248LikesXray XB4 thread
07-04-2015, 01:03 PM
#8536
Tech Regular
Looking for a bit of gearing advice. I am running a 6.5T motor, on a fairly large track, 30-32sec lap times. I had it geared 18/81 and my motor was getting hot, 175-180f, with speedo temps of about 130f. (it was a hot day as well, 90-94f)
The speedo would go into reduced power due to the motor temp, had the limit set to 80C (176F). No boost or turbo set. (I have increased the temp limit for the motor to 120c (248f) so it will not shut down, but may fry the motor!)
Tomorrow is going to be even hotter, may hit 100f, not sure what way to go with the gearing, up or down? Thinking I should put a fan on it as well.
Any advice is welcomed! And by the way, the buggy is fantastic, I was only 1sec. off the fast guys pace, and this was the first time running off road in 20+years.
The speedo would go into reduced power due to the motor temp, had the limit set to 80C (176F). No boost or turbo set. (I have increased the temp limit for the motor to 120c (248f) so it will not shut down, but may fry the motor!)
Tomorrow is going to be even hotter, may hit 100f, not sure what way to go with the gearing, up or down? Thinking I should put a fan on it as well.
Any advice is welcomed! And by the way, the buggy is fantastic, I was only 1sec. off the fast guys pace, and this was the first time running off road in 20+years.
Never checked temps, but it'll happily run 10+ mins.
07-04-2015, 02:25 PM
#8537
Looking for a bit of gearing advice. I am running a 6.5T motor, on a fairly large track, 30-32sec lap times. I had it geared 18/81 and my motor was getting hot, 175-180f, with speedo temps of about 130f. (it was a hot day as well, 90-94f)
The speedo would go into reduced power due to the motor temp, had the limit set to 80C (176F). No boost or turbo set. (I have increased the temp limit for the motor to 120c (248f) so it will not shut down, but may fry the motor!)
Tomorrow is going to be even hotter, may hit 100f, not sure what way to go with the gearing, up or down? Thinking I should put a fan on it as well.
Any advice is welcomed! And by the way, the buggy is fantastic, I was only 1sec. off the fast guys pace, and this was the first time running off road in 20+years.
The speedo would go into reduced power due to the motor temp, had the limit set to 80C (176F). No boost or turbo set. (I have increased the temp limit for the motor to 120c (248f) so it will not shut down, but may fry the motor!)
Tomorrow is going to be even hotter, may hit 100f, not sure what way to go with the gearing, up or down? Thinking I should put a fan on it as well.
Any advice is welcomed! And by the way, the buggy is fantastic, I was only 1sec. off the fast guys pace, and this was the first time running off road in 20+years.
I run a 5.5 with 18 pinion and motor runs about 150. Could go either way in gearing. I've seen temps drop going up in pinion but not always. You could be under geared and spinning the motor too fast. What is the timing set at on the end bell? I would definitely run a fan on both esc and motor in hot temps. Also I know you've probably checked but make sure nothing is binding in the drive train.
I just checked the motor on my motor checker, it is a new Tekin redline gen 2, I installed it out of the box. The timing was set to 10 on the can, which was 38 actual deg.s. One thing of note, this is the worst sensor board I have ever tested. With 9 deg phase variation. I set it to 0 on the can, 30 deg. actual timing, my Kv dropped 50, but amp draw went down almost 1 amp. This motor does not respond to timing very well.
The poor sensor board will account for some of the heat, and backing the timing down should help as well. I will put a fan on it just to be safe.
07-04-2015, 08:24 PM
#8538
I run an Orca 6.5t and it gets about 160f with 18/84 after a good bit of running. I'm sure if I turned down the timing a bit it'd cool down. Also with the '15 car and a shorty there's plenty of room for a fan when you run in super hot conditions. Your temps sound like Florida!
07-07-2015, 11:38 AM
#8542
just an fyi, discountrcstore now carries xb4 parts!
07-08-2015, 12:41 AM
#8543
Is anyone running the shelle 1.5/1.1 and the 1.6/1.1 shock pistons in there xb4, are they a worth while upgrade, and has anyone using them seen performance gains. Currently running on a medium size outdoor track with medium to high grip
Last edited by HSV427; 07-08-2015 at 12:58 AM.
07-08-2015, 09:57 AM
#8547
Tech Master
iTrader: (15)
I was looking around at some older set ups and noticed Tyler Vik used the 6 degree front camber blocks at OCRC and other places, yet Martin Bayer is running 12 degree hubs, mostly for carpet, but also for testing at OCRC....anyone else running the 6 degree? What do you like about them vs. the stock 9 degree? Are the 12 degree really more for the added initial turn in on carpet?
07-08-2015, 06:03 PM
#8548
The 12 degree blocks will be a little lazy off center but have smoother steering, and a little extra at the end of the turn. The 6 degree blocks will be twitchier and harder to drive, but will react better off center. That's the kind of feel I like personally, but I'd say it's up to you and one isn't really "better" than the other, it comes down to the driver. On something ridiculous like carpet though, where you have so much steering and grip already, the 12s will really smooth the car out and carry more corner speed.
07-09-2015, 10:00 AM
#8550
Is anyone running toe out higher than stock which is 0 in the front and if u are which insert??