A brushless MRX-4 or Evolva 2005

[captain harlock]

Excuse me, friends,

I'm thinking of a very fast brushless 1/8 on-road machine.
Speed I want to reach is not really something big.
100mph or so is the norm.
I've found these two machines to be my ultimate candidates.
What recommendaions do you people have as for what brushless system should I use and how many lipos?

Thanks,

Alawi El-Jifri :dft009:

[squeeforever]

I would choose a 10S LiPo setup with a CC HV110 ESC using the mechanical brakes and probably a Neu 1515...

[captain harlock]

Well, 10s is waaay too much. 6s seems good.
Dont make the size and look of these cars fool you, they're quite light actually.
How about a 1930/9( already have it) and my current 149.18 controller with 5 or 6s?
It might get me to 100mph or atleast high 80s, right.

[Serum]

i am doing a serpent at this moment. it's one of the nicest conversions to do IMO. The cars don't use a rear diff, i updated mine with a ball-diff, no idea how it goes, but i like the idea of having a diff in it.

I will do some testing with 5S, it will weight about 5 - 5.5 lbs, and 100 mph is completely useless. aim for the 60-70 mph. It makes more sense. 6S is not needed. since it weights almost half of an e-maxx and 6S for a maxx is too much already.

My plan is to try a 7XL/XL2400 and see what it does. i thought about getting a Neu 1512 with 2000 or 2600 kv.

Since it's lightweight, i think a small motor (such as the 1930) would do great.

[captain harlock]

Here's a tip for you regarding the ball differential:

USE CERAMIC BALLS FOR BOTH THE DIFF AND THE THRUST BEARING. YOUR DIFF WILL KISS YOUR HANDS FOR THAT. TRUST ME!

[Serum]

Thanks for the tip, Where to pick them up?

The thrust bearing is doing fine. it's an SKF bearing

The balls are FAT, so is the entire bearing kind of thing which is used. It's got a nice 'slipper' on the diff as well! it's made by Hudy, a true piece of engineering art..

[captain harlock]

Hudy ROCKS!
If you go to towerhobbies, type acer racing in the searching engine and it will present you to a large list of ceramic ball sizes and bearing kits for different cars.(They're not in stock, yet).
Boca bearing got a very large selections of ceramic ball sizes, too.

[Serum]

It's using 3/16th thick balls, would be about 40 bucks..

acer doesn't have such large balls..

[rcjmaxx]

I currently have 2 Hpi Super Nitro BRUSHLESS cars.These are 1/9 scale chassis' but with Wolfpack Radicals wheel conversions I can run 1/8 onroad wheels and tires(Serpent,Mugen,Proceed)same as Evolva,MRX-4.With this setup I can run an 1/8 scale body and fill it out nicely.I run a Feigao 12xl and 36120 ESC.With 6 cell lipo I run 60ish mph pass after pass at 130 degrees.I am currently testing this setup with 8 lipo cells

[squeeforever]

Captain, the reason I said 10S, is well, A. I'm a HV freak and B. You said you wanted 100mph. It's just not possible without a super HV setup. Like 8S or more...

[captain harlock]

Now it makes sense, Squee.
Okay, my mind is set on the MRX-4 with a 1940/8, 6s Evo20 and my 149.18 controller.

Being around the sixties, rcjmaxx, isn't really cool for an onroad machine, but then again, the super nitro is not dialled for hi speed applications like the Evolva or MRX-4. Those two machines with a .21 or a .28 engine made some amazing speeds at the worlds over 100mph. I guess it would be at least at the hi 80s with the 1940 motor.
Its costy, but I'll try to make it my ultimate rc project besides the Phase.2 SuperGorillaMaxx of mine.

Serum, your Serpent is 1/10 scale, right? Those are 1/8 scale, FYI.
And, if you are still interested in the ceramic balls( 40% lighter than steel balls and countless times as hard), go to www.bocabearings.com and probably you'll find what you need.

[captain harlock]

Yup, found that size at Boca. $4 for each ball, but the outcome is surely worth it.

[Serum]

No, the serpent is 1/8th fyi.

100 mph is redicilous and completely useless. Shoot for yourself, but what's the use of a car that you can only run straight. If you want pure speed another model can be picked as well.

[captain harlock]

You did not get the point. It can run at 100mph, but you wont loose control over the vehicle like you would with the other cars. You probably know better than me, you have one in your hands already, these are similar to a formula racing machines. If 250-300mph is rediculous for a Nisan Skyline, it is very reasonable for a Toyota GT-1 24hrs endurance race machine.
I'm not trying to talk big, but I'm just trying to point out my view of these 1/8 onroad vehicles. There's no comparison between a racing horse and a wild shita. The shita would run at a frenetic pace of 60mph without tearing it's muscles while a racing horse can't go over 30-35mph.
Once you finish the Serpent and give it a run, you'll realize that there is a huge gap between it and a touring car. I've seen the Evolvas in action in front of me at my local track, and their speeds at the first gear are simply out of discription.:)

[Serum]

Yeah, i've seen a few in action, but the difference between 60 and 100 mph is HUGE.

My idea was to mount a thin carbon fibre plate underneath the entire chassis, to get less air-resistance. and to suck the car on the road. perhaps this is an idea for you too.