6-speed drag racing tips

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Since I get tons of emails/pm's about this stuff.
I figure I could get the ball rolling and everyone can add their experiences and input.

There's alot to consider.
I can't stress enough seat time. You have to know your car and study it especially the launch.
Driving on the strip is different than the street.
Here are some things that will make you ET the best even though I may not recommend this for everyone especially a beginner. You need to work up to some things and thats why seattime is so critical.

The launch is critical. Therefore you need a good clutch that can handle a high rpm launch. Launch rpm will vary depending on tires/track conditions/type of clutch. Dual disks should launch lower and same for drag radials vs. slicks.
I always slip the clutch. I like the clutch to slip slightly as the tires spin a few rotations. Keep it simple. If you start at 4500 rpms and 14 psi in a slick and the car bogs then you need to air them up or raise launch rpm or both.
Records and good data are important to achieving your goals quicker.
Try changing one thing at a time and in small increments. We can get anyone started with ballpark numbers and then the fine tuning is up to the driver.
On MT drag radials and a 450rwhp car I would start around 20 psi and 4500 rpms. This would vary due to type of clutch and track conditions, etc.
The one tricky thing is with dual disk clutches I've learned. Some guys bog and think they need to raise rpm launch to compensate but the miss the initial spin prior to the bog. In this case you often need to lower laucn rpm and raise tire pressure. This will allow the car to spin slightly less intially and carry the spin thru the bog.( atricky concept but it work). A good video from the side will help analyze the launch. smoother is always better. I can show you a video of a car with a hard htting dual disk clutch where we maximized the launch. IMO the more air you can run in your tires the better it will et provided enough traction for the launch. (So I would rather run more psi and launch easier than less psi and launch harder).
My take on Al flywheels is that if you can match the launch of a steel flywheel, you will et better. They are harder to launch but you will be rewarded when you figure out the launch. I always do a full burnout. Slightly smaller if I'm hotlapping. I use a broom handle to keep the clutch engaged while the car is sitting esp after several hot laps.
Keep an eye out for coolant and oil temps as they can affect your run although I don't get too crazy with that other than a general range.
Having an adjustable master cylinder is important too. I f you find you are having a hard time shifting at high rpm then open up the master and keep the pedal engagement high for the strip. Use a good clutch fluid and change it often.(ranger technique helps) If you overslip the clutch on the launch it can lock you out of gear so be cognizant of this and make proper adjustments/maintenance.

Shifting near the limiter without hitting it is usually the best for et with our cars. Nicking the limiter won't hurt that much and it proves that you are buzzing high enough. An occasional nick of the limiter is therefore good and confirms you're "in the game". Short shifting kills et in a racing. It's not all about how fast you can pull the shifter. It's a coordinated effort with your arm and your leg and timing is critical.
The biggest mistake I see/hear is staying on the clutch too long after the shift. Don't forget to get your left leg off the clutch as fast as you pushed it in.
Having a well setup and tuned heads/cam package is obviously important here. The higher you can safely buzz the motor is better assuming your car makes power in that rpm range. Practice shifting drills help build muscle memory. Whatever shifter feels best to each individual is my recommendation.
The more gearing the better for the launch and to keep you up in the pb quicker. But again the whole combo has to be balanced and matched. Don't forget tire diameter.
You want to be at the top of 4th gear going thru the traps for max et.
This can be accomplished with gears and tires too.
A good rule of thumb can be to cross the line 2-300 rpms above peak hp.
It's important to take advantage of all these things mentioned since our motors don't produce alot of torque n/a relatively speaking.

The suspension is fine stock for high nines so unless your going faster I wouldn't do much there other than get a drag racing alignment.(topic for another time). Lowering on the stock bolts doesn't hurt 60' and has other advantages.

Taller sidewall tires hook better, so 15 is best 16" hooks better than 18" tires. However don't over tire your car. If you can't spin them with a good burnout then the tires are too much. I see alot of guys that want more traction but they have tires good for 1.4x's. You need a good burnout, proper clutch release, proper launch rpm, and the right psi. If you have MT et street radials in 17" and your cutting 1.6-1.7x's then the problem is not the tires. I remember a guy posting that his near stock c5 Z06 was blowing the tires off. He had a stock clutch and mt et street radials and asked what tire would hook better. Guys were recommending et streets in size 16 to him. I guarantee you something else was wrong. It obviously wasn't the tires plus the stock clutch cannot handle those tires for long. I run a 28x10x15 drag radial or slick stiff walled and it holds my cars power at 20 psi for the radial and 15 psi for the slick. Don't be afraid of narrow tires, they roll better and are lighter.
Just run skinnies up front if you go with 16" slicks out back.

Quick tips:
Shallow stage
Keep car light as possible
Air up the fronts
Do a proper burnout and spin up to the line
Change on thing at a time
Take good logs
Powershift will et better whn done correctly with sticky tires
More to come

Having strong parts in the car will prevent breakage and allow you to get more seattime.

