About as hard a launch as I can get, (1.23 60 ft.)as low as the car sits and it's center of gravity, the bars are probably not doing much, i'm gonna raise them Friday night and see http://www.lowcountrydragway.com/images/Race%20From%204-1-06/58.html http://www.lowcountrydragway.com/images/Race%20From%204-1-06/23.html
rick, you know those pictures are just getting me more disgusted with my 1.84 60's don't you. looks great.
Good grief, I'd SAY you've got some meats under that thing! (second picture) Is your 1.23 on the FRONT wheels or the REAR wheels!
I used to be hard on bars..........oh wait.........different bars.......never mind Looks killer!!!!!!!!
It's on the front tires Rick, it's only up like that for a split second...the bars are only 3 inches off the ground and it hits them so hard it's as if it knocks the car back down. Anyone want to venture a guess as to what it might do to the times and launch geometry with bars off? or raised? Curiousity is gonna get the better of me.
Just maybe you can drag the rear bumper like Stephen Great pics I can't wait to see this beast in action at the round up
Rick, I DON`T speak from expieriance but I think I would raise them first...make a few passes ,then decide if taking them off is a good idea. It might let you get a "feel " for the taller wheelie instead of just putting it on the bumper and possibly causeing you to "panic lift" (like most people would) and cause some damage. Thats my .
Raise them a little first....dont just take 'em off What are wheelie bars? Well...obviously, they're there to control what is called pitch rotation and front end lift. The WBs "can" be a great tuning aid, but if you don't know what you're doing and don't know where to start, they can also be a nightmare. If you're hitting them pretty hard now, chances are that you're also hitting them SO hard that the rear tires are lifting up off of the track slightly...causing some tire spin and inconsistent 60' times. Raising them "might" help get the car up on the rear tires a little more, but if your car is a ladder bar rear suspension, chances are that you're just going to hit the WBs just as hard. With the front end up higher, if you still hit 'em pretty hard, you stand a chance of losing control....and we don't need that! 'Course you already know that they can also steer the car if set right. This is where you have to be really careful. Either way, if you're hitting them that hard, it might be a good idea to change the instant center. Moving it down and rearward should help. With ladder bars, just move the front mounts down one hole. On a 4 link, you have to "plot" out ALL of the IC locations (can be done at home easily) and go from there. This is exactly where a 4-link has a distinct advantage. There are many, many more combinations to work with instead of 3 or 4 measly holes in the front brackets like on a ladder bar setup. Also, ladders tend to "hit" the tires harder....but we'll save that for another lesson LOL. All that said, you can just raise them a little at a time. Some cars, depending on things like weight distribution, locations of the centers of gravity (both vertical and horizontal), like to pitch rotate a little more and get up on the rear tires for a longer period of time. The downside is that sometimes it can be wasted motion....energy that is used to pitch rotate could be better used to propel the car forward. Now, if I was tuning your car (and take this with a grain of salt...because I have not seen your car actually leave the line in person), I would move the IC location downward and shoot for an ant-squat around 80-90%. This would let the car's rear squat some at launch, yet still propel it forward and allow just enough pitch rotation to "get it on the tires". sorry for all the tech jargon...but if you have an 8-second car such as yours, sooner or later, you're going to want to learn this stuff if you want to be competitive. It ain't rocket science--merely plain physics and math calculations. If you don't already have it, it'd be a good idea to pick up a book called "Door Slammers" by Dave Morgan. Trust me when I say that it is considered the Bible of door slammer chassis tuning. Do I use WBs? No...I haven't seen a real need to put a set on yet. I guess I could, but so far, I have been able to move the instant center locations in order to induce/reduce pitch rotation. Bottom line (in my case) is consistency, and the combination I have chosen has been working. Some days with good air, it will lift 20-24" and carry them 60-70'. Most days, it just lifts 6-8" and carries 15-20' and JUST sets down...and basically "dances" on the pavement until the high gear shift. I usually don't feel the front settle...it is a very soft, predictable ride. Typical of a 4-link rear suspension...very smooth and predictable. I do have more than 100% anti-squat, which means that the rear of the car "raises" when I hit the gas...it doesn't squat...which in turn plants the rear tires harder. I guess I could try a little less, but why. It works...and works pretty darn good, so don't go messin' with it. Bottom line is tuning...a good suspension and chassis is absolutely worthless if you aren't willing to invest the time to try different things. Just make small changes at a time...don't go overboard, and most importantly USE YOUR HEAD.
i bet if you took the bars off you will get the icky feeling in your pants... better leave the bars on the car... its running fine as it is..
The inconsistency in my 60's is what is what is hurting me the most in my ability to chase the car. They can range from 1.22 to 1.32, on a good day they stay around 1.25. It is a 4 link and I don't have any anti-squat, i'm only gonna raise the bars a little at a time. I'm hoping the inconsistency is not due to changing track conditions, if it's the car at least it's something I have some control over. I'm also gonna get a close up video of the wheel spin coming out of the hole. Thanks for the advice Todd, Im sure it will help. Losing on a red light is one thing...losing on a breakout because you 60 dropped .04 is quite another. A little side bar...for you racers running a throttle cable...can it and put a throttle rod in...I made one with 10.00 dollars worth of stuff from the hardware store and the difference in throttle response was incredible...not a big deal for a someone leaving on a transbrake but if your footbraking it could be huge. I also put some Moroso Ultra 40 plug wires on...with my ignition system it made a big difference too.
I was arguing this in another thread the other day (Newton's Third Law). Where were you THEN to help defend me? 'Sounds like you've got some experience in this field. I'm glad there are guys like you (and others) here to answer newby questions that I'm sure I'll have once I finally get the car to the track.