16LikesSerpent S411
12-21-2012, 09:11 PM
#4861
i did notice going stiffer was worse on the mod car. i was running grey/white with the same
350 cst all around and the car was much easier to drive.
recently tried yellow/grey and it was a drift car pretty much, dispite driving corners at the same speed..
i might chalk some of that up to the used up muchmore tires vs the newer sorex's i had on the stock car but it was a night and day difference. i would expect mod cars to be stiffer to soak up the weight transfer from higher speed but could be wrong..
running on virgin carpet for the first time in mod, so probably no swaybars, lots of droop and light oils/springs and little camber.
i did notice some cars using pro dive and pro squat last year to help with traction. ill have 6 hours of practice on friday, 2 hours on saturday, so hope i can figure out what my car is doing in that time. i still noob after all.
350 cst all around and the car was much easier to drive.
recently tried yellow/grey and it was a drift car pretty much, dispite driving corners at the same speed..
i might chalk some of that up to the used up muchmore tires vs the newer sorex's i had on the stock car but it was a night and day difference. i would expect mod cars to be stiffer to soak up the weight transfer from higher speed but could be wrong..
running on virgin carpet for the first time in mod, so probably no swaybars, lots of droop and light oils/springs and little camber.
i did notice some cars using pro dive and pro squat last year to help with traction. ill have 6 hours of practice on friday, 2 hours on saturday, so hope i can figure out what my car is doing in that time. i still noob after all.
12-21-2012, 09:25 PM
#4862
also, this car doesnt seem to have a wide steering angle.
on my stands, i try to set my touring cars up to 25º full lock but this car doesnt seem to go that far? im running pancar servo savers on both so they should have enough swing but the link will hit the swingrack before i get to 25º
on my stands, i try to set my touring cars up to 25º full lock but this car doesnt seem to go that far? im running pancar servo savers on both so they should have enough swing but the link will hit the swingrack before i get to 25º
Which link hits the rack? Sounds like something isn't quite right in the setup, ff you've got enough top deck clearance, lose the drop down ball-joint on the servo saver, that will raise the link and should give more lock.
HiH
Ed
12-22-2012, 12:37 AM
#4863
pretty much stripped down the suspension on the mod car tonight. changed all the arms, the uprights and chubs/steering blocks. noticed the car had one hard and one soft suspension arm in the front, redid all the shimming to factory ect. still a ton of play in the front end mostly around the chub. is there anything i can do the tighten it up? i didnt change any of the hardware but the pins looked new.
the hubs were also on the wrong side which might have mucked with the steering angle some.
tommorrow ill reset all the turnbuckles to manual spec and put it on the stands again. really pays to strip a car down when you buy it used. dispite only being run a few times. tried to mimic the team car wheel base which seems to work well, but have the rear arms pushed all the way back with a half mil shim behind them.
quite an easy car to work on except for the top deck. it gets bunged up on the belt and your antenna tube. have to pull the tube, which ive had to put a hole in to prevent kinging my antennas, but even then getting it out from the belt is a little fiddly.
i had a steering ballstud pop off the swingrack last day out and it took a bit of disassembly to get it hooked back up lol. basically removing the steering rack from the car. which is easy i guess, but i only have one 2mm driver.
basically a complete rebuild. maybe tommorrow ill go find a underground parkade with blacktop.. which is probably very rare but wanna see how this thing works before the big one.
the hubs were also on the wrong side which might have mucked with the steering angle some.
tommorrow ill reset all the turnbuckles to manual spec and put it on the stands again. really pays to strip a car down when you buy it used. dispite only being run a few times. tried to mimic the team car wheel base which seems to work well, but have the rear arms pushed all the way back with a half mil shim behind them.
quite an easy car to work on except for the top deck. it gets bunged up on the belt and your antenna tube. have to pull the tube, which ive had to put a hole in to prevent kinging my antennas, but even then getting it out from the belt is a little fiddly.
i had a steering ballstud pop off the swingrack last day out and it took a bit of disassembly to get it hooked back up lol. basically removing the steering rack from the car. which is easy i guess, but i only have one 2mm driver.
basically a complete rebuild. maybe tommorrow ill go find a underground parkade with blacktop.. which is probably very rare but wanna see how this thing works before the big one.
12-22-2012, 12:48 AM
#4864
Sounds good. Best advice I can give you then is get set up close to kit, and then don't do anything to it until you've run it at the big day 
By all means get it checked out on the blacktop, but there are just too many other variables to start making changes. 
Good luck!
Ed
By all means get it checked out on the blacktop, but there are just too many other variables to start making changes. Good luck!
