• Welcome to RCTalk! 🚀

    Join the #1 RC community where hobbyists connect, share, and get expert advice on RC cars, trucks, boats, drones, and more!

    • ✓ Friendly & passionate RC enthusiasts
    • ✓ RC tips & troubleshooting
    • ✓ Buy, sell & trade RC gear
    • ✓ Share builds & upgrades

Forward only conversion ='s does nothing for more speed!!!

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
3

30%NitroBoy

Hardcore RCTalk User
Messages
1,671
Reaction score
0
Points
0
RC Driving Style
WHaddup guys,

Well I've decided definitevly from much experience with various Maxx's now that the Forward only conversion doesn't add any noticable top end MPH or acceleration off the line on a Maxx(nice run-on sentence..hehe). I've driven five buddies Maxx's before and after the "foward only conversion".

We used an older LEO radar gun that doesn't read in 10/ths of MPH so if their was an addition of 8/10ths of a MPH (would be somwhat significant but not much) then we couldn't read it. THe radar gun used was properly calibrated and properly tested by running my Rx-7 @ 70MPH. We tested the Maxx's on a huge open Airstrip (the only place you'll ever be able to top out most anything from Schumacher..lol). All had identical gearing before and after for pure top end speed. Well, their wasn't a noticable increase in offf the line punch and their was no increase in top end MPH. If their was an increase in top end MPH then it was less then 1MPH...lol.

I've talked to various Traxxas "tech's" and all have said that the forward only conversion will add 1/8th of a MPH to your top end or less.

SO in conclusion, The Forward only conversion is nice to get rid of that sometimes horrible clattering noise that bugs many Maxx owners (it's gets rid of a ton of reverse gears). In very high HP applications it might be nice to get rid of all the reverse gears but I've never heard of any specific problems when you use metal gears for the regular gears. For many people like myself, getting rid of the noise doesn't outweight having reverse which is very nice @ times. It doesn't add any speed or increased acceleration that's noticable.

To each their own but always interested in real 411 for for fellow hobbyists.
Peace
 
The performance gain may not be noticeable, 30, but it has to be there. 100 grams or so less weight, much of that being rotating mass in the transmission, meaning quicker spooling of rpm's.

As far as benchmarking any performance increase I could never say as the FOC was done in conjunction with a .21 conversion.

I couldn't stand the chattering and I love the smooth positive takeoffs.
 
Originally posted by wdavidhicks
The performance gain may not be noticeable, 30, but it has to be there. 100 grams or so less weight, much of that being rotating mass in the transmission, meaning quicker spooling of rpm's.

As far as benchmarking any performance increase I could never say as the FOC was done in conjunction with a .21 conversion.

I couldn't stand the chattering and I love the smooth positive takeoffs.
Click to expand...

Sup man,

I agree and disagree with ya but in the end we can all hopefully agree to disagree...lol.

Their's no noticable increase IME in "take-off"...if it's their then it's extremely subtle. I'm no super pro but I'm very experienced in RC in general. Yes, your reducing rotational mass which can be very important in RC nitro in general.....but...what's rotating in the tranny?? On a .21 conversion it might be more noticable but I doubt it.

If anything I wanted to prove to many that you don't get a SERIOUS increase in top end or off the line like many would let you believe. I'll probably do a FOC on the Drag Maxx that I'm building but it's nice to have reverse on my "daily driver" that I'm building up. The noise use to be annoying as hell @ times but I got use to it. At first I thought my Maxx was phucked up like many people. I think all LHS's that sell the T-maxx should inform their buyers of this noise but many don't care or don't know.

CIAO
 
I will agree with 1 point but not another. I will also ad another point that was totally missed in your test that is relevant to the real world of off road RC.

1st,
No you will not get any top end speed increase. This isn't the point of an FOC. You need to change gear ratios for that somewhere in the drive train.

2nd,
I totally disagree in the findings you came up with in your test in regards to not having a significant improvement in take off.
Installing an FOC removes an internal transmission clutch that is designed to slip during take off. You now have a direct drive eliminating any lag-time from the transmission. I also know from personal experience using the same exact T-Maxx and swapping transmissions on the spot to test the difference. Granted I didn't use a stopwatch to time it however the difference is significant.

