Monday, June 29, 2009

VTA for fun (and profit? not!) - Tamiya parts arrive!

So, the points series is on hiatus for a couple weeks to give folks a breather, and it's back to racing for glory (only)!

I wound up racing Friday and again this past wednesday - The track layout hasn't changed from the last week of the points, so I don't really touch the car. Friday was good, we were racing while massive storms raged outside. MSI has these really high warehouse windows, and the lightning flashing across the black sky through wthose windows looked very evil-scientist-movie-esque! I managed to drop my fast lap time down to an 11.58 or so, and wound up handing the radio to Dave to drive the main. It looked a little loose - I may have put the traction compound on a bit too soon (as I was going to get dinner), and he wound up finishing just ahead of Marc, but managed only an 11.7.

Anyway, Wednesday was more of the same - I made some small corrections to the droop on the suspension arms, but otherwise changed nothing. It was a low turnout night, only 8 guys, 5 of whom were going to be in the A. I hit 25 laps on my first qualifier, and then 24 in the second and 24 again in the main *hmmmm*. In the main, I got some intense racing with Kevin and his TC5, and dropped my fast lap down to 11.504 - Kevin hit 11.496 for a fast lap. The car may be a handful to drive, but I feel really in tune with it now.

Today, the Tamiya parts I've ordered have arrived - I'm like a kid at Christmas waiting to get home and work on the car. In my posession, I have a 416WE spool to mate to a low friction 36T one-way pulley from a TA05 to create a spool with the same number of teetch as the Kawada diffs have. I have a 416WE low friction front belt, a 416 (normal) rear belt which is 1 tooth/3mm longer than the Kawada belt. I have four 44mm lightweight swing shafts with matching lightweight axles and all the crossjoints needed to build them. Essentially, the entire driveline from a 416WE is going into my car. I will do some weight comparisons of the components for grins as this was not just to replace wearing parts, it was to reduce rotating mass and free up the drivetrain!

Yes, it looks like a Tamiya store exploded at my desk!

Thursday, June 18, 2009

VTA points week #8 - the final week!

Week #8, the final week and I'm sitting in fourth, but Jeff in third has been seen nowhere, and may wind up having a third goose-egg which would essentially eliminate him from contention.

I got there early so I could work on the car using the setup board I had made. It's 7 layer 1/2" birch-veneered plywood, and was the platform of the first cross-cut sled I made for my table saw. It's pretty flat and stable, but I forsee 1/2" or 3/4" melamine in my future. Last week I had added massive negative camber to over-compensate for the traction rolling I had been doing. I took that out and set a nice 2 degrees at each corner. I then re-glued the outside lip of every tire AGAIN as one of them had apparently peeled in the main last week. I had plenty of time and took it out for a few laps on the new track layout and it was sliding just a bit, but showed no signs of wanting to go over! I chose a taller gear (4.5 FDR) and just relaxed and chatting with Dave, Matt and Kevin until qualifying.

The first qualifier was mediocre and I had a few issues on the track and the car started to feel awkward to me after that, like it was slowing or rubbing or something just wasn't right. I turned 24 laps, which was still fifth fastest, but a ways off the pace. My fast lap time was a 12.0.

In the pit after the qualifier, I spotted the problem - the same tire had broken the bead again. Since I had nearly an hour, I glued it once on the inside, once just under the lip 15 minutes later, and finally a ring all the way around. Sadly the tire had a bit of a "lump" to it, but I flattened it out best I could. I geared up as I was being run down in the straight still but didn't change a thing otherwise.

The second qualifier was damn good for me and was incident free! I slotted up to a 25/5:06, which was good enough to qualify fourth in a TOUGH field. With James, John & Mike ahead of me, but Kevin, Greg & Jeff behind me for the main.

