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Old 09-16-2001, 08:59 AM   #376
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Hi guys and greetings from Malta.

Dave, Thanks for input regarding tweek etc. I have gone one further with mine since I have completely eliminated the top plate and just hooked an aluminium rod with a rose joint at each end, onto the two bulkheads. It seems to work OK.

Had a bad time with the real car a couple of days ago. Dropped a valve with the obvious consequences. Josh and I took the engine to bits last night but I don't think I'll have it running in time for next Sunday's hill climb.

Darkside. Yes sir.....he's done it at last. You know what I think about JPM. He should have done it ages ago. I agree, it was a good exciting race.

Off home in a minute to watch the Indy champ car race from Germany. Shame about Zanardi isn't it.

Son Josh is well back into RC and is going well. It does of course mean that I spend more time playing with his car than with my own....but then you're a Dad so you know what I mean!!!!

Regards

Joe from sunny Malta.
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Old 09-16-2001, 10:15 AM   #377
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Cool Hey johnbull...

You probably know about roll centers...Am I correct:

Quote:
OK, lets start by looking at using the upper hole when mounting the arm to the bulkhead/chassis (either end). Using the upper hole will raise the roll center. Using the lower hole will lower the roll center. The center of gravity is always higher than the roll center, so raising the roll center closer to the center of gravity will cause less roll, so more responsive. On the hubs, using a higher hole will lower the roll center, away from the CG. This will cause the car to roll more, so I think it will feel smoother.
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Old 09-16-2001, 11:09 AM   #378
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Hi guys and greetings from Malta.

SPEEDO. I read the same quote on roll centres and tried it all out.

I raised both front and rear inner upper arm mount points, and found the car much more sensitive, with much less body roll. Remember that in my case, with plenty of droop I get lots of body roll. I decreased this by using roll bars both front and rear, but now that i raised the inner pivot points I fond the car even better. in fact it was so much more sensitive it took a bit of getting used to.

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Joe from sunny Malta.
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Old 09-16-2001, 01:29 PM   #379
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joe, thanks, but when I wrote that, I am talking about the lower arm, not the camber link.

Using the upper inner mount for the camber link would make the car more responsive, I realize...but here I am talking about the lower arm, am I right there?
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Old 09-16-2001, 01:30 PM   #380
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adam, I think for the older shorter shocks you use one of the two upper holes, and for the new rear shocks (longer) you use the lower two holes.

Josh
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Old 09-16-2001, 01:57 PM   #381
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you mean sus arms right??
ok thanks..!
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Old 09-16-2001, 02:15 PM   #382
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Thinking about it, I think I have it backwards...It should read:

OK, lets start by looking at using the upper hole when mounting the arm to the bulkhead/chassis (either end). Using the upper hole will lower the roll center. Using the lower hole will raise the roll center. The center of gravity is always higher than the roll center, so raising the roll center closer to the center of gravity will cause less roll, so more responsive. On the hubs, using a higher hole will raise the roll center, away from the CG. This will cause the car to roll more, so I think it will feel smoother.

I think that's right now, isn't it?
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Old 09-16-2001, 10:18 PM   #383
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Default Long rear Shock shafts

You know, I built an SP for a guy recently and all 4 of the shock shafts were the same length. I've been running my standard shocks and the car is pretty dialed. I don't know if its a misprint or whether I'm missing something but I didn't see any longer ones in there.
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Old 09-17-2001, 12:01 AM   #384
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Dave,
Not absolutely sure, but I think they are referring to whether you use the long or short shock ends in reference to the shock length. The shafts are all the same size.I belive the long ends are for rough/ bumpy asphalt, and the short ones are for everything else.

I put some pics of my new Micro that I custom painted in the Micro thread.... go cheak it out!
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Old 09-17-2001, 01:02 AM   #385
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Hi guys and greetings from Malta.

Dave. Yoke now produce a larger....longer shock body. The advantages are: Larger means it can hold more oil. Longer gives the same effect as having longer shock shafts, meaning more travel.

Basically when I did my Yoke for more droop - or travel if you like, I simply used slightly longer shock shafts. The TC3 shocks are slightly longer, and I know guys running very quick TC3s with no rebound spacers in them - meaning more droop - or travel. On our circuit, which whilst being very grippy is also very bumpy, this sort of set up seems to work very well. It makes the car much more forgiving.

