Front Tires Popping out of the Beams.

[Curly1]

So my Front Engine Dragster had problems with wheel hop. I made a bunch of chassis changes, went through 5 different tire combinations and added more bars in the chassis an finally the got that issue resolved. But.... Now it pops the front tires out of the beams.

So I have moved the battery from the middle and put it up in the nose. I had some weight on the nose and moving the battery up there will have a net increase of about 15 Lbs on the nose and hope it helps. May have to add another weight plate up there. One other thing that is related is this dragster does not seem to steer good at the finish line under full power. I think front end is simply too light. Do not like adding weight but need to do something.

Anything else I can do to help keep it from popping out of the Beams?

I am going to lower the Two Step a few hundred and see if that helps. My car is now hooking up pretty good but I need to stop the popping out of beams.

[Supercat]

Additional weight in the front is not a bad thing...
In the picture below (our car) I have 60lbs of lead, 2 fire bottles, fuel tank. Just behind the fuel tank is the XSpower battery.  We now have a nice balance on the run.
We are moving the rearward fire bottle forward and putting the battery in front of the new larger fuel tank
Our new engine is 3X"s the power of the current setup.  We also have an additional 40 lbs of lead plates if needed for the front.

[THE FRENCHTOWN FLYER]

Curly, Maybe a smaller slick would help? What size slick are you running? Do you have on-board data acquisition? A bit of tire slip may be needed at the hit?
I battled similar issues with my altered. Every so often I'd go red big time (-.030 - .050 on a full tree top bulb) and I knew it wasn't from rolling in too deep or anticipating the light. Smaller tire seemed to have stopped it.

[masracingtd1167]

I think the only way to solve it is to add some weight to the front end ! I use my wheelie bar but I run a soft side wall slick and have my bar hit when the tire squats ! If you mess around with your rpm at the hit it's going to mess with your reaction times !

[Curly1]

Thank you for the replies. Putting my wheelie bar back on did seem to help but did not resolve the issue. I have already moved the battery and will add a plate to mount more weights up front. The battery nets about 15 Lbs more than the weights I had up front but still think I need more.  I do have data logger.

[JrFuel Hayden]

Very offten I have suggested adding ANOTHER 20 lbs on the nose, to help balance the car.
I race NHRA Heritage JrFuel 225" wb with the motor out 48" and 45lbs on the nose , I know of JF cars with 75-90 lbs on the nose.
If you don't like adding weight , the best is to change the chassis so your motor is out more, and move everything out front. 
Neil and Parks has built cars with the motor out [ center of rear axle to the back of the block ] 50" and 55" .
Also you could run a looser converter, the current Comp Elim champion [ B/ND] is running 9000 stall with 10.5 x29" slicks and my 21" front wheels for more roll out. [ 5"]
Jon Hansen , Hayden Wheels , 800-624-3803

[Curly1]

Thank you I will add more weight.

[Curly1]

So I have lowered the two step from 4400 to 4000, moved my battery from the middle to the nose and added a weigh plate and about 35 Lbs additional weight.

If that does not work then I will try to set up a mechanical advance distributor to pull some timing out at lower RPM. I hate to do that because I think it may make the car less consistent.

[THE FRENCHTOWN FLYER]

Let's start with something simple. How much tire pressure do you have up front? I lowered my tire pressure from 45 psi to 35 psi for a little bit more roll out. It may help you too.

[Curly1]

I have lowered my front tire pressure to 32 which is fairly low on the little skinnies front tires. I am racing this weekend so should have some more info soon. I have moved some weight from middle to front then added some more weight up front to. Then lowered launch RPM 400 and will try that.

[Curly1]

Okay so for the report on how it worked.

 I Won!

 Reaction times came back and it worked quite well. Won a few rounds on the tree. Even handled better on top end. Before it just did not want to steer on the top end, I would be cranking wheel over and it kept going where it wanted to. Never had to abort a run but I was having to work it. Now it works better. I believe what was happening was the front end was so light under full power the front tires were scrubbing and not working good.

[slingshot383]

Lot's of information needed: How far out is the engine (axle centerline to back of block), What stall converter, What transmission, What gear ratio, What size slicks, What length chassis, Lowering your launch rpm with increase converter shock and will increase the tendency to pull the wheels out of the beams, a good launch requires wheel speed. Lots of things come into play, a converter that is to tight will tend to allow for dead hook, Wrong size slicks, or rearend gear ratio will also cause it. Balance of the car (this is where how far the engine is out in relation to chassis length comes into play.

[Paul New]

Put the wheelie bar almost on the ground

[Curly1]

I did lower the wheelie bar and it helped a little. big improvement was moving more weight up on the nose. Much better. Does not pop out of the beams now and drives really good.

[hemidakota]

What does the front end weigh? My FED has never been on the track but I have been told the front should weigh approx 375 to 400 lbs to work correctly. Think Frank Parks told me that...