It can't hurt to mikronite and cryotreat parts in trans and rear, but not critical.
The smoother you launch the better, which includes some clutch slip, the less likely to break something. If you wheelhop, abort the run.

There is so much more and we can add as we go along here.


Found this post by Rob Z in 2008. I lived buy it and it did nothing but help alot. i have also been getting alot of pm's on how to help hook or 60 peoples car's well i say read this and live by it if your M6 because this is word for word how to go about it.

Rob

 

awesome write up. will be trying it friday

 

Nice. Thanks for the knowledge

 

This is a really good right up. But the concept that I don't quote understand is the slipping clutch concept. Everything that I have been taught is that if you have to slip the clutch to keep the car from boging then that means you don't have enough gear in the car.

 

Ill be trying some of this stuff tonighjt hopefully if the weather allows,,except the slipping the clutch, I dump mine at 5K on the lingefelter box, excellent helpful tips thanks....

 

Instead of side stepping the clutch, I read somewhere a quick slip (let go) of the clutch will help the 60? Not sure if that is correct or not, but I look forward to trying it next month.

 

tires spin, clutch slips, or engine bogs. its physics

 

Swap in an automatic...

 

If the tire, clutch, and gears all work together the car will not bog. I know this might not be the best example but look at pro stock those car do not bog, so you really can not say it is physics. Another example is if you look at old footage of stock eliminator cars from the 60s and 70s when they ran 4 speeds those cars didn't bog and they ran a 2.30 first gear not a 2.66 like ours. What I was taught by an old timer was that in order for the car to leave properly you need a first gear ratio of around 13.0 to 13.5 to 1. You obtain this through multiplying the rear gear by the first gear ratio.

 

you may sir have alot to learn. Prostock or anything with a liberty trans has power controled clutch. they are able to adjust how hard and fast the clutch engages. In there setup they are slipping the clutch some not much but some.

if non of this is true why are all the fastest 6speeds running slipper clucth's????

Here is a vid of RobZ's car Running a 255 tire that righta 255 25 or 26 tall not sureon a 16 rim and cutting low 1.3x 60's with a slipper
http://www.youtube.com/watch?v=FJed6...eature=related

and if you dont have a slipper then yes i have found the fast slip to be the best and proved it on my car and DTB's car as well..

 

Mathematics

 

I think you might be taking my questions as criticism but all they are, are questions. It just seems to me that if you slip the clutch you are leaving some E.T. On the table. Maybe I am just not understating the physics side of this but If you use the gears as the mechanical advantage and put the appropriate size tire that will let the car stick then there would be no bog. I know the pro stock reference was a bad one (I even think I stated that) but this has been proven a long time ago in the late 60s and early 70s in stock eliminator and the very early days of pro stock.

 

The guys in this vid does not seem to slip the clutch and it doesnt bog or spin?

<iframe title="YouTube video player" width="480" height="390" src="http://www.youtube.com/embed/WR8NZB32Ntc" frameborder="0" allowfullscreen></iframe>

http://youtu.be/WR8NZB32Ntc

 

the problem with what your talking about is not the clutch or the tire. if you dump even with the right gear and the chassis will load very fast and hard but just as fast as it loaded it unloaded and start's to bog or a nasty spin. good shocks to slow down the effect of unloading and alot of seat time can get it done. but mostjust do a fast slip at thats point not a dump.

 

First let me start off by saying that i by no means am trying to disrespect you in any way but in the video that i posted can you please explain where the car boged or where he sliped the clutch becasue im am honestly not seeing it. here is another video of the same car from the outside. http://youtu.be/GSyrw1VGnSk

 

but the slipper was cutting a better 60 then taners car with out spray and less power hhhmmmm and that run taner cut a 1.34 if you ask me the slipper is worth it.

 

The tires are spinning. Its only a couple of revolutions but it is what keeps the car from bogging. Something has to give when you let go of the clutch. Its either going to:

A. Spin the tires
B. Slip the clutch
C. Bog
D. Dead hook and put the car on the bumper hard

If you have a car on bias ply tires then you can dump the clutch and the tires will spin a revolution or two and keep the car from bogging. If you have a car on radials you will need to slip the clutch since radials won't recover once they start spinning, you need to dead hook them.

 

Very nice tips OP ... glad you reposted it. I will be starting at square one with an M6.

 

ill be honest with you I do not know anything about tanners car, so as far as power levels and being on spray I can not debate that. All im saying is I can find a lot more videos of people with fast street car like tanners and the guy that you posted side stepping the clutch than slipping it. Let me ask you a question lets say my car cuts 1.70 60ft with a 3.90 gear is my car going to run quicker 60ft time with more gear or by slipping the clutch?

 

If you have a stock style clutch (non slipper) its going to be quicker with more gear and dumping the clutch. It will need to be a bias ply tire though.

If you went with a slipper clutch it would be quicker. It gives you a lot of adjust-ability.