question about yanking the tires during launch

[2QUICK2B6]

what affects yanking the tires? i've seen low 11 second cars with at least 1 tire up, and then i've seen 9 second cars without wheelie bars not yanking at all. i know cars with the HR bar don't yank them. can someone elaborate on this? i want my car to yank them at least a little bit. what's the best set up for that? grumpy's car has the atr bar and his car doesn't even yank them. and that's goin high 9s. he says it just goes. i understand that some guys don't want to yank them. so obviously it has to do with the suspension. shocks? any input? thanks.

lake wood 90/10 fronts 50/50 rears shocks moroso Drag springs in the rear air bags with metco upper and lower control arms a loose converter and good brakes with a sticky track and my car will yank the drivers tire up on DR's and its only in the 11's. Like someone said above its all how the car transfers its weight on the launch ... ive seen very slow mustangs jerk both tires up and put them back down.

 

[it's just a six]

Without a t-brake it will be hard to hold the boost. You could get air realy easy with just slicks and a t-brake with a hard boost launch. Foot brake it will be hard. You will need a good converter to spool that 66 quick enough to get air.

If you run a hydroboost brake system, brakes should hold.:biggrin:

 

[Red C5]

I was told that in this vid, my GN picked up the tires a few inches off the ground. I've got a little bit of suspension and a trans brake.

[YOUTUBE]n8WJHIXJQ5s[/YOUTUBE]

 

[bison]

If you run a hydroboost brake system, brakes should hold.:biggrin:

Probably not unless you used larger rear wheel cylinders (which are a no no on wet pavemen). I think the piston is the same size on the hydroboost and the powermaster:biggrin:

 

[rwrows]

Probably not unless you used larger rear wheel cylinders (which are a no no on wet pavemen). I think the piston is the same size on the hydroboost and the powermaster:biggrin:

my car has the factory brakes and i can hold 20 lbs of boost at the line. i put the pedal to the floor and have a stock converter. i use the parking brake. who needs a tranny brake? lol

 

[Grumpy]

ok ..back home here. here is Melissa's 10.10 @ 132/133 with a 1.47 short time (I think) Foot braking it!! .. car just took off.. after the run she left the track and drove to Dunkin Donuts for her morning coffee We are goin to work on her short time this year (I hope).. Still goin to keep reg street tires on the front.. but we are not goin to do a 2 foot wheelie's

 

[corsair231]

What I've seen done to some "home brewed" (ie: lowbuck, redneck) racers is that they would install a short length of chain between the a-arms and an upper mounting point. It would basically limit the amount of travel for the wheel to drop. What would happen is that when the rear squatted enough the slack came out of the chain and it would "snatch" the front wheel off of the pavement theoretically giving more weight transfer and better bite to the rear. I've seen it on more than one car but like I said they were racers. I would be very hesitant to trying anything like that, especially on a streeter.

 

[turbodave231]

The geometry of the rear suspension will ultimately dictate whether the car wants to pick up the front tires.

If you were to project the imaginary lines formed by the rear control arms forward into the car, the point where they intersect is called the Instant Center. The location of the IC changes with the location of the control arm attachment points and ride height.

The "Neutral Line" is an imaginary line drawn from the rear tire contact point thru the Center of Gravity out toward the front of the car. IC's that fall above the Neutral line and near the CG will cause the front to lift.

Knowing where the IC is located will help you tune the suspension for a "bigger hit" or "softer hit" and will control or cause wheelstands to happen.........but it is surely not the only factor involved with big wheelies.

Take a look at the video below..........Huge wheelies. Right? I know exactly where the IC is located. A few small changes, (torque converter and tires) caused my car to do violent wheelstands. Another small change (front suspension travel limiters) calmed the car down with no other changes....and the car now is in the 1.28-1.30 sec 60' range. The car will leave with about 2 feet of air under both tires and great traction.

If you really want to understand what is happening with your car and suspension, buy the Doorslammers book by Dave Morgan and his 4 link calculator software. If you can digest this information, you can then start effectively tuning on your suspension. Tuning your suspension without good information is a waste of time and money, IMO.

Dave

 

[V6RACER]

Too much launch RPM/Boost, no limiters on front, and aggressive rear suspension.. Learned a lot that year..



Big Wheelie from Need2Speed's Dead Hookers II at B- Video

 

[bison]

Too much launch RPM/Boost, no limiters on front, and aggressive rear suspension.. Learned a lot that year..



Big Wheelie from Need2Speed's Dead Hookers II at B- Video

What the hell was that under your car? Looked like the exhaust hanging down.

 

[XXQUICK6XX]

Here is some of mine.

 

[XXQUICK6XX]

Another

 

[V6RACER]

What the hell was that under your car? Looked like the exhaust hanging down.

The test pipe slipped off the down pipe.. Have V-band clamps now.

 

[pacecarta]

hey rodger
heres a wheel up pic for you


on an 11.98 pass
stock turbo, stock sway bars , footbraking on a D5 converter

 

[Sydwyndr]

The geometry of the rear suspension will ultimately dictate whether the car wants to pick up the front tires.

If you were to project the imaginary lines formed by the rear control arms forward into the car, the point where they intersect is called the Instant Center. The location of the IC changes with the location of the control arm attachment points and ride height.

The "Neutral Line" is an imaginary line drawn from the rear tire contact point thru the Center of Gravity out toward the front of the car. IC's that fall above the Neutral line and near the CG will cause the front to lift.

Knowing where the IC is located will help you tune the suspension for a "bigger hit" or "softer hit" and will control or cause wheelstands to happen.........but it is surely not the only factor involved with big wheelies.

Take a look at the video below..........Huge wheelies. Right? I know exactly where the IC is located. A few small changes, (torque converter and tires) caused my car to do violent wheelstands. Another small change (front suspension travel limiters) calmed the car down with no other changes....and the car now is in the 1.28-1.30 sec 60' range. The car will leave with about 2 feet of air under both tires and great traction.

If you really want to understand what is happening with your car and suspension, buy the Doorslammers book by Dave Morgan and his 4 link calculator software. If you can digest this information, you can then start effectively tuning on your suspension. Tuning your suspension without good information is a waste of time and money, IMO.

Dave

Here is a wheels up shot

 

[rwrows]

hey rodger
heres a wheel up pic for you


on an 11.98 pass
stock turbo, stock sway bars , footbraking on a D5 converter

sweet! is that scojack's car? what was the 60 ft? what tires?

 

[2QUICK2B6]

Iv got 2 pics of barley picking the drivers tire up on short 275/50/dr's

 

[Underboost]

2006 WCN
60ft 1.54 11.34 @ 116mph

 

[Roc87]

2006 WCN
60ft 1.54 11.34 @ 116mph

That's a great ET for the MPH, I have got to get my 60's down to see if I can come close to that, trouble is our track seems to be prepped with butter & sand

 

[Underboost]

That's a great ET for the MPH, I have got to get my 60's down to see if I can come close to that, trouble is our track seems to be prepped with butter & sand

Thank You! That was a full weight car.

HR Bar, 373 gears, 1lb in each airbag, 3200 stall, Tbrake @ 18psi ,Turbo PT-61w/ 63., Stock heads.