I think the Novak GTB is worthy of it's own thread. Thanks to FishRC for pointing me/us to the info on the newest Novak brushless/brushed controler...

http://www.teamnovak.com/products/brushless/gtb_system/index.html

The quick run down... Footprint: 1.16” x 1.49” (29.5 x 37.8 mm), Input Voltage: 4-6 cells (1.2V/cell), Weight: 1.36 oz. (38.5 g), On-Resistance: 0.00040 ohms (per each phase -3); 0.00013 ohms (brushed mode), etc...

Now, thats not quite as small as the Novak GTX brushed controler, but the on-resistance of the GTB in brushless mode is comperable to the GTX, and the GTB in brushed mode has LOWER resistance then the GTX does... (GTX on-resistance is listed as .00034 ohms)

The GTB appears to be what I would call a true competition level brushless controler... at least for those of use who compete with RC vehicles that operate between 4.8 and 7.2 volts... If you want to run higher voltage then that, then the GTB is NOT for you.

I'm geeked about this GTB... I wish it had more programablity... but then I'm just a geek who loves to tweak things myself. It will more then likely run just fine without more programablity.

Awesome! For offroad I think my SS5800 combo is good enough for now but I may be upgrading the ESC next year. Would be nice to save a little weight on the ESC since batteries just keep getting heavier and heavier.

Not exactly sure how much closer we are to actualy seeing a Novak GTB... but I just ran across some new information... It seems the GTB will now ship with a fan instaled on the heat sink...

http://www.teamnovak.com/products/brushless/gtb_system/index.html

No definitive answer, but it would seem that the fan would proably not be a nessesity when using a 4300 motor, but will be come increasingly more important with more powerfull motors... but I don't think they switched to delivering with the fan simply because they thought it looked cool.

any test report?
how is it compare with Lrp sphere?
is gtb used for brushed motor good as gtx?

I don't think they've been released yet to the general public... I have heard/seen a few reports from sponsored drivers who say they are great... (but that's what they get sponsored for, to promote the product)...

The GTX has a on resistance of .00034 ohms, the GTB is said to have a on resistance of .00013 ohms. That indicates that electricaly speaking (Ohms law and all that) the GTB will be better then the GTX is...

If using in 4cell oval racing I wonder if the fan is removable? And or if needed if used for brushed mod or brushless oval use?

Anybody heard when it's available? I know they keep changing the date.

will the new GTB speedo matched with the current SS 4300 motor, be the same speed as the current SS4300 systems.. I like the smaller size, but if it is not exactly the same i wont be able to purchase it to use in the class..

You should be able to put your motor you have on the GTB, I think even the Reedy motor will work also. I see Tower hobbies had limitied quantities of them the other day!
Rex

the ss 4300 description states it is like a 27 turn motor,... we all know it is faster.. but on the GTB description it states the 4300 on the GTb speedo is like a SS4300 (10 1/2-turn

Tower currently lists the GTB 5.5 system as available early september... The GTB 6.5 system is available in 'limited quantities'... and the GTB controler by iteself as available in late September...

So... it would seem that GTB systems are hitting the retail market...


Anyone seen one in a local hobby shop yet?

If I wans't so broke... I'd order a 6.5 system... but then 5.5 should be faster... and I'm still broke. I'll have to save my pennys to possibly buy a GTB controler... looks like I've got a month or so to save.

Just to let everyone know.. i just got an email back from novak... the new GTB speedo is not the same as the ss speedo// so if you run 4300 class, you can not use this speedo.. Its is faster, and more powerfull then the ss speedo.. Now if you could get everyone to get the new speedo, you would be set.. But from the specs, it is considerably faster.. 10 turn verses what it is now..

Burbs - the 4300 motor is a 10.5 turn (and always has been), and the 5800 is an 8.5 turn. You can't compare the number of turns between brushed and brushless directly, because brushless motors are wound in a "Y" configuration (one end of each coil connected to a common point), and brushed motors are what's called "delta" (think triangle). The current in a brushless motor must flow through 2 poles worth of windings, so you basically have to double the number of brushless turns to get a rough comparison to brushed motors. The brushless will run a bit better than this, due to no losses in the comm/brushes, and has stronger magnets, but a has smaller diameter rotor and more voltage drop across the ESC, so trying to come up with an exact equivalancy formula is very tricky. I won't know for sure until I get my hands on one, but I suspect the GTB will slightly improve performance of both the 4300 and 5800, but it probably won't amount to a huge gain. Except that the ESC will never "go thermal" (though the motor still might). It DEFINITELY WON'T make the 4300 run like a 10-turn.

Judging from the amount of heat generated by the Super Sport ESC the GTB will improve performance about the same as switching from a Rooster to a GTX. I know there is quite a difference between the Rooster and GTX but the on track performance shows very little performance. On occasion I use to put in a reversing ESC for practice (before I got the SS5800) and my laptimes did not improve any.

