Jrx2 motors

[pmathews924]

Trying to remember what was hot back in the day...we ran two motors in our car, mostly in stock class races.

B&R stock
Slot Machine

What was a good modified motor?
What did y'all run in your jrx2?

[madweazl]

Had a B&R Bullet in mine that I absolutely loved. Probably my most favorite stock motor until the Peak Performance Beast came out years later. Had some Race Preps that I liked but nothing as much as the B&R.

Edit: on the mod front, I mostly had Twisters.

[fredswain]

I think I tried everything. Trinity Monster Stock, B&R, Race Prep, Revtech, Reedy, Revolution, Twister and I'm sure some others I'm forgetting. I think my overall favorite was the Trinity but it was close with a few others. The Reedy is the only motor that I've ever owned where the end bell flew off after landing from a jump. It was a big surprise to see that happen. The Revolution was first motor I ever had in my JRX2 but I was less than impressed with it. The B&R I think was fine but I don't remember anything spectacular about it. I can't think of why I didn't like it though but I never wanted another one. I really liked the Race Prep, Revtech, Twister and Trinity motors. They all seemed comparable to each other but were a bit different in the way they produced power. I'm pretty sure I bought each of these again at some point. I know on my RC10 I mostly ran the Trinity and Race Prep while later on in my JRX2 I ran mostly Twister and Revtech.

The only oval race I ever ran was actually my very last race ever and that was with my JRX2. That was a first in the B main using the Revtech. My batteries were horrible since I was so hard on them as a kid so they'd dump me out of A main contention. Most of my track success was with the Trinity Monster Stock. I ran timed brushes on it and went down a pinion tooth. My friend Paul could always out drag race my car with his RC10 and he only ever ran Race Prep. Even when I ran Race Prep he was faster. Back then he took the time to carefully deburr his 6 gear like in the Jim Halsey video and I didn't. That made a bigger difference between our speeds than just motor alone. Ah memories...

[pmathews924]

I may have ran a Twister as well now that I think about it...but I know when it was race time the B&R was in the car. We didn't spend a whole lot of time messing with motors though because we were the lone graphite chassis racing against all gold-pan RC10s and Optimas. Speed wasn't going to lose me a race, but handling could so we focused more on that.

You said some of them were different in how they produced power...how so? Were certain motors quicker off the line and slower in the top end or vice versa?

[dldiaz]

My favorite mod motor in the JRX-2 was a Trinity "Joel 'Magic' Johnson" motor (black canister, green label w/J.J.'s signature).
I believe this was a 17-turn motor, a great punchy motor for off-road.

The few times I ran dirt oval I used a Twister (black can, red label)
- I think it was an 11-turn?
This motor was pretty weak off the bottom and ballistic fast on top!

[pmathews924]

I think there's actually a Magic Johnson Trinity on eBay right now...thought about buying it, but figured I should make a decision first before I just start collecting cans.

[pmathews924]

Ok...and this is a dumb question but one I have to ask.

What's the difference in turns/turn ratios as it applies to racing and car performance? Can I throw anything in my car? I was 7 or 8 when we were racing so I can't remember a thing.

[dldiaz]

The basic idea is: The lower the turns, the higher the RPM's.
Of course, a high RPM motor will usually have less bottom end torque.

Something in the 14- to 19-turn range is good for off-road or general bashing,
lower than 14-turns will get hot pretty quick in the back yard,
higher than 19-turns start to get slow...
(exception being the full-race spec 27-turn 'stock' motors,
which are pretty fast)

[pmathews924]

So...19+ turns will make you quick out of the gate but you won't have much top end, and 14- turns will give you a ton of top end, but not much acceleration. 99% sure my stock motors are 27x1 but I'll check the vintage motor thread to make sure. I know my stock motors are fast, but I want to go faster.

[fredswain]

Stock motors were 27 turn. Modified was basically everything else.

[Charlie don't surf]

The lower number of winds, the more torque and RPM- the lower the number of windings (single, double, triple, quad, quint) the more that wind number is compounded. There are other factors such as brush diameter, orientation, timing and circular mills in the eddy, but that's the idea-

[dldiaz]

A lower turn motor will generate a higher peak torque number, but at a higher RPM, thus requiring a numerically higher gear ratio for good acceleration.

A lower number of winds will give more abrupt power delivery, such that a "quad" wind will have a smoother, more linear power feel, while a "single" wind will be closer to an on/off switch.

[pmathews924]

So if I went as low as possible on the turns, I could offset the lost acceleration with the right gear ratio...but I would want a quad wind so it's smooth on the throttle.

[JK Racing]

I always ran a 13X3 Twister, had boxes full of 'em Mostly the gold label motors, went I went into dirt oval, I swapped to a 11X3, red label motor, still Twister. I had even bought the Twister motor lathe, used to take 2 days before racing and put a cut on all my motors and freshen up or replace the brushes.

Ahhh, the days of motor maintenance. I miss it.

[madweazl]

Little bit later down the road but 10t doubles were my favorites. Peak Performance had a 10x2 with lay down brushes that was one of my favorite motors of all time (thought it was the Nightmare but that was a 27t).