Ed
12-22-2012, 01:02 AM
#4865
i usually run kit setting before i drop anyone elses setup on a car. typically they are derived from a lot of factory testing on different conditions and work pretty well. i might change damping or roll center shims but not a lot else.
im still running kit settings on my 12r5.1 with onpoint chassis. able to keep pace with any of the newest cars out. bought that car as my first 12th scale used and was in the bottom heat. this year im mixing it up with the top 5 and all i really change is rollout and rotate my tires.
cant be doing too bad. last year i was a 100% never touched rc noob. now im mixing it up with the top 5. sure there is some credit due to upgrading equipment SOMEWHAT. and a lot of vrc time, but still new to setup changes and how they change the car. i can only learn a sliver that in vrc, and certainly don't learn driver etiquette in a race with more experienced guys.
but.. having said that. id still be int he bottom heat without vrc. 25 minutes/week doesnt cut it when dropping thousands on this gear.
im still running kit settings on my 12r5.1 with onpoint chassis. able to keep pace with any of the newest cars out. bought that car as my first 12th scale used and was in the bottom heat. this year im mixing it up with the top 5 and all i really change is rollout and rotate my tires.
cant be doing too bad. last year i was a 100% never touched rc noob. now im mixing it up with the top 5. sure there is some credit due to upgrading equipment SOMEWHAT. and a lot of vrc time, but still new to setup changes and how they change the car. i can only learn a sliver that in vrc, and certainly don't learn driver etiquette in a race with more experienced guys.
but.. having said that. id still be int he bottom heat without vrc. 25 minutes/week doesnt cut it when dropping thousands on this gear.
12-23-2012, 08:58 PM
#4866
Been playing around a lot today with the steering on the car, after modding it earlier last week. I've since trimmd the upside down steering posts down, and had a play around with the bump-steer shimming.
Actually, the whole bump-steer thing is something that I think is starting to become more used, and dare I say it, something that the Xray boys have picked up on more than anyone else. Looking at setups from the T4, there is a big difference in the bump steer spacing used on carpet vs asphalt (3mm difference).
The bump steer is the main reason I believe that the lowered (411FF) steering posts seem to work better on the rug as well... but I'll come back to this.
So, anyway, some more pics of the finished mod. I'm actually using a 1mm shim under the posts now, which overall drops the rack 3mm compared to standard.
I've also switched out the drop-down ball joint on the servo horn (that's something I've never been totally keen on, as I think it does some strange things with the geometry on turning), and using a standard ball joint (2nd pic), and with the link low on the cross brace, there is plenty of top deck clearance.
The other thing I've had to do, and it's only because I want the option there in-case I want to run more ackerman shims, and that's shave some material off the rear of the 1.5 suspension block (3rd pic). I run 1.5mm shims most of the time (Keeps the ackerman close to kit when running 2.0/1.5 front blocks, which moves the front wheelbase forward), but with 2mm (4th pic, left joint) there is now more than enough room.
Anyway, what's the point of all this?
Simple put, it gives way more options to play with the bumpsteer as previously mentioned. Now usually, you don't want any bumpsteer, as it can make the steering do strange things, but as I already mentioned, the Xray boys are making use of bumpsteer to improve the car on asphalt.
The theory behind bumpsteer is to have the steering link parallel to the wishbone, so that under compression, the steering doesn't gain/lose toe-angle. At extreme's, the car can start to be very nervous with a lot of it, as small bumps will cause the car to turn on it's own..
But (and I'm getting there slowly!) this can be used to advantage. Adding shims to the steering hub induces toe-in under compression... which when turning adds outer wheel steering angle. And this is where I'm thinking there is something to start playing with. Outdoors on asphalt, mid-corner steering is king. Having the suspension add angle mid-corner (whilst under compression) would more than likely be advantageous. Thats why, IMO, the T4's are running large numbers of shims under the steering hub outside.
However, on carpet, to try and stop the car flipping over-itself and/or parking mid-corner, using less shims can take away mid. And this is why I think running the FF posts are working well indoors, with less bump-steering effect, due to the greater angle of the links. Lowering the steering without adding shims to the hub achieves the same effect, as there is a greater link angle added.
The 5th pic shows the difference between say an Asphalt and Carpet setting. The left side is low/asphalt link (4.5mm shims), whilst the right is the FF posts copy (2.5mm shims). Quite a big difference in the angle, with the left hand side very flat, and the right being close to parallel with the arm.
Of course, having the steering lower in the car will help a bit from a CoG point of view, but overall, the biggest effect, IMO, is link angles/bump steer.
Won't get an opportunity to test out this until the new year unfortunately, but it's high on my list to work through
Regards
Ed
Actually, the whole bump-steer thing is something that I think is starting to become more used, and dare I say it, something that the Xray boys have picked up on more than anyone else. Looking at setups from the T4, there is a big difference in the bump steer spacing used on carpet vs asphalt (3mm difference).
The bump steer is the main reason I believe that the lowered (411FF) steering posts seem to work better on the rug as well... but I'll come back to this.
