Typhon Donut Man's Typhon GT Build

[The Donut Man]

I've been meaning to do this since I joined the forum, so here goes. I started speed running two years ago with an open-wheel Typhon, then last year I stretched it and went GT. There are a lot of sweet speed runner build threads on here, so I wanted to highlight some of the little custom/different things I've done!

My current setup:

• Castle XLX
• TP Power 4070-CM 2200kv
• Graphene Panther 6S 6000mAh
• Ripple Killer cap pack
• Futaba 3PV w/ R2006GS receiver

Plans for this summer: I'm hitting high 120s-low 130s, so it's time to ditch the GRP S5s I've been running and switch to foams. I'll be sticking with 6S this summer in order to make sure the car's good on foam before going to 8S, but I'll be fabricating some parts in prep for a dual battery setup regardless. I'd like to push for 140s on 6S, but my faith in the XLX isn't incredibly high. Do you all think I should bite the bullet and switch to an XLX2?

Stay tuned for highlights of the build!

 

[The Donut Man]

First thing to cover was GT body mounts; I used a Mugen MGT7 bumper/body mount set (Mugen PNs: E2413, E2414, E2415). The bottom mounting holes of the bumper line up perfectly with two of the M4 bolts holding the diff case to the chassis, so I just had to bend up a small joiner plate to connect the front bumper to the front diff case. I've seen the top connected using zip ties, heat-formed plastic, and the stock Mugen plastic piece dremeled to fit, but I wanted more rigidity so 0.0625" aluminum was my choice. Then I got it anodized black because I'm picky like that

I trimmed the foam down a bit for the shell to fit, but other than that this was pretty plug-and-play!

For the rear, I measured the spacing between the body post mounting holes and drilled two clearance holes into my already-shortened rear shock tower. I got two M3 25mm threaded standoffs from McMaster-Carr (PN: 95947A716) and bolted it up behind the rear shocks. Everything just barely clears and it allowed me to use the space on the Jag body where the wing gets cut out. I have plenty of clearance for the rear wheels (minus when crashes push the shell down mid-tumble) and all the body mounts are pretty shock absorbent! They're flexible for impacts while also being stiff enough to hold the body well during a run.

 

[LibertyMKiii]

Your attention to detail is very visible here. Nice work!
My stuff tends to be a little sloppy and rushed.

Many people have found that running fans on the motor isn't necessary, but a good fan setup on the XLX will probably be a good idea. Not sure if you have seen the videos on removing the heatsink on the XLX and fixing the thermal paste, but that is also a good mod to do.

Looking forward to seeing your progress this next speed season!

 

[The Donut Man]

Your attention to detail is very visible here. Nice work!
My stuff tends to be a little sloppy and rushed.

Many people have found that running fans on the motor isn't necessary, but a good fan setup on the XLX will probably be a good idea. Not sure if you have seen the videos on removing the heatsink on the XLX and fixing the thermal paste, but that is also a good mod to do.

Looking forward to seeing your progress this next speed season!

Thank you! Yeah, so far my motor has been pretty cool, but the fans came in a 4-pack so I wanted to put them to good use. I did do the thermal paste fix and I’m glad I did; there wasn’t much on there and it was all dry. My max temps in the past are around 180 degrees F so I’m hoping to see it drop at least 10 degrees.

 

[The Donut Man]

How is everyone tracking their log data? I started keeping a record last summer and now I like to plot all the important values of a run to look for trends.

 

[LibertyMKiii]

How is everyone tracking their log data? I started keeping a record last summer and now I like to plot all the important values of a run to look for trends.

I love this sort of stuff, glad to see others are doing it!

I capture a few other data fields in addition to the ones you have like ambient temp, motor timing, and wind speed. Notes about run like location and other setup specs like battery, motor, kv, esc, cap pack because I change them often and wont remember

While increasing your gearing you can really see where the motor becomes saturated with amps and its time to give up on adding gearing to the setup.
Most of my data is on another PC but this one is an example while running the Limitless on 2s with the mighty little TP4050. The orange line I like to track the calculator speed at 3v per cell versus actual GPS Speed. Once these two lines separate its over...

It is very likely I had a 91 mph run possible in there, but I gave up on 2s running.

 

[Notoriousone]

I love this sort of stuff, glad to see others are doing it!

I capture a few other data fields in addition to the ones you have like ambient temp, motor timing, and wind speed. Notes about run like location and other setup specs like battery, motor, kv, esc, cap pack because I change them often and wont remember

While increasing your gearing you can really see where the motor becomes saturated with amps and its time to give up on adding gearing to the setup.
Most of my data is on another PC but this one is an example while running the Limitless on 2s with the mighty little TP4050. The orange line I like to track the calculator speed at 3v per cell versus actual GPS Speed. Once these two lines separate its over...

View attachment 129832

It is very likely I had a 91 mph run possible in there, but I gave up on 2s running.

I see Jason Flores has a new 3s challenge..

 

[The Donut Man]

I love this sort of stuff, glad to see others are doing it!

I capture a few other data fields in addition to the ones you have like ambient temp, motor timing, and wind speed. Notes about run like location and other setup specs like battery, motor, kv, esc, cap pack because I change them often and wont remember

While increasing your gearing you can really see where the motor becomes saturated with amps and its time to give up on adding gearing to the setup.
Most of my data is on another PC but this one is an example while running the Limitless on 2s with the mighty little TP4050. The orange line I like to track the calculator speed at 3v per cell versus actual GPS Speed. Once these two lines separate its over...

