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Old 07-21-2003, 05:13 PM   #2761
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This weekend, I raced my 705 in Renton Washington. The track is huge parking lot-style and was treated with traction compound. Where I am from we don't get to run on tracks that size or treated with traction compound. Holy toledeo what a difference! It became clear that Renton's style of track is where the 705 excels. The traction was mental and 2nd gear got heavy workout. I also got to see some of the nation's elite drivers duke it out. Rad.

One of the Serpent drivers gave us the low-down on a new clutch set-up. Apparently, instead of switching out the flyweights and replacing the spring and shoe, he had simply taken off all of the bevelled edge of the stock shoe. He said it gave way more punch.

As for the nitro content/shimming issue (that I have posted about elsewhere), I ran 30% without any extra shims in my SX12 3P MS Race for the first time. Tons of power and no problems with blown plugs or flame-outs.

During qualifying, it was slightly cloudy. It was warm, but not hot. Traction was amazing. My car hooked up perfectly. For the mains, the sun came out and the track got super hot. With the same setup I had run in qualifiers, my rear end was uncontrollable during the main. It was like driving on ice. I would have thought traction would get better with heat. Or is there an optimum temperature, above which traction gets worse? I was running 45/40 durometer. Would have I been better off using 45/42, or 45/45?

Last edited by chachi; 07-21-2003 at 05:27 PM.
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Old 07-21-2003, 08:43 PM   #2762
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Quote:
Originally posted by modellor
Some people mount the Serpent steering rods on the top side of the servo saver and cut away a bit of the plastic end to allow them to fit. We tried this here and found that it makes the plastic part a bit weak.
You need to file and sand off a little on the servo saver. Not the ball cups If you sand the ball cup ends, that will make it weak of course.
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Old 07-21-2003, 08:58 PM   #2763
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Quote:
Originally posted by chachi
One of the Serpent drivers gave us the low-down on a new clutch set-up. Apparently, instead of switching out the flyweights and replacing the spring and shoe, he had simply taken off all of the bevelled edge of the stock shoe. He said it gave way more punch.
Yes, the 705 really shines on a huge track

What do you mean by "taken off all of the bevelled edge of the stock shoe"? Which shoe are you reffering? The clutch shoe or the flyweights? Any pics?

Quote:
Originally posted by chachi
During qualifying, it was slightly cloudy. It was warm, but not hot. Traction was amazing. My car hooked up perfectly. For the mains, the sun came out and the track got super hot. With the same setup I had run in qualifiers, my rear end was uncontrollable during the main. It was like driving on ice. I would have thought traction would get better with heat. Or is there an optimum temperature, above which traction gets worse? I was running 45/40 durometer. Would have I been better off using 45/42, or 45/45?
I noticed that too on the last weekend I raced my car. When the weather was cool in the earlier part of the morning, traction was superb with the tires I had. Once the sun came up and the weather got hot in the afternoon, I lost traction mostly in front and the car was understeering bad. In my case, it could be that the rear tires got more traction than the front when the track heated up and probably contributed to the understeer because of the too much traction in the rear.

For your case, it could be that the front tires were giving more traction than the rear when the track heated up which contributed to the oversteering.

I think I see a relation here... Harder shore tires will be more consistant and do better on a hot track while softer tires only do good on a cold day. You were using harder shore in front than the rear were you? I was using softer shore tires in front and harder in the rear...
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Old 07-21-2003, 09:15 PM   #2764
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Quote:
Originally posted by InitialD
Yes, the 705 really shines on a huge track

What do you mean by "taken off all of the bevelled edge of the stock shoe"? Which shoe are you reffering? The clutch shoe or the flyweights? Any pics?



I noticed that too on the last weekend I raced my car. When the weather was cool in the earlier part of the morning, traction was superb with the tires I had. Once the sun came up and the weather got hot in the afternoon, I lost traction mostly in front and the car was understeering bad. In my case, it could be that the rear tires got more traction than the front when the track heated up and probably contributed to the understeer because of the too much traction in the rear.

For your case, it could be that the front tires were giving more traction than the rear when the track heated up which contributed to the oversteering.

