10R5 project 1 - 105R5.1

This is the first of two projects I've been working on to evolve the spec of my Associated 10R5 GT car.

This one answers the question of what a 10R5.1 might have looked like, has Associated built one. As the 12R5.1 was a minor evolution of the original spec, so the project focusses on small upgrades rather than radical design changes.

1) R5.1 rear end

A major difference between the 12R5 and 12R5.1 was the rear pod, which was opened out and re-balanced for the weight of brushless motors. As the 12R5.1 and 10R5 share the same bottom pod plate, this upgrade only needs four Associated parts to complete.

Part numbers are:
4688 Upper Pod Plate V2
8536 Motor mount
4687 Cross tube
8537 left side rear bulkhead

Whilst a brushless motor fits fine in the original 10R5 pod, the more open R5.1 version makes it easier to get the motors in and out of the pod. It is also easier to route the power wires and sensor cable.

Spacing is equal both sides, so I've just added a couple of thin axle spacers on either side.

2) Yokomo spring mounts

The 10R5 side springs mount onto plastic mouldings, that in turn screw into lond 1.5mm grub screws. Tweak can be adjusted by tightening and/or loosening the grub screws on either side.

The grub screw has to make its own thread into the plastic moulding. And rarely goes in straight. So the side spring gets offset sightly, which is most notable when adjusting the grub screw.

Yokomo make a metal version for their R12 12th car. These can be ordered from Japan or US shops (part number to follow). The metal version has a thread for the grub screw and as result goes in straight. I've found some thread lock before assembly will avoid any movement...which would play havoc with the tweak!

3) Yokomo rear cross brace

As well as the metal side spring mount, Yokomo also make a stronger replacement for the rear brace standoffs. In the 10R5 kit these are two threaded tubes. The Yokomo version comes in one unit, with a solid bar to brace the two sides.

There is an American company making a similar product. I'll dig out part numbers for each.

4) In-line steering blocks

These replace the 10R5 steering blocks, the front axle and the small screw that secures it. The King pin needs to move freely up and down, and in the kit version the blocks are plastic. They often need a reamer to remove excess plastic from the moulding.

In-line blocks are made up of two parts - an outer plastic moulding, and an inner metal axle. This metal part also includes the hole for the king pin, making this a metal to metal contact (so a tighter fit, and smoother movement. The axle has a 4-40 nut rather than the M3 version in the kit. The wheel bearings fit the same, although some spacing is needed as this axle is wider.


Full part numbers and pictures will follow. I'll have the car with me at Ardent for the first GT10 + F1 National next weekend if anyone wants a closer look.

For this project I've also looked at the Yokomo R12 front end, which works very well on the 12th car. This has a shock absorber instead of the fixed front end brace. The wider 10R5 front end would make this an interesting challenge, as the shock will need to a lot wider. More thinking required on this!

An update on Project 2 will follow - 10R5 with centre mounted LiPos.

Cheers
Mark

Hi Mark

Just looked on the Associated site. . .

its back for a limited time ?

Associated Factory Team _RC10R5_Kit

So have they gave up on this or is it not supported in the states

Gazza wrote:Hi Mark

Just looked on the Associated site. . .

its back for a limited time ?

Associated Factory Team _RC10R5_Kit

So have they gave up on this or is it not supported in the states

Hi Gazza,

Associated had announced the 10R5 would be discontinued...then got a flurry of orders. So a small supply of new kits are available to order.

Whilst the class has been fairly popular in the States, the kit hadn't sold in the numbers needed for Associated to keep the kit a going concern. Both the 10R5O oval version and 12R5.1 are still being made, and Associated have a great reputation for keeping spares available for old kits.

I've also seen a healthy supply of decent secondhand 10R5 cars for sale recently. So if you want one, then they are out there

Cheers,
Mark

Thats good to here as I know of a few who have them

I have an Xray link at the moment just waiting for some tyres

markb wrote:

3) Yokomo rear cross brace

As well as the metal side spring mount, Yokomo also make a stronger replacement for the rear brace standoffs. In the 10R5 kit these are two threaded tubes. The Yokomo version comes in one unit, with a solid bar to brace the two sides.

