Herder Truggy
- Thread starter tkr
- Start date
IMHO, the McMillin V-8, 1 car is serious competition to the Herbst team.
PJCinLV
http://www.off-road.com</A>
Hated by Eco-Freaks and Bob Yen.
PJCinLV
http://www.off-road.com</A>
Hated by Eco-Freaks and Bob Yen.
The Herbst family does put a lot into this sport and have been doing so for many years. It's kinda cool to have some of the less funded teams become a serious threat. Mcmillin proved that you dont have to lead to win, John Herder has proved that even the Best equipment does break down( Herbsts at Laughlin) and Damen Jefferies just flat outran them at Teribbles Town.Good for them and hopefully this is not the end of the list of great racers beating out the high dollar teams.
Well said Mike! It's all a matter of doing your homework and a little luck. It also is another indication of which way technology is heading. It is interesting to see things coming together between brute strength and light weight sophistication. In the fastest classes, you will see the front AND the rear engine concept end soon, the solid rear axle will go by the wayside, after that, no more by-pass shocks. This isn't that far away. Problem is, that's when the cars will start to all look alike!
Some high dollar cars have already stopped using by-pass shocks and coil springs. They are using
single, very large gas pressure shocks (these can be identified by a “shaft” size of around 3
inches. (hollow of course) These provide damping and springing. The huge shaft-piston provides a
lot of fluid flow to work with both internally and externally out the top. This does not mean that
by-pass shocks and coil springs are obsolete. They are still winning races and will be around for a
while. And history has not been kind to gas-pressure-only springs in racing applications. So far, in dezert applications at least, internal by-pass shocks just can’t flow enough fluid at the right time and are not easy to tune like their tube covered counterparts.
One drawback to by-pass shocks are that they cause mechanical pressure spikes on the chassis
and control arms. These components then have to be made stronger. This raises sprung and
unsprung weight. A lot of control arm cracking is from this and often NOT from bushes, rocks or
“unexplainable” racing stresses. They also cannot hold the coil spring, so you have to mount
another shock just for that. This also adds weight and interferes with proper design of the upper
control arm on front suspensions. The by-pass tubes give the shock the critically needed position
sensitivity. This position sensitivity is just as critically needed by the spring. This is why coil-over
shocks are laid down, springs are stacked on top of each other or both. This is not done just to
give the overall “right spring rate.” It is done to create a custom spring rate at different positions
or "position sensitivity." Unfortunately, laying the shock down does not provide nearly enough
rising rate or more specifically the needed rates. Stacking springs does not provide it either
because there just is not enough room on any shock for enough of them the right size. You end up
with a compromise of mismatched spring and damping rates. If you watch closely at some of the
most successful cars like the Herbst’s Truggy for example, you can see the wheels actually stay up
and hang in place for nearly a full half second after hitting a big bump, before beginning to
descend during rebound. It’s quite amazing to watch. This is because of the very high damping
rate at the top of the piston travel but lack of matching high spring rate at that spot only. Right
now this all still works because of the brute strength and weight of the cars. As they become more
sophisticated and efficiently designed these drawbacks will become more pronounced. Herder’s
Truggy may well be another dilemma unfolding. Some of these vehicles are becoming too light to
work well with a 500 to 600 pound solid rear axle (with wheels, etc.). When unsprung weight
exceeds around 7% per corner (12 to 14% per axle) you will start have problems controlling axle-
chassis movement. Actually, 600 pounds unsprung in the rear of the heavy TT’s at over 6000
pounds (10%) is not far from Formula 1 ratios! (70 plus 70 or 140 in a 1400 lb car = 10%)
I apologize for not directly answering your question. But unless by-pass shocks get a little more
sophisticated, this is why they are slowly on their way out. I can tell you that front suspensions
will probably be using a simple single coil over unit with a flat rate spring and smooth, spike free
pressure application before long. How, is the real trick...
single, very large gas pressure shocks (these can be identified by a “shaft” size of around 3
inches. (hollow of course) These provide damping and springing. The huge shaft-piston provides a
lot of fluid flow to work with both internally and externally out the top. This does not mean that
by-pass shocks and coil springs are obsolete. They are still winning races and will be around for a
while. And history has not been kind to gas-pressure-only springs in racing applications. So far, in dezert applications at least, internal by-pass shocks just can’t flow enough fluid at the right time and are not easy to tune like their tube covered counterparts.
One drawback to by-pass shocks are that they cause mechanical pressure spikes on the chassis
and control arms. These components then have to be made stronger. This raises sprung and
unsprung weight. A lot of control arm cracking is from this and often NOT from bushes, rocks or
“unexplainable” racing stresses. They also cannot hold the coil spring, so you have to mount
another shock just for that. This also adds weight and interferes with proper design of the upper
control arm on front suspensions. The by-pass tubes give the shock the critically needed position
sensitivity. This position sensitivity is just as critically needed by the spring. This is why coil-over
shocks are laid down, springs are stacked on top of each other or both. This is not done just to
give the overall “right spring rate.” It is done to create a custom spring rate at different positions
or "position sensitivity." Unfortunately, laying the shock down does not provide nearly enough
rising rate or more specifically the needed rates. Stacking springs does not provide it either
because there just is not enough room on any shock for enough of them the right size. You end up
with a compromise of mismatched spring and damping rates. If you watch closely at some of the
most successful cars like the Herbst’s Truggy for example, you can see the wheels actually stay up
and hang in place for nearly a full half second after hitting a big bump, before beginning to
descend during rebound. It’s quite amazing to watch. This is because of the very high damping
rate at the top of the piston travel but lack of matching high spring rate at that spot only. Right
now this all still works because of the brute strength and weight of the cars. As they become more
sophisticated and efficiently designed these drawbacks will become more pronounced. Herder’s
Truggy may well be another dilemma unfolding. Some of these vehicles are becoming too light to
work well with a 500 to 600 pound solid rear axle (with wheels, etc.). When unsprung weight
exceeds around 7% per corner (12 to 14% per axle) you will start have problems controlling axle-
chassis movement. Actually, 600 pounds unsprung in the rear of the heavy TT’s at over 6000
pounds (10%) is not far from Formula 1 ratios! (70 plus 70 or 140 in a 1400 lb car = 10%)
I apologize for not directly answering your question. But unless by-pass shocks get a little more
sophisticated, this is why they are slowly on their way out. I can tell you that front suspensions
will probably be using a simple single coil over unit with a flat rate spring and smooth, spike free
pressure application before long. How, is the real trick...
Since I'm a CORR guy, I know Rob MacCachren runs the large gas shocks you are talking about. Who builds his shocks? I know it's somebody out in California. If somebody could give me a name and an approximate cost that would be cool. If anybody knows how they are made, that would be great too. I want as much info as possible. I'm going to talk to Rob at Crandon in two weeks and see if I can get the "low-down." Let's just say, I've got plans, and I'm not sure how open Rob will be to giving out information since he's the only guy in CORR using these type of shocks. Thanks in advance.
Joe
Joe
technology is here to stay! scully engineering is right! you know something we dont know! what is the next generation hi-tech coming on the scene! titanium brakes? cryogenics in suspension and telepathy gps? can we get hi tech companys involved? internet tracking is slow? or keep it old school...its better to be there live!!! long live off-road racing!!!!
Ahhh its easy...Use a link that increases the shocks leverage on the lower control arm throughout its travel.....Smooth rising spring and damping rate..