Speedo. There are plenty of myths about suspension tuning and location of suspension arm pivot points. What you have to see is the arch in which the suspension travels. In an ideal world we should have wheels that remain at 90 degrees to the road all the time. This would mean your whole tyre surface is always in contact with the road - giving better grip and less tyre wear. Unfortunately other factors come into play as well. Slop and G forces as well as side slip are just some of them. This is why we always end up starting off with a bit of negative camber at standstill.

As you know, when you compress the suspension the wheel moves in an arch. It will do less of this if both arms (top and bottom) are equal length and parrallel. With a shorter top arm you induce negative camber on compression. You can also do this by simply repositioning the arm to work in a different arch. such as assembling the bottom wishbone on the upper inner hole. It's all very complicated. I go for as little camber change, and as little negative as possible, seeing most importantly that the tyre wears evenly. In fact my Yoke runs 1 degree negative front and rear, as does my son's TC3.

Actually I last built a racing car...real one... almost 15 years ago, though I am presently designing a new motorcycle engined single seater for my son Josh to hill climb, so I really need to swat all my notes and read a few books. Real car suspension works in exactly the same way. If you can lay your hands on a copy, Len Terry's book called "Racing car suspension and design" explains it all really well. I need to read through it again.....for the hundredth time!

Oh by the way, does anyone know of a Suzuki Hyabuza engine for sale cheap. I'm on the market for one.

Have fun.

Joe from sunny Malta.
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Old 09-17-2001, 04:00 AM   #386
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hi guys, just testing out the new Digi cam.....here are some pics of my yok
Pic 1: tie rod on bulkhead to top-plate
Attached Images
File Type: jpg p1010001.jpg (59.5 KB, 115 views)
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Old 09-17-2001, 10:41 AM   #387
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i want to know if the handling of the MR4-TC SP is any different then the regular MR4-TC?
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Old 09-17-2001, 11:29 AM   #388
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Well Disaster: unless you run dual one ways on your MR4TC now, then the special will definitly handle differently. Some people do some quick and easy mods to make their SP full time 4wd. Is the MR4tc your driving now handling well? If it is why are you trying to switch?


Johnbull: So what do you think. Will they be able to run the US Gran Prix? The logistical problems seems to be stacking the deck agaist it. Even if they do race, it seems that M. Schumacher probably wont show. Dispite Eccelstone's threats. He may change his mind, or the race may not even happen here. Either way, its going to be an difficult situation for the FIA.
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Old 09-17-2001, 03:13 PM   #389
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Default Shock Rumor, Foamies

I just spoke to Yokomo again. The SP kits are not shipping with longer shocks in the rear of the car. But if you were to use the longer shock bodies, those are only for using the lower holes on the new rear A-arms. As stated in this thread previously, the purpose of the longer shocks would be for bumpy and low traction situations. However, if extra length is needed, it is feasible to change shock ends on the existing shocks as well. I know that most of the team guys use the previous World's style rear arm and standard length shocks on the car.

However, if you would like additional traction in the rear, trying using the upper hinge pin location on the rear bulkhead. This typically provides more traction to the rear of the car but produces more chassis roll.

RBLove - My foams are arriving this week. As soon as I have them, I'll try to find my setup and let you know what's working and what's not. If you outqualify me, my lips are sealed..lol..j/k.
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Old 09-17-2001, 03:21 PM   #390
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Hi guys. Greetings from Malta.

Darkside, I've been following the Shumi vs Bernie thing closely. it's certainly interesting, but don't under estimate Bernie....he's a hard nut!

Actually the way Michael went on before last Sunday's GP i really thought he was having second thoughts about the whole racing game, and would be announcing his retirement. His actual race made me even more convinced.

I certainly hope the Indy GP does happen, but as you say, it's not going to be easy.

Actually one of our mates from the track was holidaying in New York last week. He runs a Corally C4.1. I expect he's going to have a lot to tell us.

Took the Yoke down again today, but spent all the time playing with son Josh's car. He's going quicker each day, so it's worth it.

Regards

Joe from sunny Malta.
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