1/4 Mile Questions!

[Mohican]

Hey guys, I am about to take my car for the first quarter mile run on Friday and I have a few questions! First my car runs about 700 rwhp and I have nitto 05R 315's on stock rims. I have no work done on the suspension but that will be coming in the fall when summer is over. What rpm's are you guys launching and shifting at? Are you using launch control? Do you do a burn out to warm up the tires before your run? Also what tire pressure would you suggest? 20-25? Any other tips would be appreciated!

 

[Softballer77]

Hey guys, I am about to take my car for the first quarter mile run on Friday and I have a few questions! First my car runs about 700 rwhp and I have nitto 05R 315's on stock rims. I have no work done on the suspension but that will be coming in the fall when summer is over. What rpm's are you guys launching and shifting at? Are you using launch control? Do you do a burn out to warm up the tires before your run? Also what tire pressure would you suggest? 20-25? Any other tips would be appreciated!

I have around the same HP as you. I don't have as much drag time as a lot of others on here, but can tell you what worked for me. I've been running stock suspension as well...

Burnout= Yes. Heat them up good. I typically do a 4-5 sec burnout.

Launch Control= Yes. 3800rpm seemed to work good for me on my last track day. It was around 95 degrees, and good track conditions. Your track conditions, temps, etc will vary this though.

Traction Control= No. At least I don't. You want your DRs to work that for you if at all possible.

Shift Point= I had been shifting around redline, or about 6800-6900 rpm.

Tire Pressure= I have been running MT drag radials. 18psi worked best for me at my last track day. However again, this will vary depending on many factors. You just have to play with it a bit. Keep records of track conditions, temps, air pressures, and track times to evaluate later.

Hope that helps. It really will just come down to some "racing and learning" as not the same things works for everyone since conditions can vary so much. Just keep in mind, if you are WOT (which you will be), shifting close to redline makes it harder to not grind or even run into the notorious 1-2 shift blockage. Mine tends to grind on the 1-2, and even sometimes on the 2-3 shifts if right at redline.

Hopefully others can chime in so you can take an overall average and have a good first drag day. Good luck!

 

[biminiLX]

I ran those tires on 20x11s and ran them at 15.5 psi, 3400rpm launch, all electronics off and went [email protected] with a 1.76 60' with a 4.10, Lund tune and DRs on 20" Alcoas.
Very impressed with the tires. You will need less psi than you expect, you'll be very unhappy with 20-25psi, 15-16psi is my rec.
I did a quick transition from clutch to throttle, swapping feet quickly, not a dump.
Good luck, its a blast on track.
-J

 

[biminiLX]

Long burnout and shift 66-6800 1/2 and 2/3, try 6400 3/4.
And to both guys above, swap your rear gears or your clutch will be junk after a few trips, this car WAY too heavy with a tall 1st gear to run 3.31s, 4.10s perfect if you're under 800rwhp, 3.73 if above that.
-J

 

[Softballer77]

Long burnout and shift 66-6800 1/2 and 2/3, try 6400 3/4.
And to both guys above, swap your rear gears or your clutch will be junk after a few trips, this car WAY too heavy with a tall 1st gear to run 3.31s, 4.10s perfect if you're under 800rwhp, 3.73 if above that.
-J

My best 60ft was 1.84 with those 3.31s...10.86 at 134, but with a couple mods. I need 4.10s for sure. I'd say that should be an easy 10.4 with 4.10s. (tongue twiser). So far, clutch holding up strong. Has about 16 passes on it all with DRs, around 11k miles total now on car. DD . Only thing I DO like about the 3.31s is I go through the traps right at 68-6900rpm in 3rd. Where are you at in 4th going through the traps biminiLX? Had been wondering that. Noticed Birdoc was sticking with 4.10s as well? I agree though...it's hell launching consistently with those 3.31s.

 

[biminiLX]

You would be around 6500rpm at your trap speeds with 4.10s I'd guess, I was like 6300rpm but without mods so just under 129mph.
With the mods I have now, I'm expecting high 130s traps and my built rear will have 3.73s (if it ever gets done---need to email chassis shop now ;-) )
I will probably take the car to the track as is now with the stock rear, but I was trying to avoid that and braking an axle or Torsen.
My comment on the clutch is just that you don't have enough mechanical advantage with the 3.31s and it WILL lose the clutch in short order, sounds like you've been lucky to this point.
I'm not upgrading the clutch either until it blows
-J

 

[paluka21]

You would be around 6500rpm at your trap speeds with 4.10s I'd guess, I was like 6300rpm but without mods so just under 129mph.
With the mods I have now, I'm expecting high 130s traps and my built rear will have 3.73s (if it ever gets done---need to email chassis shop now ;-) )
I will probably take the car to the track as is now with the stock rear, but I was trying to avoid that and braking an axle or Torsen.
My comment on the clutch is just that you don't have enough mechanical advantage with the 3.31s and it WILL lose the clutch in short order, sounds like you've been lucky to this point.
I'm not upgrading the clutch either until it blows
-J

Good point on the clutch. Even with 4.10's, most drag radials for these cars in 20" are taller than the stock tire anyways, hence widening the rear gear ratio to something more along the lines of a 4.00 or 3.90 with a 4.10 rear. ( depending on the actual tire height. )

 

[carguy19]

In my drag radials I use 12-14 psi (Same nittos as you) to get the best 60 ft times.

I dont use the launch control. (if you can drive and practice you will get a better 60ft and better overall time without it).

Leave on the last yellow light, dont wait for the green, by the time you react the light will be green.

I set my shift light to 6300 and by the time the light goes off and I react I shift at about 65-6600. You dont need to rev the car to the redline. If you are at the end of the 1/4 mile and close to the traps and are at 64-6500 in 3rd gear, hold that gear instead of shifting though even if the car revs to 68-6900. Another shift will slow the car down.

 

[Softballer77]

You would be around 6500rpm at your trap speeds with 4.10s I'd guess, I was like 6300rpm but without mods so just under 129mph.
With the mods I have now, I'm expecting high 130s traps and my built rear will have 3.73s (if it ever gets done---need to email chassis shop now ;-) )
I will probably take the car to the track as is now with the stock rear, but I was trying to avoid that and braking an axle or Torsen.
My comment on the clutch is just that you don't have enough mechanical advantage with the 3.31s and it WILL lose the clutch in short order, sounds like you've been lucky to this point.
I'm not upgrading the clutch either until it blows
-J

I'm with you on the axles. Was planning on doing a few other things in there when the gears get swapped as well. I admit, I think I have been lucky too. But, I'm wanting to keep going with it till she fries as well. So far smooth sailing (knocking on this desk wood over here...), but if I keep going up in HP I know it's only a matter of time. Eh, I'll take more pride hanging that smoked one up on the wall than one that was fine but I swapped it anyways.

 

[Softballer77]

Leave on the last yellow light, dont wait for the green, by the time you react the light will be green.

That's like number one for sure on every first time racer's checklist. Surprised I didn't mention that one for him. Good catch.