Tommy R's Yokomo DRB RWD Drifter

[Tommy R]

There's been quite a bit more progress on the DRB since I last posted. The gyro and servo are still working well and I've been continually making improvements to the suspension. I adjusted the front end quite a bit for more angle without binding and it seems to be working. I'm also still trying to get the rear end softer and may have finally stumbled upon a solution. You see, I'm running Wrap Up Next rear arms/hub carriers and it moves the lower shock mount all the way out to the carrier. This does a few things, but two downsides are less overall suspension travel and a stiffer effective spring rate due to a lack of mechanical advantage when the suspension tries to compress the spring.

I picked up a set of super soft (12.25?) rear Wrap Up Next (WUN) VX springs. That seems to have helped a bit compared to the MST yellow/orane springs I'd been running lately. But perhaps more importantly, I moved the hub carriers inboard just a bit. The WUN carriers/arms have lots of adjustment available, which made this possible. This narrowed the track, but also have back some mechanical advantage to compress the rear springs. In order to keep up with everyone at RC Garage in Houston, I've been experimenting with adding weight to the rear end, as well.

One of the next things I wanted to do was upgrade the motor. In all honesty, the Speed Passion 10.5 has served me quite well and I don't have any complaints about it, but I wanted something a little nicer for this build. I did a bunch of research and had decided on a Tenshock 4 pole motor, but they're next to impossible to find. I'd heard many people speak highly of Acuvance motors, though, so I decided to give one of them a try. Couldn't locate any 10.5s in stock so I opted for a 9.5 instead. In preliminary testing, it doesn't seem to be excessively overpowered at all, so I think it should work out just fine.

But there's a bit of an issue with mounting the motor. With the solder tabs oriented where I wanted them, they were contacting the chassis brace.

That's not good. I could clock the motor over about 60 degrees, but now the angle will make it difficult to cleanly route the power wires to the motor.

Since I'm not sure I could find a happy middle ground between the two positions, I opted for the latter. Honestly, it's not as "clean" as I'd prefer and I think I'll eventually shorten the wires to tidy things up a bit more, but it's not too bad the way it is.

I also moved to a larger spur/pinion. Running a 112/36 which puts my final drive at 8.29 now.

Steering lock is adequate.

 

[Tommy R]

Then it was time to continue with some of the "fun stuff" and do some more accessorizing of the body. It was a little plain so I added a bit of flair. It's a drifter, after all!

I really don't like something about the exhaust. I think I need to add some tubing in front of the tip to make it look more realistic. Or maybe pop a hole low in the quarter panel and route it through the body?

Rear bumper is held on with magnets and occasionally gets ripped off...

And the bike rack can be removed easily, as well. Here it is in "comp mode"! Ha!

 

[BoogieBANG]

Just yesterday I was thinking of getting into the rc drift scene, I was looking around facebook for a small community and couldn't find anything. But then I saw your pictures at Houston RC Garage and thank you! I'm gonna check it out tonight. 8)

 

[Tommy R]

Just yesterday I was thinking of getting into the rc drift scene, I was looking around facebook for a small community and couldn't find anything. But then I saw your pictures at Houston RC Garage and thank you! I'm gonna check it out tonight. 8)

Just replied to your post on Drift Mission. Glad to see you're joining in on the fun, man. Come out this weekend for the comp! Should be a blast! "thumbsup"

 

[Tommy R]

I've always felt the rear suspension was too stiff on this chassis. I blame the Wrap Up Next rear suspension moving the lower shock pivot point to the hub carrier, as opposed to the control arm the way most suspensions are set up. I've tried some pretty crazy soft springs to no avail. I've been running the stock 3 hole Yokomo pistons, but I ordered some PCB hand drill bits online and they finally showed up the other day. So I added some holes to the rear shock pistons and now they're 6 hole pistons. The rear suspension (with 15WT oil) is nice and squishy now.

I've also been continuing to work on the front suspension since it's needed more work than the rear. Surprisingly, the rear worked pretty decent considering how stiff it is. But getting lots of steering lock while avoiding the wheels binding, getting good Ackerman, eliminating crabbing, etc. all takes a lot of time and tuning. The car's not there yet, but it's getting closer. No useful pics to show for that stuff, unfortunately, since lately it's just been turnbuckle adjusting.

