new brushless for stadium truck?? - Page 2 - RC-Monster Forums

MetalMan · 06.14.2006, 06:49 PM

I don't think any place can start taking preorders yet. The new date is the 19th - Monday.

If you want the 7700, make sure you have VERY good batteries. Anything much less, and it won't perform as well as you want it to. But just so you know, the 7700 is mainly for touring cars. It's not well suited to offroad trucks.

06.14.2006, 10:18 PM

He's got an onroad truck so that shouldn't be a problem

sleepy23 · 06.14.2006, 11:04 PM

yeah my t4 is onroad only and current weighs in at 2lbs 15oz with battery, body and ready to race... its just about a touring car killer.

MetalMan · 06.14.2006, 11:22 PM

Then go for it! What battery and battery configuration are you using?

sleepy23 · 06.15.2006, 12:09 AM

currently i have been running a 20c 2s kokam lipo pack. i am looking to maybe upgrade the battery along with the esc and motor.i may hld off a bit long and go for the mamba rather than the 380c motor. i have a few more mechanical mods i want to do first and then will be ready for a new powerplant and about a 75mph truck (or faster)

MetalMan · 06.15.2006, 08:49 AM

You're going to need a more powerful battery (higher voltage) and a slower motor to even attempt 75mph. Maybe you could try the 4600 motor from CC and 4s Lipo.

sleepy23 · 06.15.2006, 09:42 AM

well i know i need atleast a 3s lipo to get much faster, but I dont have a charger for 4s, so 3s is the limit. I have a 3s right now, it doesnt really fit the battery tray but based on the speed tests i have done with the gps, i ratio'd out the speed I should see with the 3s and even accounting in a 10% reduction for increased wind resistance, I should still see about 68mph.
i think you might be thinking of a true stadium truck and its setup. my truck is technically called a stadium truck, but its slammed and heavily modified. the drivetrain rotational mass has been reduced by about 40 grams ( i think that includes the cvds, but cant remember at the moment). the truck is lighter than a tc4 in race trim.

MetalMan · 06.15.2006, 02:01 PM

What size are the tires? Are the wheels lightened as well?

Based on the equation: Kinetic Energy = 1/2 x mass x velocity^2, a small difference in the speed of the vehicle requires more energy than a small difference in weight. So just getting to a high speed requires a lot of energy. BTW, power (Watts) = Energy (Joules) / time (seconds).

SpEEdyBL · 06.15.2006, 08:26 PM

Also, wind resistance increases by square. You might need 5-6s lipo for 75 mph in a truck and weights to keep the front end down.

Sleepy, the kokam 3s 3200 is the same size as a regular 6 cell pack. And so is a max amps 3s 4000 pack, except it can only do 48 amp cont. Tcolesen, do you think the max amps pack would handle the 4600 kv mamba motor?

MetalMan · 06.15.2006, 09:34 PM

It might push the pack, especially with higher gearing. On standard gearing, I can see it working pretty decently.

P.S., that's MetalMan to you :005:

sleepy23 · 06.19.2006, 12:42 AM

yes, the tires are lightweight and so are the foams. i will be making my own custom rims soon that will be the lightest ones out there.
the 3s i have basically sucks as it was not the size the company said it was suppose to be..couldnt send it back.
i also feel like i can get about 68-70 out of a 3s lipo. i can tell you guys dont think it is possible, but with this particular truck and its one-off design...its possible.

MetalMan · 06.19.2006, 09:29 AM

You're most likely going to need more than 3s to get past 55mph. 4s should take you to 60-65, and then you'd need more voltage to go faster (5s/6s).

sleepy23 · 06.19.2006, 11:04 AM

no way...i am pulling 50 with the weight of a gps on top and that is with a
2s. I have made several mods since I did that run and would bet large sums of money that i am at 55 right now with my 2s. I will try again soon on the speed runs and see though.
heard anything about the cc release for today? I am going to go looking for it.

Bmr4life · 06.19.2006, 12:54 PM

hey OP, have you GPS'd your ride to verify the 50mph top speed on just 7.4v? If so, how much runway does it require? thanks

cart213 · 06.19.2006, 01:54 PM

Over 50 mph is impressive on 2s, if that's how fast you're actually going. Like metalman said, though, 3s will be a stretch to hit 75 mph like you want to. The faster you go, the harder it is to go even faster. I think you'll need 4s (at least) to reach over 75.