I think you will. From my experience a heatsink is pretty much needed on the quark in any 1/8 or MT application. Even if its not absolutely necessary it will for sure help keep you expensive ESC investment cooler and healthier.

i only askesd as i will have my esc before my heatsink will arive and i will want to use it lol so do you think i should run it untill i think it is too hot and then give it a rest to cool down?????? i wont be running long as i only have rubish 3300 oam cells so about 10 min run times so do you recon it will be fine for little while ?????????
thanks for your guys help so far it has been great

I dont think you will hurt anything by trying it out. Just pay attention to the esc temps and you should be fine. The best place to monitor the Quark temp is right where the motor wires come out of the esc.

I recently purchased a 125b for my XB8 and XT8 conversions. It was much smoother than the MM I tested, but that was before the latest MM firmware update. This was expected as I am using a Neu 1512 2.5d on 4s, which didn't play nice on the older MM firmware. Once rolling, the MM wasn't bad, but when you are running a track and being marshalled, starting from a stop is something you have to plan for. I had to gear the MM so conservative to avoid cogging that I could not take real advantage of the torque of the Neu motor.

I have been pleased with the Quark speedo, however, I have had an issue with the case/heatsink separating from the fets/board. When using the car the board would slide inside the case and actually push the endcaps loose. It wouldn't come apart completely, but the end caps were popped loose at the end of each run. This last time was the worst where it actually knocked the top plate loose too. The FETs are no longer securely attached to the adhesive pad and heatsink. I guess now would be as good a time as any to do the adhesive mod. While I have the controller open, any reason to replace the stock capacitors or add additional ones?

Hey guys!!m Great insight on the Quark!! I am presently using a 125 on 4S in a TC4 with zero problems and I am extremely pleased!!! I am setting up a Inferno GT to do 6S with a Neu 1512, either a 2D or 2.5D on the 80. This is going to be a high speed car just for 10-15 passes. Opinions??