There is an American company making a similar product. I'll dig out part numbers for each.


Mark

The US company is Team Tamale they also make stronger pod plates which are prone to bending

http://home.earthlink.net/~cbradshaw25/id36.html

Jason

Team Tamale - that's the one (thanks Jason). I'd forgotten they also did the stronger rear pod side plates. Shame they are shiny ally rather than blue anodised.

After the Arden BRCA round it looks like Jason and I have followed boradly the same path. The 12R5.1 rear end and front in-line blocks. The Yokomo parts both beef up parts I think needed it - the side spring holders are a big improvement over the plastic mouldings in the 10R5 kit.

Surfed for other options for this project over the weekend. Not convinced by some of the front end options, but did see some R5 ally parts anodised in different colours (silver, red, black). My 10R5.1 still be sticking with blue anodising for now...

Good result at the Ardent meeting. Now looking at if I can get any running in before the Mairtime BRCA meeting...BRCA TC section duties and other plans are making that look unlikey!

I was surfing some Japanese and US sites looking for the Yokomo parts I've fitted. They are made as options for the 12R5, and I'd assume date back to when Yokomo ran modified Associated cars before they produced their own R12 12th car.

What I didn't realise was the R12 has similar parts for the rear brace and side spring holders. The designs and dimensions look very different, especially as the side springs look to be slightly bigger.

The 12R5.1 rear pod is the one I'm running as it's only 4 x Associated parts. It works as the 10R5 bottom pod plate was also the one used for the 12R5.1

There are similar parts on the Yokomo R12 car, but I'm simply not sure how much of that rear end you'd need to fit. They look trick, especially the different top plate design. But without a R12 kit to measure and compare, it's too much of a risk buying some parts then finding I need a bunch more.

One other thing I have fitted are the IRS metal replacements for the plastic front suspension balls. Pan cars don't have much front suspension movement, and so it needs to move freely over the limited travel there is. Reaming out the front hub and polishing the pins will help. But the plastic balls can bind, and the metal replacements do smooth the travel out even more.

I ordered these direct from Dave Irrgang and his IRS site (top service).

IRS also make a top range of pan car parts. Jason B recommends the replacement LHS hub carrier (opposite side to the sput gear). It;s the narrow one and uses two screws to clamp the hub to the axle, which is more secure than the one screw on the 10R5 kit part.

I'm also running some of the Associated ally screw kit to save some weight. As this car is well under the 930g limit, I've used these to lower the centre of gravity in the car. So the chassis screws are still steel - especially the front bumper screws, and the screws for the front suspension mounts as both are vulnerable in heavy front end crashes. The screws high up in the car is where I'm using ally.

This does still mean I have to run 30-35g somewhere in the car. I've tried to run this towards the front to improve turn in. I also run the batteries in the forward position for the same reason.

Cheers
Mark

brill mark keep em coming

Great info Mark thanks for all the tips
Any chance of some pics of the car and layout

Si

Si wrote:Great info Mark thanks for all the tips
Any chance of some pics of the car and layout

Si

Here's a couple of mine to be getting on with.

Jason
https://servimg.com/view/16560851/2
https://servimg.com/view/16560851/1

This is the rear hub I use

http://teamirsrc.com/index.php?main_page=product_info&cPath=6&products_id=108

Jason

Glad you're enjoying the update Si and Neil (Si - I think you got most of this on our PMs!)

That's the hub thanks Jason

I'm not back home now until Monday...working in London, then straight to Cotswold to run the Touring Car National. Unfortunately no Hara to watch this year.

However lurking in my stock of Snowbirds and Florida pictures, I did find a shot of the front end (and the Vegas pit towel!). I have a hunch I took it before a re-build of some sort...



