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Old 03-09-2011, 09:18 AM   #946
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Got my 417 a few days back. Lovely little refinements here and there

Has anyone got an opinion on the performance on high traction carpet against 416X?

So far every big meeting I attend, where the grip comes up drastically due to the amount of cars present, the Tamiyas grip roll the most and become less competitive as the day goes on whilst the Xrays become more competitive and grip roll the least

From what I can tell the Tamiya has amazing levels of grip, which can lead to worse laptime when traction is high, especially in stock where the key is to preserve momentum and corner speed

In modified where there is so much power, a lot of traction would be beneficial on corner exit, and also helpful to scrub the speed off on entry, which might explain why its so good in modified, and the set ups used by the team, none of which work for me at all (plus I am not an alien driver)

I run my X very stiff now, this has helped a lot, wondering if there is anything I haven't considered yet

I want the car to float on top of the carpet, not bite into it, especially at the front, that is where the time seems to be lost

Definitely got some ideas of my own to try in future, but please feel free to chime in it all helps !
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Old 03-09-2011, 09:43 AM   #947
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I had this exact problem with my 417 at Snowbirds. Widening the car all the way around is the only thing that stopped the roll for me. Even gluing the sidewalls didn't do the trick. I've since learned there's other things I could have tried (positive front camber), but I'd never dealt with traction roll before, so I was on my own.

I know nobody wants to hear it, but I really like how the car works with the long arms and no sway bars. Most other brands don't run nearly as narrow as the Tamiya. Maybe that's slower, but it beats being on your lid all day. Try keeping your setup the same (blocks and all) and just going to the long arms. Maybe even use wide hexes in the rear. Try it with and without swaybars. It's an easy change, and will only cost a few bucks in parts. You might be surprised.
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Old 03-09-2011, 12:17 PM   #948
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Quote:
Originally Posted by syndr0me View Post
I had this exact problem with my 417 at Snowbirds. Widening the car all the way around is the only thing that stopped the roll for me. Even gluing the sidewalls didn't do the trick. I've since learned there's other things I could have tried (positive front camber), but I'd never dealt with traction roll before, so I was on my own.

I know nobody wants to hear it, but I really like how the car works with the long arms and no sway bars. Most other brands don't run nearly as narrow as the Tamiya. Maybe that's slower, but it beats being on your lid all day. Try keeping your setup the same (blocks and all) and just going to the long arms. Maybe even use wide hexes in the rear. Try it with and without swaybars. It's an easy change, and will only cost a few bucks in parts. You might be surprised.
Do you have a part # for the arms you use? My car is acting the same way that hana166 described, plus has very little rear grip and I'm struggling to find a solution as well.
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Old 03-09-2011, 12:19 PM   #949
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Whats the best price you can get on the TRF417 in the US and from where? I had a 414 back in the day and loved it. Prices are always a bit exp but you generallyget what you pay for.

Thanks

dw
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Old 03-09-2011, 12:32 PM   #950
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Regarding traction roll, I had some interesting experience in my past race. I made the lower suspension block higher (higher roll center) by 0.5mm shims and my car was traction rolling on carpet. I NEVER had traction roll before I made this change. Setting-wise, everything else stays the same, so making the roll-center higher made my car traction roll.

If you look at Jilles's setup, he actually lowered the suspension block to negative number (by flipping the block with reduced shims) to combat traction roll. What I think is, the track has so much traction that, during the initial turn, too much cornering force is acting on the suspension too quickly, causing the car to dig-in suddenly and roll over. So with lowered roll-center, the suspension has more movement to absorb the sudden initial force.

However, lowering roll center does make the car lazier to steering input. But when the grip is too high, it's a better way to reduce steering sensitivity and traction roll.

Same with longer arm, which gives a bit more movement to absorb the cornering force, but also reduces responsiveness of the suspension.

Just what I found out.
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Old 03-09-2011, 01:06 PM   #951
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Great, very interesting comments. I understand what you're saying regarding the RC. I did try the lowering of front roll centre, and it did work, to an extent, but I found with the increased mid corner roll the car was rolling a lot in sweepers, and harder to punch out of the exits, at is was not really flat enough to get hard on the throttle

I have an unusual set up (not saying its good for others!) which is really good on smaller carpet tracks, 1mm under the front blocks and 22lb TOP springs, and use the post, original X deck and lipo plate (42182) so I was expecting a potential problem with traction roll, but actually the car was really good at high and medium speed, staying flat and carrying a lot of corner speed, but traction rolling only when I lifted off into slow corners, which is when the weight transfers to the front, digging in and rolling the car. I was able to attack the faster sections quite aggressively, the more I kept on the power the better it was !

If the car is pitching off power with 22lb springs I need to look at other additional measures. A lot of the guys swear by gluing the sidewalls but another driver told me he was using 1E or 1F blocks at the front of his 417 and it worked so syndr0me I'm hearing you on that. I'm definitely going to try this

What I'm searching for is a flat car, its easier to control on big carpet tracks, and importantly I reckon its more consistent at different speed corners around the track, making it faster

But I'm rolling when getting out of the throttle, particularly at low speed, so I'm thinking, instead of using no sway bar to use a 1.8mm bar. One thing a front bar does well is prevent hooking at low speed, whilst increasing initial response at high speed

It could be just what you want - a flat car to carry big corner speed which refuses to hook at low speed when you have to get out of the throttle

Well just some further thoughts
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Old 03-09-2011, 01:13 PM   #952
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Default Rolling issues

Are you guys running on carpet or asphalt? I've been running my 417 stock setup now for a month with no traction/rolling issues. The carpet at our track has high high traction like serious black grooves going on. The only significant changes I've made on the car are zero rebound in the shocks, 45 wt f/r, 0.5 mm shim taken out from the front block and 1 mm spacers all around. The car is dialed no rolling no nothing. What tires are you running?

