Tuesday, June 28, 2011

F1 video from Strictly RC

You can now watch me continually blow the end of the short chute during practice, LOL.  Thanks to Heinrich for posting this video.  Note the yellow/orange/white F103 was the Pit Shimizu shod ride of Tom King, and the yellow car was the British Menace, Anthony Cotes (hope I spelled that right)

Pit Shimizu tires...on going info

So a couple weeks ago at the track here, Chauncey (known as cheROK 1212 on rctech..) ran the medium Pits on his F104 and was fast and happy with the tires (0573 and 0578??!?!).  Then this weekend, Tom King (no relation) showed up with Pit mediums on his F103 (0543 and 0547??!!?).  Once the tires broke in, his car was dialed as well.  He said he bought the mediums based on Chauncey's experience.  Our track is a parking lot sprayed with cheap rootbeer, so grip is usually at least medium/low or medium.  I know this post from rctech.net detailed using a little harder rear to get the car steering more.  Anyway, just thought I would share this with everyone.  I really don't know too much more (I hope those part numbers are right),  as I have been running Tamiya tires to work on my TCS setup, but both cars looked good and had happy drivers.

Thursday, June 23, 2011

What F104 should I buy?

Tamiya has a ton of variations on the F104 platform.  This seems to confuse a lot of people, so I think a quick run down on what to use for what type of racing would be helpful.

First off, if you are running an "open" class, with no width or manufacturer restrictions, it would pay to look at a 3Racing F109, the F103 in it's various forms, or keep your eye out for a used Exotek chassis.  These cars are usually faster than a narrow F104.  They can also be cheaper depending on what model you buy.  An F104W may also be a good choice, but the other cars are a little more sorted in wide form.

The HPI F10 can also be good for wide or narrow with an Exotek chassis.  It may also take some more option parts to make it work in wide form from what I hear.

F104 Pro Black Special--Best deal hands down to run carpet on foam tires.  Everything is in the kit.  The regular Pro kit is ok, too, but you don't get the aluminum motor mount and aluminum pivot plate included.
 Even on 3rd party rubber tires, the black car is the way to go. Pit Shimizu tires fit the stock foam rims.

If you're looking to go cheaper, or your racing rubber, the McLaren and Ferrari kits are not bad, but for foam you will need minimally a set of tires and wheels.  The FRP chassis is stiff with the posts installed, and really the the only big disappointment is the friction shock.  The TRF shock is probably the one must have thing.  The motor mount is nice, but not something you HAVE to have, at least not right away.

With Tamiya you can be on the "option part installment plan", and add things as you go.  This is not the cheap way, but it's cheap to start that way.

Obviously, no civilians have an F104X1, but it would probably not be bad on carpet for rubber tire with the long top deck.  I guess we'll have to wait and see.

If you can wait a bit for an F104X1, it looks to be the premiere model for rubber tire asphalt racing.  I have not done a ton of foam tire racing on asphalt recently, but it would probably be great for that as well, possibly with some changes.

The Pro or Pro Black special models have all the extras, but are a bit backwards for rubber on asphalt.  You will wind up changing a lot of parts to build traction into the car.  At a minimum, you would want to buy a split upper deck or cut the stock one to put more flex into the car.  The other thing is that really, the stock graphite chassis is far to stiff for rubber tire.  Not bad if you plan to race foam in the winter as well, but not the best deal overall.

The basic kits are actually a pretty good deal here.  Really, a set of Tamiya option soft rear tires (under $10) and the shock are what you need, if that.  The friction shock might not even be that bad, but limited spring selection is not so nice.  However, the steel axle is a plus, FRP upper and lower plates, and the bodies that come with these kits have a bit more rear downforce.   Not a bad deal at all, and you can add parts as you see fit.

Friday, June 17, 2011

Monday, June 13, 2011

Tamiya F104 Tire preparation

This past Sunday I was able to firm up some theories on what works with the Tamiya rubber tires for the 104.  Lately, I have been getting the feeling that "oily" tire preparations of any sort make the car get greasy or loose feeling.  That includes all of the Tire Tweak, SXT 2.0, Paragon, Jack, etc.  After using Sticky Kicks Blanco, a treatment similar to Buggy Grip, but less aggressive, I felt that any oil type additive was leaving the tires somehow more slippery or greasy.  The "softener" type additives penetrate the tire, but they flash off quickly the same way motor spray does.  