What you'll notice by comparing the photos is that Jason and I run weight in the same place - just behind the servo. What you won't see is a slightly different approach to front caster settings...I run zero degrees, and Jason runs five degrees. The spacers mean we're pretty close overall.

Changes since Florida are limited for me. I've taken out the 13.5 motor (Epic Duo 2, bargain price and very quick) and put my trusty GM 10.5 back in. Plus a move from Spektrum to Futaba FASST which is the best thing I've done in ages (Jason is old skool with 40Mhz).

I am still grinning after spotting how far forward the PT is on Jason's car

markb wrote:
Changes since Florida are limited for me. I've taken out the 13.5 motor (Epic Duo 2, bargain price and very quick) and put my trusty GM 10.5 back in. Plus a move from Spektrum to Futaba FASST which is the best thing I've done in ages (Jason is old skool with 40Mhz).

I am still grinning after spotting how far forward the PT is on Jason's car

40Mhz gear is a stop gap my 2.4 FASST sytems are all in 24hr cars at the moment

Mark, Transponder is that far forward because I don'twant to loose like Hupo did

As I'm not now home before BRCA Round 2 at Maritime, prep and packing had to be done in the sunshine yesterday.

Car prep was pretty light touch. My IRS order had arrived, so fitted the new left side hub. I have photos to upload one evening this week so will explain how the revised spacing worked out. Only other chassis prep was a diff rebuild, as it is not my favourite Sunday morning job

Fitted a Reedy sticker to the shell as this will be the first meeting I'm racing at since Mike's passing.

Packing for Maritime means two things. Firstly only take what you really need, as you'll be carrying it up the steps Secondly pack it in as few bags as possible, to avoid a third trip up and down the stairs. I think I've got it down to two trips (one bag, one truer box, two bodyshell bags).

I've got Friday off, so Fran is picking me up from Docklands to drive down to Goodwood. We're at the Festival of Speed on Friday (woo hoo!), and then driving up to the hotel near Maritime on Saturday afternoon. Fran has found a resturant for Saturday night, and we're booked and good to go (ps - anyone who thinks my preparation is good, should see and hear Fran in action!)

Photos to follow.

10R5 Project 2 got a few minutes spent on it yesterday. This is the chassis for LiPos fitted along the chassis rather than across. The side struts are now the same height, the shock has more angle after fitting the IRS medium height ball joint, and the second left hand side hub replaced one I had to butcher to remove (very overtight from previous owner!)

Cheers,
Mark

The Yokomo blue ally side spring holders can be seen fitted with Associated Gold springs:



These metal front suspension balls from IRS will really smooth out front suspension travel:



The IRS replacement for the LHS hub clamp:



I've spaced out the front suspension, and you can see the 1mm spacers and how they are positioned here:



The final two photos show the 10R5.1 rear end, taken from 12R5.1 parts. Much neater solution and easier access all round.

The IRS LHS hub is fitted. What I did find is it is much narrower than the kit version, so needed a lot of spacing out. Three options - two I rejected as a lot of small washers isn't ideal, and spacers outside of the hub aren't freely available for 4-screw GT car mounts (I use them a lot for Jaco PRISM wheels on my 12th car). Turns out the Associated diff cone is almost ideal...plus one more thin spacer.





For those wondering how to check LHS and RHS diff spacing is equal:~
- Fit diff and wheels to the car
- Take a digital vernier and fit the point side of into the hole in the middle of the bottom pod plate.
- Measure distance from the centre hole to the inside edge of the RHS wheel
- Measure distance from the centre hole to the inside edge of the LHS wheel.
- Add spacers to whichever side measures shortest (or eventually remove a spacer from the longer side)
- Re-fit and check again

Personally I'd adjust large 1-2mm spaces, and when it gets to small 0.1-0.3mm differences then I'd stop fiddling!

I also noticed the IRS LHS hub seemed heavier than the 10R5 kit unit. No surprise really as it has two clamping screws rather than one. When I've got more time I will see how different the weights are...

