Ladderbar front mount

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Gary 540
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Ladderbar front mount

Post by Gary 540 »

Hi all,
Can someone tell me if my chassis racecar will wheelstand more with the front ladder bar mount on the Cris Alston 36" ladderbars all the way down to bottom on front mount ?
The thing leaves like a bus, even though it can run 9.80s.
Be nice to get a wheels up photo of the thing.
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Post by speedtalk »

The lower hole should help a fuzz, but you can't do much with a ladder bar - the IC is pretty much fixed.
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Post by Gary 540 »

Thanks Don.
It only has my low torque 350 chevy 490 HP street engine in it, things should change when it it gets 740 ftlbs & 850 HP 540 BB.
It has a 51-49% front rear weight, & weighs 2300lbs on track with driver.

Gary.
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Post by speedtalk »

Gary 540 wrote:things should change when it it gets 740 ftlbs & 850 HP 540 BB.
Yep, that'll help :D
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Post by rfl28 »

gary,...if you want to strike the tire harder move the front heim joint up a hole, this will shorten the lever action of the ladder bar , help transfer more weight,...and maybe get your wheels up...that's a light car to have ladder bars...i've got a '65 chev II w/ ladder bars, have played around with them a little, but my car's 3200#'s w/me onboard....good luck w/ the bb...it should haul the mail!!!!!
stand on it!
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Post by speedtalk »

rfl28 is right, if you want hit the tires harder use the upper hole. To help pick the front end though, use the lower. Of course, this is assuming the car dead hooks either way. Again, you can't move the IC much with a ladder bar, so it won't make much difference either way.
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Post by Guest »

Thanks rfl28 & Don, I have played with it again and will race it on 13th November.
Might just need a big wad of torque.
Car hooks perfectly coming off trans brake.
1.3s in 60 with guttless motor. and wrong converter ( too low )
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Post by hookdaddy »

The simplest way to look a ladder bars is this - if you could take a big framing square and line it up on the bottom bar with the other leg of the sguare lined up on the center of the front rod end. Everything forward of that line is the weight the ladder bar must "lift" to transfer weight. You can see how moving the bar down also moves the top of the perpendicular line forward reducing the weight the ladder bars "see" and the work required to lift the front end.
The problem comes when you make it so easy to transfer weight that the front suspension can't control what's happening. Many racer's get the front coming up so fast that the front suspension tops out before the car can build enough forward momentum to overcome the negative weight transfer caused by a front suspension that is now trying to go the other way.
Most cars don't have the horsepower necessary to keep the wheels going up while accelerating forward so they "drop the nose" and unload the read tires.

But to get back to your original question - simply raising or lower the front tells me nothing if we don't know where you are in the first place.
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Post by Gary 540 »

Thanks Don, brilliant answer. My car does top out the front suspension, and maybe it is turning the tyre just a tiny bit ? I will put a mark on it and get someone to watch.
Many racer's get the front coming up so fast that the front suspension tops out before the car can build enough forward momentum to overcome the negative weight transfer caused by a front suspension that is now trying to go the other way.
Most cars don't have the horsepower necessary to keep the wheels going up while accelerating forward so they "drop the nose" and unload the read tires.
Don I would love to work with you on setting this car up a little better if you could please spare the time to help.
But to get back to your original question - simply raising or lower the front tells me nothing if we don't know where you are in the first place.
What information would you like, so maybe I can get this car leaving on the back wheels ?
Regards
Gary.
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Post by hookdaddy »

Gary - what you need to remember (other than what I first posted ) is that how most people discuss ladder bar tuning assumes that the lower bar starts out level (parallel to the ground ). This isn't always the case. I'd assume (and you now what that does :D ) that your bottom bar is parallel or pointed slightly down hill. Is that right? If so remember that once you get past level (so that the imaginary vertical line is starting to lean back. It begins to require the ladder bar to lift a higher percentage of vehicle weight in effect slowing down the rate of rise. Depending on your starting point you may just need a small adjustment. You should also use a good set of fully adjustable front shocks (rear one are a good idea too) DON'T use 90/10's or 3 way adjustables !! Their problem is they really adjust the shocks resistence during both the bump & rebound process equally and usually don't allow the front to settle fast enough at speed.

Id'd be glad todiscuss any of this further. You can get my email address or phone # off my web site at www.swracecars.com
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Post by Bumps440 »

Don I have all S&W parts in my car and while it is working well now, I did have a problem with the ft rising too fast last year and have since fixed the problem. BUT I , like most who come to this board are eager to learn as much as we can about all subjects. So I would hope that you would post to this board the solutions , and tendencies of what adjustments do what and what is the logical fix to many peoples hook problems. This is a subject that is hard to get answers for in the real world. I would like to just follow along on this discussion for now , and would ask Questions as necessary.
Thanks for taking the time to get involved in some of our hook problems.

Bob
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Post by hookdaddy »

Bob - I'll be around but as always feel free to call me anytime.
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Post by Gary 540 »

Don I sent you an email to above link.
I have put ladderbars on top hole, a pretty big angle change, adjusted the koni's to full soft, bump and rebound, given it a tiny bit of negative pinion angle ( pinion angle has nothing to do with hook, only helps the rear uni to live correct ? )
Will run 6 psi in rear 14x32 Goodyear slicks.
I will leave off the trans brake at approx 5000 ( new converter also )
I am racing it today so it will be interesting to see what the hell happens.
Hope it doesn't still leave like a bus.
Regards
Gary..
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Post by hookdaddy »

Gary - you are correct on pinion angle. With ladder bars there is no way for the pinion to move like it could due to leaf spring wrap up.

Be careful with all these big changes - it's real easy to get "lost" and not know what fixed what.
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Post by Gary 540 »

Hi Guys, Raced the car on the 13th Nov. " still leaves like a bus " ?

Maybe I should start screwing aroung with shocker settings, and put a longer travell front strut in the car with a heap more stored energy ?

9.90 with a 1.5 60' Yuk, 136 mph.

Gary.
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