drag motor help

[mach1stang]

hey guys, i am working on saving for a pro mod drag car (its the top one in the link) http://www.grandmotorsports.com/otherdrag.asp and i plan to use a mm i have a 7700 in my b4 buggy (aka the bling 4) and i love it. it is a awsome motor but i am wanting somthing a little more on the top end side for the drag car but i dont need a lot of torque seeing as the rolling chassis is just a few ounces. i plan on running 6-8 cells what would be a good higher rpm motor?

[BP-Revo]

Running 8 cells on the 7700 should be plenty.

However, you could try a 1920/6 or 1920/5 or even a 1920/4 if you want to be totally insane.

The 1920/4 will provide nearly 70,000RPM under load on 8.8V (assuming your batteries hold 1.1V per cell with 8 cells).

I think that'd be a bit much though. Probably be good on 6 cells for a dragster.

I'd personally run a 1920/5 on 8 cells. It will give around 50,000RPM under load, which seems good.

I'd also run lots of large capacitors to help your batteries maintain higher voltage under load by smoothing out the current draw. I added more caps to my HV-Maxx before and it really helped with acceleration (but take note this adds strain to the ESC).

[mach1stang]

ok i just want a bit more top end and kinda stay away from all the bottom end to keep it from blowing the tires away every time.

[lydiasdad]

Then just gear it higher

[mach1stang]

yeah i will do that anyways but you have to think the whole car wont weigh more than a 1.5 pound.

[skellyo]

Originally Posted by mach1stang

yeah i will do that anyways but you have to think the whole car wont weigh more than a 1.5 pound.

Yes, it will.

IB4200's are 2.4oz each; 6 = 14.4oz, 8 = 19.2oz
This is also not counting battery bars and wire

Mamba Max motor = 7oz

Mamba Max ESC = 2.5oz

Vehicle = 7.5oz (with no body or servo)

Average Servo = 2oz

And the body is probably at least 2oz also.

That puts you at about 2 1/4lbs with 6 cells or 2 1/2lbs with 8 cells. That's a 3/4-1 pound heavier than you're estimating and doesn't count the battery bars, wire or a receiver.

[mach1stang]

it is not a average servo it is a mini servo and i am pretty sure the weight includes the body i mean it is still a super light car with everything.

[skellyo]

From the website text:

Weight (rolling chassis minus body and electronics)
7.5 oz.

[mach1stang]

o i must haved missed that.

ah ha kody, not to much lighter then my cyclone loaded man, even thos theres nuthin to it

bp, u are crazy!!! u must of cought the lmt feaver LOL

If you are going to get into some real drag racing, try the 5700 motor. Drag racing isn't about having the hottest motor that you can get with the most rpms. Drag racing is about getting power to the ground. In the MM line, the 5700 does this the best.

[mach1stang]

yes your right but the 5700 has alot more bottom end, and that can great for a good track that has been lathered with sugarwater and all that stuff but then on some tracks it could be your worst nightmare. I think i am going to with the six i will have plenty of chassis placments to toy with it will keep the weight down and it should have some times with the 7700.

Just trying to give you the benefit of what I've experienced. I'll bet you come back to the 5700. It's what we did.

[mach1stang]

you have ran a drag car?

i havent, but i second him 100%

but idk that he knows that u already have the 7700 and speedo from ur bling 4, so yeah