Drag racing 101

George Blake

DONATING MEMBER
Re: Drag racing 101

Burnouts:

Here's Kilgore's take (he's right)
Kilgore reports the burnout procedure is usually the culprit for failed sprags. "Guys hit the throttle hard in First gear during the burnout. This rattles the tires at the same time they shift into Second, and that's what kills the sprag." Kilgore also said, "The sprag does all the work to stop the high-gear drum and accelerate the car, so the key is to minimize the shock load to the sprag." Examining the sprag in Smith's trans revealed it to be off center on the high-gear drum, which placed all the load on roughly four to five of the elements (there are 34 total).

The solution, according to Kilgore and several other transmission people we talked to, is to modify the burnout procedure. In Smith's case, Kilgore modified the Turbo 400 for a manual valvebody and instructed Smith to always do his burnouts in Second gear. This prevents a gear-change hit from hammering the sprag and rolling it over during the burnout. With an automatic valvebody, the best routine would be to gently start the tires spinning and quickly shift into Second gear before using heavy throttle to heat the tires.

Same thing for Gil Younger.
Put the 80e/400 in 2nd gear. This applies the band if you have one so the drum isn't spinning the wrong way and you WILL take off in 2nd gear. Shift it up into 3rd, then let off.
Big thing is NOT to let the tires grab or allow a shift into 2nd that will hammer the sprag. The problem is there is zero load then you smack it. It will roll over or damamge hard parts. The drag racing itself will nomally just wear clutches (2nd gear normally) unless you have a modded 2nd clutch set.
 

12secondSY

Syty Killer :(
Re: Drag racing 101

Good info george

As long as we're adding info I thought I'd put in a little more just so its all in one place

Stolen from sportmachines.com

Boost launch

Procedure:

1.Put the transmission in (N) Neutral.

2.Rev the engine while simutaneously pushing down HARD on the brakes.

3.The brake will set a lot tighter because the engine will produce more vacuum assist.

4.After doing this for a couple seconds the brake will be as far down as it will go.

5.Keep the brake all the way depressed, and shift the transmission into Drive (not Overdrive).

6.Start pressing on the gas pedal now to build up boost.

7.When the boost is where you want it and it is time to go, release the brake and slam the gas at the same time.

8.Typically, boost levels of somewhere between 0-5 lbs is good. Try launching at different levels to see which works best with your truck. You want a little chrip from the tires but not a lot of wheel spin. With a stock truck it's difficult to get a lot of wheel spin, but with Recipe #2, it's definitely possible.
 

George Blake

DONATING MEMBER
Re: Drag racing 101

I've had to repair a few "neutral drops" with guys doing this. You have to pay attention to what you are doing.
Please remember to LET THE RPMS COME DOWN before shifting into D.
If you shift into D while revving up in park or neutral, or you do it before the rpms come down to idle, you've done a neutral drop and you will break something.
 

Tooky

Serious about performance
Re: Drag racing 101

What happened to the bold claims of the 4L80 being "indestructible" and "you cant break it even if you try" and how it's the answer to every 700R4 problem? Now it seems like there's a certain way to gingerly drive it to avoid breaking it. And if you have too much power it will burn up 2nd gear?? I thought a junkyard 4L80 with a Transgo shift kit will handle 800HP all day long, according to so many posts I've read.

Don't get me wrong, I'm doing a 4L80 in my truck someday in the future, no doubt about that. Its just disappointing to hear these overzealous claims all along and then find out the TRUTH is that you STILL have to be careful driving it; -- I'm already used to doing that with my 700R4.

All this just makes me be VERY skeptical whenever ANYBODY makes an extraordinary claim, because it ALWAYS seems the truth is so much more disappointing than the original claim. :roll: Know what I mean???
 

dgoodhue

BuSTeD 4.3
Re: Drag racing 101

George Blake said:
I've had to repair a few "neutral drops" with guys doing this. You have to pay attention to what you are doing.
Please remember to LET THE RPMS COME DOWN before shifting into D.
If you shift into D while revving up in park or neutral, or you do it before the rpms come down to idle, you've done a neutral drop and you will break something.