So, anyway, some more pics of the finished mod. I'm actually using a 1mm shim under the posts now, which overall drops the rack 3mm compared to standard.
I've also switched out the drop-down ball joint on the servo horn (that's something I've never been totally keen on, as I think it does some strange things with the geometry on turning), and using a standard ball joint (2nd pic), and with the link low on the cross brace, there is plenty of top deck clearance.
The other thing I've had to do, and it's only because I want the option there in-case I want to run more ackerman shims, and that's shave some material off the rear of the 1.5 suspension block (3rd pic). I run 1.5mm shims most of the time (Keeps the ackerman close to kit when running 2.0/1.5 front blocks, which moves the front wheelbase forward), but with 2mm (4th pic, left joint) there is now more than enough room.
Anyway, what's the point of all this?
Simple put, it gives way more options to play with the bumpsteer as previously mentioned. Now usually, you don't want any bumpsteer, as it can make the steering do strange things, but as I already mentioned, the Xray boys are making use of bumpsteer to improve the car on asphalt.
The theory behind bumpsteer is to have the steering link parallel to the wishbone, so that under compression, the steering doesn't gain/lose toe-angle. At extreme's, the car can start to be very nervous with a lot of it, as small bumps will cause the car to turn on it's own..
But (and I'm getting there slowly!) this can be used to advantage. Adding shims to the steering hub induces toe-in under compression... which when turning adds outer wheel steering angle. And this is where I'm thinking there is something to start playing with. Outdoors on asphalt, mid-corner steering is king. Having the suspension add angle mid-corner (whilst under compression) would more than likely be advantageous. Thats why, IMO, the T4's are running large numbers of shims under the steering hub outside.
However, on carpet, to try and stop the car flipping over-itself and/or parking mid-corner, using less shims can take away mid. And this is why I think running the FF posts are working well indoors, with less bump-steering effect, due to the greater angle of the links. Lowering the steering without adding shims to the hub achieves the same effect, as there is a greater link angle added.
The 5th pic shows the difference between say an Asphalt and Carpet setting. The left side is low/asphalt link (4.5mm shims), whilst the right is the FF posts copy (2.5mm shims). Quite a big difference in the angle, with the left hand side very flat, and the right being close to parallel with the arm.
Of course, having the steering lower in the car will help a bit from a CoG point of view, but overall, the biggest effect, IMO, is link angles/bump steer.
Won't get an opportunity to test out this until the new year unfortunately, but it's high on my list to work through
Regards
Ed
12-23-2012, 10:10 PM
#4867
Tech Fanatic
Thats interesting, as I can get my car easily to full lock (knuckle touches C-hub), and I have to dial the steering back down.
Which link hits the rack? Sounds like something isn't quite right in the setup, ff you've got enough top deck clearance, lose the drop down ball-joint on the servo saver, that will raise the link and should give more lock.
HiH
Ed
Which link hits the rack? Sounds like something isn't quite right in the setup, ff you've got enough top deck clearance, lose the drop down ball-joint on the servo saver, that will raise the link and should give more lock.
HiH
Ed
I use a xray servo saver as well.
12-28-2012, 01:57 PM
#4869
Is there a wider offset hex hub to fit this car? The rim hex is very shallow on our Jaco spec tires, so I'm afraid of stripping out the rim if I add wheel spacers.
12-28-2012, 02:44 PM
#4870
is that what you are talking about?
12-28-2012, 02:49 PM
#4871
Good to know, but are they for any 5mm axle or 5/32” axles.???
12-28-2012, 03:14 PM
#4872
Hi Steve, you can go up to 1mm of spacer on the JACO wheel before it becomes a problem......I wouldn't go farther than that though without going to a wider hex. You can use the Xray wide hex but it has to be reamed out slightly to work, but has the same plunge depth for the pin. I have done this with the -.75 hexes with no problem.
12-28-2012, 07:18 PM
#4874
Hi Steve, you can go up to 1mm of spacer on the JACO wheel before it becomes a problem......I wouldn't go farther than that though without going to a wider hex. You can use the Xray wide hex but it has to be reamed out slightly to work, but has the same plunge depth for the pin. I have done this with the -.75 hexes with no problem.
12-28-2012, 07:54 PM
#4875
Based on overall widths of the hex as follows;
Stock Serpent = 5.48mm
Xray -.75 = 4.27mm
Wray +1.5 = 6.12mm
Ed, your steering rack mod seems to work well on carpet as well, I hope to run your V2/V2.4.5de/V2.1.5e/v2.2.1e this Sunday, but the prior mods do show good results so far.
Thanks
Stock Serpent = 5.48mm
Xray -.75 = 4.27mm
Wray +1.5 = 6.12mm
Ed, your steering rack mod seems to work well on carpet as well, I hope to run your V2/V2.4.5de/V2.1.5e/v2.2.1e this Sunday, but the prior mods do show good results so far.
Thanks