...not that the car needs a weight loss diet. Just I'd prefer to add weight low down and central to the chassis, rather and higher up and across the axle.

Mark
BMI make 3mm machined spacers that fix the need a dozen shims with that left hub. One spacer and two shims is bob on with BSR wheels. Remind me at the weekend I should have a coupke kicking about.

Jason

The BRCA GT/F1 National went well for what are now three 10R5.1 cars in Team Doris! Jason and I were joined by Luke Burley, who's clearly listened to the advice from Jason (mostly!) and I. I noticed the 12R5.1 rear end and in-line blocks on Luke's car, although didn't look that closely for any other mods.

Fran and I had been to the Goodwood Festival of Speed on Friday (if you've never been, make sure you do...soon!). And had decided to skip practice for a lazy and sunny day working our way along the south coast. I arrived chilled and just in time to carry my kit up the Maritime stairs before it closed, and then off to the Encore and a cracking meal out. We met Wim (Goss...AMC models) in the bar when we got back, and he'd hoped to get his kit up the stairs but had just missed out.

Sunday morning and one of the joys of staying at the Encore is that I can leave Fran in the room and walk over to the Maritime track.

Practice was handy as I'd not raced on that track layout. First lap was a "check everything is straight" one at half speed, then I cranked it up. And immediately remember just how much turn in my car has

A bit of a wake up call part way through practice when a purple car I didn't recognise seemed to have a similar pace. We ended up on the same part of the track and I was really loosing out at the start of the straight, but committed driving through the infield would catch that all back up and more. It was good to have a workout in practice! Turned out the purple car was the BMi of Chris O'Donohue running a 2S LiPo and 17.5 motor. That explained the accelleration

I'd run Jaco Lilacs for practice, so went back to the BSR/CRC tyres for qualifying. Round one was interesting as it turned out Luke + Jason + I all preferred the same spot on the rostrum, so two of us had to move. Jason lucked out with the far end and spend the heat re-learning the corners, and I was a couple of steps further in and was doing the same. Luke however had it nailed and set a time we couldn't get close to all day. I had caught Jason on the stagger and was just ahead...then clipped the last corner (doh!) and lost out by 0.1 seconds.

Round 2 and I re-ran the same tyres. I'd re-learned the leayout by now, and after an accident for Luke I was tucked up behind Jason and leading the heat. A couple of corner taps dropped me back but I got back on the pace. A better run and put me a couple of tenths ahead of Jason who didn't improve.

Round 3 and I didn't want to run tyres for a third time as the racing line was black with additive which had already lifted the inside wheel on the first lap around the sweeper. I wasn't as ahppy with the car balance, and had a couple of smacks into the barriers. After one a big black blob flicked up, and I was certain I'd chunked a tyre. I checked afterwards and hadn't but I had put a rip into the front of my faithful old red + white Sophia shell.

Round 4 and a new shell plus my final set of tyres from the Snowbirds. A much smoother run resulted in a slight improvement...bascially I'd done the same time in three rounds! Luke was a lap up and in pole, me second and Jason very close in third. Associated 10R5.1's in a 1-2-3 front of the grid lock out

The final was going to be interesting as we'd have ten cars rather than the six in heats. Luke chose the inside line from pole (I'd have done the same) leaving me on the outside and thinking how dirty it might be out there. And how much better Jason's line looked!

An even start at the front saw Luke, I and Jason stay in order for the first corner. Then a couple of laps to let the additive and grip settle down, and we were off. I was in the middle and had to back out of one run on Luke as it was going to end in tears, and keeping one eye on Jason. Good close racing, and as we approached the first back marker going onto the straight I clipped a marker and dropped back behind Jason.

Then it all went a bit downhill. More barrier taps including one around the sweeper left me down the field. I had to work hard to recover positions, and with the layout as it was had one really on clean place to over take into the hairpin after the sweeper. The front of the Sophia shell had tucked in, which didn't help. Pushin hard I regained fouth with a minute to go, and set off after Chris O'D for third. My car was settled down now, and I was gaining hand over first. Last lap saw me close right in, but not enough for a pass. So close...but...

