Lauching techniques for BFG Drs

[Grabber07']

I did a search and couldnt find what I was looking for. I am a newb when it comes to using Drag radials... I am going to the track this friday for TestNTune and my goal is a 12sec run. Can anyone give me some tips when it comes to prepping and launching off the line with 275/40/17 BFG drs? Tire pressure?

These are the things I know about the strip and drs.

1) Drive around the water
2) back your rear tires into the water box
3) Do a slight spin to get them wet
4) Pull about a foot out of the box
5) Engage line locks
6) Not sure wether to do a 1st gear or second gear burnout?
7) How long of a burnout? (these tires have 4 runs on them... will i need to break them in?)
8) Release line lock and spin forward out of the water
9) Prestage and get my RPMs up
10) Move slightly forward to get fully staged
11) What RPM do I launch at? Some say 3500Rpms some say 4500rpms?
12) Leave at the last yellow (Do I put the gas to the floor and slip the clutch? Or do I let her out?
13)Shift points... my car feels good well above 6000rpms... I usually shift 1-2 2-3 at 6400-6500 and I have to baby 4th into gear... tranny doesnt like the quick shift above 6000rpms

Are there any other tips? We do have an air pump out there so I can mess with tire pressure... are there things to watch out for as far as what the car is doing so that I can mess with tire pressure or RPMs to adjust for it?
Thanks in advance guys!!

 

[stkjock]

Paraphrasing Marc -aka Chevy Killer and his great advice...

I'd suggest a 2nd gear burnout... get the MPH to 50 or so for 3-4 seconds at least to get good heat in them. as far as the launch... you'll have to play with that IMO to see what works best.. I found slipping from 3500 worked for me. but i use 265/40/18 which have less sidewall. on the tire pressure start at 16 or so and check if after every run.. I started at 17.5 and after 3 runs I checked and they were 22!!!

shifts I think you go it in (13)... I had the same issue into 4th... and learned the hard way about that!!!

most tracks will have a compressor out for use

 

[Grabber07']

Paraphrasing Marc -aka Chevy Killer and his great advice...

I'd suggest a 2nd gear burnout... get the MPH to 50 or so for 3-4 seconds at least to get good heat in them. as far as the launch... you'll have to play with that IMO to see what works best.. I found slipping from 3500 worked for me. but i use 265/40/18 which have less sidewall. on the tire pressure start at 16 or so and check if after every run.. I started at 17.5 and after 3 runs I checked and they were 22!!!

shifts I think you go it in (13)... I had the same issue into 4th... and learned the hard way about that!!!

most tracks will have a compressor out for use

Thanks I appreciate it!! So I guess the tires increase in pressure when they get warm..makes sense. Ill start at 16 per your request and check it after a run or two. I'll deffinitley do a 2nd gear burnout for at least 4 seconds.... and play with it on the lauch... Ill start at 4000 and see what happens... if she bogs I will give it more RPMs ...if she spins Ill back off a tad. Hope this works for me!

 

[DONTLIKEYOU]

5000rpm with fast slip(almost dump) but just enuf to keep it from bogging with 16psi

 

[Grabber07']

NICE!

 

[flounderlipps]

I run the M/T drag radial 275/40/17 @ 17 psi
I launch under 3000rpm then slip the clutch and punch it my best 60' is 1.61

 

[n0nleft13]

Hey flounder, did you take that black magnet off your trunk. I would have sworn that was your car sitting in front of AAAA bike shop last night.

 

[flounderlipps]

Yes that was me
I was gettin a hoagie @ sac o subs

 

[n0nleft13]

Ok. I saw that and thought it was you. What made you take the magnet off?

 

[Grabber07']

Thanks for all of your suggestions guys... I guess we all have our own sweet spot in the rpms and clutch to lauch at. I will have to practice practice practice and find my own.

So how long does everyone do their burnout for. Do i just do it till i see smoke??

 

[matt texass]

wait till the smoke has a yellowish tint

 

[Grabber07']

Thanks for all your help guys on launching advice... it served me well!!! My first 12 second run with bolt ons!! Your so close Roper So Close. My car definitely had more in her. The air was great! I think a 12.8 or even a high 12.7 was possible but with the amount of cars there we only had time for 2 runs..which was crap by the way! but what can you do ya know? The Sway bar delete gets in this week and goes on... I will also be using a shorter belt on our next drag outing...so we'll see what she does! Cant wait to see what Longtubes and a one-piece driveshaft does. OH and I know the reaction time was crap, but there was no one racing me due to an overheater in the other lane...so I took my time and wanted to make sure i got a good launch..due to it might takeing me another 2 hours just to get back in the pits to do another run because of the amount of cars.

Im also going to post this in the timeslip thread... Thanks for everyones help!!

 

[1Fast05Turbo]

So what was your launching RPMs? did you slip or dump the clutch?

 

[Grabber07']

So what was your launching RPMs? did you slip or dump the clutch?

Launched at 4000rpms and I slipped the clutch.

I want to get my 60ft time down to a 1.7 or below... any thoughts on how to do that?

 

[1Fast05Turbo]

Launched at 4000rpms and I slipped the clutch.

I want to get my 60ft time down to a 1.7 or below... any thoughts on how to do that?

Practice. You need to find that optimum combination of launching RPMs, tire pressure, clutch, and suspension adjustability.

 

[Grabber07']

Practice. You need to find that optimum combination of launching RPMs, tire pressure, clutch, and suspension adjustability.

Your absolutely right. I still need to get an adjustable Upper control arm, adjustable panhard bar, D-spec shocks, sway bar delete, etc

Also I am sure there are more things I can do to improve my 60ft.... I will definitely play with the tire pressure. I have been keeping it around 18psi and rechecking it after every run to keep it at 18psi. It seems to be hooking well, I guess Im just not leaving hard enough...Im sqeezing her out of the hole...most likely need to up the RPMs a couple hundred and slip the clutch a little better.