I've also been working on reducing the amount of camber I run. I'm now down to about -2 in the rear and about -3 or -4 up front. This was my steering lock/Ackerman before the camber change and some ride height changes. I'm working on getting it back to this. (7mm offset wheels shown)

I also got rid of the bumpsteer.

So our drift group all painted up grey "team" bodies to use at comps. And we have a comp tomorrow in Houston. Only issue is the guys don't all have their bodies painted yet so we're just running whatever bodies we want for this one. No worries, I've been working on some changes to my S13 Silvia body and am looking forward to running it tomorrow now that I've given that shell a new lease on life!

The inner fender kit is from Pandora and it was quite a bit more challenging to install than I anticipated. I'd recommend installing the inner fenders before cutting off the outer fenders for anyone considering this. The inner panels were painted black on the inside then black on the outside, followed by a bit of white overspray to make it appear that the car was originally white. For the rear fascia I decided to mix it up and just go primer grey. I then covered it all with some blackwash for depth.

Then I added a Yokomo intercooler (again with blackwash) with some styrene tubing, as well as built a tube bumper from styrene. I plan on adding a bit more detail to it all before I consider it done.

 

[Tommy R]

On a different forum, I was asked how I mounted to magnets for the roof rack and rear bumper on the Corolla. Here was my reply:

So here's the "less glamorous" side of this shell. LOL... The magnets for the roof rack are simply covered in hot glue. They've held great. Also shown are the magnetic body mounts that are temporarily holding the body posts, as well.

Here you can see all the hot glue I used to attach the rear fascia to the body. I didn't use it to attach the light buckets because those will eventually come out so I can add the LEDs.

Look closely and you can see a magnet encased in hot glue. This is one of the two bumper mounts.

Lastly, here you can see the magnets affixed to the bumper. What I did here was glue the magnets to a chunk of styrene to get the depth of the magnet correct. Once that was where I wanted it, I filled the entire thing with hot glue. This held the magnets and styrene in place, but it also added a lot of structural integrity to the thin bumper's Lexan. Now it can get ripped off on the track and I don't have to worry about it getting torn.

 

[djjiz]

Good call on the camber settings. Too much is never a good thing.

Ever use the MST DK progressive springs? The heaviest set is still too light on a ms01d pro with a shorty pack. You're welcome to have them if you want.

 

[Tommy R]

Not sure to be honest... I'm currently running a set of soft MST springs on the rear (orange/yellow) and I think they may be the softest they offer. Not sure, though.

I also don't think I mentioned that I'm now running a ball diff in the rear. Not sure if the difference was all that dramatic compared to the spool, but the car is working pretty well. I may try loosening it up just a bit to see what it does. But right now after adding a lot of toe out, the car is working pretty well. It's liking to be thrown into the corner pretty hard, but is working great. We had a big open house at RC Garage in Houston this weekend and I ran through about 4 battery packs! Had some great tandeming with a lot of different cars. Really learned a lot about trying to tandem very closely and modulating speed. So much fun!

 

[djjiz]

These guys. Not sure why they made them so soft but your application sounds perfect. Cover shipping and they're yours.

Max Speed Technology RC Drift Springs DriftMission Your Home for RC Drifting

 

[Tommy R]

Thanks a lot and I appreciate the offer, but the MSTs I'm running right now really seem to be working great so I think I'll stick with them for now. "thumbsup"

 

[Tommy R]

This past weekend, RC Garage in Houston had their open house and we had a fantastic time! I burned through nearly 4 battery packs and finally had some good opportunities to practice some close tandem runs. So much fun! And yes, I added a bit of rust to the Silvia.

 

[Tommy R]

A video from the RC Garage open house in Houston. Such a great time!

https://www.youtube.com/watch?v=vql4ddSV2KA

 

[Tommy R]

Got some updates to share...

I installed a Wrap Up Next 5mm thick motor spacer. This allowed me to clock the motor where I wanted without the motor tabs contacting the aluminum bridge. I also swapped over to white Yokomo ball cups and installed some Kazama adjustable height shock mounts. I'm struggling getting the positive Ackerman I want without having to resort to excessive toe out, however. If anyone sees anything in my setup that I should change to get more positive Ackerman, please let me know! Here's some pics.

