corax
07-12-2011, 06:29 PM
I ran across this stadium truck resto/refurb thread over on another forum -> Click Me (http://www.specialstage.com/forums/showthread.php?44037-Toyota-MTEG-Stadium-Truck-Build). Actually, the guy's making it into a stage rally machine. Interesting reading for fans of the old school jumping Toys
http://www.racefactoryinc.com/racegarage/stadium1.jpg
Some of the suspension tech is strange to me, but I imagine it was the height of innovation back in the day. Take for example progressive rate front torsion bars - here are some of the suspension highlights:
This truck was built before the use of bypass shocks. It was also built in a time period when rising rate suspension was first being used on dirt bikes. Toyota (PPI) use "A LOT" of rising rate suspension design on this truck.
Front suspension uses triple rate torsion bars on the lower arms & a single "bump stop" torsion bar on the top arm. All stages are adjustable and many different diameter (rate) torsion bars are available.
http://www.racefactoryinc.com/racegarage/ppi_frontsusp1.jpg
Front shocks (3) are lay down cross-over style on front.
http://www.racefactoryinc.com/racegarage/ppi_frontsusp2.jpg
Front suspension is "limited" around 16", but can cycle 18+
http://www.racefactoryinc.com/racegarage/ppi_frontsusp3.jpg
The rear suspension of the truck gets really interesting…Cantilever arms on rollers, bump control on shock extension, dual torsion bars. Rear suspension is also "limited" to around 16", but can get much more. Toyota had limited the suspension on the truck to get it to “fly” level.
http://www.racefactoryinc.com/racegarage/ppi_rearsusp2.jpg
Rear suspension uses a cantilever front arm that extends (pulls) the shocks on wheel up travel & compresses the shocks on wheel drop (normal rebound). Complete opposite of how most suspensions function. The cantilever arm also uses a torsion bar for the spring.
http://www.racefactoryinc.com/racegarage/ppi_rearsusp1.jpg
The rear arms also use torsion bars for an additional spring. As the axle cycles forward, the spring rate is increased at a rising rate as the axle pulls on the arm/linkage forward.
http://www.racefactoryinc.com/racegarage/ppi_rearsusp3.jpg
The cantilever arms rest on top of the axle between a set of rollers. As the wheels compress, the roller roll up the arm changing the rate (rising) of the shocks and torsion spring).
http://www.racefactoryinc.com/racegarage/ppi_rearsusp4.jpg
http://www.racefactoryinc.com/racegarage/ppi_rearsusp5.jpg
interesting observation on the remote reservoir shock from the pre-air bump days
Noticed something when looking at the front shocks. The reservoir hose connects a couple inches from the top of the shock body. Some say this changes the force when the piston passes this area. Somewhat of a bypass "shock" type of effect, but not as extreme. (see BajaBill's description below)
http://www.racefactoryinc.com/racegarage/ppi_shocks3.jpg
"With the reservoir hose lowered down the body of the shock, that is one of the first hydraulic "Bump Stop" designs, when the piston passes the reservoir hose the compression becomes stiffer (opposite of a bypass)"
http://www.racefactoryinc.com/racegarage/stadium1.jpg
Some of the suspension tech is strange to me, but I imagine it was the height of innovation back in the day. Take for example progressive rate front torsion bars - here are some of the suspension highlights:
This truck was built before the use of bypass shocks. It was also built in a time period when rising rate suspension was first being used on dirt bikes. Toyota (PPI) use "A LOT" of rising rate suspension design on this truck.
Front suspension uses triple rate torsion bars on the lower arms & a single "bump stop" torsion bar on the top arm. All stages are adjustable and many different diameter (rate) torsion bars are available.
http://www.racefactoryinc.com/racegarage/ppi_frontsusp1.jpg
Front shocks (3) are lay down cross-over style on front.
http://www.racefactoryinc.com/racegarage/ppi_frontsusp2.jpg
Front suspension is "limited" around 16", but can cycle 18+
http://www.racefactoryinc.com/racegarage/ppi_frontsusp3.jpg
The rear suspension of the truck gets really interesting…Cantilever arms on rollers, bump control on shock extension, dual torsion bars. Rear suspension is also "limited" to around 16", but can get much more. Toyota had limited the suspension on the truck to get it to “fly” level.
http://www.racefactoryinc.com/racegarage/ppi_rearsusp2.jpg
Rear suspension uses a cantilever front arm that extends (pulls) the shocks on wheel up travel & compresses the shocks on wheel drop (normal rebound). Complete opposite of how most suspensions function. The cantilever arm also uses a torsion bar for the spring.
http://www.racefactoryinc.com/racegarage/ppi_rearsusp1.jpg
The rear arms also use torsion bars for an additional spring. As the axle cycles forward, the spring rate is increased at a rising rate as the axle pulls on the arm/linkage forward.
http://www.racefactoryinc.com/racegarage/ppi_rearsusp3.jpg
The cantilever arms rest on top of the axle between a set of rollers. As the wheels compress, the roller roll up the arm changing the rate (rising) of the shocks and torsion spring).
http://www.racefactoryinc.com/racegarage/ppi_rearsusp4.jpg
http://www.racefactoryinc.com/racegarage/ppi_rearsusp5.jpg
interesting observation on the remote reservoir shock from the pre-air bump days
Noticed something when looking at the front shocks. The reservoir hose connects a couple inches from the top of the shock body. Some say this changes the force when the piston passes this area. Somewhat of a bypass "shock" type of effect, but not as extreme. (see BajaBill's description below)
http://www.racefactoryinc.com/racegarage/ppi_shocks3.jpg
"With the reservoir hose lowered down the body of the shock, that is one of the first hydraulic "Bump Stop" designs, when the piston passes the reservoir hose the compression becomes stiffer (opposite of a bypass)"