View attachment 129832

It is very likely I had a 91 mph run possible in there, but I gave up on 2s running.

That graph is a great idea! Just made my own. Did you land on 3V per cell based on your voltage drop? My average minimum voltage is around 19.8V which translates to 19.8 ÷ 6 = 3.3V per cell, so that's how I calculated my theoretical top speed. I'm using the scriptasylum calculator. It seems to be a good benchmark as the calculator says my max RPM should be 43,560 and my actual RPM for that gearing ranges from 42,713-45,371. Makes me wonder if my motor is actually higher than 2200kv It looks like as I max out the gearing with a 30T pinion and gear higher, my graph will start to look like yours. Thanks again for sharing!

 

[LibertyMKiii]

That graph is a great idea! Just made my own. Did you land on 3V per cell based on your voltage drop? My average minimum voltage is around 19.8V which translates to 19.8 ÷ 6 = 3.3V per cell, so that's how I calculated my theoretical top speed. I'm using the scriptasylum calculator. It seems to be a good benchmark as the calculator says my max RPM should be 43,560 and my actual RPM for that gearing ranges from 42,713-45,371. Makes me wonder if my motor is actually higher than 2200kv It looks like as I max out the gearing with a 30T pinion and gear higher, my graph will start to look like yours. Thanks again for sharing!

I believe no 2 setups are the same so you have to start with an easy gearing based on 3.3v calculations and then take the RPMs from 2-3 runs data logs to determine what voltage makes my calculator match.
(reminder to other readers to leave the castle data logs at 1:1 gearing so it does not skew the rpm numbers)

At some point the motor saturates with amps and does not go faster. This is where larger motors like the 1/5 scale having more torque can be more efficient.

This number of voltage per cell is sort of a moving target as the amps go up the voltage drop will increase. Despite what the voltage is in the logs there is some "slip" of what the motor is trying to do and what the actual rpms are.

 

[The Donut Man]

Has anyone compared 1/8 foam tires for speed running? I'm reading that BSR double-pinks or purples are common, but I've also seen Sweep Racing has several hardness foam tires for about the same $$. I'm starting to prep for this summer so I would appreciate any input!

 

[LibertyMKiii]

Most of my experience with foams relates to 1/10 scale.
I had tried some BSR 25 shore and 38 shore. The 25 shore didn't "feel" like it had any more grip, but destroyed it self very quickly. The 38 shore held up easily 3x better. With foams that is a big deal because they are sensitive to rocks and debris on the road causing "chunking" of the tire.

For 1/8 scale I tried double pink BSRs on the Typhon 6s as well as Purples and didn't have issues with either other than lack of grip compared to GRP All the top speed runners stick with and recommend purples so I would imagine it is best to stick with one shore rating so you get used to it.

This may be helpful also:

 

[Edough13]

Best place to pick up some BSR foams? I've looked a little bit but not found a lot think I've seen some double pink and an orange set. Thanks for any links and info fellas!

 

[The Donut Man]

Best place to pick up some BSR foams? I've looked a little bit but not found a lot think I've seen some double pink and an orange set. Thanks for any links and info fellas!

I've seen them on:

Amain: https://www.amainhobbies.com/bsr-ra...tire-white-2-purple-bxrc8034/p500579?v=585658

Ebay: https://www.ebay.com/itm/BSR-Racing...413737&hash=item4dbda0b8e7:g:rQIAAOSwQndgLpov

islandhobbynut: https://www.islandhobbynut.com/prod...e-black-rim-edition-17mm-hex-1-8-scale-c8034b

Save some for the rest of us though

 

[Edough13]

Shoot I may be able to pick up 1 set lol, only @Lovestricken would have to buy 2 of each compound for spares

 

[LibertyMKiii]

Been curious to try Gone Bananas (Facebook purchase only) a lot of guys are running them now.
Also Schumacher is available from Michael's RC hobby
https://www.michaelsrchobbies.com/jb40g-gt8-rally-pre-glued-foam-tyres-40sh-103mm.html

***Edit they are out of stock

 

[3d-rc.myshopify.com]

Shoot I may be able to pick up 1 set lol, only @Lovestricken would have to buy 2 of each compound for spares

You say that like it's an addiction??? Its called being proactive

 

[The Donut Man]

I'll snag some purples then! Thanks for the input.

Look what just came in the mail...

 

[The Donut Man]

I'm considering the pros and cons of switching to an XLX2 before I run this summer.

Pros:

• Significantly reduced ripple voltage
• Cooler running temperature
• No clipped current readings
• Overall, less of a system bottleneck

Cons:

• Would anyone buy a used XLX?
• More $$ spent

Because I'm running a TP Power CM-style motor, my amp draw is already clipping around 320A at moderate gearing. Even with a RK cap pack, I'm also in the 8-9% ripple percentage range. I'm running a solid battery (Graphene Panther 6Ah 6S) so I'm not worried about killing my LiPo. Are there any other advantages/drawbacks to upgrading that I missed? All opinions welcome.

 

[Doom!]

I can't answer this question because I don't have clue what I'm doing! I do however love these threads because you guys do know what your doing. Speaking of which, you know your going to do it, get the XLX2, sounds like it's worth it.

 

[Edough13]

I'm sure someone will pick up the XLX as well