So a well deserved pole and win for Luke. Congrats and no surprise to anyone who was fortunate to watch Luke race Tamiya F1's...

Second to Jason which pretty much ties up the championship, as I can't go to Teeside (on holiday). And an excellent third place for Chris who proved 2S and 17.5 is a fast and competitive package.

So slightly dissapointed with fourth, but a great day's racing in very good company.

On the car set up front the only real change from Ardent had been the IRS LHS hub. Worked very well all day so a thumbs up from me. The tyres were slightly smaller...simply a case of wear. The Lilacs lose very little foam on each run, and I'm now down to 53-53mm on the three sets I have. They have no real chunks either, thanks to regular application of superglue around the wheel rims.

Next race for project 10R5.1 is now the IIC and Vegas

So a few weeks to enjoy summer and work throgh the TC Nationals. And then planning and prep for Vegas...

As Mark has said a successful weekend for the Team Doris Associated 10R5.1s 3 cars all built and set up as discussed in this thread locking out the first 3 spots on the grid.
Having run out of my preffered additive Speedtech foam liquid I was forced to change to CS High Grip, which I normally run on my 12th scale. Had to open a new tin and discovered half way through the day that it would appear that the oil content has been reduced as it's much thinner than it used to be. Which explains why my car felt a little more edgy than usual

I think the championships can still be won by me, Chris (2s) O'Donohue, Chris Taylor and Luke Burley (hope he's on holiday!)

Roll on Teesside, good luck in Vegas Cheese and remember "MAN UP and show those yanks how it's done"

Jason

Fair point Jason - I'd forgotten the other potential winners for a best 2 out of 3 series. Teeside will be interesting then

I do need to look a ore cunning solution for the foam bumper. The Sophia shell may handle well but doesn't always cope well with a heavy front end shunt. I'd found that out the hard way in an early meeting when one side bent in around the headlight.

Having ripped the front spoiler on my original red and white shell, I did fancy getting even more repair tape sorted. Done well and it wouldn't be an issue, but slighty out and the shell would catch on the carpet.

So a switch to a new Sophia shell was in order. I'd mounted this one forward slightly as many of the US set ups mentioned this and I wanted to see what different it made. What I learned is having shaped the bumper to the original shell, the more forward one had more air gap. So a shunt in the final saw it bent back at the front of the bumper.

Jason had mentioned taping the foam to the carbon bumper to limit any crash damage. It's not fool proof but I will try it.

I'll be getting some foam blanks to make up a more substantial bumper. The width across the car isn't an issue...but a taller foam to support the front end would help no end. I don't think an additional body mount in the middle of the bonnect would work (a Touring Car fix).

Send PM to Buddy rc. . . on here he has GT10 foam bumpers

Got some interesting stuff on order so an update to come when it arrives

The pace of 17.5 and 2S cars at the Maritime National means I've giving serious thought to project 2. It's currently set up for an in line 1S LiPo, but needs work for a taller 2S.

This one needs another thread of it's own...

I'm also going to write a summary of the fun I had racing in the World GT class at the Snowbirds earlier this year. That also needs another thread of it's own...

looking forward to a good read markb

markb wrote:Got some interesting stuff on order so an update to come when it arrives

RCDEVIL perhaps

Jason

jasonb wrote:

RCDEVIL perhaps

Jason

Perhaps

Good news = I picked up the RCDevil 10R5 bumper from the post office last night. Looks good, with a flush fitting bumper beneath solid foam and a carbon brace up top.

Bad news = all too late to fit and photograph last night, and as I'm working in London for the rest of the week it will have to wait until the weekend.

The 2012 Snowbirds dates are also released - 31st January to 3rd February. Fran and I are working out if we can make it...which will need some very cunning planning of holidays. More on that later.