R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 02-26-2003, 07:35 AM   #46
AP
Tech Rookie
 
Join Date: Feb 2003
Posts: 12
Default

Quote:
Originally posted by LaxRacer
Ok ... if you are ripping the car apart ... check your bearings again .... specifically the ones near your diffs, also check the ones at your axles ... but I don't think its your bearings.

I think problem is your diff. If you have the time switch it with the rear one and run the car. If you have the money get a whole new diff. To test since its a pain to get to the rear diff. With out knowing your rebuilding practice, if you have ripped your diffs apart and not replaced the diff nut thats the problem.

Since its consistent in spinning out in both directions and at speed it really sounds like the diff.

I need clarification on your droop setting ... Is 5 mm saying you have 5 mm of droop or 0 mm of droop since you have a 5mm ride height ? Its an often miscommunictated setup setting.

Now setup stuff that you can do while the car is open ... Go one spring rate softer in the rear, go a 1 mm to 2 mm lower on the car all the way around, if you track can handle it (I have found that the Pro2 hates being high) Up front try going with 0 or -1 of toe, Enough camber for even tire wear. Camber links hub side high, chassis side low. Shocks set for you driving style. In the Rear, go with -1 toe blocks, put your Camber links at there hightest mounting locations. shocks set to your driving style, also make sure you rear hubs are in the bottom hole. I once put the car back together wrong and put them in the top hole by accident.

how are you settin your ride height ??? Don't use the tweek screws to set ride hieght , and try not having too much preload on you springs, especially if you are using HPI springs. If you have the money Get Xray springs, for the New Xray shocks, not the Serpent shocks.

IF you can get your hands on some of those cone washers ... install them under the rear bulkead, it works the same as the handling kit, it will change the rear roll chacteristics.

Try finding Dr. Diffs Web page, and try some of those setups.

You might want to do the Camber link conversion, look at Thads car on the HPI website. Or if you search around you can find pictures of Hara's car that he was using before the Pro3 was released, he only ran the pro2 like twice, but his setup is interesting.

Hopefully that helps, and gives you alot to think about.

C
I'm sorry I have made this so difficult to understand. I'll try again. The ride height is set at 5mm, buy using preload spacers on the shocks NOT the droop screws. The droop is limited to 5mm buy the droop screws. So, with the car setting level I can place a 5mm spacer under each corner of the chassis.Then, I can also raise the reae of the car an additional 5mm before the tires lose contact with the surface. I hope this is more clear.
AP is offline   Reply With Quote
Old 02-26-2003, 07:43 AM   #47
Tech Elite
 
Cole Trickle's Avatar
 
Join Date: Sep 2001
Location: Denmark / Europe
Posts: 2,571
Default

Hmmm, seems to be okay.

I still believe that something have been overseen.

Please tell us what you have done since your last post. Did you checked all our suggestions? What about the body?
__________________
Schumacher Mi5 - Sanwa MT-4 / RX-462 / KO Propo PDS-2123 - Nosram 5600 X-treme Saddle Pack - LRP SPX Zero/X12 17,5 - Nosram Stealth Touch Evolution - MAAS SPS 9250
Cole Trickle is offline   Reply With Quote
Old 02-26-2003, 12:35 PM   #48
Tech Adept
 
Join Date: Aug 2001
Posts: 105
Send a message via Yahoo to LaxRacer
Default

I think I have figured it out.

I am still sticking with the Diff, as the main problem.

Butttt .... I think you might be getting to much lateral chassis roll going into corners. With the amount of droop you are running. Try going with less droop, maybe in the 2-3mm range, its a subtle change but It should help.

Also what are your shock lengths ??? Try and limit you shock down travel with internal spacers. I am currently using o-rings to limit my down travel, and unscrewing the shock end to get length and the correct droop. Also are you using HPI standard ball cups and ball ends on your shocks ??? Consider picking up the heavy duty ones, as the don't go sloppy as fast, or consider doing a captured ball conversion for you shocks, it makes it easier to do adjustments.

Last question which might drive the nail home so to speak ... Do you have noticable body roll ? Try the side to side test at speed that is. If you are getting alot of roll thats the problem. If your not getting any thats the problem. You will know what is just right.