I touched nothing for the main even though I felt I was slightly overgeared. It was a VERY rough start, and was the exact opposite of last week. The pile up happend in turn three again, but as Mike was being Mike and pulling out of the pile up, he punted my car through the turn and halfway over the board leading to the straight. I was able to drive off of it and rejoin the race in dead last. From there it was just a matter of driving down folks, and I had worked my up a few positions thanks to other folks having mishaps and keeping my own race just as clean as could be. I battled with Jeff for a while to maintain fifth, and eventually pulled away and past a rolled-over Kevin to take fourth. It was smooth sailing until about 30 second to go, I've got a 2.5 second lead on Kevin and James comes up to lap me. I let him by in the second to last turn of the lap, and just as he gets by, he bobbles and hits the board , and I hit him, which of course, sends my car upside down (remind me to use lighter paint next time), letting Kevin past me. I finish in fifth, a bit dejected from that and the fact that trophys and prizes are only for 1st through 3rd.

I don't forsee a new car in my future anytime soon due to the $400+ price tag for any new machine I would consider. I may pick up a used one though - John's Tamiya 415 MSXX is a tempting bit of kit, but I still enjoy giving people a run for their money with an eleven year old car.

Sidenote - Why am I being passed in the straight by Greg, who is using the same speedo, motor, battery and using a taller FDR than me? I think that's a function of the driveline having too much drag in it. I checked out his car a couple weeks ago and you spin the rear wheels together and the drivetrain continues to spin for a while - mine comes to a pretty quick halt. I tore the car apart to work on the bearings and individually, the rear diff, center layshaft, and front one-way all spin very freely, but as soon as I throw the belts on, it comes to a grinding halt - mostly it's the rear axle/belt. I believe I will be ordering a set of low friction belts for a Tamiya 416 WE soon. The front belt is the exact same length, and the rear belt is one tooth longer, which should free it up a bit - and if the belt is too loose, I do have a rear tensioner I can use. I think I will also be ordering Tamiya 44mm lightweight CVD's and outdrives at the same time to reduce the rotating mass by a bit, not to mention the front driveshafts are starting to wear a bit. A 416WE spool with a TA05 18 tooth low friction pulley should also drop right into my car to further reduce the rotating mass.

I'm still tempted to get the BOCA bearing ceramic bearing kit for the car, but that's $120 I'll wait to spend...

Next week : Non-points series racing. I do hope people still show up!

Thursday, June 11, 2009

VTA points week #7

Week #7 was the penultimate week for the current points series and going into it, I was tied for fourth with Bob running his XRay 007 Mustang.

Having raced the previous Friday with freshly cleaned off tires, I was still worried about traction rolling. I moved the lead weight that was outboard of the motor to the center of the chassis directly below the antenna to get it more centered as I tipped the car going both right AND left. I also added crazy camber to the car to try and get a bit more slide in the corners.

I banged out a pretty good qualifier in round #1. I had just one incident, but was it a doozy - I flipped in the middle of the track, and watched as the marshall waddled over to the car, bent as little as he good, and flipped the car over byt he end of the body (ya, it was the big guy) - for a stunning lap of ~20 seconds. My lap times for most of my laps were high 10's to low 11's, so that was nearly a full ap lost, and I still finished with a 27/5:05 if I remember correctly, still not making the 28 laps, but damn close. Fast lap for me - 10.5.

The Second qualifier was really strange, the car was back to traction rolling! I did that once or twice and the car started to feel strange to me. I heard Mark tell me to pull my car off the track as it had ripped the new carpet - DOH! Sure enough, right in the middle of the sweeper, the carpet had a small square standing straight up. He said something about my body posts, but they were rounded on the top (thanks to Kevin breaking both of them when hitting me in qualifier #2 the Friday before), and to this day I don't recall rolling the car in that turn when he called it, and have no idea how it happened, or if it was even me. Regardless, I felt bad about it.

In the pits before the main, I went over everything on my car - the body posts, the chassis screws, and the lower part of the body and couldn't find any answers. I did find just a bit of rubber on the left side of the chassis, so I gave all the shock collars a tweak to stiffen them up a bit. I cranked in additional negative camber on all the wheels and superglued the outside bead of every tire.

