RC10Talk - The Net's Largest Vintage R/C Community

As the title implies I need some help figuring out my gearing. I will most likely be running a 2500-3500mah lipo, and a modern modest brushless/esc combo (probably a ez-run 13.5T). I will also upgrade the Trans to a RPM 2.65 Trans with a B4 Slipper. Would the B4 slipper conversion convert my standard Stealth to 2.65 or do I need to use the RPM Trans? From what I understand the only real difference from the RPM to standard Stealth is the top shaft.

I should be able to use the B4 top shaft with the RPM Trans but does it even make a difference? Considering all this for bashing and the occasional track day, what gearing- Spur and Pinion would you guys recommend w/ the stock stealth and B4 slipper and what would you recommend with the RPM trans?

Sorry for all the questions, thanks in advance!

first, you can't use a b4 slipper setup with the rpm 2.65 trans. the trans conversion comes with a topshaft with fewer teeth, thus giving it the lower internal gear ratio. therefore, the b4 topshaft will not fit in the rpm housing, and you can't attach the b4 slipper to the rpm topshaft. the only slipper setup you can use is the one from the 2.25 stealth, or the one from the 2.40 (b2, b3, t3).

as for gearing, someone else will have to help with that. i don't own any brushless stuff. but, it's gonna depend on what trans you eventually end up with.

Well most 13.5t brushless people I run with use between 78-81 spur and 24-27 pinion. You just have to play with it and check the temps on your motor, after a good 5-6 minute run the motor should still be cool and if you have a temp gauge a good temp is around 150 give or take 10 degrees. I run 5700kvh and use 81/23, i recently picked a lot of pinions and im playing with new gearing now. A lot will depend on the type of track you will be on, do you need torque or top speed. I advise do a lot of research and take your time because you dont want to burn that motor up, so just be careful on your gearing. Oh and i run the 2.65 trans with 2s lipo/5000mah.

Would I be better served to upgrade to the RPM Trans w/ B3 slipper or just use B4 slipper conversion on my stock Stealth? Does the B4/Stealth combo affect the Trans ratio at all?

i crash cars wrote:Would I be better served to upgrade to the RPM Trans w/ B3 slipper or just use B4 slipper conversion on my stock Stealth?

that's kinda up to you. do you want a 2.65 trans or a 2.25?

i crash cars wrote:Does the B4/Stealth combo affect the Trans ratio at all?

no.

The RPM Trans would be better for the more modern brushless systems and should give me better acceleration?

i don't have experience with brushless stuff, so someone else can answer that. but, a lower gear ratio is gonna give you better acceleration.

scr8p wrote:first, you can't use a b4 slipper setup with the rpm 2.65 trans. the trans conversion comes with a topshaft with fewer teeth, thus giving it the lower internal gear ratio. therefore, the b4 topshaft will not fit in the rpm housing, and you can't attach the b4 slipper to the rpm topshaft. the only slipper setup you can use is the one from the 2.25 stealth, or the one from the 2.40 (b2, b3, t3).

I thought RPM still offered their "hydra" top shaft for their 2.65 trans, allowing one to use the B4/T4 dual disc slipper setup?

Then you use the RPM "hydra" gear cover to accommodate the longer top shaft...

If you are going to run BL, stick with the 2.25 stealth. Convert it to run the B4 slipper, if you like to run the hotter motors with a lot of slip. The BL motors like to be overgeared compared to brushed, so the 2.65 is really not necessary. I run the stock stealth with a 13.5. Gearing is 81/24. With 17.5 I run 81/28. My slipper is stock and stays locked most of the time running on high bite tracks. This is ballpark gearing. You might have to do some experimenting on your own depending on the ESC/motor/and the temps the motor runs at with your gear.

Some say optimum gearing will get your motor temp up to 150-160 degrees F after 6 min of race pace. If you use a small IR temp gun to check this with, make sure you put a 1" piece of black electrical tape on the motor to get the correct readings. If you dont, you will be reading false temps based off of reflection.

Brandon G wrote:If you are going to run BL, stick with the 2.25 stealth. Convert it to run the B4 slipper, if you like to run the hotter motors with a lot of slip. The BL motors like to be overgeared compared to brushed, so the 2.65 is really not necessary. I run the stock stealth with a 13.5. Gearing is 81/24. With 17.5 I run 81/28. My slipper is stock and stays locked most of the time running on high bite tracks. This is ballpark gearing. You might have to do some experimenting on your own depending on the ESC/motor/and the temps the motor runs at with your gear.

Some say optimum gearing will get your motor temp up to 150-160 degrees F after 6 min of race pace. If you use a small IR temp gun to check this with, make sure you put a 1" piece of black electrical tape on the motor to get the correct readings. If you dont, you will be reading false temps based off of reflection.

I have kit # 7011 is is a 2.25?

Brandon G wrote:If you are going to run BL, stick with the 2.25 stealth. Convert it to run the B4 slipper, if you like to run the hotter motors with a lot of slip. The BL motors like to be overgeared compared to brushed, so the 2.65 is really not necessary. I run the stock stealth with a 13.5. Gearing is 81/24. With 17.5 I run 81/28. My slipper is stock and stays locked most of the time running on high bite tracks.

I just picked up the RPM trans and will regularly run brushed but may drop my BL system in it.

Does 'really not necessary' = not a good idea? Problems ahead? Poor performance?

Thanks.

what brushless are you going to run? I ran a 17.5 with a stock 2.25 stealth this weekend, B4 top shaft/slipper upgrade. Performed flawlessly. I was geared 26/81 with 35 degrees of boost (suffice it to say, a lot!). Car had fantastic acceleration and ballistic top speed.

RPM tranny is unnecessary in my opinion. No problems, no issues, just not necessary.

Stock stealth (For me) is enough, i for one is using a 8.5T HW Motor with a B4 slipper upgrade, only problems encountered is the front wheels tends to fly with the slipper not properly set. other than that no issues.

I just got a hydra top shaft for RPM conversion tranny, i have yet to try to it on, maybe after CNY i will have something posted in here.

JK Racing wrote:what brushless are you going to run? I ran a 17.5 with a stock 2.25 stealth this weekend, B4 top shaft/slipper upgrade. Performed flawlessly. I was geared 26/81 with 35 degrees of boost (suffice it to say, a lot!). Car had fantastic acceleration and ballistic top speed.

RPM tranny is unnecessary in my opinion. No problems, no issues, just not necessary.

I have three BL motors - 10.5, 13.5, and 17.5 (all Novak, the 13.5 is a Ballistic and the other two are Havoc Spec). Not sure which of the three would go into the 10T with the RPM, either the 13.5 or 17.5. My 10T uses a B3 slipper set-up.

I also have a B3 with the B4 slipper upgrade - that will run with the 17.5 Havoc.

I have another 10T with the 2.25 and B4 slipper which I plan to run the 10.5 just to see how much it can take!

Any gearing advice would be greatly appreciated.

what speedo you plan on using for the 17.5? Boost/Nonboost?

10.5, Truck, start around 20~22/84, check temps after a few minutes.