The rumors in the Supra community at the time were about a special ECM from Japan specifically for magazine testing. If you run the math, it's pretty obvious this car wasn't making the rated 320 at the crank even with the 3415 curb weight of the hard top (mine weighed exactly 3415 on a certified scale, oh how I wish the F were this light).

So I have my doubts the Torsen is "at fault" here.

CarbonISF

Have any of the gear ratios or final drive changed over the years? Besides that, are you comparing to someone with a different overall tire diameter?

Roffles

Good point, but I should also add that I can confirm from my brother's '08 versus my '11 that his car "jumps" off the line, where with me, my tires sort of chirp and drag for just a tiny bit before it jumps. I also noticed it on YouTube videos and connected the dots from there with regard to the newer model year reviews being a tenth or two slower. I immediately put the blame on the Torsen gearing itself for the launch... thinking perhaps his open differential, by nature of its design, is locked and loaded and ready to fire. I never thought to seek comment or feedback from CL, but it's a difference I have observed.

Juanca

iTrader: (5)

^^^ I've mentioned this before, my '08 ISF was quicker off the line than my '12 ISF.

SeanGTS

iTrader: (1)

Update:

Raise the PSI last weekend, Quick quick burnout through 1st, maybe a 2 seconds worth at most... Couldn't break 2.0 seconds with my 60 foot on two attempts. Left after that. DA was near 2,000 for this event, as air temps were near 82 degrees. Bummed! I feel like I could do better with street radials!

The damn thing just bogs bogs bogs from 2-4k rpms, and then it takes off, frustrating! ALL nannies off, punching it to the floor.