1/8 mile Avalanche drag race results this past weekend

Well I entered my Av in the 1/8 mile drag race street class this past weekend in Elliot Lake Ontario. MY best time was 10.61 seconds and my worst was 11.01 seconds. My fastest speed was 67.1 mph. There were only a couple of other trucks there that i could compare my times to.

2002 Dodge quadcab best time 12.2 seconds

2002 2500 chev quadcab 6.6L diesel 9.75 secs, he was chipped and was propane injected, awesome truck

Ford Lightning 8.5 secs

there were two 1992 Dodge dakotas with 318 engines
they both ran about 11 seconds each.

1997 1500 chev reg cab with 5.3 engine ran about 11.5 to 12 seconds

not to many others worth mentioning. What a fantastic weekend.

My Av sure surprised a few people



Boombastic of Manitoulin

Great job!!
I see you've upgraded the exhaust, anything else? Show us your mods!!

i was like whoa!!! at first. i thought you said 1/4 mile times. then i slowed down to see you were talking about 1/8 mile times. good run.

That's impressive, congrats.

Besides any mod's not in you sig -- did you remove the skid plates?

Joe

Glad to see another one taking up the sport - that number would put you in the very high 15's in the 1/4 mile.

I run 9.0 in the 1/8 - try to avoid lightnings

To Yakmar when I figure out how to post a pic or two, I wil post them

to joediver, i didnt remove any skidplates, is there a benefit to doing that?

and for gandolphx, those r some awesome times your truck runs

Boombastic of Manitoulin

Thanks for the info and way to go Boombastic.

Question?

How did you launch? Did you do the "stomp it to the floor and go" , or did you do the "roll on the accelerator method" that 11H talks about to help with the torque management ?

Sounds like you had a blast.

Rainman0901

I have been trying both launch methods too. I think I like the ease into the pedal and have it floored around 8-10 mph, this seems to give me the quickest launch.

~bekind

Even more impressive with a nearly stock Av, here is some applause coming your way.

The advantage of removing the skid plates is slightly less weight, probably not enough to make a huge difference.

Joe

As I read the responses to my post, it has just dawned upon me the the reason for the good times at the track is a that I race the 1/8 mile in 4wd Lo, it is probably not the healthiest thing for the tranny and the t case. But u should see the look of shock on the other guys face as you whoop his butt, for me it is addictive , and I have whooped some serious butt out on the street.

P.S I wonder if 11H could give us lesson on what this does to the tranny.

Boombastic of Manitoulin

Wow I can't believe the Av can do 67 mph in 4 lo. Thats some serious stress on the drivetrain. But hey, that's what warranties are for! I am scared to do anything faster than 10 mph in low, I don't like the way it feels when it shifts gears in 4 Lo...

~bekind

my 2000 chev silverado would also do the same kind of speed in 4 lo. 4 lo has three gears in it, so it can do those kinds of speeds without redlining.

Boombastic of Manitoulin

Hey there 11h can you tell how hard, if at all, drag racing in 4 lo is on the transmission.

Boombastic of Manitoulin

I am not 11H, but I know that many of us launch our trucks in 4HI for the 1/4 mile - not all that unusual, but of course we expect to rebuild transmissions before 100K

gandolphxx said:

I am not 11H, but I know that many of us launch our trucks in 4HI for the 1/4 mile - not all that unusual, but of course we expect to rebuild transmissions before 100K

Click to expand...

So Gandolph, are you saying that the parasitic loss caused by AutoTrac affects the truck exactly the same whether it is in 4WD or 2WD, and if so, that the reason for racing in 4HI is purely for traction? Is it detrimental to attempt this in tow/haul mode?

If the track is in good shape I will launch in Auto which is less drag but still gets the launch effect that I need to get 3.5 tons moving in a straight line.

If the track is schlocky, like late in the runs, I will use 4HI to accomplish the same thing.

