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Old 06-26-2013, 05:54 PM   #16
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Hi

Thanks for all the good info. I'm trying to work with OD on the specific issues we are having - rear end overtaking the front on acceleration. My latest theory is the droop I have in the rear pod is causing rear steer. I will be trying it out with a totally parallel setup this weekend. If we an crack this nut then propper tuning is next. I get the feeling it could be very fast if we can work this out.

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Old 06-27-2013, 10:25 AM   #17
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We raced the Pardus tires in the UF1 MIDWEST series all last winter. I found that both the inside and outside of the side wall on the front tire should be completely glued up, and possibly slightly onto he tread on the outside if traction dictates. We also glued the outside of the rear sidewall.

...

One thing the car had from the first run was a ton of corner speed, that was instantly noticeable.
Thanks robk, this is all really useful information for running with Pardus.

I am currently running with a shorty pack that is positioned back in the car, with electronics right behind the servo. The car always seems to cut in really hard at the start of a corner, but then it can't follow through mid to exit. As soon as you get into the corner, the car just wants to push out really badly. The car also seems to be lacking on-power steering. I am running about 1mm of front droop, as per recommendations from Brad Palmer and OD.

Going to a stiffer center spring really does seem to help steering, but with the Pardus tires it seems to be a fine line before the car starts to square up corners.

Can anyone comment on the width restriction for IIC? Is it 190mm?
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Old 06-27-2013, 11:27 AM   #18
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Hi

Thanks for all the good info. I'm trying to work with OD on the specific issues we are having - rear end overtaking the front on acceleration. My latest theory is the droop I have in the rear pod is causing rear steer. I will be trying it out with a totally parallel setup this weekend. If we an crack this nut then propper tuning is next. I get the feeling it could be very fast if we can work this out.
Same issue here. Please keep us informed.

I have discovered the same, rear onpower spin, with short packs forward, short packs rear and full packs. In order of magnitude (more to less). It seems that as I have gone from less aggressive front ends - EXOTEK to standard Tamiya front end with offset steering knuckles the car, thus deadening the initial steering input, the car has mellowed out but still has the tendency to over rotate the rear mid to exit.

I typically run PIT tires and have found that my setups previous on the F104v2 don't survive too well on this car. Nevertheless, if someone has a starting setup for the PIT tires - please forward it.

I have reached out to PETITRC.com to see if they had a cache of setups they havent posted but there does seem to be a lack of setups in circulation.
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Old 06-27-2013, 11:45 AM   #19
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It seems like this car is very sensitive to how the diff has been set; do you think that might be playing a role?

I can't seem to get the diff tight enough to where it won't occasionally slip, while still feeling smooth. Whenever it does slip the car will step out. If I lock the diff so it doesn't slip, it feels absolutely horrible.

This is on carpet though, so not sure whether it is entirely applicable.
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Old 06-27-2013, 11:53 AM   #20
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It seems like this car is very sensitive to how the diff has been set; do you think that might be playing a role?

I can't seem to get the diff tight enough to where it won't occasionally slip, while still feeling smooth. Whenever it does slip the car will step out. If I lock the diff so it doesn't slip, it feels absolutely horrible.

This is on carpet though, so not sure whether it is entirely applicable.
The diff mechanics arent different from the Rebel 1/12. My Rebel 1/12 seems to do well with near-tight/slip - that is of course with foam tires.

The rubber tires on the F1 might present another variable. I'll have to try a diff setup out of my F104 to see if that is it.
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Old 06-27-2013, 12:38 PM   #21
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The diff mechanics arent different from the Rebel 1/12. My Rebel 1/12 seems to do well with near-tight/slip - that is of course with foam tires.

The rubber tires on the F1 might present another variable. I'll have to try a diff setup out of my F104 to see if that is it.
I've found that the kit bearings for the T.O.P. pan cars do not make good thrust bearings. I tried an aftermarket steel bearing there and had instantly better diffs
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Old 06-27-2013, 12:55 PM   #22
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I've found that the kit bearings for the T.O.P. pan cars do not make good thrust bearings. I tried an aftermarket steel bearing there and had instantly better diffs
Do you have a suggested supplier for those bearings?
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Old 06-27-2013, 03:25 PM   #23
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The diff is a problem with rubber tires, especially so with Pardus as they are heavier than Pits. You really do have to run the diff tight or you will slip the diff off almost all the corners.

