Truck Rake

Dazed&Confused said:
Ok so what about the 2wd pullers? How do you all feel Rake effects them?
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grant less then 10 pull into this...

more rake i have had the better the truck responds
ie
33/35 f/r not droped the t/b
33"/35" dropped t/b
30/35" droped t/b no blocks
30"/35" droped t/b and block with rear set ~.5" above empty ride hieght as per center of wheel well to ground. thats roughly ~4" worth for vertical travel between loaded ride hieght and empty ride hieght.

granted with ~1200-1500lb of sand(pending fuel tank level) in the bed behind the rear axle the front naturally raise 1-2" when i weigh fronts ~3700 rear is ~4300 loaded. empty im 3900/2900

i currently put air bags on 2 weeks ago so i can keep the ~empty ride hieght and run X" suspension travel that some orgs run.

it seams to be working... im looking droping the front tires down to 25-26"dia

going back to what cooper said... truck is running darn near level
5328_1179131792026_1040072946_540755_2688813_n.jpg
 
Think of it this way for a minute:

Raise the ass 2". Drop the hitch 2" to get back to 26".

Raise the ass 10". Drop the hitch 10". And so on.

What has changed in the relationship between the hook point, the distance and elevation to the rear axle, and the center of gravity of all the mass on the front end?

Almost nothing! Fractions of a %, maybe...
 
nwpadmax said:
Think of it this way for a minute:

Raise the ass 2". Drop the hitch 2" to get back to 26".

Raise the ass 10". Drop the hitch 10". And so on.

What has changed in the relationship between the hook point, the distance and elevation to the rear axle, and the center of gravity of all the mass on the front end?

Almost nothing! Fractions of a %, maybe...
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were is you point of measure ment for rasing the rear mat?

on a CCLB 1" of travel at the axle center line is 1.2" at the hitch

example take a red rydder wagon... wieghs 100lb.

what is the most effective position one can put their body in to pull the wagon? level? or raked forward?

same thing with tug-a-war...

how about strong man comps when pulling trucks, trains, busses ETC

principle is still the same right?
 
Sledpuller said:
If Ya'll recall, my truck was set up to run 1" of travel. It had about a 1"-2" rake without the front weights.

I only added weights on the left front. When it was hooked, the front would even out, the truck bent in the middle, my rear springs compressed 1" to the stops, and it looked about level going down the track, except for the 10" space of air between the cab and bed, lol..

If the truck is bowed in the middle, you are planting all the wheels.
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Hiow much of the frame was cut ??
 
thoughts from 15 years of experience buildin trucks- and having calculated all of the weights, and the leverage angles, and the physics of rake

A raked truck with a good chassis will outpull a level truck with a good chassis every time

to prove the point for yourselves all you need is a fish scale a ruler and some weights

drill five holes 1/8" apart in the front of the ruller, and two or three in the rear.
then about two inches from the end of the ruler drill a hole to be the pivot point

use a nail or whatever you like for a pivot through that hole

now take a paper clip and some lead fish line weights and make up a couple weights

place one in the front most hole and the fish scale in the rear most hole

hold the ruler level on the pivot n pull on the fish scale and record how many ounces pull there is.

now hold the ruler so the rear of it is lower the nthe fron n measure the pull on the scale.

now let the front end of the ruler be the lowest point and measure on the scale for drag

now do it all over again putting the weights in different holes, and then again placing the scale in a different hole

You will soon see it takes a lot more pull on the scale to get the weight to over centre on the lower setting then it does when the rear is level or lower
and that changin the weight location makes a huge difference as well

it is exacty because of leverage that it works this way, because the centre of gravity of the truck is much different when the truck is raked


not to mention one can gain an inch n a bit on hitch shortening if all it has to be is the rear most part of the truck which is generally about 5' on the track more distance all things bein equal
 
Mmm...OK.

Not one mod truck is raked. I guess you're saying they're all dipsticks. Like maybe all the Formula One guys should stop screwing around with technology and such and go ask the NASCAR guys how they should set the cars up.

The fish scale test is a step in the right direction. Do you save any actual data or are you just going from memory like you usually do?
 
Ok you cant compare tube frame trucks with true pulling hitches and front stops to what most of us have DD
 
LOL were do I set my reece hitch compared to theres ? I can go on with engine mount / location / how much weight do I put on to set my front stops? OOPS dont have those

Closest thing I have is a weight box and I rarely use it cause of the doubled stack ramps

I'v ran rake and with out lucked up and done good with both , IMO its a toss up for ones truck
 
Rods said:
LOL were do I set my reece hitch compared to theres ? I can go on with engine mount / location / how much weight do I put on to set my front stops? OOPS dont have those

I'v ran rake and with out lucked up and done good with both , IMO its a toss up for ones truck
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I hear ya, but the same physics apply, unless mod truck defy physics. :hehe: Which would be cool anyway!
 
nwpadmax said:
I hear ya, but the same physics apply, unless mod truck defy physics. :hehe: Which would be cool anyway!
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compareing purpose built tube chassis to a OEM chassis frame... you should know better matt.

apple and oragnes.....
 
malibu795 said:
compareing purpose built tube chassis to a OEM chassis frame... you should know better matt.

apple and oragnes.....
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:hehe: You guys kill me....I'm out. Y'all are just going by your butts.

Go read a statics book and re-start the thread when complete :D
 
nwpadmax said:
:hehe: You guys kill me....I'm out. Y'all are just going by your butts.

Go read a statics book and re-start the thread when complete :D
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lets see some numbers mister :poke:


sound like you are saying your butt can gues better then everyone else butt :hehe:
 
not sure who nwpadmax is but whenever you have empirical data of your own to refute other peoples work and experience with, then you might call em down or make fun of them

if you actually have "your OWN real time data" and not conjectured data on rake - post it - I would love to learn and make another foot or so on the track
 
Rods said:
Ok you cant compare tube frame trucks with true pulling hitches and front stops to what most of us have DD
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malibu795 said:
compareing purpose built tube chassis to a OEM chassis frame... you should know better matt.

apple and oragnes.....
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Why can you?

seeker1056 said:
not sure who nwpadmax is but whenever you have empirical data of your own to refute other peoples work and experience with, then you might call em down or make fun of them

if you actually have "your OWN real time data" and not conjectured data on rake - post it - I would love to learn and make another foot or so on the track
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If you had a clue you might who he is you would not be so mouthy. His truck pulls very good for a reason. He knows what he is doing. Figuring things like force is what he does for a living as an engineer. He has plenty of real data and a Champions jacket to cover that data with.
 
If there wasn't difference, NWPA dmax, then a Mod hitch would be legal in the street class, eh?


Cooper is living proof you dont have to know anything to get a good hook in every now and then.:kick::hehe:
 
nuthin mouthy here - just asked for sumthin other than retorts and denigration to peoples posts and questions
I have heard him spout before, on other threads n still waitin for the backup - tellin me he is summ kinda engineer dont mean sheet to me

Show me the money

prove to me empirically and theoretically and for real that rake doesnt matter and I will retract my post AND apologize

given the number of raked trucks that outrun the not raked trucks i have seen - for whatever reasons - I dont see that data forthcoming

prove physics wrong and show me that changin the centre of gravity doesnt change the lift characteristics and thereby the minor increases in traction - inches matter in pulling - hell tenths of inches matter
 
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JOHNBOY said:
Why can you?
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i try not to compare apple to oranges...

and yes a purpose built __________ vehicle will be 99% of the time be 10x better then a OEM built ________ vehicle for the masses .

OEM chassis and tube chassis vehicles are on two completely diferent palyign fields.
 
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