Just to make sure I was getting a true result, I once again tried a oil type additive.  The result was the same as what I have been getting all along, a sliding race car.  Once I went back to the Sticky Kicks, that car was back to normal.

Speaking of Sticky Kicks, it produces a car that steers and has rear traction, but balances towards a bit of oversteer.  I feel like this is a pretty good balance, since these cars are fastest when they have a lot of steering and you can be on power as much as possible.  At the same time, there may be some track situations where it's more desirable to have a car with a balance toward understeer, or at least stability.  At that point I would suggest just cleaning the tires with Simple Green.  I tried this as well Sunday, and I was amazed at how much the characteristics of the car changed.  It went from a bit on the edge of oversteering to locked down enough that I had to dial in dual rate to get the car through the corner.  This is good however, if you're on a slippery track.  Extra wheel throw is not efficient, but being able to jump on the power especially if the other cars are not as hooked up can be a big advantage.  As the tires warmed up, the steering did get a little better.   Simple Green is probably not a bad idea to start at a track with, and then move to other preparations as track conditions dictate.

Monday, June 6, 2011

TCS MEMPHIS race day

On race day, I got there pretty early.  The track would probably keep changing, so I wanted to make at least a couple practice runs to see where the track was headed.  The club decided not to re spray the VHT, so I assumed that the traction would continue to diminish.  Fast lap on Saturday was at 19.1, and I don't think we came within half a second of that Sunday.

I switched to black front springs from gold after the first run I made, mostly because they calmed the front end down a bit, and actually added some turn in.  That may sound contradictory, but I think the car was diving around, but didn't turn in positively.  The car stayed flatter with black springs.  In addition, I added a shim on the front axles, I think a .5mm.  Again, this was just to stabilize the car a bit.

The goal on the day was really to just get the car dialed in with small changes.  Saturday, I was able to get the major stuff out of the way, so here it was just small stuff.  Mostly, this was front ride height, shims on the kingpin, and height on the rear shock, not necessarily in that order.  After a few practices, I started to raise the front end up again.  The car was not getting the forward traction it needed, and raking the car back just seems to get the forward bite back into it.  I had taken all the posts out of the upper deck as well, so the car was able to flex a ton.

The front end actually wound up where it started, raised front ride height and an almost flat upper front arm.  I had raised the arms at the kingpin by 1mm on Saturday, but by this time it was too much.  After i brought the arm back down, the car still had plenty of steering, but I had more confidence to drive it in traffic.

The rear ball on the shock was actually key to how the car worked.  I was amazed at how big of an effect that had on the traction of the car.  I felt like soft rears and kit fronts with stock inserts were the tire to run, and there was a sharp difference between a raised shock and lowered shock.  Really, that tire combo would have been hard to use without raising the shock up.  .

Speaking of the tires, I ran the soft rear and kits in the first round, and I was able to qualify first.  At the same time, I had to stay up on the wheel big time, as it was sensitive.  For the second round, I switched to a set of kit fronts with a sedan insert in the front, but the car pushed at first and never picked up any steering.  I had hoped it would balance the car out, and maybe even be better at the end of the race.  I tend to think that to be fast the car just has to be a bit on the edge unless the bite is out of control.

For the main, the kit fronts with stock inserts went back on the car.  I was starting second to Bruce "Doc" Hickman, who had been fast all weekend.  The track continued to go away, so I figured I would just try to keep it close until the tires warmed up.  Right behind us was Rocky, who was racing F1 for the first time, but he had shown to be a good driver who was still dialing in his "rent-a-ride".  

When the tone went off, I was able to keep pace with Bruce.  We were able to break away from the pack a bit, but both our cars seemed to be a bit slippery at first.  As far as I could tell, he had a slight advantage in the infield, and my car got onto the straight and through the sweeper better.  We went a round a few laps until we got into traffic, and bumped a bit, and I backed off so Bruce could maintain his position.  As all this was happening, Rocky was able to gain ground and come back into touch with us.  I tried to stay close in traffic, and at one point Bruce touched a corner while we were getting around another car.  I was able to get into first at this point.   As Rocky came up on Bruce, I was able build up a decent gap getting onto and off of the straight until I could relax a bit.   At that point, it was going to be hard to make up enough ground in the time left to catch me, so I was able to take the win with a little gap.

