Car diet

So, I've put both my B4 and T4 on a diet! Both were overweight and I wanted to get both as close as possible to the ROAR minimum weights of 1499g for buggy and 1701g for truck.

The buggy was easy to get under weight, by installing Lunsford titanium screws and ball studs. I would have rather used aluminum screws, but AE doesn't sell an aluminum screw kit anymore :( They used to for the B3. Thus my final setup is:

Factory Team B4 Kit with all carbon parts
Factory Team aluminum in-line front axles
Factory Team titanium turnbuckles
Lunsford titanium hinge pins
Lunsford titanium shock mounts
Lunsford titanium screw kit
Lunsford titanium ball studs
Airtronics 94157 servo
AMB personal transponder
Futaba R604FS receiver
LRP Sphere Competition ESC with heatsink attached
LRP X11 17.5 motor with optional thin cooling plate
Reedy 35C 5000mah lipo battery
14g lead weight in back of chassis
AE wheels with JConcepts Bar Codes with standard inserts
JConcepts Illuzion body and wing
Race weight is 1500g, 1g above the minimum weight :)

The truck was a bit tougher to get close to the minimum weight. It has all the same equipment as the buggy except for the following:

LRP Sphere Competition TC with heatsink and fan
Orion 17.5 motor
Orion 30C 3800mah lipo battery
Race weight is 1724g, 23g above the minimum weight.

I was originally using my Reedy 35C battery, but the truck was 1785g, a whopping 84g overweight! (nearly 3oz!) Thus, I switched to the Orion battery. While lighter, the Orion battery felt as if it didn't have the punch that my Reedy pack did. I confirmed this at the last JBRL race at Hot Rod Hobbies. I ran the Orion battery in round 1 of qualifying, then the Reedy in round 2. The Reedy pack had noticeably more punch! And my lap times proved it as I was nearly 0.5 a second a lap faster! Unfortunately, my laps weren't as consistent, as I needed to get used to the increased punch.

My friend purchased an SMC 40C 4700mah pack in the Hot Rod Hobbies shop. I weighed this pack and it was only 24g (0.8oz) heavier than my Orion pack, but 37g (1.3oz) lighter than the Reedy pack! With its 40C rating, it should have close to the punch of the Reedy pack, but only weigh a little more than the Orion pack! I went into the shop and picked up 2 of these packs for myself! My truck's race weight with this pack is 1748g, 47g overweight. (1.7oz) To lose this extra 47g, I'd need to change to a lighter ESC or receiver or find more lighter parts, or maybe modify some parts myself! I have also found that the weight will change a lot, depending on what tires I'm running.

I tested the Reedy, Orion, and SMC packs on my Turbo35 charger at a 20A discharge rate and 6.6V cut-off. The results were:

Reedy 35C, IR=5.1, avg discharge voltage=7.54
Orion 30C, IR=9.0, avg discharge voltage=7.33
SMC 40C, IR=6.8, avg discharge voltage=7.48

The lower the IR (internal resistance) and higher avg discharge voltage, the more punch and power, the pack should have. Thus, the SMC pack has similar punch and power to the Reedy pack while being lighter! It also has more punch and power than the Orion pack, while only being a little heavier. I will be racing the SMC pack this weekend at round 4 of the OCRC Sat Series, comparing it to the on track performance of the Reedy and Orion packs.

Stay tuned for the results!

Awards!

Stock Buggy A Main, 3rd Place

JBRL Round 1, Hot Rod Hobbies, 5/24/09

Stock Buggy A Main, 5th Place (Left)

Stock Truck A Main, 3rd Place (Right)

JConcepts Wave Race, OCRC, 5/17/09

Stock Buggy A Main, JBRL Round 1

Qualified 3rd with a 15:14, then barely finished 3rd turning a 19:20, in the 6 minute A main. I made a mistake in the 1st turn, and rolled, but rolled back on my wheels! I survived the melee through the quads and came out in 5th. I then battled with Josh Mitchell for 4th, but he wrecked and gave me some breathing room. I then chased down Bill Koch in 3rd for the last half of the race. When he slowed to let the leader Brent Calvert by, I closed the gap! He then made a mistake in the quads, and I passed him for 3rd! I raced back to the line and made it across for a victory lap securing 3rd, while Bill was caught on the line. Thanks Dan for recording my race!

New You Tube Vids!

Even though I didn't write anything about the races over the last month, I do have a bunch of YouTube Vids!

These are all from the JConcepts Wave Race.

New action photos!

The first two are from the JConcepts Wave Race held last weekend at OCRC.

These two are from the Round 3 of the JBRL Series held at OCRC the first weekend of May.

Thanks Jason and Nick!

Even though I haven't updated my blog lately, I've been racing a lot to practice for all the races over the last month. Since my last race entry about Round 2 of the JBRL at Revelation, I've run Round 3 of the OCRC Sat Series, Round 3 of the JBRL at OCRC, and the JConcepts Wave race at OCRC. In between those races, I've been racing the Wed, Fri, and Sun club races at OCRC and working on my cars between race days! Whew! Which is why I haven't updated my blog lately :(

Then the next 3 weekends are the make up race for Round 1 of the JBRL at Hot Rod Hobbies on 5/24, then Round 4 of the OCRC Sat Series on 5/30, and then Round 4 of the JBRL at Pegasus! Busy!