teambighead

It's not the 'under geared / over geared" that I'm worried about... It's the fact that at 81/30 your motor is hanging WAY further back than what the set up is designed for. You basicly have a much larger weight bias towards the rear of the car....

This is why you are finding that you need to thicken up the rear of the car with both oil and springs. Get the right spur gear and shift the motor back forward where it is supposed to be.

That on it's own will free up the car a lot...

ps- I'm sure PL would rather their rear tires win with a different front tire over having a loss with their front tires.

aeRayls

iTrader: (3)

Rich, get the 72 spur and start at a 27 pinion, it WILL make a difference.

What up?

iTrader: (14)

I just got an e-mail from a someone I have been trying to order the .5 Rayspeed hubs from and he is saying Yokomo has discontinued it. Anyone hear of this?

I'm going to try it without them this weekend and see what happens and go from there.

Wild Cherry

You should do great with out the .5 hub....

What up?

iTrader: (14)

Yeah that's what I was thinking too. From what I am hearing the hubs really help in Mod but if you run 13.5 or 17.5 it wants to push even with a good tire set up.

What up?

iTrader: (14)

So I ran the light set up tonight with a 17.5 without the .5 hubs on a dirt track. Ran wide PL fronts with M3 Holeshots in the back and the car handled everything well and was very good but it did have a push that was manageable. I tryed leaving the weight in the tranny like before but I think I will move that weight under the battery with the others.
My weight on the car is 1515g.

Wild Cherry

Remove the weight in ft of the transmission...

Car will have improved high speed steering if you do ...

Rich Panganiban

iTrader: (72)

I got a hold of a 75T spur and installed it. It does move the motor forward quite a bit. I'll give the Lightweight setup another try with the new spur and post my feedback on here. Thanks again for the help.

What up?

iTrader: (14)

Yeah thats the next thing I just needed a starting point.

richard.bratton

iTrader: (4)

After racing Losi cars since 1999 or so, I switched over to the B4 this weekend and tried this setup at Thunder RC in Nashville. Don't have the .5 degree hubs, started without weight (1386 grams) and the car felt pretty good but had a little mid corner push. After adding weight to bring the car up to 1510 grams, the car was absolutely on rails. It felt much more planted and had loads more steering than anything I've felt on the XXX platform.

xDaRReLLx87

Put 1.5oz weight in the front nose with a LiPo Battery

Put 3.2oz weight in the front nose with a LiFe Battery

Putting weight on the front increases steering traction and also requires less weight than it would in the battery tray.

If you find you have to much weight you can always chizzel some lead away on further testing, im sure the B4 is a little different than my XXX-CR

richard.bratton

iTrader: (4)

To make 1510 grams, I added 4.5 ounces. I put (2) 1/4 ounce blocks in the rear on each side, 2 blocks on the front, 4 on the servo, and 10 a blocks on the battery brace. My thought process was to keep the weight centered in the car to not upset the balance. I have mixed feelings about adding weight in the front. Although weight in the frong would increase front traction, that added inertia could make the steering slow to respond. I think it would decrease initial turn in, but give you good mid and exit corner steering. I had tons of steering with the weight as described, but will replace the lead with a lipo plate under the battery and add to the front as needed for min weight. This was my first weekend with the B4 as I've always been a Losi guy. Needless to say, I'm sold on the B4. Loads of steering and very stable!

Rich Panganiban

iTrader: (72)

Alright, gave Cavalieri's CRCRC setup another try. This time I ran it with the 72T spur. It was a night and day difference from the last time when the buggy pushed really badly. I was pretty shocked moving the motor forward just a few mm made that big of a difference. Good call teambighead.

However, I did make a few changes to the setup to free up the rear end a little more, which allowed me to really drive it really aggressively in the corners. From Cavalieri's setup, I changed:

Ran the stock 0 degree hubs
27.5 weight Losi oil in the rear
Removed the limiter in the rear shock and unscrewed the shock end 1 turn for more down travel.

With these changes, the buggy was really good. It remained very stable at speed, but allowed me to be really aggressive entering and in the middle of the corners.

cleblanc

iTrader: (49)

where are you guys finding the smaller spur gears in stock???

xDaRReLLx87

Depends on your Car's setup, my car never pushes to be honest I have way to much steering But I prefer that, you get the push effect if you add to much weight or have wrong front shock angles my friend. You car has more weight than mine therefore more sluggish but I have an XXX-CR and you have a B4 The weight you have is to much so you had to put more weight in the rear section, if you want more front traction and more nose dive on jumps just add drag brake, that way you ensure you do not add to much weight but still get your desired effect. Your using Lipo's and im using Life's my batteries are way lighter so I would have to say you have way to much weight, I balanced my car on the "Center of gravity" point of my car, so I have perfect balance from front to rear.