I need help, I have only been able to land one 2.0 launch in my 350z drag strip career (1.5 years been to track 15 times or so). I just put on brand new BFG's KDW 265/40/18 and still getting a constant 2.2 - 2.4 60'. I am so freaking frustrated with this.

My trap speeds are great 100 to a high of 103. Last night at the track I ran 14.1 2.3 60' and 14.2' 2.4 60' twice. Im running 18psi in rear tires and Launching between 2200 - 2500 rpm. I know im capable of a 13.5 if I can get my 60' at a 1.9. PLEASE HELP!!!!

 

18 PSI is ridiculous for me: Way too much rolling resistance.

I am not sure what you expect from street tires. 2.00 seconds is not easy. Look at the Top-25 all-motor times here. Only 11 racers with street tires are running 2.00 seconds or better.

https://my350z.com/forum/drag/233840-top-25-1-4-mile-times-for-tt-st-supercharger-nitrous-bolt-ons-stock.html

Maybe its the tires? I race Goodyear Eagle F1 GS-D3 235 mm wide.

 

It didnt take much for me to get 2.0 60ft. with the AT5 in my heavy G35 with street tires . In a MT6 it maybe harder , but I think alot of it has to do with how the track is prepped and how much VHT is sprayed down to get traction on the launch.

 

Should I try upping my PSI? what rpm do you usually launch at?

 

Yea I agree....here in bithlo i cant see it being great track prep.

 

If I could see a video of a run so I can see/hear if your just spinning, or bogging I could better try to help you. Any chance of that? I hit 2.0's on my 2nd and 3rd runs stock first time out. My first was a 2.18 Keep trying you will get it!

 

I drop my pressure real low like 13-15 psi on my 295 35 r 18 firehawks. I do have the lowest trap speed on the post but it isn't because of my tires though. Most of the tires that we run on the z have a stiff side wall make the tires want to hop. I get no hop with my tires at the track. hope this helps.

 

25 PSI. RPM is about 3,000.

 

actually I do have one on you tube i put on a while back when i was completely stock i will try to find it ppw 350z vs older bmw m3 not great quality but you can see my luanch fine. let me know if you check it out if id ont post it withina few



found it http://www.youtube.com/watch?v=RKDJaeFdj1k ran 14.0 2.2 at 101. comp stock M3 ran 14.1

 

will definatly try it out this weekend. i have never put my psi that low and i do get a little wheel hop some times so we will se what happends tomorrow night.

 

will give it a shot also.....will post outcome tomorrow night if i make itout

 

Hard to tell cuz the M3 is closer to the camera, but judging by how you initially moved forward well, then kinda hesitated Id say your trying to slip the clutch too much. Almost looks like to me your letting the clutch out S L O W and then hammering it. You wanna try to make the transition from clutch in--->clutch out while easing into the throttle a very quick one. Some spin is ok! No spin is a bog, too much spin sucks. Adjust rpm and clutch disengagement speed until you nail that 2.0

edit-btw I always run 27psi inthe rears and its worked well for me. Start at 30 and drop 1psi per run if the car seems like it needs a little bit more traction with a given launch. Write down launch rpm's and tire pressures down and keep a log. See what works best and what doesnt and adjust accordingly. ALWAYS shift at redline! Good luck.

 

yea i think any time i hear tires squeel i tend let off the gas to hook up but maybe i should just keep it to the floor, i could possibly be riding the clutch too, i will keep a close eye on it and adjust as I go..........thanks again i will definatly try some new things tomorrow and let you know the outcome

 

Yes, I see many people thinking their cars need to dead "hook" to have a good 60ft time, that is not the case. A little bit of wheelspin is essential, dont just keep the gas floored if you hear it, you need to be at almost 100% throttle by the time you let the clutch out. Chances are if yuo are WOT and are stills lipping the clutch out you will spin like a **** or burn your clutch. Try to go WOT right as you are coming off the clutch completely. Finesse is the way to go, the smoother you make the transition the better your times will be. Get vids if you can...

 

Try to picture this in your head:

Transfer weight over the rear tires - hit the gas hard. When the tires catch, the front of the car rises. Hit the gas hard.

a. Try to follow and car with 10.5 inch slicks. Put your front tires in his clean patch.

b. Steering wheel straight.

c. Stage shallow. Pre-stage. Move forward a couple of inches until the stage light is flickering. Move forward one inch.

d. No tire dressing.

e. Have a good time.

 

I should post the slip I got from my first track attempt with the new vette last week. After seeing my pathetic 60' time, the op would feel alot better.

 

A lot of great advice here for you OP. When you go to the track, don't worry about the light until you get the car dialed in. That can make you jump the gun sometimes. Once you have that sweet spot figured out then practice cutting the light. Make sure you notate, or mentally remember what rpm incriment you are at also, so you know how to adjust and improve it. Good luck. P.S. I have an open diff and cut a 1.79 on Dr's a couple times, but my norm is a 1.9-2.1. I need a LSD badly.

 

I only ran a few times, and i ran on a bad day. I got a 2.1 something on my first try and heres what I did:

Tire pressure was at 28psi. I have soft tire walls already, so I dont need to drop the pressure too much. I have aftermarket suspension, so I get no hop even at full pressure.
No burn out, go around the water box.
Rev to around 3500, dont drop the clutch but slip it so the RPM stays at around 3500 until you let the clutch go. This should be very quick, and you should be smooth. Jerkiness causes the car to loose balance and spin even more.
Shift at redline, especially 1-2 and 2-3!
Ride 3rd gear out, this is where you pick up most of ur speed in the 2nd 1/8th mile (learned that the hard way, i shifted early and lost 4mph on trap! gained no time)
After the car runs, let it stay warm. N/A cars put out more power when warmed up a little bit, contrary to what people believe, letting hte car cool isnt always a good idea. Warm engine, cold air--> best combo.

 

take it from me, practice makes perfect. it took me i think 4 trips to the track before i cut a 2.0 60ft. just keep practicing, good luck!!!

 

Off topic, but for test and tune Bithlo is FAR better than gainesville on track prep. I've got friends cutting 2.0's consistently in M3's where they get a 2.1+ consistently up here.

Just out of curiosity, I picked up a tenth in my 60' doing this in my old car, but it kills the clutch. Is anybody loading the clutch when the first stage light comes on and using the e-brake to hold the car still? Having the clutch/engine loaded against the e-brake always squatted my car down some and gave me a little more bite off the line.