Sometimes you need to go to a bigger pinion to actually keep the car from over revving. BL motors, especially high winds, have a lot more torque. It's not like stock motors in the old days, too small a pinion is just as bad as too big.

I've gotta try something before I hurt my motor, as it is now if I developed a small bind issue in a run it would prob cook itself. I'll do like you said and temp it every minute and see what happens. I already use the largest spur and pinion that will fit in the car when I choose a ratio to go with. My T4 (VTA) has a 106/53 in it now

SS, what kind of difference in lap times are yall seeing between GT and TC?

We tried the same thing tonight with a motor that did not necessarily like the gearing of the motor it replaced. Went from a 4.1 to a 3.8. Much cooler temps, but are no were near the super low 3's some have mentioned. This was going from a SS to a ballistic.

Rob K, seriously thank you for the constructive input on the topic and without feeling the need to tell us how many National, Regional, local titles or TQ positions you have taken in the last year to make a point. LOL

Alloyslash - Now that the GT cars are geared properly the difference between them and 17.5 TC is .7 - 1.0 sec per lap.

I heard that...lol

Hey, DON'T FORGET THE ROW OF PICS too!! roflmao

Rob K has won something?

Matt was .1-.2 faster running 3.3 but his consistency wasn't as good between fast lap and avg .( it was harder for min to run fast and efficient. But with the 3.75 FDR his lap times r way closer together

I am in NO way looking for more speed. My entire issue is with the heat I'm getting with the gear I'm running now. I am not able to drive the car smooth and efficiantly yet, so I am getting some heat that a smoother/more experienced driver wouldn't.

I think the D3.5 21.5 is just a motor that runs hot. I have one and so does another guy I race with and they both run really hot. I geared mine at 4.36 FDR with max timing at it was coming off the track at 180deg. If I went any lower on the FDR it would just get hotter and really slow down if I took timing out of the motor it just ran slower and was still hot.

I run my SP 21.5mmm at 4.26FDR and it runs at 170deg all day.

Kevin have you tried going up on gearing with the D3.5? There is a sweet spot to it. I keep mine around 160 degrees. I have found either way you go it can cause changes.

Only the hearts of millions of fans...

You have a 21.5 D3.5?

The D3.5 21.5 is nothing like the 17.5 every 21.5 that I have seen or heard about runs really hot....must be something with the wire they used in the 21.5...

Sorry to butt in, but with that gearing, you're running an fdr of 5:1. I would think smaller spurs (80's - low 90's) is what you're looking for, not larger. Unless I'm reading it wrong.

A 106/53 combo in an XRay T3 and T4 comes out to a 3.8fdr (106/53x1.9). I posted that as an example of how I run the largest spur/pinoin combos, while still achieving the desired ratio. A rule of thumb with the XRay's 1.9 internal ratio is that for every 2 teeth you go up, or down in spur size, you can match it with a 1 tooth change on pinion and achieve the same ratio.

106/53
104/52
100/50
96/48
92/46

All of those combos will net a 3.8fdr. I normally run a 3.6 in my VTA, but went up because I'm racing at a smaller track this weekend.

I'll go with a 96/55 combo (3.32fdr) and see where it gets me next week at Thunder R/C