 

[Tommy R]

I also finally got around to adding some lights... 3mm white LEDs behind the red painted rear tail lights.

3mm white LEDs also behind the clear headlights and amber painted "fog" lights.

I didn't illuminate all the lights, just the main ones. Didn't want it looking too busy.

And here's the "ugly underside". It's a 240mah 2s LiPo sending power to a converter, which spits out the power to the 6 LEDs.

 

[Tommy R]

A couple pics from Saturday night's session...

 

[CM9000]

hey hey. ive seen this build on mission.

can you do a write up on the lights for the scale guys? and where to get that "converter"?

I like the wagon. not to keen on the sil.

im a hardcore iron mask guy. r31's are my favorite day in and out.

 

[Tommy R]

hey hey. ive seen this build on mission.

can you do a write up on the lights for the scale guys? and where to get that "converter"?

I like the wagon. not to keen on the sil.

im a hardcore iron mask guy. r31's are my favorite day in and out.

I picked it up from Mouser: http://www.mouser.com/ProductDetail...GsmoEFRKS8JjZftvakwHMhjR4UjynVdhbrt1wBZpCpQ==

Basically, you just hook up a small 2s LiPo to it and it outputs 6v. I hooked it up to several 6v LEDs in parallel. Only issue is there's no low voltage cutoff for the battery so I picked up a super cheap aubible buzzer from Hobby King for that. I haven't used it yet, but I will next time I run.

You lost me on the iron mask reference, I'm afraid.

 

[Tommy R]

This wagon and Sil Look amazing. I am afraid to continue to look at drift setups. You have Done an amazing Job love the bike Rack.

Thanks very much!

 

[Tommy R]

The car has been working really well and I've been doing a TON of traveling for work lately. The good part about the travel is it let's me spend more time at RC Garage in Houston drifting with a bunch of really cool folks. But because I've been busy I haven't had chance to post up many updates. Well, here's some... :mrgreen:

First, here's some pics of the current setup. The car is really working great and I couldn't be happier with it, to be honest.

Second... Well, the Corolla body is supposed to be a team body for use when we do competitions. I've been using it all the time, however, and it's going to really start showing some wear unless I use something else from time to time. Yeah, I've got the Silvia, but with the body changes like the front tube work, it's kind of fragile and I want something I can run and not worry too much about. Basically, I need a basher body.

That was the plan. Things don't always go as planned. As I began to put source parts for the "beater", it started getting nicer and nicer. Well, anyway... Here's some pics.

Silly Tamiya window masks. Bah! It's an Rx7, by the way.

The first stage: paint. A full can of Spazstix metallic green backed with silver. It came out darker than I'd expected and I'm told the pics don't do it justice and it looks much better in person, FWIW. But it's gotta start somewhere, right?

More in the next post...

 

[Tommy R]

Tamiya bodies are usually pretty well done. They're very accurately modeled and strong. However, they're often narrow and will pretty severely limit your wheel options. Fortunately, Demi Works has a solution with their Rocket Bunny kit. I bought the side skirts/flares, but also bought the front fascia/rear spoiler set. Here's the initial mockup.

Showing the increased tire coverage with the RB kit.

And the rear.

Because the rear of the body is so low I had to get creative on the rear body mounts.

Got the sides all mounted up with the ABC Hobby hardware.

Light buckets are painted in gloss black to blend in well with the black painted Lexan in those areas.

Or maybe black wheels?

The "flip up" headlights are non-funtional. The housings are just Shoe-Goo'd into place. The only front lights will be in the buckets just underneath. But that clear glass just makes it too easy to see all the wires and such within the chassis. Yuck.

Windows are now tinted (Tamiya Smoke), a windshield eyebrow has been added front and rear, and I felt this car deserved a wing. Note the side view mirrors are ABS plastic so they were painted silver, then the green, and then I clearcoated them. Still not finished, though....

Front fascia trimmed, intercooler added, front and rear lights...

And cracked the driver's side window.

I still have to add the backfire exhaust, but other than maybe adding some stickers here and there it's all done. If the front end gets torn up, I may install the RB front fascia.