There are 2 flaws in your testing. the first one is you are using 2 different trucks. As hard as you may try, they will never be setup the same. Tuning and engine condition will be the biggest factor. There are several other factors to look at as well. Did you replace both clutches so they are matched? Did you do a torque test on the slipper to make sure they both were set the same. 1/32nd of a turn on the slipper nut can make a big difference. I'm not trying to discredit your work but there are a lot of factors to consider.

My 3rd point is that your test wasn't real world. A T-Maxx at WOT for a long distance will top out at XXX speed depending on the gears. What you didn't do was time how long it took to get up to top-out speed, or how long it took them to go xxx distance. To me this is the real test. Place a line at 10 feet and drag-race them or time how long it takes them to go the distance. Do the same at 20, 30, 50 ft you will see that the FOC is faster in this test. To further test try on different surfaces, street dirt, grass.

For an off road truck short distances are the true real world test. If you think about it, how much time do you spend at top speeds WOT as compared to stop and go or slow and go. These trucks are designed for grunt not speed. I believe you also need to take into account the durability an FOC adds to the transmission.

Its always nice to see people doing tests but you preformed the wrong tests to evaluate the true purpose of an FOC.

-Ed
 
Last edited:
Hey Eddy...good to read ya,

I totally disagree with this statement and I'll tell you why. "This isn't the point of an FOC". Their seems to be a TON of new Maxx people that seem to think that the FOC will add ALLOT or any real Top end speed to their Maxx. If anything I wanted to dispell this myth about FOC.

I digress on one point and agree with some of what your saying about testing. It wasn't totally scientific but proved much to my friends and I who spend BIG BUCKS on our big boys toys. How's that for "real world" testing my friend...lol. I had no intention of spreding hersay VIA bias test results and if that was the case I apologize.

I'll get back to many of your good points in great detail when I'm not so mentally spent. FYI, I can do allot more testing and try to be as "scientific" and un-bias as possible.
 
I wasn't trying to imply that your test was bias, not at all.
Its great to see you and others out testing and reviewing. Its even nicer to have a place to post it and know that it will be read and pondered over. I had to read it a few times to realize that for MY DRIVING STYLE your tests were not the proper ones.

For anyone wanting or considering an FOC your info will help put them on the proper track to making a decision. My info will offer a different light on the same subject.

Isn't this hobby great!

I'm never satisfied with whats available and when I find a new part or way to do something I have no bones about getting and trying them. If they work, great if they don't, well just another part for the box. My parts box is like a hobby shop. At this point I have 3-4 Engines, 5 sets of 8 shocks, 3 transmissions, 3-4 skid plate sets, 3-4 sets of diffs, and the list goes on. I have no bones about yanking something that doesn't cut the mustard. I have a box just like the one I described for each of my 7 RCs. Point is, I have a FOC in my CyberMaxx and it is IMO a must have for getting out of the hole quickly.

-Ed
 
I did the FOC conversion for 1 reason only... no slamming of trans on take off. I didn't do any scientific experiments, but i use the BFH theory. For those of you who don't know it's Big F'n Hammer.

As with any engaging system, having a slamming effect (BFH) in a high torque situation isn't a good route to take. Applying power smoothly as possible makes for a longer lasting drivetrain.

I would rather walk to my truck a few times a day to kick it backwards a foot, than replace trans gears every other gallon of fuel. Considering all i do is bashing (never been to a race track), this works out well for me.

As a kid with a wise older father, i learned that there are easy ways to do a hard job. Of course this was after the "I told you so" look my dad would give me whenever i broke a wrench, snapped a lug nut off a car tire etc.

IMHO, do what works for you. If you don't mind tearing the trans apart, the diffs, replacing stripped gears and broken axles a little more often, keep the reverse. I prefer to drive my truck as long as possible between breakdowns and rebuilds.
 
It's no wonder it chatters.

gear.webp


The spring-loaded pawl on that output gear can only grab two pins, 180° apart, inside the transmission clutch bell.