Also the setups that I have used with sucess off Diffs page are thats, stock class, and Bill "ballistic" Martinez's setup.

Keep us up to date.

C
LaxRacer is offline   Reply With Quote
Old 02-26-2003, 12:48 PM   #49
Tech Elite
 
popsracer's Avatar
 
Join Date: Oct 2002
Location: "Hot, Sunny Southern California"
Posts: 3,120
Default Try going with less droop, maybe in the 2-3mm range

This is a good recommendation for Droop. Usually a little less in the Front is better, with no more than 5mm in the rear (I run 3mm rear/ 2mm Front).
I don't like using O-rings as limiters. They compress and sometimes unequally side to side. I try to avoid using spacers if at all possible. If I can't get the shocks short enough with the ball end adjustment, then I will use PLASTIC spacers inside. I also adjust my total shock length to be equal L/R by .0005 using Digital calipers.
popsracer is offline   Reply With Quote
Old 02-26-2003, 02:42 PM   #50
Tech Adept
 
Join Date: Aug 2001
Posts: 105
Send a message via Yahoo to LaxRacer
Default

Great suggestion on the shock length Pops.

And yes thats true about the o-rings. So I guess I should say why I prefer them. I prefer them because they are compressable as well as they repound, with threaded shocks you can acount for differences in sizes by compressing the limiter, unlike using hard plastic limiters. I just find I have more control with the o-rings. But I will say that its personal preference.

C
LaxRacer is offline   Reply With Quote
Old 02-26-2003, 08:19 PM   #51
AP
Tech Rookie
 
Join Date: Feb 2003
Posts: 12
Default

Quote:
Originally posted by Cole Trickle
Hmmm, seems to be okay.

I still believe that something have been overseen.

Please tell us what you have done since your last post. Did you checked all our suggestions? What about the body?
I have tried all the suggestions posted here. My shock lengths are 62mm front, and 64 mm rear. I am running a HPI Mustang body. I thought chassis roll also, until I tried each cobination you can muster with the HPI sway bars. Going with the stiffest front and softest rear gets it into a corner perhaps a lttle more before the spin. I have tried droop settings from 0mm to the now 5mm in 1mm increments with no success. I have tried spacers on the shocks from 1mm to 10mm in all possible cobinations, thats 110 possible cobinations, and all those possible cobinations at all ride heights, at 20 wt oil to 80 wt oil and those possible combinations and on and on and on I think with all possible cobinations to all settings I have tried to date 428 setups. At 5mm it is maybe a little better. Right now I am running 'Takeoff CS22 to CS27's in all possible combinations. I even am man enough to admit that it might be my driving style, and no one here has brought that up, but when even the best drivers in our club can't get it set up to corner with their driving styles it makes me wonder. I shuld point out that several club members have let me try their cars and I can be just alittle slower than they are and not had a problem with other cars hooking by my driving style. I will be switching the diffs from end to end this weekend as I have not yet tried that. So I guess I will start another notebook ( it will be the 4th) and go through all setups with the diffs switched. We will see.
AP is offline   Reply With Quote
Old 02-27-2003, 12:26 AM   #52
Tech Adept
 
Join Date: Aug 2001
Posts: 105
Send a message via Yahoo to LaxRacer
Default

Ok the last of the Extreme suggestions

I am at my limit of ideas. If you know any with a digi camcorder. Record your race. And email Kent or Frank directly and send them your video. They might be able to get thad to give you some more suggestions.

C
LaxRacer is offline   Reply With Quote
Old 02-27-2003, 12:54 AM   #53
Tech Master
 
veecee's Avatar
 
Join Date: Sep 2001
Posts: 1,439
Trader Rating: 34 (100%+)
Default

AP, not sure if u've addressed this but do you have one-ways? As I said previously a worn one-way bearing with deliver all drive to the rear wheels and nothing to the front. I have had a similar experience to you previously but managed to discover the faulty one-way. So if you have a one-way, swap it out for a new one or test the car with full-time 4 wheel drive first...
veecee is offline   Reply With Quote
Old 02-27-2003, 01:38 AM   #54
Tech Elite
 
Cole Trickle's Avatar
 
Join Date: Sep 2001
Location: Denmark / Europe
Posts: 2,571
Default

Until I read your post, AP, I was thinking of the droop as the main problem also.

