Novak

[jrjr]

What is the difference in the GT7 and the GTX? The GTX costs more but has a lower amp rating. Just curious. Time for a new ESC and I want the best!!

[CharlieS]

Hello,

The current ratings for the ESCs really shouldn't be compared. The technology in the GTX is much newer and is rated slightly differently. If we use the "older" specs, the GTX rated currently is about 100 amps more then the GT7. We didn't get the updated Specs in time for the release of the GTX, so it's a bit confusing.

Also, no ESC really can handle anything close to the rated current. R/C Battery packs are capable of "around 150 amps". The wires would melt at 500 and 600 amps as well.

Thanks
Charlie

[RS4rally1124]

so basically all of these new fancy high poewer esc's arent that much betetr than say my tc2??

JT

[CharlieS]

Well, in the GTX we've gone to faster switching, and improved the drive circuit pretty substantially. All the team drivers noticed improved throttle response. The weight savings alone will make a small difference. But the actually power handling has gone up slightly, so you'll end up delivering more of what the motor is asking for instead of building up heat.

Thanks
Charlie

[RS4rally1124]

oh alright then. i guess i may need a newer esc. although will i really notice it in club level racing. i barely noticed the difference between a 17 turn and a 16 turn.

JT

[jrjr]

Well, in the GTX we've gone to faster switching, and improved the drive circuit pretty substantially. All the team drivers noticed improved throttle response. The weight savings alone will make a small difference. But the actually power handling has gone up slightly, so you'll end up delivering more of what the motor is asking for instead of building up heat.

Thanks
Charlie

Why then does the GTX have heat sinks and the GT7 does not?

[Terry_S]

So the GTX has now increased from a 150A rating to a massive 700A rating, that's an unbelievable 370% increase. I would like to see the manufacturers data to back that claim up. Maybe the MOSFET manufacturers made a big error when they published their data, I find that hard to accept. The best specified SM MOSFET I've seen is rated at 30A (at 25 deg C ambient temp). To get the current rating up to 700A there would have to be a total of 23 MOSFETs rated at 30A each inside the GTX, and that's only for forwards there's also the brake MOSFETs to fit in too. Personally I doubt the revised ratings. The newer type of SM (surface mount) MOSFETs have lower current ratings than the older TO220 type MOSFETs so all the new generation small size ESC's have lower current ratings, but often an improved on-resistance over earlier ESC's, which is more important when comparing ESC specs.

[CharlieS]

That's why I hate Ratings so much. They are fairly worthless when it comes down to anything.

You're right and wrong a the same time. There are many different types of Mosfets and many different ways of them being rated. Your experience may be otherwise, that's fine too. The Original Specs given for the parts we used in the GTX came out much lower then the GT7, this is because they were a differnt spec given at a different dissapation. When making the specs match, the Actual number is much higher. Now this number is useless, our battery packs aren't even capable of half the rating, so why bother anymore anyway. And yes, the specs are at 25C in most cases. We put that in the specs, but it doesn't make it into many of the "Press Releases" that are put out.

At a club level, it's hard to say if you'll notice a difference, it might not make you faster or slower, but it will give you a different "feel". Usually the updated ESCs feel more linear, and run slightly more efficiently. This can be better runtime, but really I don't think it's noticable unless you're making a huge step.

The GT7 did have internal heatsinks actually, the GTX has one on the outside because it is a different "design" of ESC slightly, the Mosfets are much different/updated.

If you guys have any questions at all, feel free to email us directly.

Thanks
Charlie