Judging from the amount of heat generated by the Super Sport ESC the GTB will improve performance about the same as switching from a Rooster to a GTX. I know there is quite a difference between the Rooster and GTX but the on track performance shows very little performance. On occasion I use to put in a reversing ESC for practice (before I got the SS5800) and my laptimes did not improve any.


WOW. Great info... Keep up the good work.

Thanks

I belive that the differances between such controlers will be more obvious in 4 cell oval racing. It may seem somewhat counter intuitive to those who are not firmilar with basic electronics... however in 4 cell oval I think the average current use is higher then it is in any other form of RC racing. Based on the GTB specs the power loss/wasted energy will be .7 watts at 30 amps, and 2 watts at 50 amps. At 30 amps, there is something like 3.4 watts wasted/consumed by the SS controler and at 50 amps the ammount of power consumed by the SS controler is more like 9.5 watts. It's very easy to average 30 amps discharge during a 4 cell oval race, even stock classes come close to 30 amps average. If your averaging 30 amps, then it's a pretty sure bet that you ocasionaly draw more then the average... Because 4 cell operates at a lower voltage, that loss of power is a bigger percentage of the total power available to the racer. Therfore... I think 4 cell oval racers will notice the differances between the SS controler and the GTB, more so then any other class of RC racing.

Dyno is probably correct, particularly out of the corners.

Maybe a big heavy sedan on carpet with foams would notice a little difference in the pop out of the corners too.

I just received my today and was wonder if anyone raced it yet. A little disappointed with the size. The height with the fan is the same at the SS and SS+ but it is just a tad smaller. Looks like I'll be using it mostly in 4c oval stock....I was planning on replacing my GTX on my touring car but there is hardly any room for the speedo

If your running this with a brushed motor (you said 'stock') you shouldn't need the fan... the specs of the GTB in brushed motor are pretty much as good as you can get in a ESC these days, and you really should not need the fan. I bet even with a 19 turn motor you'd not need the fan in brushed mode.

Even in brushless mode, you probably will not need the fan to run the 4300 motor... But without actual experiance that's just a guess... The more powerfull motor you use with it, the more likely you'd need the fan...

According to published dimensions, it's still the smallest brushless ESC out there (see attached image). Although I did discover that both Novak and LRP's dimensions do NOT include the circuit board that sticks out where the motor leads are attached. Their LxW dimensions are just for the plastic case. The Sphere and Novak SS sizes shown I measured, the GTX and GTB are guesses based on published dimensions + 6mm for the circuit board.

We went and picked one up at our local HS, $219.99 ! Put it in the XXXBk2, way more power than his 12 turn v2 my son raced with last weekend. Lots more drag brake to simulate the brushed motors. Only gripe is the esc is a little tall with the fan to fit in a buggy good.
Rex

Forgot to mention we got the 5.5 turn. The only downfall is they are still heavier than brushed combo's. It weighed around 65 grams (over 2.5 ounces) heavier than a Gt7 and a Orion V2 motor.

I just got my GTB/5.5 combo, and have to admit I'm surprised at how big it is. Seems the "official" dimensions don't count the circuit board that sticks out 2 sides of the ESC. And the power capacitor is HUGE! A revised size comparison is attached. (Strange that the LRP doesn't have any capacitor. I wonder if there will be a noticable efficiency difference between them?)

On the bright side, it runs like the often mentioned "molested monkey" (or something like that). I ran a couple practice packs in my TC3 at a road course race (there was no mod class present). I never quite got the car's handling right, but it was as fast as the Nitro cars on the straightaway, and ran 6 minutes on a 3300 battery. I guess if it runs this well, I can live with the size (it's still smaller than the SS).

kevin,

2 questions:

- where did u get the GTB/5.5, and how much

- what are the ratings on the cap? i am running a spektrum, and will be using it w/ 4 cells. i dont have the spektrum cap yet, but if the GTB cap is the right size, i wont need to:)

I got mine from a local hobby shop, who got it through Great Planes (a.k.a. Tower's evil twin). I had them order it as soon as Novak announced it, and it showed up last week.

Not sure about the cap value. It is soldered to a small circuit board with other electronic components on it, with heat shrink covering the whole assembly. Do you need a special cap to use the Spektrum on 4 cells? Mine works fine on 6.

I got my GTB/5.5 and put it in my XXX-T outlaw truck with a 86-12 gearing and it just flat gets it done ! I will never run a brush motor again.

I do wish you could actually detune it like the Super sport. I wouldn't be afraid of the 6.5 turn, actually might be more controllable.
Rex

i have the 5.5 system in my bk2 buggy and it has all the power i will ever need. i never really ran much mod before but this last weekend i ran it against some pretty good competition and i definitly had plenty of speed down the straight. more importantly the throttle/brake feel is very smooth and you can make many adjustments to the esc.
as for having a throttle limiter, just back down your throttle endpoint. i do this with my hv maxx system in my e maxx and i can run better laptimes.

Does anyone know how the LRP Sphere compares to the GTB. Does it perform as well?