I made the A-main based on my 1st round qualifier and was even starting fifth. Both Bob's made the A this week, first time Bob Z. made the A ever in VTA. It was an interesting race - the tone went off and we all went through turn one and two and a giant pile up in turn three found everyone in front of me on their lid or against a board or facing the wrong way as I drove through them all! I lead that lap and the next and was over-adrenalized and tapped an inside board, sending the car onto its lid (god I hate that about these bodies) letting three by me in the process. Running in fourth is a much easier experience and the rest of my race was uneventful. I think John won just ahead of either Mike or Greg and I finished fourth, ahead of Bob, which broke our tie for fourth in the points.

Monday, June 8, 2009

VTA LiPo/21.5 Pics

So, I guess I'm not necessarily running old-tech anymore except for the chassis itself. I am now outpacing a couple of drivers I noted were really giving me a run for my money when I ran 4cell/27t by a couple laps!

Got the pics of the unusual layout I came up with for the Kawada to run in VTA. The car is perfectly balanced left to right without adding any weight (when counting a 15g transponder), however the lead on the chasis is to try and help that side stay down on the high speed sweeper at our track. I need to get the car to stay rubber side down when I'm really pushing it.









Ran on Friday last week too. Cleaned the rubber off the tires and got the car turning quite a bit better - too well in fact as it's going lid-over when I push it hard... I did improve from Wednesday though and was on a 28/5:08 pace in qualifier #3 before boarding it with about 20 seconds to go - would have been good for third fastest. In the main I was pushing hard battling to stay ahead of Kevin and heard a 10.5 called out - sadly the printer was out of toner for me to verify this. May add more weight just to keep the car off its lid.

Thursday, June 4, 2009

VTA points week #6

I got a chance to run my "new" setup for the first time, so I got there as early as I could to get a few laps of practice in and make any tuning changes. The car pushed quite a bit and I upped the Dual Rate up to 94 so it would make it around turns. Sadly, I don't actually know what my D/R was at last week as I inadvertantly left my radio on, killing 8 NiMH's and in the process it adjusted my steering trim 75R and my DR down to 0. It was odd, turn the car on and the wheels go to the right and don't turn - I thought the servo had been toasted or something.

I chose not to change the setup for the first qualifier as I thought I could just sauce the whole front tire, instead of just half, and slow down a bit before the turns. Qualifier #1 was horrible. The car pushed in one turn and was loose in the next - it just wasn't handling in a manner I was comfortable with. After that qualifier I swapped the B's in the Rear for D's and the C's in the front for E's and re-adjusted my ride height and droop. After a bit of testing, I was very happy with this change, and I've geared down just a touch from a 4.28 to a 4.35 FDR.

Qualifier two started out great! I caught a few guys, and was on a 27 lap pace until I made three stupid driving errors trying to put the car on a tight line and going too tight. I finished with a 25/5.01 but the A-main cutoff was 25 laps luckily, and I was started last - my favorite place to start! I had turned a 10.7 in this qualifier and was running individual lap times well - the fastest lap was turned by James at a 10.1. Bob, who I have been having good times with racing and on the stand and I was tied with in the points series, crashed out of his second qualifier and really only had his 24 lap qualifier to count, did not make the A.