Also wait and feel for the transmission to engage, before brake torqueing the motor. I tried to rush this procedure at the track in my old Typhoon, and OMG does it make an awful noise (essentially a N drop)
 

George Blake

DONATING MEMBER
Re: Drag racing 101

What I'm saying is that you have to drive it properly. You gonna drive down the street at 40mph and then shift it into reverse? Why not? Because it's stupid. Shifting a trans into a neutraldrop at 5500 RPM will destroy it. Doing a burnout, letting it hit 2nd gear and then lifting so it busts the sprag. Not smart. It will take it but not over and over. Do that ONE time in your 700, have a trailer nearby. You have to be smart. You can break it if you don't know what your doing. Neutral dropping any trans is stupid. Plain and simple. I can build an 80e that WILL take over 1800HP when driven correctly. The drums I am using in my two current builds have ALREADY been established in 7000+ pound vehicles making over 2000HPWill your 700 do that? Get real. 80e is the route. Driving it "like you stole it" and doing a neutral drop at 5500 RPM has nothing to do with each other. Same old Tooky. How ginger do you think Adam, Jeremy, Jeff, and Frank are being to theirs? Renz was in the passenger seat and I was in the back during Hardman's craziness. A 700 would not have taken that ONE trip the way Mike treated it. He gave rides. The proof is out there. Talk to any reputable trans builder and they WILL tell you the same things as stated above. Please be safe.

Guys, please remember, shifting ANY OD trans 80e,60e,700, anything from a driven gear to neutral WILL make the direct gear driven assembly run almost 3 time engine speed with no load. This is incredibly dangerous. I mean, exploding parts dangerous. This is why YOU MUST RUN A TRANS BLANKET OR SHIELD. It is a fact of racing and why rules are made the way they are.

There is being careful and being safe. Please be both.

The nuetral drop repairs I was referring to was in 700r4's, Tooky. One busted a sprag and the others busted the rear planetary. I have not seen a neutral drop damaged 80e yet, but the mechanics are possible. Revving it in neutral and then engaging "DRIVE" or "OD" will engage the forward clutches making a hell of a boom. It's just not smart.

And if you have too much power it will burn up 2nd gear
Who said that?
Too much power for a 700(where your mindset is at) and too much power for an 80e are not even in the same ballpark.
What normally happens is that 2nd gear will wear before the others do. I have personally spoken with people making well over 1000HP who have made in excess of 1000 runs and the 2nd gear clutches are what wear out first. The fix has been done and is not an issue anymore for those making those HP levels. Of course your post had nothing to do with drag racing.

Tooky said:
What happened to the bold claims of the 4L80 being "indestructible" and "you cant break it even if you try" and how it's the answer to every 700R4 problem? Now it seems like there's a certain way to gingerly drive it to avoid breaking it. And if you have too much power it will burn up 2nd gear?? I thought a junkyard 4L80 with a Transgo shift kit will handle 800HP all day long, according to so many posts I've read.

Don't get me wrong, I'm doing a 4L80 in my truck someday in the future, no doubt about that. Its just disappointing to hear these overzealous claims all along and then find out the TRUTH is that you STILL have to be careful driving it; -- I'm already used to doing that with my 700R4.

All this just makes me be VERY skeptical whenever ANYBODY makes an extraordinary claim, because it ALWAYS seems the truth is so much more disappointing than the original claim. :roll: Know what I mean???
 
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dgoodhue

BuSTeD 4.3
Re: Drag racing 101

12secondSY said:
A local guy(well what used to be local to me) made this video for first timers going to the drag strip. Thought some people on here that might be new to it would appreciate it.

http://ModdinArt.com/DragRacing101.wmv

More on staging
http://grinnerhester.com/race.html


It wasn't the best I have seen. It could use a few pointers. I often find that the peope who want to learn how to drag race, often search and look the answers. The intended people who these should be watching/reading 'a how to drag race' don't.
 
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