RC

You guys are insane, for my track the 5800 has too much power, I can't imagine the 6.5 or the 5.5. I spanked the field this past summer and just about everyone of them were running 10 turn V2's. My track is really bumpy though.

RCAVENGER, I was told you would need a cap on the open channel on your spectrum receiver or a receiver pack to keep the voltage from dropping and putting the rec in fail safe mode. You will still need the cap on the speedo too. The caps are available through your local hobby shop where you bought the radio. It already has a servo plug on the end to install it.

Splat - I haven't had a chance to do any scientific testing yet. Stay tuned......

Pat - While I choose not to comment on the mental health of my fellow racers (they might comment on mine!), it does matter what kind of racing you're doing. Touring cars on parking lots can use pretty much all the power you can get (the Novak 5.5 or Reedy fit this description nicely). Last time I ran offroad, seems like I usually ended up with a 14 turn in the truck, which is basically equivalent to the 5800. Traction, bumpiness and length of straightaway would obviously figure into it as well.

We didn't have any problems running ours with a Spektrum in a M8. Pat, we wanted our 5.5 turn to run in a Custom works type sprintcar, the 5800 wasn't quite enough. Guys run down to a 7 turn brushed, with the big wing it takes some good Hp. My son also races offroad, they run 10-12 turns, I think it's good to practice with too much power then when you run a 12 turn it's easy.

Rex

Over on the 'Oval' section there was a report of some folks having problems with the GTB and a 5800... something about they were slowing down for periods of time and then back up to full speed, etc... Not sure of any details, but thought it was worth mentioning... Suposedly the LRPs running the 5800 were fine...

Anyone else know of any problems with the GTB?

Only problem we've been having is flipping over backwards! lol

Rex

The only problem I've had is that all 4 tires spin when I pull the trigger. :D

Will this system run twenty minutes with lipos???

thanks
dave mac

Only problem I have is the fact that I cant get one yet. My lhs has not even had one on the shelf.

I dont think Novak is keeping up with demand yet. Tower was selling them before they let them go to the Hobby shops. The local HS ordered a bunch and only got 2, I got lucky and got one of those 2. (219.99) Well worth the wait If you have to wait.
I think with the fan it will run 20 minutes if not overgeared, the Speed control will take a 4 or 4-1/2 turn I heard.(brushless)
Rex

I ran mine in a TC3 on carpet today. I can't comment on Lipos, but after draining a 3300, the motor was about 140° and the ESC was only 117° (with fan). I seriously doubt any motor currently available will get it anywhere close to thermal shutdown. Maybe if you took the fan off and ran it outdoors in Phoenix in July????

Kevin...any comments between the GTB vs LRP? Have you been able to do any testing?

Nothing "scientific" yet, just blasting around the track in practice time (no mod racers lately). The LRP definitely ran a lot hotter, and needed a fan (outdoors) to prevent shutdown. That was on 6 cells and a fairly open track (i.e. the throttle was open a lot, too :eek: ).

Do you guys know the name of the system you can run mod, and or stock, just by flicking a switch.

thanks
Dave mac

The original brushless system with the 5800 had 2 settings, Stock and mod. They have replaced it with the new Super Sport with now runs brushed and brushless but no limit on power. You would have to use different motors the 4300 for stock and the 5800 for mild mod. The GTB with the Velocity 5.5 and 6.5 are ballistic!

Thanks Ken

There really is no system that allows you two run 'stock' and 'mod' at the flip of a switch...

The Novak SS had several modes... one limits the RPM of the motor... However this is not a very smooth limiter and when you bump up against it, it's very noticable. Near as I can tell... there is/was almost no practicle use for the rev limiter feature on that controler...

The speed/proformance of the brushless systems are largely defined by the motor you connect to the controler... there is not magical flip of a switch in a way that would be useable for both 'stock' and 'mod' without chaning the motors, etc... at least not in any of the systems I've seen.

One thing you could do if you wanted less power would be run 5 cells instead of 6. I was pretty close to trying this at the end of this outdoor season when everyone quit showing up to race after labor day.

Ran the 5.5 turn in 12th yesrerday and it's pretty quick. It's about like running a 9 turn but you have to gear it up like a 10. The batteries and speedo get hotter than the motor does.

It looks like you can run pretty hard without the fan on 4 cells without any problems but I think that in oval, you'll want to keep the speedo cooled off.

I have a buddy who put the 5.5 in a t4, and ran it for 40 minutes (lipo) non stop, no issues, said it was awesome, absolutly loved it, I have mine comming this week. Said it was Smooooooooooooooooth, and fast as all blazes.

Hello all, I have just ordered mine a GTB 5.5, It should be hear in a week or 2. I have the SS 8.5 esc with the 5800 motor. I any really pumped up to get it it to my B4 and go off roading. When I first installed the SS in my T4 it was amazing the power it had. I just cant wait to find out how much power the 5.5 has.

How much more does the 5.5 have over the 5800? Also is the 5800 equel to a 8.5 turn?

Thanks Semore