I didn't like the stock diff rings as they seemed to require way too much sanding to get flat. I put some CRC rings on that seemed a little better. I also was able to get a slapmaster thrust to work. You have to use the medium sized spacer he sells. The other thing you need to do is cut down the plastic diff nut so it doesn't rub on the diff cap and unthread itself. I won't say it solved all problems, but it seemed better.

Lloyd- Run the pack forward and run a stiff center spring. Like I said, I was all over with the shock, but at the end of the year I ran a really stiff center spring with the battery forward. Also try reducing front droop. I don't know how you set yours, but I use a Team Durango screw td701001 which has 1.5mm wrench hexes on both ends. You can adjust the droop from the bottom of the arm in small increments.




Also, how do you have your ackermann set up? Are you forward or back on the knuckle?

As far as asphalt, I would go with either the old F104 Tamiya kit front tire or the Pardus front. They will balance the car out a lot better.
And minimal rear droop will probably help too.
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Old 06-27-2013, 03:46 PM   #24
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I've found that the kit bearings for the T.O.P. pan cars do not make good thrust bearings. I tried an aftermarket steel bearing there and had instantly better diffs
^ This.

The TOP kit bearings come with a really light oil... makes for great front wheel and rear axle(motor pod) bearings, but not so much with the axial loads a diff bearing sees.

Ive used the standard flanged 1/4" Avids with good success. They are grease packed instead of oil, and they are cheap enough that you can use a new one every time you rebuild/clean your diff. I used a more expensive piece from Boca for a while that had a really heavy grease...worked great, but I had a hard time stomaching ~$5-6 a bearing when they only lasted twice as long as the $1 Avids.
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Old 06-27-2013, 04:34 PM   #25
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Do you have a suggested supplier for those bearings?
As James said above, Avid or Bocca are good bearings. Honestly, I have used steel bearings from RC 4 less for years with good results. Ceramics are great on the rest of the car but steel seems to hold up better for the thrust.

Interesting about the diff rings, since they all come from the same place. They vary in flatness from batch to batch, though, we had some pretty funky ones a couple of years ago. Sometimes the lightweight rings are better, sometimes the other way around. BTW, I never sand diff riings
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Old 06-28-2013, 11:47 PM   #26
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I'd really like to find someone with a surface grinder to flatten diff rings. I even priced one myself a while back. You don't want to know how much (5k for a POS)
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Old 06-30-2013, 09:55 AM   #27
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Hi

Thanks for all the good info. I'm trying to work with OD on the specific issues we are having - rear end overtaking the front on acceleration. My latest theory is the droop I have in the rear pod is causing rear steer. I will be trying it out with a totally parallel setup this weekend. If we an crack this nut then propper tuning is next. I get the feeling it could be very fast if we can work this out.
Well, this was not the magic bullet.

Open to ideas. Even minor miracles.
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Old 06-30-2013, 10:36 AM   #28
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I'd really like to find someone with a surface grinder to flatten diff rings. I even priced one myself a while back. You don't want to know how much (5k for a POS)
I wonder if that's what B-Fast uses to grind his rings. I looked at belt sanders with a fine grit sanding belt, but I wasn't sure if it would work.
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Old 06-30-2013, 04:01 PM   #29
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Originally Posted by Dustyrc View Post
Hi

Thanks for all the good info. I'm trying to work with OD on the specific issues we are having - rear end overtaking the front on acceleration. My latest theory is the droop I have in the rear pod is causing rear steer. I will be trying it out with a totally parallel setup this weekend. If we an crack this nut then propper tuning is next. I get the feeling it could be very fast if we can work this out.
I would think you would want to add pod droop to increase weight transfer when on power. Increasing front droop will also increase weight transfer. I've also found stiffer side springs will increase traction coming out of a corner cause it puts more pressure on the rear tires.
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Old 07-02-2013, 07:34 PM   #30
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Default Rebel F1

Mike (TOP) called me abought this car while sitting at USGP - T12. With all that was going on in front of me, I had to have one. The car is beautiful. I run it at Mikes in Dallas and maybe not a front runner but still the car is so smooth and much fun to drive. I run an Exotex front end as well, battery forward cooper side springs and a cooper center. My car seldom if ever lifts the inside wheel. I found Droop at rear and front is critical to my driving. I did have to lengthen the motor slots a bit when I added a CRC spur for a smoother diff. It's a great car!
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