ATKM5

I have tried just about everything... I run the car in raised mode, with suspension on comfort and trans in "S" mode. I powerbrake to 1200 rpm and go 75% for a sec and then mash it all the way down....

So far I have achieved a 12.411@115.3 mph with a horrid 2.05 sec 60"... I have a feeling that if I'm capable to run a 1.8-1.9 sec 60, I'll be in the 12.3xxxs.

So any opinions? Suggestions?

What tire pressure should I run??

I'm running 295s in the back and I'm still struggling...

FYI, I have an 08 CLS63... I just posted here because there is more people here...

V12Godspeed

What tires are you using? Drag radials? Some MT's should do the trick...or some R comp tires.

Mikesamg

Exactly what tire size and type? 19's 20's, contis or toyo, what? The general rule I was always told by my drag racing buddies is the wider the tire the more grip but the thinner the tire the more speed. Also the taller the tired the better...so 22's may make you look cool with the ladies, it only makes me grin if you try to line up against me!

ATKM5

19x8.5 front, 255/36/19
19x9.5 rear, 295/30/19 - Hankook Ventus V12 Evo, UHP tire.. I run at 2.8 bar, should I lower the tire pressure??

DAGREEKNYC

get youself a set of rear light wieght drag wheels with drag radials . go 18 x 8.5 inch kosei or OZ ,they are about 18 lbs a piece and together with the drag radials you will get down to under a 1.7 for sure . look at juice63 's cls . he has gotten down to a 1.47 60ft !!!!!! and he runs a flat 12.0 .

Dont forget u will be dropping almost 20 pounds in rotating mass and usual rule is for every 10 pounds of rotating mass u drop its like shedding 100 pounds from the car .

enzom

If your goal is just sub 2.0, you don't need to change your wheels. I assume your tires have decent tread and they are reasonably soft.

Do a nice burnout, shallow stage. DON'T POWER BRAKE. Lift off the gas and when you are completely off, roll firmly into the throttle without stomping.

If your track is cheap and doesn't spray VHT, it will be difficult. But not impossible.

jturkel

Drag Radials

do you have a mechanical diff? not sure if the 63s have 'em

and VHT. some guys used to literally put soda on their tires or another sticky substance to help increase traction. every little bit counts.

oh. and if you don't get DRs, practice on ur tires until you get to the point where you can apply as much throttle as possible without getting wheelspin!

jikjak

what is shallow stage?

since u say dont power brake, does that mean that u dont hold the rpms at 1000-1100rpm at all? i thought we were supposed to keep it around there before launching.

benz_addict

Don't worry man I have a feeling you will beat your time Wednesday night. I just hope I'm under 13s it will be my first time dragging the CL LOL.

benz_addict

Soda??? I will try that hope they don't kick me out

enzom

Shallow-staging is when you get to the tree, stop as soon as the second set of yellow staging lights light up. After you light the first set, inch up ever so slowly until you trip the lights.

Remember that the throttle and brakes are all electonically controlled. When you are pressing both the throttle and the brake, it confuses the ECU. Also, with so much torque on tap, without drag radials, you will spin if you are over 1,200 rpm at launch. Just trust the torque. I don't touch the gas pedal until I am off the brake.

chiromikey

enzom's right when it comes to launching most 55's. the best 60ft times have all come from this method.

Hammer Down

Is that CoCo?

jturkel

thats what i have been told by some "ol' timers" though i've never tried it myself lol

some links i came across in searching to make sure i wasnt making a ridiculous claim lol

http://www.ls1tech.com/forums/drag-r...emade-vht.html

http://www.rctech.net/forum/electric...ackbite-2.html

jikjak

thanks for the pointers, i guess thats why i was struggling and unable to get under 2s when i was at the strip a couple weeks ago on street tires.

does this method also apply if u are on DRs?

if u drag experts have a minute, please take a look at my thread and see if u can help me out.

https://mbworld.org/forums/w211-amg/...rag-strip.html

chiromikey

yes, in my experience it works for both street tires and d/r's.

jikjak

ok so on DRs, do not hold the revs up at all?

i guess next time, just do a burnout, shallow stage, and when the light goes green, let go of brake and just hit the gas. would that be correct?

chiromikey

yep!

ATKM5

Thanks for your help guys! I heard that 55s just roll into the throttle, I just though that 63s need power braking. Just a couple more things,

1) How long should I keep the burnout going?
2) What should my tire pressure be?

Thanks again for all your help!

benz_addict, you will definitely break 13s, lol... Can't wait till Wednesday to race that IS-F, lol.

chiromikey

1) burnout length depends on track prep. more prep = shorter burnout and vice versa. i typically go until i see smoke in my mirrors.

2) my opinion on tire pressure is different than others and most people tend to disagree with me...however, my 60ft times tend to lend credibility to my theory. on street tires i run very near manufacture recommended pressures. on d/r's i run between 23-28lbs.

most people will say to lower pressures much more but i've found it to be counter productive. lowering pressures on street tires was an old trick that used to work well with bias ply tires. it would allow the sidewall more opportunity to flex and absorb the tq load. it doesn't work the same way with radials, and especially with low profile radials. you're not going to soften the sidewall on a low profile tire so lowering pressures isn't going to help the sidewall absorb the tq load. also since the sidewall doesn't soften, it's the contact patch that will distort on low profile radials. this causes a cupping where the inner tread lifts and you lose contact with the ground, therefor decreasing traction.

with d/r's (besides what i've previously mentioned) i believe it's also the weight of our vehicles that allows us to run more pressure. typically you would lower pressure for the same reasons stated above but with the weight of our cars, the sidewall will absorb plenty of tq compared to the typical gutted out 2k lb mustang running the same tires. therefor, i tend to run about 10psi more than most people.

Exotic-metal55

I found 26-28PSI to work time and time again for street tires. I have even helped a lot of people with 20`s improve launch and ET from setting street tire pressure in this range.. No doubt, with street tires, it is not about the sidewall flex, as there is virtually none. For me it is about getting MAX contact patch to the ground. At MFG air pressure (40ish) , the outside corners do not make contact and with to low PSI the center of the tire cups in.

You can stand behind the car with full PSI and see the full tread is not making contact (At 27PSI full contact) . Again , this is my opinion/experience and best pressure for most street tires. My invo street tires have a little softer side wall than many tires and they like 24PSI range..

+1 on drag radial presure.

enzom

I would do my burnout until I could see a hint of smoke.

I used to drop the rear PSI to 25 lbs. In my most recent runs, I left the pressure as it was (35 psi), and my 60' times were still good. If I still had the car and attended another rental, I would probably start off with stock pressure and then drop to see if I saw any benefits.

ATKM5

Cool! Thanks everyone, I will report back after Wednesday!

juicee63

A 2.05 is not horrid a 2.5 is horrid, LOL.

your trap and ET is good. You have a fast car , jeez is it stock?

You could start pushing for the CLS 63 record.

ATKM5

I think I'm very far from a record, lol. Its pretty much stock, I took out the charcoal filters, put in K&Ns, and removed the resonator, that's it... Do you powerbrake or roll into the throttle?