Author Topic: Weight bars  (Read 12580 times)

dreracecar

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Re: Weight bars
« Reply #15 on: April 25, 2017, 04:20:07 PM »
When I build a front axle, I drill a 5/8" hole in the spindle boss and weld it with the hole towards the axle tube. You can then hold the axle straight up and pour the shot thru the king-pin opening into the axle and seal it with the spindle king-pin instalation.
 Ti bolts offer the strength of steel for the weight of aluminum but are really not any stronger as there are different grades, also Ti is notch/scratch sensitive, and if you back it with anything coated with cadnium it will errode the Ti.

Offline FEDNV

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Re: Weight bars
« Reply #16 on: April 25, 2017, 06:38:24 PM »
Thanks Bruce my axle is full!!!

Offline Scott Krieger

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Re: Weight bars
« Reply #17 on: May 01, 2017, 11:08:39 AM »
Add No Weight.
Kills E.T. & MPH. Costs money, Harder to push, looks Ugly.

Launch in High Gear. adding a Safety Lock-out Button to avoid down shifting, if a two speed.

That will calm that lil shorty down. Cost you maybe two tenths in E.T. and you keep MPH.
Plus no shifting means (one less thing) equally consistency.

My Daughter's car is a 174" triple slip joint, BBC 550 HP, Turbo400 3 speed, 370 Gear, 10.5x31x15 M/T tires. No-Electronics.

Launching in 2nd gear, only Costs us about two tenths E.T. No MPH loss 1/4 mile. Calms the car enough to keep the front down.
First gear launch, car will carry the front about 30' landing back down about 50' out, running a .100 faster at the 60'.

Enjoy


Offline PSweeney

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Re: Weight bars
« Reply #18 on: May 03, 2017, 02:25:56 AM »
adding weights to balance the car is no bad thing, it doesn't have sufficient weight over the axle to steer at speed or with the chute out.  It was always going to get weight added, it was just a question of how.  I now have 38lbs in my weight bar and with a properly adjusted wheelie bar and some wheel speed, it should calm it down.

High gear is an option, but I'd be concerned at reaction times and trans temps.  I wouldn't do it without a valve body change to retain the transbrake and I don't like leaving off idle.

Offline Scottmech

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Re: Weight bars
« Reply #19 on: May 08, 2017, 08:15:34 AM »
Add No Weight.
Kills E.T. & MPH. Costs money, Harder to push, looks Ugly.

Launch in High Gear. adding a Safety Lock-out Button to avoid down shifting, if a two speed.

That will calm that lil shorty down. Cost you maybe two tenths in E.T. and you keep MPH.
Plus no shifting means (one less thing) equally consistency.

My Daughter's car is a 174" triple slip joint, BBC 550 HP, Turbo400 3 speed, 370 Gear, 10.5x31x15 M/T tires. No-Electronics.

Launching in 2nd gear, only Costs us about two tenths E.T. No MPH loss 1/4 mile. Calms the car enough to keep the front down.
First gear launch, car will carry the front about 30' landing back down about 50' out, running a .100 faster at the 60'.

Enjoy

I agree launching in 2nd will settle it down, but....respectfully disagree on other stuff.

Ur running a 3 speed.  2nd gear in a 400 isn't 1:1...more like 1.48:1.  You loose more ET with glide (normally aspirated) cause 2nd gear is 1:1.

With pro tree.......hard to get good reaction time in lunching in second (unless you have trans brake that works in second). If racing full tree and foot brake it's a moot point.

I have a 140" WB, SBC making about 420 hp, glide w/brake and 30 x 10.5 inch tires....and no wheelie bar. 

Impossible to get out of the hole in first at full throttle with no weight on front when using TB. 60 ft times were abysmal....  I had to launch in 1st for reaction time and shift to second .2-.3 sec into run to keep front down.  Really ate into the ET.  If racing and index or dial in that's not a problem.  I just wanted more ET out of the car to see what it can do. 

Put 100# on front.  Can launch full throttle on the brake and knocked 2 tenths off 60 ft time. Goes straight as an arrow. Also picked up 3 tenths at 1/8th shifting 1.5 sec into the run.....which is no where near the 7k rpm it needs to shift at.....so there's WAY more in it. 

And with how well the fronts planted...have room to remove some weight off the front if I want...but seems to have a good balance now.

I know guys running 7.0 pro with 300# of weight on front, cutting 1.1 60 ft times and never touching the wheelie bar.  Didn't seem to slow them down much....lol









Offline THE FRENCHTOWN FLYER

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Re: Weight bars
« Reply #20 on: May 15, 2017, 08:16:12 AM »
As a long term solution would you consider moving the engine "out" further from the axle CL? I did that on my wheelstand prone Logghe altered (moved the engine 7 in. forward) and it turned it into a totally different (tamer) animal, without the penalty of added weight. This solution addresses the real elephant in the room.



Prior to moving the engine I was using 80 lb of lead on the axle. Note wheelie bar positions.
« Last Edit: May 15, 2017, 08:30:22 AM by THE FRENCHTOWN FLYER »

dreracecar

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Re: Weight bars
« Reply #21 on: May 15, 2017, 08:41:29 AM »
7 inches is a bunch to move an engine, not from a weight standpoint, but a chassis design/engineering potential issues. Adding weight is the quickest way to garner results in the beginning, later on if a new chassis is to be built, one can use that information in order to move things/engine around to achive the same balence as adding the weight did with design and engineering

Offline THE FRENCHTOWN FLYER

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Re: Weight bars
« Reply #22 on: May 15, 2017, 08:59:17 AM »
FULL DISCLOSURE: I should have mentioned I DID front-half the entire chassis - after an intimate head-on encounter with a seductive concrete guard wall.

Offline PSweeney

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Re: Weight bars
« Reply #23 on: June 04, 2017, 02:37:35 PM »
No way would I move the motor out, it's purposely built to emulate a 60's digger.  I have 38lb in a weight bar, some shot to fill the axle and more lead for a weight box.

Offline THE FRENCHTOWN FLYER

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Re: Weight bars
« Reply #24 on: June 05, 2017, 01:55:23 PM »
7 inches is a bunch to move an engine, not from a weight standpoint, but a chassis design/engineering potential issues.

TRUE

I mis-spoke. I lengthened the wheelbase seven inches while moving the engine out two inches. The other five was to make room for a radiator and alternator so I could drive it around without being towed on the end of a string. I guess not having to get a tow back from the big end doesn't make it nostalgic anymore too.