Sup w/them 2024 Summer Projects?
Apr 21, 2021, 10:17 AM
#3092
first off we need to get on the same page - that is not a truck. now that we have that out of the way get one of these guys https://www.blueox.com/trailer-towing/swaypro/
i have a 2" and a 2.5" with 600 and 2000lb bars respectively. the 600lb bars work well with an open car trailer. its a game changer.
with the car facing forward id scoot it back a few inches to the end of the trailer.
i have a 2" and a 2.5" with 600 and 2000lb bars respectively. the 600lb bars work well with an open car trailer. its a game changer.
with the car facing forward id scoot it back a few inches to the end of the trailer.
Apr 21, 2021, 11:18 AM
#3093
first off we need to get on the same page - that is not a truck. now that we have that out of the way get one of these guys https://www.blueox.com/trailer-towing/swaypro/
i have a 2" and a 2.5" with 600 and 2000lb bars respectively. the 600lb bars work well with an open car trailer. its a game changer.
with the car facing forward id scoot it back a few inches to the end of the trailer.
i have a 2" and a 2.5" with 600 and 2000lb bars respectively. the 600lb bars work well with an open car trailer. its a game changer.
with the car facing forward id scoot it back a few inches to the end of the trailer.
I can't really roll the car backward any more. I had to strap to the upper, rear control arms. There is about zero inches left to tighten the straps. I don't have anything further forward to attach to. The trailer deperately needs to be two fee longer. Once I sell this one and get another, I'll be good to go. Until then, here we are...
This is as the car sits now. It's a few inches rearward from the first picture I posted. Now is top, then is bottom. Sliiiiiiight improvement...ish. Airbags are coming in today to help me limp along for my trip. Once the bags are on and filled, I'll adjust the height of the hitch/ball. It should be spot on, we'll see. I test drove the truck last night and it did great. No sway, at any speed, even with the wind. Definite improvement.
Apr 21, 2021, 07:22 PM
#3098
Marshal is referring to t-hooks for the OEM strap down points. I use them up front cause splitter block anything else. But in the rear i run the strap over the subframe which works for my particular setup.
https://www.amazon.com/Products-11-7...056696&sr=8-56
https://www.amazon.com/Products-11-7...056696&sr=8-56
Apr 22, 2021, 07:52 AM
#3099
So interesting testing this weekend. We had some really tight corners with digs and I was struggling hard with getting power down on exit with hopping. I have had a few ideas lately of another cause of corner exit and testing this weekend was good learning along with bringing up new questions and thoughts.
Ok, here is my idea of what at least my car is doing. Around apex, Im getting back on throttle heavily which I can do cause my rear diff is extra spicy. I most definitely have inside rear in the air and depending how tight the corner is, it can be very high. When I get on throttle the outside rear slips and lets the inside slam down which has a sudden increase in grip stopping the slide. That sudden increase in grip lets the outside catch and re-lift the inside along rebound pulling it up. That continues till the lateral load doesnt allow the outside to slip.
So the goal needs to be to lift a tire off throttle but have it quickly but gently set back down on throttle so both rear wheels are doing work and not lifting on throttle.
Over the weekend I dropped rear bar rate but before thinking about rebound potentially being a cause I was increasing to compensate trying to keep entry balance. The bar change was pretty much un noticed but the rebound definitely made hopping worse everywhere. I was like 2/24 clicks from full on the flags. So I dropped -12 from full rebound and the change was dramatic. Car was rotating under throttle but pretty much no feel change off throttle.
On my list of internal questions.
Next Steps:
Ok, here is my idea of what at least my car is doing. Around apex, Im getting back on throttle heavily which I can do cause my rear diff is extra spicy. I most definitely have inside rear in the air and depending how tight the corner is, it can be very high. When I get on throttle the outside rear slips and lets the inside slam down which has a sudden increase in grip stopping the slide. That sudden increase in grip lets the outside catch and re-lift the inside along rebound pulling it up. That continues till the lateral load doesnt allow the outside to slip.
So the goal needs to be to lift a tire off throttle but have it quickly but gently set back down on throttle so both rear wheels are doing work and not lifting on throttle.
Over the weekend I dropped rear bar rate but before thinking about rebound potentially being a cause I was increasing to compensate trying to keep entry balance. The bar change was pretty much un noticed but the rebound definitely made hopping worse everywhere. I was like 2/24 clicks from full on the flags. So I dropped -12 from full rebound and the change was dramatic. Car was rotating under throttle but pretty much no feel change off throttle.
On my list of internal questions.
- How do keep minimal wheel lift off throttle, minimal rebound, but also have lift rotation?
- Can I drop rear bar a lot more to the point rear rebound can be increased for entry but have less effect on exit?
- Will bumping front rebound help with inside rear drop rate (if one corner goes down the other must come up)?
- Will Toe-in help with the outside rear slip/hop?
Next Steps:
- Put in softer bar that is similar at full stiff than current bar at full soft to play with going even softer
- Add 1/8" toe-in. Currently at 0.