I have a friend who runs a 2500HD with a 150 shot of nitrous and he has to run 4HI

I have never tried a 1/8 track, I might be tempted to try 4LO, but only if I absolutely had to - currently I am in excess of 75 MPH at the 1/8 mile point. That would have been 2nd gear in my '67 GTO, it shifted into 3rd @ 105 in pedal to the metal mode.

Holy dog p*ss ... 4LO ?!

I was thinking to myself, high 15's ? ... Wow! ... Then I read you're running in 4LO ...

I'll try to put this in perspective with our trucks (1500 series)... The driveline in the 1500 avalanche (rear half) is good for about say 400-450 lb ft of (motor output) torque give or take (in a straight line; equal traction under each tire) depending on who you talk to it varies ... Now that's full-on torque; from a dead stop ... That's the worst case scenario... Once you're in motion things aren't as stressed ... The truck is designed with it also in mind that you will shock load the driveline a bit too... As long as you're not doing neutral drops, it will take it ... Now I wouldn't go hammering it to the floor from a stop with a 5,000# trailer out back though...

Now enter 4LO ...

When you are locking the driveline in 4LO or 4HI, the torque split is 50/50 ... This means that the rear driveline and front driveline share the torque the motor is making ... No biggie to the driveline now right?

Not totally... The transfer case in 4LO in the 1500 av has a reduction gear ratio of 2.72:1 ... This takes your front and rear diff to a 10.14:1 ratio presuming you have 3.73 gears ... Now, that's a down and dirty ratio (any time you increase drive ratios through gearing, torque multiplies... assuming there is input torque ... ) ... Things start spinning really fast really quick within that T case ... Remember also, the T case input is taking all that output torque from the tranny... Now reduced to 2.73:1, the whole driveline spins faster sooner under great/er torque multiplication ... Everything has to happen perfectly ... Traction, parts alignment, tire height, etc...

Climbing hills at say 3,000 RPM in 4LO in first gear has some serious torque multiplication but you are not coming out of first gear... the inertia of the truck and the driveline is much less, and if something binds, and even if the tires don't
slip all that much, you have less chance of breaking something... Things are happening at a slower speed all around ... Runnning an avalanche down the 1/8th mile on a paved track while going through the gears is IMO the ultimate test of it's driveline ... If it didn't break, it's worthy ... I'm not trying to pound it into anyone, but it is testamant to the precision and strength of our trucks 4x4 system...

Now to comment on "other settings" ...

It's one thing to run balls out in autotrac where there is slippage... (not too bad as long as it's not all the time... I would change the fluid after a hard night at the track though...)... It is also another thing to run in 4HI at a track (worse than running in autotrac I'm guessing because there's no slippage if something binds but at least you're running 1:1) ... But running in 4LO through a reduction of 2.72:1 on an aluminum T case in a 6,000+ pound truck, well I already said it...

You're riding on the odds if you do it ...I wouldn't do it in my truck ...

Now if your truck held together and it's not making funny noises from the driveline, you are probably fine... Maybe even better than fine... Because it possibly passed the ultimate QC and endurance test... Like a rock they say ... !!!

11H

*** I got a little nuts on the details, but I thought some may be interested in more than: "be careful" ... If I mis-spoke something, please provide corrections ... Sometimes I know what I'm trying to say, but don't say it right ... LOL

Thanks for the awesome input 11H. I have raced my truck in 4lo about 30- 40 times and have not had a single bit of troulble(knock on wood), hopefully 100 k from now i can say the same thing. I have decided not to race like that anymore, unless i absolutely have to, eg. a cocky fordboy or dodgeboy egg me on at the lights

Boombastic of Manitoulin

Interesting comments about performance in 4WD.

Check out these stats:


ACCELERATION (Seconds)
Zero to 30 mph: 1.3
40 mph: 2.6
50 mph: 3.6
60 mph: 5.3
70 mph: 6.9
80 mph: 9.2
90 mph: 11.8
100 mph: 15.0
110 mph: 19.5
120 mph: 26.7
Street start, 5-60 mph: 6.3
Top-gear acceleration, 30-50 mph: 8.4
50-70 mph: 8.1
Standing 1/4-mile: 13.8 sec @ 97 mph


Now try to guess what 4WD / AWD 2004 production vehicle generated these numbers.

