R. Mutt

Bringing this one back from the grave. I've just finished reading through this entire thread and appreciate most-wanted's recommendations. I'm getting so fed up of running ****ty 60ft times. I rarely get seat time in my evo at the track because of work and how much rain we get in Vancouver. Add to that I get maybe 4 runs on a night with 30m-1hr gaps because of bad luck with track delays and guys breaking stuff. Anyway, I have more than enough power to crack a low 11/high 10 with a good 60ft but have been struggling for the past couple years to better an 11.6.

Based on reading this thread I think my two main problems are:
I'm keeping the clutch planted instead of just below the engagement as per most-wanted's "trigger" example) while on my stationary rev limiter which is set pretty low at 5,250rpm (I'm paranoid about slipping the clutch by letting out too slowly / letting it out too quickly and damaging the tcase)

My two best ET's with the car are within a couple hundreths of one another but with completely different 60ft, shifting and resulting trap speeds:

60 ... 2.197 1.834
330 ... 5.285 4.961
1/8 ... 7.753 7.580
MPH ... 103.47 92.65
1000 ... 9.854 9.794

1/4 ... 11.632 11.614
MPH ... 127.24 124.22

car makes 520whp/480ft-lbs on dyno jet and weighs 3250lbs. I'm running an exedy twin HD with ACT monloc. Looking at my trap speed which is consistently in the 126mph range - a low eleven, even a high ten should be doable.

Left run

• Shifting around 7500rpm (staying in the powerband as the boost and power start to drop off soon after.
• 245/35/18 Pilot Super Sport @ 32psi (I know...way too high).
• Evo 9 has a shorter 4th gear so I end up shifting into 5th hence the higher trap speed.

Right run

• Shifting around 8250rpm (power drops off...just wasting time needlessly).
• 265/35/18 RE71R @ 27psi
• Ran out 4th gear but keep hitting the limiter just before crossing the line (rev limiter is at 9k as the valvetrain is built to handle it)

Here are my questions if anyone has input and experience I'd really appreciate it:

1. I want to try running around 20-22psi in the tires but a few people have told me that it's not safe to go below 25psi because of the stiff sidewall. I'm asking from a safety (later down the track) and performance perspective if it's okay to try or not.
   
2. Is it really worth increasing the stat rev limit to 6,250rpm? I feel like this is overkill for my setup which is already spinning like crazy and building solid boost off the line.
   
   Note: My stat rev limiter is 5,250rpm and I build over 20psi at the line). My issue is that I mostly spin off the line and then hook in second. Even though I'm slipping the clutch I know for sure I'm letting the clutch out too quickly and not modulating my right foot on the throttle. I'm thinking it might be worth leaving my launch rpm as is and focusing on getting a solid hand of the engagement point and slipping it properly. I figure if I get that down and still see 1.8+ 60ft times then the problem is either tire pressure/launch rpm or both. Right now my 60ft times are consistently in the 2.0 range
   
   
3. I should also mention my alignment settings are somewhat aggressive as I run muellerized Ohlins set up for AutoX: F -3* camber / R -1.8* with Toe F 0 / R 1/16" In. which could be affecting things as well.
   
4. I am installing energy suspension rear diff bushings. I've read and been told that these should help wheel hop and 60ft times. I'm also hoping it cleans up some of that "slack" drivetrain feeling when putting around town in 1st/2nd gear at low rpm and throttle. Any truth to these things? What did you guys notice if you did this mod?

mt057

iTrader: (6)

Seems like you have answered your own questions. Turn up the rev limiter and don't sit on it as long. Shift earlier to stay in the power band till fourth then rev the sucker out.

Building too much boost on the line can cause you to spin due to all the torque. Turning up the two step will help you fall into the right rpm range while quickly slipping the clutch. Boost will build quickly if you are in the right rpm range for the turbo. Hope that makes sense.

With my FP Red, I would set the 2step to 6200. Build about 5psi maybe 10psi on the line and go. Don't worry about trying too much build boost on the line.

I cut consistent 1.7 60' times with street tires.

Jbundrick

This is what I've been searching for the past week. Just looking to see what mid- low 7 1/8 slips look like... I'm mostly stock and have a best of 8.40 (1.85 60' leaving around 5500). Now I see a few more things to try and get the most of of this setup before I start putting on the fp black and supporting mods. And I know my clutch will have to get changed soon.

NIevo

iTrader: (10)

Although it's been years now since I ran I do remember getting the 60' down was tough for me at first as well. I went from consistent 1.9's to consistent 1.6's just from adjusting my 2-step and clutch slippage. I was running stock size Hankook Ventus HRII's at the time as well. My 2-step was set at 6100 or 6200rpm if I remember right toward the end. I think I was building just under 15lbs of boost at launch. Like was already mentioned, if you build to much all you do is blow off the tires even with AWD.

As for the clutch I had the Cusco Twin Disc which I believe is the same as the Excedy. I would slip it for a little time at launch just to keep it at the edge of traction. Don't get me wrong, it takes some practice and it is a fine line between a 1.6 and a 1.9 60'.

As far as tire pressure goes I was running about 20 or so PSI in mine and never had a problem.

With your MPH you should be knocking on 10's for sure. I was running mid/upper 10's with only 4mph more then you.