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Can having to much left rear drop cause the car [black front rocket] to carry the left front -- have been told a heaver rr spring [225 to 250] an/or a left front teather will help solve this problem -- sny ideas/iinformation would be extremely helpful -- thanks in advance
Yes too much hike “can” be part of the problem. But like you have been told, a stiffer RR spring, or a spring that reaches max loading and takes its set sooner during shock travel, will help keep the left front down by keeping the right rear up a little bit higher. Think of the cars platform. Most of the time the right front is buried (which also assists in keeping the right front down), and the left rear is hiked. Now the hike CAN contribute to the left front lifting, but there are other factors that have more play in this because aside from hike lifting the left rear corner it also helps plant the RF. The main contributor is front roll stiffness versus rear roll stiffness, however you must keep in mind how the platform changes under braking as well as acceleration play a big role in this as well. If the front is too stiff, and you’re too soft on the rear, the car will want to pick the left front up because the roll angles do not match up and tend to favor understeer, which is what happens when the LF picks up, most of the time at least. A tether can actually make this worse if you’re not set up properly. That’s why you were recommended to run a tether with a bit stiffer spring than you are running in the RR.The tether tries to keep weight transfer down, once it hits, the car has to try to lift all that weight up. If it’s tethered low the car doesn’t have much leverage to transfer weight back onto the RR. However if corner speed is high enough and the RR is too soft it can just pick up that corner and carry it. If you’re running a bit stiffer RR spring, it will not only help you gain side bite that was lost from the tether, but also helps keep the RR corner higher slightly which helps keep the left front down.Quote:
Originally Posted by LIS20
In summary: if your RR spring is 200 and your RF spring is 450, you can't run any drop compared to a car with a 275 RR spring and 275 RF spring.
Is that rf 275 with bumpstop or dual stage setup and how much drop are we talking between the two?
Again. It depends. What height do you have your bump stop/dual stage lockout set at? What are the rates? What is your shocks compression setting? If the RF becomes too stiff too soon, the rear is able to roll easier than the front, it doesn’t matter what you have for type of secondary suspension in this case, you can create wheel lift. The key to keeping the left front down is keeping the rr up a bit higher, the RF down lower, and well, keeping the left front down, which is why a tether is used. There isn’t just one answer for that question because it depends on the heights at which you have everything set. Another part of this that we haven’t talked about is bernoulli's principle. The lower you can keep the nose and the more sealed off it is, the easier it is to keep it down with aero loading. As the pressure differential increases, meaning lower pressure under the nose, and higher pressure above, downforce becomes a LOT stronger. If the suspension in the rear especially the right rear begins to compress too much past a given height, that left front corner of the nose opposite to that right rear begins to rise up, and the pressure differential decreases as there is an increase in the lower air pressure under the nose when the seal opens up more under the car. This is also why it’s important to keep the right front down. Hiking the left rear too much can begin to lift the left side of the nose because it increases weight transfer onto the right rear, however when that point occurs largely depends on the height at which the RF corner reaches max loading, and the height at which your RR reaches max loading as well how much LF droop limiting you are putting into the car. Using shock location and length you could keep that left front tire connected to the track even if there was no spring contact. So how much travel you have last ride height (droop limiting) also comes into play.Quote:
Originally Posted by hunterracing
There isn’t one right answer because it depends a lot also on where the dual stage engages versus a bump stop. If both the dual stage lock out and the bump stop reach peak loading around the same height, there is no difference.
So in theory a guy would be better off with running bumpstop a or dual stage stuff instead of a 275 or softer on rf with nothing
It depends on what you’re trying to doQuote:
Originally Posted by hunterracing
If your intent is to knock the wall down, try a 250 on the RF with no bump stop.
That be last thing we want to do lol
A simple way of thinking about this or figuring out what you need to do is:
Think sitting in a regular 4 leg wooden chair and stick a 5 or 6" block under the LR and then saw off some from the RF for RF compression.
Then lean back in the car and see what happens. Then think about what needs to happen to stop this. Several things can be done to help this.
seen a race won back before bump stops and duel stage on a 200 lb rt front , it was coil binding , when track was smooth , it was bad fast , but it was dangerous and broke stuff.........Quote:
Originally Posted by Matt49
so when you get more drop then what the car builders recommend would you lower the jbar on frame side bcs of the more drop or leave it alone
I’ve never ran anything under 350 without a bump. Lol I did try a 150 once to see what it would be like. Wasn’t bad when I kept everything loaded up and was dragging the brakes a bit. Tap the brakes a little harder in the corner, the car would rotate on the spot, let off quick and it would push like a mother. Wasn’t bad for that night because I had a guy over driving behind me and I’d just back off, point a bit lower and get by him. Hooked up track. Would have been a bit different on a slick track. Never ran it again though lol. It was just working the hell out of the right front. But yeah like Matt said. Unless you’ve got something really crazy going on, you’d just end up plowing into the wall.Quote:
Originally Posted by Matt49
hunterracing, adjust limiting device