Too much power

[simonrhart]

I took my Xray '15 out for a first run a couple weeks ago - and wow, I found the car to be very agile and nimble - which is great. It will take some getting used to compared to my old car. I did find however, I just have too much power. From mid to full power I found the car would lift the front up and flip over at times. It happened from a standing start too.

I am running Orion gear, with a 5.5T motor - with no boost. I am running a 20 tooth pinion with temps around 60degree c. I was thinking of increasing the pinion to reduce torque, perhaps to a 21-22. This might tame it down a bit. Don't really want to move to a 6.5T motor because I love the speed down the straight! and this speed comes in handy on big tracks not to mention I am not sure if a 6.5T will fix this issue either because higher winds tend to have more torque.

Anyone else seeing this with their XB4?

Cheers
Simon

[sime46]

Most people I know run a 6.5 in theirs(me included). It's easier through the twistys and not so fierce on and off power. I tend to run turbo timing for the long straights so you have the speed you need when you do actually need it. Xb4 is a very free running car with low transmission losses so it'll always spool up rather quickly.

[simonrhart]

I might change to a 6.5. First I will try gearing down to a 18t pinion, seems a 20t on a 5.5 is a little too much looking at various setup sheets.

The car has such little resistance, the drive train is very free running and the car is very light. Mine weighs in at c1830 grams in shorty config. All this adds up to a lower wind motor I think.

[simonrhart]

Originally Posted by simonrhart

I might change to a 6.5. First I will try gearing down to a 18t pinion, seems a 20t on a 5.5 is a little too much looking at various setup sheets.

The car has such little resistance, the drive train is very free running and the car is very light. Mine weighs in at c1830 grams in shorty config. All this adds up to a lower wind motor I think.

Thought I'd update. At the regional today, I geared the car down to a 18 tooth pinion on a 81 tooth spur and that was perfect, it made the car so much easier to drive. I then added boost for straight line speed. Qualified 6th in B not too bad given 2nd race this year and 2nd time out in the XB4.