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Drag race the Maxx

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OS4ever

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Location
Newport News, VA
RC Driving Style
  1. Bashing
  2. Racing
Ok guys,

Here is my problem. I have a tmaxx with a OS.18. I have the new style tranny (the grey one) with a 20t clutch bell and a 58 spur. A 58 spur is high as I can go with this tranny. Everytime I race my little bro his 2.5r blows me away. I get him off the line but he runs me down horribly and passes me about 25 yards in. His setup is old tranny (black one) with 20t clutch bell and 72t spur. I am even running beadlock rims with integy street tires. My temps are on at 220-240 but I just dont know what to do. I know the OS is capable of beating him, but what am i doing wrong.

PS. He wont drag my RC10gt with OS.18 though!!!


much help needed :\
 
Are you at peak rpm's when he's passing you?

I'm not familiar with the newer tranny but it sounds like you need to gear higher (smaller spur or larger c/b). He's killin you in the top end so you're gonna need to give up some of that launch in return for some top speed.
 
no, i just hit second gear and he comes flying by. . The only other choice I would have is to go 21t clutch bell. . .I'm out of ideas. . I thought the larger the spur the higher the top end, am i wrong?
 
No. Larger spur = better acceleration, less top speed.

is he already in 2nd gear when he's passing you?

See. Because you are geared lower than he you are killin him off the line. However, your tranny is shifting to 2nd too early and the lack of acceleration in 2nd gear is allowing him to pass. You want to make as adjustment to your shift point. Are you familiar with how to do that? If not, try searching the forum. I know it's been discussed a few times. You can also check your manual. It will show you how to make that adjustment as well.
 
yea hes in second when he passes me. . .My tranny shifts late enough as it is now, so adjusting it would probly make it worse. . I could always shorten the shifts and switch to a 54t spur gear???

much help needed
 
traxxas says you can run between 220 280 so try raising the temp and switch out some gearing really you will just have to play with it
 
O.K. I wasn't familiar with the newer 3.3 tranny so I did some digging and this is what I've come up with. These are strictly tranny numbers with the c/b spur combinations you noted... do not include diff ratios. I assume they are the same.

Your gear ratios (3.3 tranny) ------------------- His gear ratios (2.5 tranny)

1st gear ------------- 9.593 ---------------------------------------8.460
2nd gear------------- 6.653 ---------------------------------------5.778

If you go to a 22T c/b you'll be closer
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXJF62&P=7

1st gear------------ 8.721
2nd gear----------- 6.048

If you go to a 23T c/b you'll be very very close to what he's running
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXPUJ9

1st gear------------- 8.342
2nd gear------------ 5.785

I would try the 23T c/b and see how you stack up. Get as much as you can out of the engine and if you need to do any more tweaking you could try fiddling with different spur gears. But you definitly need to run ratio's closer to what he's got to be more competitive. Obviously with a 23T c/b you won't smoke him off the line like you are right now, but the overall race should be a lot closer. Also, having a 3.3 tranny you have the option of running a couple different internal options as well which give you more room to tweak if neccessary.
 
Last edited:
Thanks Lessen,

I have a 22t clutch bell i am going to put on right now. What options do I have as far as internal work on the 3.3 tranny?

:thumbup:
 
OS4ever said:
Thanks Lessen,

I have a 22t clutch bell i am going to put on right now. What options do I have as far as internal work on the 3.3 tranny?

:thumbup:
Click to expand...

There are two options for 2nd gear I believe. I think stock is the 'in between' ratio. I believe there is a "close ratio" and a "far ratio" set of internals. I think 1st gear stays the same but 2nd is either a little bit lower (close) or higher (far) ratio. So if you like your 1st gear performance you go opt for the far ratio internals if you want a little more top speed. Doing that won't have a negative impact on your 1st gear acceleration.
 
:
Lessen said:
There are two options for 2nd gear I believe. I think stock is the 'in between' ratio. I believe there is a "close ratio" and a "far ratio" set of internals. I think 1st gear stays the same but 2nd is either a little bit lower (close) or higher (far) ratio. So if you like your 1st gear performance you go opt for the far ratio internals if you want a little more top speed. Doing that won't have a negative impact on your 1st gear acceleration.
Click to expand...

:thumbup::thumbup::thumbup:
 
I'm running a newer style tranny in my big block maxx and just upgraded to a 23 tooth clutch and 56 spur. This is a great combo with the standard ratio gears. I have also run the wide ratio gears but it gets a little squirrley when hitting second gear due to the severe ratio shift. My Axial .28 has a lot of low end torque so maybe 22/56 would be better for your application. You can also change the ratio by changing tire size. I run two different sets of tires depending on where I am running. Just my 2 cents good luck with your truck. I am going to try drag racing when it gets going again in the spring. Too cold to drag here in Maryland now. We are still running some no limit events this winter though.
 

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