I think I see a relation here... Harder shore tires will be more consistant and do better on a hot track while softer tires only do good on a cold day. You were using harder shore in front than the rear were you? I was using softer shore tires in front and harder in the rear...
On Chachi case, It could also (possibly) be that the rear tires wear off faster than the front that makes the front bigger then the rear by much. Usually happen on big track.
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Old 07-21-2003, 09:31 PM   #2765
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Quote:
Originally posted by nizee
On Chachi case, It could also (possibly) be that the rear tires wear off faster than the front that makes the front bigger then the rear by much. Usually happen on big track.
Good point nizee That was one of the reason why I went with harder rear than fronts besides trying to get more steering...

Talking about tire wear, I was actually using a 4.5 mm split in the last race with 18T side pulley, 47T rear diff and 22T brake pulley. I'm happy to find out and report that after 30 minutes, the split was almost about the same which means that the tire wear rate for the froint and rear is about almost the same

Next race is going to be on a huge track where NTC3s will be using 21/27 gearing. I hope to be able to use 15T/20T pinions and 50T/44T spurs using the 18T side pulley and 22T/47T optional pulleys.
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Old 07-21-2003, 09:50 PM   #2766
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Quote:
Originally posted by InitialD
Good point nizee That was one of the reason why I went with harder rear than fronts besides trying to get more steering...

Talking about tire wear, I was actually using a 4.5 mm split in the last race with 18T side pulley, 47T rear diff and 22T brake pulley. I'm happy to find out and report that after 30 minutes, the split was almost about the same which means that the tire wear rate for the froint and rear is about almost the same

Next race is going to be on a huge track where NTC3s will be using 21/27 gearing. I hope to be able to use 15T/20T pinions and 50T/44T spurs using the 18T side pulley and 22T/47T optional pulleys.
D,
That is a niceeeee track !!! Wish we had something like that here.
Which part of M'sia is that? KL?
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Old 07-21-2003, 09:58 PM   #2767
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Quote:
Originally posted by nizee
D,
That is a niceeeee track !!! Wish we had something like that here.
Which part of M'sia is that? KL?
About 50 to 60 KM (31 to 37 miles for the metric deficient ) down south of KL. It's in Seremban.

The track has very minimal fascilities. Not like the track you see in Vila Real, Portugal. That's an envy of everybody in the Rc community. Yes, there are pit tables but no toilets Well, you just need to walk further a little to the nearby sport complex if you want to take a decent leak

When you decide to come down in this region, you should bring and play the 705 there
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Old 07-21-2003, 10:07 PM   #2768
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Quote:
Originally posted by InitialD
About 50 to 60 KM (31 to 37 miles for the metric deficient ) down south of KL. It's in Seremban.

The track has very minimal fascilities. Not like the track you see in Vila Real, Portugal. That's an envy of everybody in the Rc community. Yes, there are pit tables but no toilets Well, you just need to walk further a little to the nearby sport complex if you want to take a decent leak

When you decide to come down in this region, you should bring and play the 705 there
We have to bring our own table here!!! Buy our own tent to shade from the sun during summer!! As always, we gotta find a nearest fast-food restaurant to take a leak.

If i happen to move back to SG, i would definitely take a road trip one of the weekend to race there.
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Old 07-21-2003, 10:22 PM   #2769
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Quote:
Yes, the 705 really shines on a huge track

What do you mean by "taken off all of the bevelled edge of the stock shoe"? Which shoe are you reffering? The clutch shoe or the flyweights? Any pics?
I didn't get a chance to see it, but it was the clutch shoe. Normally it is shaped so the outside matches the contour of the clutch bell. He used a lathe to remove all of the outside up until the surface that is perpendicular to the flywheel pins. I have attached a picture. He removed everything outside the red line from what I understand.


Quote:
I noticed that too on the last weekend I raced my car. When the weather was cool in the earlier part of the morning, traction was superb with the tires I had. Once the sun came up and the weather got hot in the afternoon, I lost traction mostly in front and the car was understeering bad. In my case, it could be that the rear tires got more traction than the front when the track heated up and probably contributed to the understeer because of the too much traction in the rear.

