quote:

Originally posted by David Covey:

quote:

Originally posted by TOP38:


Is this a hardtail car?

There are a number of reasons cars want to wheelie, no enough nose weight, converter, rear gear and tires all contribute to this but also the height of the motor in the car. The more power you have the lower it needs to be. If you have enough power that you need to manage it at the launch with a hardtail then a wheelie bar is your friend and it's not to prevent big wheelies! And, No matter what, the car needs to be balanced for the combo, if it' too light up front it will be impossible to tune without limping it off the starting line.

No it is a Yanser 245in dual shock (Santhuf)
If you are not aware of them. It has the suspension (shocks/springs)right behind the driver. The engine, trans and diff are mounted like a hard tail. No driveshaft.
Engine and trans are in plane with the pinion using a coupler. So in order to get the engine lower in the car I would also have to rotate the pinion down.
I have 100 pounds in the front of the car 60 about 90 inches back which is as close as I can get to the front without making brackets, and 40 right at the tip of the chassis in front of the tires.

Dave

No experience with that deal, I do remember a car that had a joint just in front of the driver's foot box that had big wheelies also, ran TD at Maple Grove a good 4 years ago or so, should be able to look it up on youtube.
Weight on the nose will help but no where near as much as a solid framed car. With your deal, it has a running start at the weight in this position, wonder is you moved it back closer to the joint would help. Do you have a data logger? and if so are you monitoring the shock travel and rate?
How fast are you going or trying to go? A wheelie bar should still help tuning your combo.

Also have you talked to the chassis builder for his two cents?

Too be honest, I would not choose this kind of a chassis for a fast dragster.

lol...the op just got everyone riled up then ghosted

quote:

Originally posted by TOP38:

Also have you talked to the chassis builder for his two cents?

Too be honest, I would not choose this kind of a chassis for a fast dragster.

Top,

I have a data logger but do not monitor the shocks. I did on my door car, but not this one.
As stiff as the shocks are it seems to act like a slip joint. Shutting the Santhuff extension to full tight it is very slow to allow the suspension to separate. I did try ro talk to Yanser without success, but had a couple of other Yanser guys talk to me and help. That helped more than anything.
I think I am going to go back to an earlier shock setting where the car will leave the line then pick the wheels up. At least It should help with it red lighting.

As to not choosing this chassis. If I had known at the time how fast it would be, I probably would not have bought it.

I do have a wheelie bar for it, but because of how hard it is to put on and off I have not tried it. Yeah I know..lol

Thanks for your thoughts..

Dave

quote:

Originally posted by jenavet:
lol...the op just got everyone riled up then ghosted

Lol sorry about that. Been at the track all weekend.

Finally got it to go down the track consistently today. Went from a 50 to 54 pulley and pulled another 3 degrees on top of what he was already pulling out. Went a few rounds before turning it one red. He's happy to say the least

quote:

Originally posted by David Covey:

quote:

Originally posted by TOP38:

Also have you talked to the chassis builder for his two cents?

Too be honest, I would not choose this kind of a chassis for a fast dragster.

Top,

I have a data logger but do not monitor the shocks. I did on my door car, but not this one.
As stiff as the shocks are it seems to act like a slip joint. Shutting the Santhuff extension to full tight it is very slow to allow the suspension to separate. I did try ro talk to Yanser without success, but had a couple of other Yanser guys talk to me and help. That helped more than anything.
I think I am going to go back to an earlier shock setting where the car will leave the line then pick the wheels up. At least It should help with it red lighting.

As to not choosing this chassis. If I had known at the time how fast it would be, I probably would not have bought it.

I do have a wheelie bar for it, but because of how hard it is to put on and off I have not tried it. Yeah I know..lol

Thanks for your thoughts..

Dave

Dave, The way your chassis works if the wheelie bar is too low it would stop the chassis and shock from working. I guess you would jack the chassis right behind the pivot point up until the shock is topped out and it starts lifting front wheels off the ground and set the bar height there taking into account rear tire wrap up at the hit. That bar height would be very high, much higher than a normal dragster to work right.

quote:

Originally posted by Curly1:

quote:

Originally posted by David Covey:

quote:

Originally posted by TOP38:

Also have you talked to the chassis builder for his two cents?

Too be honest, I would not choose this kind of a chassis for a fast dragster.

Top,

I have a data logger but do not monitor the shocks. I did on my door car, but not this one.
As stiff as the shocks are it seems to act like a slip joint. Shutting the Santhuff extension to full tight it is very slow to allow the suspension to separate. I did try ro talk to Yanser without success, but had a couple of other Yanser guys talk to me and help. That helped more than anything.
I think I am going to go back to an earlier shock setting where the car will leave the line then pick the wheels up. At least It should help with it red lighting.

As to not choosing this chassis. If I had known at the time how fast it would be, I probably would not have bought it.

I do have a wheelie bar for it, but because of how hard it is to put on and off I have not tried it. Yeah I know..lol

Thanks for your thoughts..

Dave

Dave, The way your chassis works if the wheelie bar is too low it would stop the chassis and shock from working. I guess you would jack the chassis right behind the pivot point up until the shock is topped out and it starts lifting front wheels off the ground and set the bar height there taking into account rear tire wrap up at the hit. That bar height would be very high, much higher than a normal dragster to work right.

It would end up pretty high for sure. I was told to set it about 4-5 inches from bottom of wheel. Not sure where a slip joint would be set.
I think it would allow tire speed (spin)but again not sure.
When I first got it I didn't do anything with the shock. It would leave the line and about 10 foot or so just whip the front tires in the air. Looked and felt weird. But I don't remember having a red light problem. I talked to a guy in Vegas that won a championship with a Yancer house car (not sure if it was division or national)and he gave me some tips on set up which is where I am today. He for sure wasn't running as quick as mine runs though.

My issue with testing is I use my first time run as a test for any changes and then if I'm not happy I put it back and then my second run is what I base my dial in on.
Probably should just test all day but the only way to do that around here is to test on a Friday night and that is the night all the squirrels come out to play. So the track is usually crap.

Overall it is a great car that throws a stupid run in the mix from time to time.

Dave

David,
Any chance the shock is topping out?

It for sure was when I first got it. You could actually feel it.
I have since tightened up the shock so much it acts like a hardtail. With every click the cars 60' improved. But it pulls the wheels almost immediately on launch. That is what causes my unexpected red lights.

Dave

quote:

Originally posted by David Covey:
It for sure was when I first got it. You could actually feel it.
I have since tightened up the shock so much it acts like a hardtail. With every click the cars 60' improved. But it pulls the wheels almost immediately on launch. That is what causes my unexpected red lights.

Dave

It gets to be a head scratcher for sure. If it's 245" long or thereabouts, and you have what sounds like a sh1tload of weight about as far forward as you can go, and if the shock is about tight enough to take the suspension out of the equation, then the chassis starts sounding less and less like the issue.
How fast are you 60' ing? What is the two step set at rpm wise? Ever try a different converter? Can you really make it less aggressive at the hit and ramp it back in quickly thereafter?

60" average .993 best .985
Launch RPM 3200-3400
Used the same FTI converter since I built the engine it was built after I dyno'd, stall 6200... Engine made 1300 HP @ 6800 1050 TQ @ 5000. with just hat nozzles, I have since tuned it using port and hat nozzles. It was making more power when the rod broke. 450 TQ at idle..lol
I have a Neil Chance converter I'm going back with for next year. But I have to send it in after I dyno the new engine.
I pull 10* at the hit and ramp it in at 1.75.
I have tried pulling different amounts and ramping it in over different times.

Dave