I switched to the SWEEP EXP 32's from APS 28's and they work wonders.

Has anyone tried removing all the 0.5 shims out under the suspension blocks?
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Old 03-09-2011, 01:22 PM   #953
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Well this is one of the answers I'm interested in. Was wondering if the 417 is different regarding traction roll. I only have this issue under certain conditions, when there are a lot of drivers traction goes up a lot. And with a big track with a 100ft straight and fast infield its worse

Here the events are sweep EXP30. I forgot to mention I reckon tyre prep might be the ticket to fast consistent laps under these circumstances. What are you guys doing?
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Old 03-09-2011, 01:40 PM   #954
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Quote:
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Has anyone tried removing all the 0.5 shims out under the suspension blocks?
Yes, that did seem to help, but not completely solve it. I also have 1E suspension blocks in the front w/ 1mm hex spacers, and 1XA/1F rear blocks (3.5deg toe in) & no rear sway bar to help keep the rear in the back.
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Old 03-09-2011, 01:44 PM   #955
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What are you running for droop?? Try running zero shock rebound (I found after making this adjustment the car seemed very flat around the corners), 2mm of up travel on the front and 2 or 1.75 mm in the rear. That will take away from the front end digging in hopefully.
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Old 03-09-2011, 01:53 PM   #956
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Originally Posted by Bad-Andy View Post
Yes, that did seem to help, but not completely solve it. I also have 1E suspension blocks in the front w/ 1mm hex spacers, and 1XA/1F rear blocks (3.5deg toe in) & no rear sway bar to help keep the rear in the back.
Mmm I like that idea, the more grip in the back the more resistance to initial turn in, so a bit less rotation and transfer. I use 2.5 max so maybe I'm going wrong there. Interesting its a potential solution by adjusting the rear.

Only thing, that big toe in will be slow down the straight on a big track though but better than being upside down I guess
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Old 03-09-2011, 01:56 PM   #957
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Originally Posted by EDWARD2003 View Post
What are you running for droop?? Try running zero shock rebound (I found after making this adjustment the car seemed very flat around the corners), 2mm of up travel on the front and 2 or 1.75 mm in the rear. That will take away from the front end digging in hopefully.
Great idea to reduce rear sag. Really makes sense. Its a primary adjustment, why didn't I think of that before? Doh...will keep car flat too. I use drilled caps always so I'm good there
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Old 03-09-2011, 02:41 PM   #958
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I can't believe I never thought to flip suspension blocks and use less than 3mm spacers under them for even lower RC.

I believe the hard version of the long arm is 51104. I'm not so sure about the mold, though, it seems like mine are a little more sloppy than they should be where the long pin goes through.

I don't know if the 417 is more prone to roll than the 416 or not. It's the first time in my 3+ years with the 41x series that I've had a car traction roll, and I'd previously traveled to the IIC 3 times. I saw cars traction rolling there a lot this year, and I didn't have any trouble with my 416X w/LiPo chassis.

I think I'm just gonna focus on this pan car for a while. I need a break from sedans and stupid rubber tires.
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Old 03-09-2011, 04:51 PM   #959
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Can someone post the available suspension blocks and their designations?

I know I've seen it posted somewhere, but I can't seem to find it.
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Old 03-09-2011, 05:15 PM   #960
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Quote:
Originally Posted by hana166 View Post
Great, very interesting comments. I understand what you're saying regarding the RC. I did try the lowering of front roll centre, and it did work, to an extent, but I found with the increased mid corner roll the car was rolling a lot in sweepers, and harder to punch out of the exits, at is was not really flat enough to get hard on the throttle

I have an unusual set up (not saying its good for others!) which is really good on smaller carpet tracks, 1mm under the front blocks and 22lb TOP springs, and use the post, original X deck and lipo plate (42182) so I was expecting a potential problem with traction roll, but actually the car was really good at high and medium speed, staying flat and carrying a lot of corner speed, but traction rolling only when I lifted off into slow corners, which is when the weight transfers to the front, digging in and rolling the car. I was able to attack the faster sections quite aggressively, the more I kept on the power the better it was !

If the car is pitching off power with 22lb springs I need to look at other additional measures. A lot of the guys swear by gluing the sidewalls but another driver told me he was using 1E or 1F blocks at the front of his 417 and it worked so syndr0me I'm hearing you on that. I'm definitely going to try this

What I'm searching for is a flat car, its easier to control on big carpet tracks, and importantly I reckon its more consistent at different speed corners around the track, making it faster

But I'm rolling when getting out of the throttle, particularly at low speed, so I'm thinking, instead of using no sway bar to use a 1.8mm bar. One thing a front bar does well is prevent hooking at low speed, whilst increasing initial response at high speed

It could be just what you want - a flat car to carry big corner speed which refuses to hook at low speed when you have to get out of the throttle

Well just some further thoughts
Whats your rear droop set at? Taking some of that out could help to stop it pitching too hard... I know it worked for me on the crazy high bite at TITC. lost a little steering, but given I had to tippy-toe it around anyway, wasn't a big problem, as could then be a lot more aggressive.
EDIT - Already been suggested... haha!

On the lower roll centre thing, I spoke to Jilles about it in Thailand. His reasoning for trying it was simply that (as has been mentioned) in high bite, you want the car to be unresponsive initially (bit like a foam car), then roll. Easiest way to achieve it is to drop the front and rear blocks. I tried it, and personally didn't suit me (too unresponsive for my style), but I do get the idea of how it would work.
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