Took my 350Z Track (Stock) to the track today. My best was 14.1@100mph. I wanted to get 13's but oh well. Time to do some mods

60ft - 2.321
330ft - 6.150
1/8ET - 9.284
1/8MPH - 79.19
1/4ET - 14.194
1/4MPH - 100.19

 

Oh ya, my rear tire pressure was at 30psi and I launched the car at 3000rpm.

 

I am starting to think that it is better not to lower your tire pressure too much on these low profile tires. I think it makes them cup and lose traction. Next time at the track I am going with about 35 psi. I think lowering them below 30 must hurt the top end performance of the car by creating more drag.

 

Good times. Did you slip the clutch?

 

this would be racing

 

Nah.....lower tire pressure=bigger tire contact patch=better launch+less 2nd & 3rd scratch

I've gotten my best trap speeds with about 25 PSI.....sure, that annoying buzzer goes off, but it's great for the 1/4.

Good runs Akira, what was the temperature by the way?

 

No offense but lowering the PSI too much is going to hurt you on a radial type street tire.

The way to tell is go and leave 2 black marks on the pavement.....if you have a good contact patch (nice and black all the way across) then you are good to go. If you have black on the outside of the tire tracks you need to add air.....blacker on the inside you need to lower pressure.

If you lower the pressure too much you will essentially be riding on the outside of the tire....street radials are not like slicks where lowering them very low gives more contact patch....slicks are very pliable and the sidewalls are very soft unlike a street tire.

 

Thanks jamr you took the words right out of my mouth.

 

No offense taken If we were talking about slick PSI's i could see this. I go down to 18 PSI on the slicks. But at 25 PSI on the street tires, i've gotten good results. Better than the results i got with 35 PSI.

 

It was around 79 degree, and I dumped the clutch at 3000rpm. Do you think I would have gotten better times by sliping the clutch?

 

I dunno.....you did it about the same way i do.....i try to get the car moving at a low RPM first, and then gun it

79 degrees is pretty good weather for normally aspirated cars......better than 102, like it is here lately!

 

nice mph....i had my tire pressure at 28 and it worked terrifc for me...i have the stock crap tires though..not sure what you have

 

I just went yesterdy to the track. I tried very hard but still only manage to get 14.17 @ 99.8 MPH. I launch pretty decent with 60' average 2.18 . I'm so mad though, since I got Borla exhaust and AEM CAI. I always spin a little in 1st, 2nd and 3rd. Like a little chirp when shifting. I always shift almost at redline. Anyone know where is it to shift best when you in already out of the hole ? Thank you. The temp was about 84 and humidity was about 90.

 

No need to do mods, get that horrible 60' down a little and you will go 13s!! For every .1 you take off of your 60' subtract .15 from your et. So if your 60' was 2.1 you would go somewhere around 13.80.

 

So if Akira drops his 60' down to 2.0 he would be running around 13.65?

 

your 14.2@100 is pretty good for a 2.32 60' get your 60' down to 2.1 and you will be into the 13.9xx

 

Thats the formula thats widely used. 100 mph is enough to go low 13s with a 1.8 or so 60'. Drag racing is about 80% 60'. Case in point I raced a LT1 at the track one day, I was on street tires he was on slicks. I spun BAD out of the hole while he pulled a 1.7 60' He ended up winning even though I pulled 118 mph and he only pulled like 106.

 

So, tell us guys, what is the best RPM to launch the car?? and when to shift??

 

Horrendous wheel hop? Center bin lid fly open and throw the rubber mat into the passenger seat?

 

I ran a 14.2 with a 2.3 60ft. When I had a 2.1 60 I ran 14.5.

Go figure.