However, it seems to me that you have tried almost everything.

So I have 2 suggestions for the moment:

1: Have there been too many setup changes in a too short time? I think it would be a good idea to go back to some sort of a good base setup.

2: Maybe you got too much braking. A stock motor brakes a lot. Some ESC's has a lot drag brake. And if the gear is low too... A simple experiment: Try to adjust your TX to have a little throttle on at trigger-in-neutral-position. That might make a big difference!
__________________
Schumacher Mi5 - Sanwa MT-4 / RX-462 / KO Propo PDS-2123 - Nosram 5600 X-treme Saddle Pack - LRP SPX Zero/X12 17,5 - Nosram Stealth Touch Evolution - MAAS SPS 9250
Cole Trickle is offline   Reply With Quote
Old 02-27-2003, 09:51 AM   #55
Tech Elite
 
popsracer's Avatar
 
Join Date: Oct 2002
Location: "Hot, Sunny Southern California"
Posts: 3,120
Default HPI Pro2 going in trash

AP;

Ok, I went through the entire thread and did not see anything about how much Camber you are running. It is my experience with ALL of the HPI cars Electric and Nitro, that they do not respond well to excessive Camber at either end. In general, no more than -1 deg F/R with best results from 0.0-0.5 degrees Camber in the Front and 0.5 degrees Camber in the Rear. Any more Camber in the Rear and the car will come around Mid Corner. Running alot of Droop in the Rear helps (5mm), but the 0.5 Rear Camber is what works best.

I also didn't see your definition of "Hooking". Mine would be that the car is Traction rolling and flipping over. "Looping" would be a loose Rear and spinning out.
Correct me if I'm wrong.
popsracer is offline   Reply With Quote
Old 02-27-2003, 12:59 PM   #56
Tech Elite
 
Cole Trickle's Avatar
 
Join Date: Sep 2001
Location: Denmark / Europe
Posts: 2,571
Default

AP, I thinks Pops got a point here.

However, I'll supply with a small note: If you use the longest camber links in the rear, then some extra camber is needed in the rear, because the rear will roll more, than with the camber links in stock position.

By the way, if yur setup works reasonably, without too big differences front versus rear, then the use of an extended camber link in the rear might help. I frequently uses this method on my Pro2 / Sport2.
__________________
Schumacher Mi5 - Sanwa MT-4 / RX-462 / KO Propo PDS-2123 - Nosram 5600 X-treme Saddle Pack - LRP SPX Zero/X12 17,5 - Nosram Stealth Touch Evolution - MAAS SPS 9250
Cole Trickle is offline   Reply With Quote
Old 02-27-2003, 06:51 PM   #57
Tech Elite
 
RCFREAK's Avatar
 
Join Date: Sep 2001
Location: MEMBER OF THE "MWC" Mimi Wong Clan
Posts: 2,414
Trader Rating: 17 (100%+)
Default Loose setup??

On the few Hpi cars that i have had even the new Nitro RS4 3 when the rear of the car was "loose: acting like the car had too much steering going into and middle of corners.. i always tended to shorten the rear camber link. Resulting in a car that pushed.

I would start from the longest camber link setup, if loose shorten the link all the way in on the rear upright (hub). Make longer if car pushed too much.. i then would set front camber to 1/2 degrees and rear to 1 degree..

I would swap the diffs and the camber link setup!!!!!!!

Hope this helps.
Let us know!!
RCFREAK is offline   Reply With Quote
Old 02-28-2003, 03:21 AM   #58
Tech Elite
 
Cole Trickle's Avatar
 
Join Date: Sep 2001
Location: Denmark / Europe
Posts: 2,571
Default To clear up a little about camber links:

"In general, you could say that the angle of the upper link relative to the A-arm determines where the roll center is with the chassis in its neutral position, and that the length of the upper link determines how much the height of the RC changes as the chassis rolls. A long, parallel link will locate the RC very low, and it will stay very low as the car corners. Hence, the car (well at least that end of the car) will roll a lot. An upper link that's angled down, and very short will locate the RC very high, and it will stay high as the chassis rolls. So the chassis will roll very little. Alternatively, a short, parallel link will make the car roll a lot at first, but as it rolls, the tendency will diminish. So it will roll very fast at first, but it will stop quickly. And a long link that's angled down will reduce the car's tendency to roll initially, but as the chassis rolls it won't make much of a difference anymore."

