Brushless Motor gear ratios

[Welshy40]

Guys,

I am curious, but do you all follow the gear ratios recommended by the manufacturer?

I have a peak 4.5t and think 14 to 1 is a bit low, and I dont have a 10 tooth pinion to do it either. Im using a ratio around 10 to 1 and was wondering if thats a bit high?

So what can i get away with before the motor over heats and stops?

All info would be welcome, just say from your experience, as i know zero about brushless.

[DCM]

Originally Posted by lazerboy

just do what the manufacturer says.

James, you know the routine, gear up a little from the recomended and see how the temps ares with it. If it is still cool and pulling away nice, gear up.

[Welshy40]

Well I gambled and as 14 to one is a near impossibility (as stated by Peak) I decided on a 10.5 to 1 ratio and worked fine. It felt like it could take some more so will gear up again at the next club meet.

The motor was hot, just like the brushed after a race and the esc was well hot. Im buying a novak fan and am bolting it onto my mamba esc and that should cool it a bit.

[super__dan]

Why oh why have you put a 4.5 in a buggy???

[Welshy40]

Dan,

Due to being unable to over gear these new motors (brushed) as im unable to get corrally motors due to the rubbish importer in this country.

Still the 4.5 seems to be as quick as my old ten double corrally that was worked on by Dave. The only thing i dont like is the noise it makes, but then again the performance is impressive.

I also have had my first schumacher tire rip apart on me. Whats going on with them, why are the tires so crap. Im going to try the GRP ones, and also try and get my money back or a replacement on these rubbish yellows.

[MattW]

If you've got a 4.5 that is "as quick" as a 10 turn, then you either a) have it miles off on gearing, or b) have a very bad motor.

[Welshy40]

Nope neither, my old ten was rapid, and even got noticed by the then yokomo team manager Brian Duggan who said it was like a missile. The 4.5 is quick and my gearing is 10.5 to one, so better than the 14.1 recommendation by Orion/Peak. Ok I havent done my ten double ratio yet which was around the 8 to 1 mark but not to bothered at the moment, as it was quicker than anything else at the event. Im more interested in setting my car up then I will see how fast i can get this motor before it overheats.

[Richard Lowe]

It's geared too high, and if its as quick as a 10 turn from 10 years ago or whenever you last raced it isn't reaching anywhere near it's potential. Can you make your Laser wheelie with it? If not it's overgeared.

From what I've found brushless is a bit wierd with gearing, if it's under or over geared you just loose all performance. If you can't find a pinion small enough (13 is the smallest I've seen, and that wasn't exactly very round) you can always fit a bigger spur. Also with brushless the speedo's are what gets hot as a general rule, as your motor is sintered it should stay cooler than the bonded motors like the LRP's. As your speedo is 'well hot' thats an indication you are asking it to pull too long a ratio.

[Chris Doughty]

LRP 4.5 is super-crazy-fast. comparing it to a 10 turn would be like comparing a 10 turn to a 19 turn.

I managed to hang onto it yesterday though, turned the speedo punch down and it just about driveable

[Lplate]

Anyone have the Nosram/LRP 5.5 recommended gear ratio?
I think I might have lost the manual. Thanks.

[Chris Doughty]

the LRP website should have the manuals available for download.

[Lplate]

Oh yeah... Forgot all about LRP website. Heheh.
Thanks.

[Welshy40]

yup my car does wheely down the straight, but only when the start happens, and if I hit full on. Its a pity as if the slipper actually worked it may be ok. I hate to admit it but these motors are much better than the brushed, only due to zero work after each race.

So you guys rekon I can gear up, well i will see how far I can get, and superb if i can. I suppose the more you gear up the less accelaration there is, so that should stop the front end taking off then.

[Northy]

Do you actually read what anyone types?

[vader]

Originally Posted by DoughtyUK.net

I managed to hang onto it yesterday though

Chris you're my hero

[Welshy40]

Originally Posted by Northy

Do you actually read what anyone types?

Yes I do, but LRP and Nosram are not sensorless so not worth reading. Besides different people handle speed differently. I want all pointers and will decide what route to take. Anyway I dont know what the fuss is about, the car handles the speed. I may buy a 3.5 for club to better the setup if I cant get this motor to go any quicker.

[super__dan]

That's just it James, you don't seem to understand a brushless motor won't actually work (go quick) unnless you are in the right ball park of ratios. If you can't make the right ratio for a 4.5, buying a 3.5 won't make it go any quicker, maybe slower and likely much hotter!

[jim76]

just let him waste his money if he won't listen! he can melt the motor and speedo by whacking on a great big pinion in a quest for speed. he may come crawling back for advice then once he's £150 down!

[Welshy40]

When I have managed to set my car up (which I still havent been able to yet due to other problems - bad preparation by me) properly then maybe I will buy a 3.5 but for a different reason, and that would be just for clubs and fun whereas the 4.5 (which seems quick enough at 10.1 ratio at the mo) will be used at the events.

The 3.5 will be used to help refine the setup on tight and twisty tracks, as everyone has said that the 3.5 is too quick for buggies (more accelaration and less top end), well now that may help to get the car set up better. The drive train will easily handle it on my car and so will the driveshafts so now all I need to do is figure out how to make a prototype slipper work properly.

Each person sets their cars up differently, mine is on tight tracks with more power (accelaration) than required.

Dan, I know your a good driver now and yes you'd hammer me big time now, I am now a F5 or whatever the lowest is and your now a F1, but i am not arguing that at all.

But you know how I used to race and how I set my cars up, ok not always set up well but I always managed to drive the car to the limit all the time, sometimes with next to no grip (Worksop) and with way too much grip (Ellesmere Port) flat out and tight. (indoors is my favourite)

It worked for me and ok I only used two setups for 4wd and also 2 for 2wd but they both worked well for me, and got the results i was after.

Yes the speed appears to have improved a lot and yes I dont have to let dave spend ages preparing my motors anymore either. The MR M he spent hours on for the Basildon warm ups was the quickest thing I have ever driven, and the 4.5t at 10.1 still doesnt come close. Also the batteries have changed big time and now I will never dump again.

I will set my car up well and when I can be bothered will prove a point, that I am not as bad as you make me out. I am no longer out for a punch up, I am out for a laugh, even at my own expense. I always have enjoyed proving points, its entertaining.

[PaulRotheram]

That's exactly what your not getting.. your 4.5 isnt as quick as your old 's*** of a stick' 10 turn brushed because you have geared it so badly and miles away from the reccomended ratio that its a pile of poo.

Trust the guys above on what they are saying, if you choose to be ignorant, then fair doo's, but theyve been using this technology for maybe over a year now.. so they know a thing or two about whats going on!

a 4.5 'should' make your car very uncontrolable, a 3.5 should be 100% out of control - ive seen the best of our class struggle with these turnings.. I whole honestly cant see you being able to handle them for a whole race at the right gearing.. unless as you have shown it is poorly geared and the performance isnt there.

Don't waste your money and get the gearing set correctly, brushless is a whole new ballgame compared to brushed so take the advice and see how it goes.