For your case, it could be that the front tires were giving more traction than the rear when the track heated up which contributed to the oversteering.

I think I see a relation here... Harder shore tires will be more consistant and do better on a hot track while softer tires only do good on a cold day. You were using harder shore in front than the rear were you? I was using softer shore tires in front and harder in the rear...
That sounds right. I was running harder tires up front (45) and their performance didn't change. My rears must have been too soft. I was running a small split with the rears 2mm less than the front and they were not hooking up right from the beginning of the main. Oh well, now I know.
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Old 07-21-2003, 10:27 PM   #2770
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Quote:
Originally posted by nizee
We have to bring our own table here!!! Buy our own tent to shade from the sun during summer!! As always, we gotta find a nearest fast-food restaurant to take a leak.
Oh yes, I see that often on the pics posted on the mytsn race report Well, we should be lucky here in a certain ways then

Quote:
Originally posted by nizee
If i happen to move back to SG, i would definitely take a road trip one of the weekend to race there.
Look me up. I'm always gain to take a drive there
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Old 07-21-2003, 10:32 PM   #2771
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Quote:
Originally posted by chachi
I didn't get a chance to see it, but it was the clutch shoe. Normally it is shaped so the outside matches the contour of the clutch bell. He used a lathe to remove all of the outside up until the surface that is perpendicular to the flywheel pins. I have attached a picture. He removed everything outside the red line from what I understand.
Ummm, if I understood it right, that means after the mod, the clutch shoes will be thinner then, right?
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Old 07-22-2003, 12:06 AM   #2772
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, if I understood it right, that means after the mod, the clutch shoes will be thinner then, right?
The clutch shoe would have a smaller diameter but the thickness of the shoe would not change. He said he removed about 50% of the mass of the shoe and was thinking about removing even more. It didn't completely make sense to me since taking away some of the contact surface area of the shoe seemed counter-intuitive. But that is what he said he had done. His car seemed to have way more pick-up than the other 705's (even taking into account the rear gear reduction).
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Old 07-22-2003, 12:40 AM   #2773
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chachi, thanks. It's clearer now after your last explanation. Did he use the black XP or just the normal stock clutch shoe?

You may be right that by cutting the shoe to make the diameter smaller, the weight of the clutch shoe is reduced. You are also right that the contact surface area is also reduced or will be non existant because I always notice that the scuffing marks are apparent at the slanted edge of the clutch shoe (where it is proposed to throw off the material) and at the mating slanted surface on the clutchbell.

I think after the mod, the clutch shoe will make contact more towards the center of the clutchbell and the axial force from the clutch and the contact surface of the shoe will be perpendicular to the contact surface of the clutchbell and not at the slanted area of the clutchbell previously with the stock clutch shoe. This is why I think the clutch efficiency increases besides the shoes being lighter and responds better.

I can see that the mod will work nicely on a stock clutchbell but I wonder if it will work on the lightened clutchbell because the contact surface where the clutch shoe mod is suppose to contact with the area of the lightened clutchbell will be less as there will be holes there instead...
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Old 07-22-2003, 12:41 AM   #2774
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Thumbs up servo savers

Quote:
Originally posted by serpentracer1
Thanks for the part numbers and the tip about the servo.Have you tried to lower the servo more or can it be done.
Try the 1/8th. scale servo saver, it has a different offset. I do believe that it also changes the ackerman slightly, but for my set up this was a good thing!
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Old 07-22-2003, 12:45 AM   #2775
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Quote:
Originally posted by Slotmachine
Try the 1/8th. scale servo saver, it has a different offset. I do believe that it also changes the ackerman slightly, but for my set up this was a good thing!
Yes, that is correct. One of the mods listed by Art Carbonell during the old Impulse days was to use the 1/8th scale servo saver. I actually almost forgot about that. Yes, it apparently gives better Ackerman

But I don't think it solves the front linkage rubbing the front belts. You still need to mount the balls on the reverse side of the servo saver in order to clear the front belt.
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