Source: http://home.tiscali.be/be067749/58/
__________________
Schumacher Mi5 - Sanwa MT-4 / RX-462 / KO Propo PDS-2123 - Nosram 5600 X-treme Saddle Pack - LRP SPX Zero/X12 17,5 - Nosram Stealth Touch Evolution - MAAS SPS 9250
Cole Trickle is offline   Reply With Quote
Old 02-28-2003, 03:58 PM   #59
AP
Tech Rookie
 
Join Date: Feb 2003
Posts: 12
Default Re: HPI Pro2 going in trash

Quote:
Originally posted by popsracer
AP;

Ok, I went through the entire thread and did not see anything about how much Camber you are running. It is my experience with ALL of the HPI cars Electric and Nitro, that they do not respond well to excessive Camber at either end. In general, no more than -1 deg F/R with best results from 0.0-0.5 degrees Camber in the Front and 0.5 degrees Camber in the Rear. Any more Camber in the Rear and the car will come around Mid Corner. Running alot of Droop in the Rear helps (5mm), but the 0.5 Rear Camber is what works best.

I also didn't see your definition of "Hooking". Mine would be that the car is Traction rolling and flipping over. "Looping" would be a loose Rear and spinning out.
Correct me if I'm wrong.
Looping then. I have never hade enough rear traction to traction roll. In fact I wouldn't mind if I did.
AP is offline   Reply With Quote
Old 02-28-2003, 04:49 PM   #60
Tech Elite
 
popsracer's Avatar
 
Join Date: Oct 2002
Location: "Hot, Sunny Southern California"
Posts: 3,120
Default Pro-2 Handling problems

In general the Pro-2 is a very good handling car. Stiff, but not too of a chassis structure.

Lets look at set-up.

Camber settings;

Front Camber links in the Stock kit locations. For Caster, I recommend 10 degrees total. This would depend on which Front block you are using. 2 degs Kick-up + 8 degs Caster = 10 Total. OR -0- degs Kick-up and 10 deg Caster = 10. Unless your racing on Carpet, 8 degrees Caster will make the steering too sensitive (for most people). 12 Degrees is just not enough low speed steering for most tracks, 10 is usually just right.
Rear Camber links usually work best with the outer mount in the middle hole in the hub (#2 position).
Start off with 0.5 Degrees (1/2) Camber at all 4 corners.

Shocks;

Adjust length to achieve desired ride height. Try to keep same end shocks within a few thousandths of each other.
45wt Front and 40wt back is a good starting point with the #3 pistons all around. If your using the #2 pistons in Front, then 60wt in the front shocks.
The Silver springs are WAY to soft without limiting roll somehow. Try something in the middle of the 27mm springs that HPI has availible (HPI has a Spring chart for downloading on their site)
Never go more than 2 steps in spring rate difference between the Front and Back of the Car (this is an unbalanced condition). I do not feel that Shock mounting location is critical on the HPI cars and is usually adjusted to make ride height.
2 degree Toe hubs in the Rear and -0- degrees toe in the Front to start.
Tires;
If you do not have the right tire for the surface it can be nearly impossible to sort out a bad set-up. Here's my recommendations:

Sorex's, on smooth asphalt (new or resealed)
Yokomo's, on older rough asphalt (grey in color)
Take-Off's, on Concrete and Asphalt.
Foams can ONLY be used on a dust free surface to work properly.

I probably left out something, but I hope this sends you in a new direction to fix your problem.
popsracer is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Offroad trash talk! Dirt McGirt Georgia Racing 6 05-06-2008 08:35 PM
Old Batteries: recycle or trash? CarlosG. Electric On-Road 8 10-12-2007 04:09 PM
Trash Talk -- beware PitCrew Northwest Racers 75 12-08-2003 03:50 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 09:18 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net