I hear ya, olds97. I did the mod and I love it. Smooth operation paidfor it. Fractional increase in speed or acceleration is a bonus.
 
The FOC will only increase the speed of off-the-line acceleration due to having no internal clutch to engage. I had a FOC T-Maxx and it made a difference compared to my neighbour's stock T-Maxx, it jumped off the line quicker- but didn't really show any difference in overall speed.
 
Yes they are a Hell of a lot stronger however not bulletproof.
Give me anything and Ill find a way to screw it up.

13tranymelt2.webp
 
GOsh damn Eddy...WTF did you do to those bro..hehe?? Somones got some power..haha. They look melted bro. Keep up the good work..lol.


Well......I've decided to do an FOC in my Maxx and I wanna bomb proof the tranny as much as possible as is apparent in the other thread of mine here.

Peace
 
NB, by reducing weight and rotational mass you get increased acceleration and top speed.

The percentage of overall vehicle weight reduction is pretty insignificant so the actual top speed gain may or may not be measurable.

The percentage of rotational mass reduction within the drive train is very significant and does increase acceleration.

Now I've seen the foc not increase acceleration once but that was due to a chassis upgrade that increased the vehicles weight.
 
Leave testing up for other people it what I say. I also say the FOC was the best $10 I EVER spent on my T-Maxx period.
 
StretchM - I'll give you and everyone else the fact that you get instant engadgement but my definition of siginificant as an engineer and your's/other's varies greately apparently. Again, their seems to be a plehtora of people that think the FOC will add significantly to the top end and if anything I proved that to be false. I'm gonna do the UE FOC on my current Maxx bad boy.

HUmbolt - $10 bucks....damn dude. I'm assuming your running the plastic Traxxas FOC. No problems with SIrio power and plastiac gears??

Peace
 
Originally posted by 30%NitroBoy
StretchM - I'll give you and everyone else the fact that you get instant engadgement but my definition of siginificant as an engineer and your's/other's varies greately apparently. Again, their seems to be a plehtora of people that think the FOC will add significantly to the top end and if anything I proved that to be false. I'm gonna do the UE FOC on my current Maxx bad boy.
Peace
Click to expand...
Ok, in laymans terms,... I put the foc'n foc in and the foc'n thing hauled foc'n ass quicker than before. It wouldn't go any foc'n faster even after adding foc'n 30% and giving it a big kick in the foc'n rear, so I patrted it out and sold/gave it away and built 2 more for twice the foc'n price and I'm still not foc'n satisfied....F&^$!!!!!:LoL: :doh: :LoL:

sometimes we confuse faster with quicker.
 
Originally posted by StrechM

Ok, in laymans terms,... I put the foc'n foc in and the foc'n thing hauled foc'n ass quicker than before. It wouldn't go any foc'n faster even after adding foc'n 30% and giving it a big kick in the foc'n rear, so I patrted it out and sold/gave it away and built 2 more for twice the foc'n price and I'm still not foc'n satisfied....F&^$!!!!!:LoL: :doh: :LoL:

sometimes we confuse faster with quicker.
Click to expand...

Haha....that's some of the funniest chit I've seen on here in a long time. I got ya the first time dude.

Peace
 
Originally posted by 30%NitroBoy

HUmbolt - $10 bucks....damn dude. I'm assuming your running the plastic Traxxas FOC. No problems with SIrio power and plastiac gears??

Peace
Click to expand...

Correct my friend, and no strippage or any other problem since the day I installed it. I have over 3 gallons on my stock diffs, and tranny without a single problem. I ran the 2.5 for a couple and the Sirio for 1. The only time my tranny was ever open was to install the FOC. Those are really the only stock parts worth a darn.

and StrecthM ROFLMAO dude!
 
Last edited:
HUmbolt - SOunds nice dude. Just out of curiosity....how is your truck geared??

Strech - still LMAO
 

Similar threads

C
Traxxas web site
Replies
8
Views
536
CronesRacing
C
C
Tmaxx web site
Replies
2
Views
288
CronesRacing
C

RC Builds

Back
Top