Blog
17.5 boosted timing and gearing – SpeedPassion Reventon Pro
I am going to be setting up 2 cars. Both are Sakura Zeros running Thunder Power 17.5t motors. This post covers car #2, which has a SpeedPassion Reventon Pro ESC. Car #1 is running a HobbyWing Extreme Stock ESC and is covered in another post. Sakuras have default internal ratios of 1.9 (= 38/20) but I’m using an optional 19-tooth center gear to change this to 2.0 (=38/19). Car 1 Car 2 Chassis Sakura Zero Sakura Zero IR 2.0 2.0 Motor Thunder Power 17.5 Thunder Power 17.5 ESC Hobbywing XTreme Stock Speed Passion Reventon Pro Firmware...
read moreBuilding TRF shocks
Jiles Groskamp… checks bladders but reuses them many times replaces shock shaft when the coating shows signs of wear fits an 0.1mm shim under the shock piston to remove play in the piston uses only 1 o-ring above the plastic shim at the bottom of the shock body – Jiles prefers the blue o-ring from MuchMore over the silicon Tamiya o-ring using quite heavy MuchMore oil – 550 wt a good compromise for most tracks uses MuchMore air remover to speed up removal of bubbles from shock builds with very little rebound (0-1mm) targets...
read more190mm shell weights – Protoform Mazda Speed 6
Here is how the weight of the regular Mazdaspeed 6 (right) compares to the lightweight version (left). That’s a difference of 17g. Most of that sits quite high, so it doesn’t surprise me that some report the lightweight body to be one or two tenths faster. [In my weight measurements I exclude the rear wing. The bodies have been trimmed except for the wheel arches, which I guesstimate to contain about as much plastic as the rear wing]. And how much does paint weigh? I painted both bodies in similar schemes. This involved one coat...
read moreCar development – 2.5 weeks out from the nats
I’ve just been stripping my car down to swap chassis, top deck, and towers install TRF shocks rebuild rear diff with heavier (2000) oil changing center pully to 19 teeth and the internal ratio thereby to 2.0 While I was at it, I thought to compare the weights of the two options I have for the front drivetrain. First, the putty-packed front gear diff weighed 39.5g. The second option, the spool, weighed 17.5g. That’s a massive 22.0g difference. The gear diff is supposed to be a bit faster into the corners, but I don’t remember...
read moreCar development – three week out from the Nats
Over the last few weeks I’ve struggled to find an easy way to bring the Sakura’s weight down from circa 1500g to the spec weight of 1380g. The easiest way to get lighter would be to go to a ~4200mAh shorty battery pack, but that would involve sacrificing the extra punch that a ~6800mAh battery delivers… and would still leave me with a left-right balance problem. Instead I’ve finally decided to replace the stock fiberglass parts with carbon fiber (narrow chassis, stiff top-deck, and suspension mounts). As a side-note, I...
read moreLIPOs in October 2012
Earlier this year I bought a couple of Intellect LIPOs: a 6200mAh 60C, and a 6800mAh 70C. My reasons were that those specs looked pretty good, prices were good from RCMart, they’re both ROAR approved, and Intellect did make great NiMHs back in the naughties. But I’m back in the LIPO market this week because they’ve both bloated a little (25.5mm thick at the outside edge and 27.4mm at the middle of the pack). Nobody else at the track is using the Intellects. Is there a reason? People ARE using LRP, Reedy, SpeedZone, Team...
read moreLovesong
Today I’ve been loving various covers of The Cure’s “Lovesong”. Here are a few: The Cure (original): Ein Astronaut & The Collaborations Club: 311: Adele: ...
read moreSprings
HPI 25mm SPRINGS (source www.hpieurope.com): Marking Code # Thickness [mm] Turns Weight [lb/in] Weight [gf/mm] Blue 1.4 6 15.3 273 Silver 1.5 6.5 16.9 302 Pink 1.5 6.25 17.9 320 Gold 1.5 6 19.0 340 White 1.4 5.75 20.3 363 Yellow 1.4 5.5 21.7 388 Red 1.5 5.25 22.4 400 SAKURA ZERO 21mm SPRINGS (source orcadigital on www.rctech.com). Marking Code # Thickness [mm] Turns Weight [lb/in] Weight [gf/mm] 6.5t 1.5 6.5 17.9 320 6.0t 1.5 6 20.0 357 5.75t 1.5 5.75 21.2 379 5.50t 1.5 5.5 22.9 409 5.25t 1.5 5.25 24.9 445 5.0t 1.5 5 26.2 468 4.75t 1.5 4.75...
read moreQuotes
“Sometimes, in the hardest moments, the best things come” – Felipe Massa on his first podium finish in 2 years (Suzuka, 7/10/2012)
read moreSaturday
Tonight I raced 17.5 blinky. Most (again, in prep for the nats) were racing 17.5 open. My goal tonight was (again) to close the gap a little. Before tonight I thought I was about 1.4 seconds down on pace. Last night I made some suspension changes I hoped would pay off. They were: Changing from the Sakura Zero shocks to HPI silvers everywhere. The HPI silver springs, at 302 gF/mm, are softer than the softest Sakura springs. Moreover since they are longer they seem to be more consistent over a longer travel range. Reducing droop (increasing...
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