I'll try to get the setup sheet tomorrow.

Saturday, June 4, 2011

Memphis pre TCS club race

Kind of a crazy day at the Saturday club race for the Memphis TCS.  I got there pretty early in the morning, and ran a bit on the track, which had not really been prepared too much.  After about 2 packs, they wound up spraying the track with VHT cut with methanol.   Instantly, we had very high traction. 

Immediately, the order of the day changed from finding stability to getting the car steering.  I wound up doing some things I would not have predicted.  I kept the 3.5mm offset steering blocks.  I tried the stock block, but it didn't seem to help much on the tight parts of the track, which were many, and almost had less steering in other parts.  This is very different from carpet, but perhaps it's a function of the rubber tires.  I feel like the the steering block is a big adjustment, where you work other things around  that decision.  So I started to raise the upper arms at the steering knuckle.  The car was very stuck so this actually was not as bad as I thought it might be.

I did also try more static camber, but it almost seemed to be riding on the edge of the tire.  I don't know if that was more a function of the tire setup, but it was not turning in the way I wanted. Going back to 1.0 camber, the car turned in better.  Angling the upper arm as I did got enough camber into the front end in roll, so keeping more tire on the ground was fine.

One more note on the front end, I did not have any grease on the kingpin to start the day, and one set of tires wound up really making the car hop.  So I went right to 120K diff oil.  Somehow, I didn't think it would make a huge difference, but in reality not only did it make a huge difference in the hopping, the  car was MUCH more responsive.  Sometimes, on carpet,  I thought some over responsiveness was coming from the damper plate, but I now think that over dampening the kingpins is a lot of the reason for the twitchiness. 

The upper deck was also part of the fun.  I wasn't sure if the added traction of the VHT would make a big difference in what I needed to do as far as stiffening the chassis.  Starting with only the pivot post connecting the upper deck, I made some changes, but that is where I ended. I tried 2 posts in both the forward and middle positions.  Both provided a more locked in feeling, but they took away some steering, especially on turn in.  The other part is that the more flexible chassis hooks the car up in general, especially in rear traction.  As the day went on, traction seemed to fade a bit, so the most flexible option was still the best.

The rear shock height was also way more sensitive than I expected.  For much of the day, I wasn't quite sure what to do to get the car to keep turning off the corner.  I tried a stiffer spring, which was ok, but not quite what I was looking for.  I took only 1mm off of the rear ballstud for the shock, leveling it a bit.  This made the car very responsive, and almost loose!   The next run I added the spacer back, along with an additional 0.5mm and this went right back toward a push on power. This actually made it possible to use different sets of tires based on how much rear bite the car had on power.  I did not change the front ballstud at all, and I am curious if it is as sensitive as the rear ball stud is.

The little 1800 pack also came out for this race, with as much traction as there was.  I ran it until about mid afternoon, when traction seemed to fade a bit.  The 1800 is perfect when traction is high, since it is obviously faster even to the naked eye.  I had a guy ask me if I had a brushless motor in the car, lol.  However, as the day wore on, I went to an Orion 3200 to provide some more mass, and that  turned out to be the best choice in the later afternoon.  The track had quite a few 180s and slow sections, so the stability and forward traction were much more valuable than overall speed.

For tires, I started with a set of Option soft rears and kit fronts, with stock inserts.  The tires actually were great.  Later I tried the same type of tires with a 26mm sedan insert, and the car actually locked down quite a bit, and started to push.  I was surprised, but even with the high air temps (99* F) softer inserts were better.  Later, on advisement from my  buddy Jay, I tried a set of tire with no insert at all.  This can actually be a good option when the temperature is high since the tire cools better. I did notice that I ran better in the last half of the race.  At the same time, as the day wore on and traction faded a bit, these tires pushed just a bit.  The stock inserts were just a bit better, especially on steering.  The thing you had to be careful of with the stock insert was roasting the tires at the end of the race. 

The car was definitely really good, so tomorrow should be very exciting...........

Friday, June 3, 2011


Tamiya Memphis regional this weekend.....will update as time allows