I geared back up for the main, there were seven of us, starting in the sideways grid pattern, odds on the outside wall, evens on the inside wall. The tone goes off, and the TQ (James) is just sitting there, as am I. I take off, blow by him still sitting there and through the first and second turns, going around Al who was tangled in something. James took off just behind me and spun my car going into turn three - thanks bud! After dropping back to dead last, I was left to run my own race, only getting back past Al due to him flipping. He came back and was able to get back around me - cleanly, thank you! I was getting lapped by James, who went from dead last to leading in fairly short order, and he came up behind me going into turn one. I decided I was going to hold my lines and, in turn, him for a while to see if he would choose to drive through me. My faith in humanity was restored when I finally let him by six turns later without him getting impatient or trying a move that was doomed to failure. The whole rest of the race was rather un-interesting - in a good way. Other than Al flipping, I don't think anyone, myself included, needed any marshalling. I didn't board the car, I didn't hit anything, and the traction rolling of last week was a distant memory! I placed poorly, finishing sixth out of seven (only because Mark broke something in the Tamiya), but I finished with a 27/5.08 or so, almost two laps faster than my qualifying time! I felt awesome after that race though! I did find out after the race that my lap times were down from the second qualifier, and talking to Greg, who finished second running the same ESC and similar batteries (just on a newer car), he was geared at a 4.45. I went up and now I think I should have gone down a bit more.

I might be racing Friday this week too - could be fun as I know the track layout well and where to gear! I have to be careful though, the last time I felt this good about a result, the next time I raced I crashed and nearly literlly burned - In the main, the battery shifted, one cell shorted out against the motor and got really hot and expanded and was no longer usable, making the whole pack useless until I found a use for a 4-cell pack.

Tuesday, June 2, 2009

Kawada VTA car 1.5

So, this continued traction rolling of the Kawada with a LiPo in it has me scrambling to come up with a solution. I've shelved the 13.5 car - which had some unique hop-up parts on it - and stolen the Yokomo shocks, the rear toe adjustment piece, the lightweight aluminum locking nuts for the wheels, and the rear belt tensioner and installed them all on the VTA car. I've gone to softer springs now as there is absolutely no rubber on the bottom of the chassis, telling me it's probably grabbing the side of the tire and rolling as opposed to using up the suspension first. I've revised the ride height downward to be 5.35mm rear and 5.25mm front, and have taken out front caster by flattening the mounting position of the lower arm. Lastly, I have added my own upper link holes in the front and rear shock towers so the upper links are as long as physically possible (quite a bit longer than possible with the stock mounting locations) and also made them parallel to the lower arms at the current ride height.

(Pics forthcoming...)

That may not completely solve it, but I think the car has gone under weight by a bit which means I will be adding some lead weights onto the lower deck of the chassis which will lower the CG a bit and may stabilize the car.

VTA points week #5

I know it's almost time for VTA points week #6, but having been traveling a lot lately has gotten me behind on a lot of things that need to be done, and updating this was way down the list of things to do.

Week #5 was the first week the car was running the LiPo with the Novak 21.5 BL motor. I keep it on the down-low too, keeping the car covered and talking about the 27t running strong for the first qualifier :) I smoked the first qualifier and was on a 26/5:08 pace (which was only about 6 seconds behind the TQ pace for that qualifier) until I was passing John who unintentionally boarded me and I lost about 3/4 of a lap due to being boarded in the corner with the slowest marshal at the track. It's not that he wasn't doing his job or wasn't paying attention, he's just larger, older, and moves a little slow (but damn can he drive a 12th scale!). Wound up with a low 25 lapper, not bad, but not great.

Second qualifier is what I'll call karma coming back as I rapidly came up to pass John in this qualifier, and just like qualifier #1 we tagged, but this time it was he that wound up on the losing end. It was a great qualifier, but I somehow traction rolled the car in the sweeper (shades of every test with a lipo in the Kawada), which threw me off for a few laps, but I wound up with a 26/5:10 or so and was the third fastest qualifier for the class.

I had some balance issues in the main due to fiddling with my radio - I moved the EPA for the throttle and brake up to 120% because I can't get the thing to stop even with full brakes applied. Well, that change really altered how the drag brake got applied and I lifted to avoid the back of someones car going into turn #1 and the car locked up the rears and spun sideways, getting me tagged. Three traction rolls through the race later and I'm still challenging Bob's Mustang for third when he makes an unforced error and I take home third, which puts Bob and I into a tie in the points series.