rear motor Optima vs Optima Mid

[Saito2 6686]

For those that have driven both, what are the different performance/driving characteristics of these two buggies? Does the Mid truly blow the old rear motor car out of the water or is a more evolutionary step? In other words, could the original Optima still keep pace with the Mids at first? Thanks for any insight.

[MadInventor 3884]

Good question, haven't got a clue myself not having owned either, but interested to see what others say.

Given that the late 80s racing was dominated by the CAT xls and the mid, I'd guess the Mid would blow the rear motor Optima out of the water, but that's just a guess. The mid is  certainly a more efficient design, and gets my vote as the Carlsberg of cars.

Best design ever ?

'Probably' 

 

[markbt73 5315]

I never raced either, but I've owned and driven both pretty extensively. The Mid is definitely more responsive, bordering on twitchy for the SWB version, which may be why they lengthened it. But it's also a lot more neutral, and jumps better. But because of that it's almost less fun than the rear-motor Optima, because it just goes where you point it without drama. I can see why it was the better racer, but it's almost dull to drive around the yard.

What always annoyed me about the Mid is fitting everything in; it's TIGHT in there. And I was running an ESC in mine, I can't imagine trying to squeeze in an MSC and antother servo. Though if they saw fit to re-release the Mid, I'd be all over it...

[Wooders28 4723]

Raced a mid for years, and still have one. The car is a joy to drive, even now it isn't embarrassingly slow around a track. I also raced an Ultima in 2wd (not an optima I know...), it was quite understeery compared to the mid, and the front end lifted easier.

Imo , the mid motor layout changed racing, although 2wd ran with the motor hanging out the back, up to only maybe 6yrs ago (RB6?) 

All modern race cars are mid motored, even 2wd.

[moffman 5752]

I've just got the re-release turbo optima never had the Optima mid (come on kyosho do us a massive favour 👍) but have raced plenty of mid mounted buggies from other manufacturers over the years including my very first 4wd buggy the boomerang and I'm only guessing that if everything is nearest to centre of gravity is going to be better balanced? Even on the budget side of the rc spectrum if the buggy has got lower end price parts on it if its balanced right that's probably the biggest gain you could put on it?

[Krustybus 214]

Yes, it's all about balance in terms of vehicle dynamics. 

Generally you want to keep all the heavy bits of a vehicle in between the wheels (although I guess Porsche have done a decent job of creating a sports car with the engine hanging out the back!)  Big powerful Audis as an example have always been known to be a bit understeery due to the heavy lump of an engine overhanging the front wheels.

Still, I've not driven a rear motor Optima (really tempted to buy one since there's no sign of a Mid rere ever appearing)) and it's been 30 years since I owned a Mid Custom Special so probably not that qualified to comment! I did study vehicle handling at uni and work vehicle engineering now though so have some insights!) 

[MadInventor 3884]

11 hours ago, Wooders28 said:

All modern race cars are mid motored, even 2wd.

 

Wasn't the rear mounted motor used to help prevent all the weight coming off the back wheels during braking ? Is it the case that modern 2wd racers use mid mounting to take advantage of the very light LiPos that can be used now ?

 

[slimleeroy 241]

On 11/24/2020 at 9:52 AM, Saito2 said:

For those that have driven both, what are the different performance/driving characteristics of these two buggies? Does the Mid truly blow the old rear motor car out of the water or is a more evolutionary step? In other words, could the original Optima still keep pace with the Mids at first? Thanks for any insight.

I have a re re Optima, re re Optima pro and an original mid.  While the rear motor cars are no slouches the mid handles better. The older designs drive more like a 2wd car.  Saying that. The rear motor optimas are more fun in my opinion

[Wooders28 4723]

8 hours ago, MadInventor said:

 

Wasn't the rear mounted motor used to help prevent all the weight coming off the back wheels during braking ? Is it the case that modern 2wd racers use mid mounting to take advantage of the very light LiPos that can be used now ?

 

I thought it was to keep the weight over the driven wheels, to maximise the grip?

Mid mounting improves weight distribution to the 4 corners, but in a modern 2wd buggy, means they can accelerate quicker, as the weight is further forward, maybe at the expense of brakes, but not sure if modern ABS brakes make up for it? (My transmitter, I can adjust the brakes per ° steering angle, full ABS brakes in a straight line, then comes off the brakes as I turn in, to whatever I set it to).

Modern buggies also allow you to adjust where the motor sits, so in low grip conditions, you can move the motor back , Schumacher did it by using a belt to drive the rear diff, and you just unbolted the motor/gearbox, move it back ,and fit the shorter belt. Others use differnet gearboxes ,stand up (gears ontop of each other) or laydown (gears in a line).