Here is a hint: It sells for about $26,000

I find these extremely difficult to believe but here is the article:

http://www.caranddriver.com/article.asp?section_id=3&article_id=6854&page_number=1

I would guess the test equipment was way off, the engine was definitely not stock, or there may be some merit in 4WD/AWD.

FWIW,

I run 9.81 seconds in the 1/8th, and I stay in 2 wheel Hi. I have been afraid to launch as hard as I do with my transfer case engaged. At the tree, I used to mash down on the brake, and push the gas pedal down to stall speed. Mind you, I didn't do this for very long, as it's not the best thing you can do to your tranny. I did it just as the lights start falling. The problem was I would get a lot of wheel spin, sometimes for a good ways down the track. I had back off of my launch rpms so I wouldn't spin. Since I have "SuperChipped" my truck, I don't have to worry about torque management limiting my launches, therefore I don't have to do a rolling take-off.

As someone mentioned earlier, remove as much weight as you can, i.e., spare tire, unnecessary fuel, tailgate, bed mat, bed panels, etc. Also reduce tire pressure down pretty low and raise front tire pressure to maximum (assuming you are running 2 wheel drive.)


Boo.

AWD Does work at the track no doubt... In all these cars though, the T case is of the setting/type to allow some slippage:

- GM Syclone / Typhoon (AWD "Bravada" Driveline)
- 1996 Porche 911 Twin Turbo AWD (0-60 in 3 sec)
- New GM Silverado SS ... (Full time AWD ... Similar to a Full Time Autotrac)
- The EXT and the New Body Escalade (in 4X trim)

... Now only if the Viper came with Autotrac ...

11H

Yes yakmar I said 4 lo. Do not try it because it is very addictive

Boombastic of Manitoulin

Thanks for the awesome input 11H. I have raced my truck in 4lo about 30- 40 times and have not had a single bit of troulble(knock on wood), hopefully 100 k from now i can say the same thing. I have decided not to race like that anymore, unless i absolutely have to, eg. a cocky fordboy or dodgeboy egg me on at the lights

Click to expand...

Boom,,,

Here's a suggestion ... I am not advising racing in 4LO at all, so don't take this post as that... I personally don't think it's a good idea... But it's your truck...

Oh, my suggestion... Our transmissions have a 2nd gear start feature for inclement weather where we DON'T want to use first gear and spin as easy ... If you were to ever race in 4LO again, don't run it in anything but 2nd gear ... That way, it will avoid banging on the 1-2 shift, and hold 2nd longer ... Plus, starting out in 2nd will still have a hellacious launch, but with a whole lot less torque multiplication than starting in 1st or drive/OD ... Hopefully you won't need 3rd gear, and you'll avoid the 2-3 shift ...

Again, I don't think doing it is a good idea period, but at least starting in 2nd will avoid the horribly high final ratio from a dead stop, and keep the T case from banging on the 1-2 shift ... (when she bangs on the shifting, remember the whole driveline feels it...)

And you won't then need your neck brace ... Or your earplugs ... I get sick just envisioning it ...

11H

Hey 11H that is some good advice, but unfortunately you do need the 3rd gear to do the 1/8 mile race.

to those who are reading this and wish to try my method, keep in mind that this is very hard on your truck.

If you still wish to do this, keep in mind that when the truck is shifting in 4lo, the shifting is hard, something like a shift kit and also when the truck is going from 2nd gear to the 3rd and final gear, the rpms are very high and you may sometimes hit the rev limiter, to fix this pay attention to your rpm between those gears and back off on the throttle, This lets the truck shift from second to third.

Boombastic of Manitoulin

02-Z66 said:

i was like whoa!!! at first. i thought you said 1/4 mile times. then i slowed down to see you were talking about 1/8 mile times. good run.

Click to expand...

If those were 1/4 mile times, I think I'm thinking about trailering the wrong vehicle.