- Play with significantly increased front rebound
Apr 22, 2021, 08:19 AM
#3100
Do you log wheel speeds? I've never seen outside wheel slip correlate with the hopping on the Berrymobile. Do you have a shock dyno plot of your shocks at the settings you are using? Think about what happens to your damping when only 3 (or possibly 2) of your wheels are on the ground and then what happens when all of the tires are back on the ground.
I need to send my shocks in to get freshened up. But thinking on valving Im guessing when I turn up rebound Im wanting low speed increase and Im instead getting high speed increase or global. From what Ive seen on some Penske valving rebound can be set to adjust the low speed slope with keeping peak forces with minimal change. Of course this is just all Im getting thinking through things in my head but definitely feels like a black art.
Found some video clips of my car on course and in normal situations (not trail braking) the inside rear is at a pretty reasonable level if not actually a bit late to come up. So Im not going to swap to smaller bar and will play with going back to full stiff on the bar, same rebound range, and -1/8in toe in instead of 0 toe.
Apr 22, 2021, 08:42 AM
#3101
Lateral slip seems unlikely to be the culprit. if the lateral grip vs slip angle curve of the tires was that peaky I don't think you would be able to save it (think snap oversteer). Tucking the sidewall is probably more likely, IMO. Tire pressures seem to be very involved in the hopping as are shock settings. BTW the high speed valving isn't 'adjustable' on the flags, the knobs are low speed bleeds (needle valves). You can buy the solution we came up with for the Berrymobile. Cusco zero-3X's custom valved by Guy Ankeny.
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Construct (Apr 22, 2021)
Apr 25, 2021, 02:30 PM
#3104
EvoM Guru
I cant log wheel speed yet but will have it soon with the new ECU. But I dont think its a wheel spin issue but more of a lateral slip as the wheel sets down. And a sudden increase in grip force from the inside and higher rebound on the inside wheel pulling it back up creating a situation where it can oscillate.
I need to send my shocks in to get freshened up. But thinking on valving Im guessing when I turn up rebound Im wanting low speed increase and Im instead getting high speed increase or global. From what Ive seen on some Penske valving rebound can be set to adjust the low speed slope with keeping peak forces with minimal change. Of course this is just all Im getting thinking through things in my head but definitely feels like a black art.
Found some video clips of my car on course and in normal situations (not trail braking) the inside rear is at a pretty reasonable level if not actually a bit late to come up. So Im not going to swap to smaller bar and will play with going back to full stiff on the bar, same rebound range, and -1/8in toe in instead of 0 toe.
I need to send my shocks in to get freshened up. But thinking on valving Im guessing when I turn up rebound Im wanting low speed increase and Im instead getting high speed increase or global. From what Ive seen on some Penske valving rebound can be set to adjust the low speed slope with keeping peak forces with minimal change. Of course this is just all Im getting thinking through things in my head but definitely feels like a black art.
Found some video clips of my car on course and in normal situations (not trail braking) the inside rear is at a pretty reasonable level if not actually a bit late to come up. So Im not going to swap to smaller bar and will play with going back to full stiff on the bar, same rebound range, and -1/8in toe in instead of 0 toe.
Hello Everybody havnt been on for a while,
If the inside rear is lifting it means the outside front is diving.
Dropping the rebound will help dampen out the yoyo effect your getting, But this is just putting a bandaid on the issue rather than solving the issue to begin with, you really need to be moving the fast bump/rebound rather than slow also.
Id be looking at trying to stop the outside front from diving so much. More high speed bump on the front or a stiffer spring up front. Loosening up the rear ARB will help to let the suspension move more independantly e.g if your outside rear is compressed and loaded up it is going to stop the inside rear from fully extending and staying on the ground so you can either try and increase the stiffness of the rear to stop the dive on the outside or you soften the rear to allow the inside and outside to move more independently. This would be trial and error to what works and what doesnt.
Maybe more bump travel on the rear and less on the front to try limit the diving is something else to explore? as in get the front to sit on the bump stops alot sooner to try limit the dive. This might induce ****loads of understeer though. Guess it comes down to corner weights also.
Now i feel like im just rambling on about nothing...
Apr 25, 2021, 03:22 PM
#3105
I actually got some videos of my car on course to watch and see how its acting and in the end, its not lifting really enough or soon enough with the bar on soft and the car is quite flat. The areas the wife was claiming we had big inside life is exactly where i would expect to have it, trail braking into areas where you just cant brake straight. So Im definitely going back to full stiff. Basically I was trying to ramp up rear rebound in an attempt to get a bit more rotation on entry but that seemed to result in occasional exit hop.
As usual, the car is stellar in its standard setup and I just keep trying variations or adjustments to see if we can get it do something different. But the base setup is crazy, Im just always chasing that next little bit of refinement.
As usual, the car is stellar in its standard setup and I just keep trying variations or adjustments to see if we can get it do something different. But the base setup is crazy, Im just always chasing that next little bit of refinement.