Adjust tranny to compensate for lean tune?

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I'm going to try and give the best detail possible on this one but It may end up requiring me to make a video.

Several of you guys know about Bryson's Revo that I purchased and got back to running condition and well it seems that it's still not perfect. I'll start from the beginning and end with today.

When I got the truck I decided to drop my 3.3 in it from my T-Maxx. The truck came to me with 15/38 gears, stock tranny and stock diffs. When I dropped my 3.3 in the Revo and took it out for a test run it was running exceptionally well. Shifting was spot on, plenty of low and top end! It ran all of about 2 hours (can't remember quite how long) before I split the con rod in my 3.3 and tore up the piston and sleeve. Check out this post for details.

Yesterday I received and install all my new goodies on the Revo including a brand new OS .21TM! I left everything the same, 15/38 gearing, stock tranny, stock diffs. The only thing that is different was an Integy 3 shoe aluminum clutch upgrade.

I broke the motor in yesterday afternoon, it was pulling wheelies by about the 3rd tank and by the 5th it seemed to be running awesome and with a little but of tuning I figure the shifting issue would go away and it would be pulling wheelies left and right. Well apparently that is not the case.

I made a trip to Hobby Town USA today since my LHS is closed and picked up some new glowplugs, fuel, pull start and tempgun. Made it back to the local track and started tuning my truck. Needles were back at stock and engine was up to running temp. Start tuning the HSN hoping for a nice gain in speed and the damn truck to start shifting into second. 1/2 turn in from stock settings and the truck was shifting but very laggy and very late :\ . I bring the truck in and check temps and I'm already hitting 300 degrees. I'm holding the trigger WOT for only about 3-4 seconds in my passes which is about how long it was taking to shift and reach full speed. So I figure maybe a new motor with different specs, the tranny needs to be adjusted.

So I adjusted the tranny a total of about 1/2 turn in to get it to start shifting better. Its still a bit laggy and the shifting isnt quite persistant. With it shifting properly the HSN is 3/4 in from stock settings and the temps with the body off are around 280, with the body on I'm getting around 310. I richened the LSN from stock about 1/8th of a turn to try and bring the temps down but then I loose some of the lower end and the temps still gradually rise up to around 300.

Keep in mind the engine was sealed before it was even broken in, the carb was sealed (except the neck) and the needles were hit with some TA green slime. I guess I should also throw in there that I was still getting a nice blue smoke trail with the temps being up there and also if anyone has any experience with the 11k carb it seems that tuning is done in much smaller increments on the HSN as you only have 2 1/2 turns out from closed at stock settings. The MSN doesn't seem to need to be messed with and the LSN at stock settings gives you about a 2 1/2 sec kill time when pinching the fuel line.

Can anyone chime in on WTF is going on?

Thanks

Oh yeah and one other issue I am having is the reciever cuts in and out, I think it may be from overheating as I had a piece of foam in wrapped around it and I cut it and only put a piece on the bottom of the tray and it stopped doing it. Later on towards the end of my bashing it started again. It will cut out and if I turn on and off the reciever it works fine for a minute or two then does it again. I changed the batteries in the remote and the receiver packs are brand new.

 

[2revo1maxx]

Richen it back up about 1 turn and work it in little by little until you hit max performance, do not go beyond that point. Use temperature ONLY to make sure it isn't under/overheating. That engine doesn't rev as high as a 3.3, so I would automatically switch to a 36 tooth spur. That will spin the 2 speed faster and help the 2 speed rpm get back to where it was with the 3.3.
Don't worry about the gear change, the 21 has more torque, I use 15/36 with an 18tm.
If all that doesn't work you may need a new 2 speed primary clutch.

 

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Richen it back up about 1 turn and work it in little by little until you hit max performance, do not go beyond that point. Use temperature ONLY to make sure it isn't under/overheating. That engine doesn't rev as high as a 3.3, so I would automatically switch to a 36 tooth spur. That will spin the 2 speed faster and help the 2 speed rpm get back to where it was with the 3.3.
Don't worry about the gear change, the 21 has more torque, I use 15/36 with an 18tm.
If all that doesn't work you may need a new 2 speed primary clutch.

Ok, shuffled through my bag of gears and found a 36t spur gear! I just got done breaking the entire motor down and giving her a good look over. Found some minute particles on the underside of the piston, so cleaned all that up check it all out, looks good. Motor is back together, sealer is drying, cleaned carb up, sealed the neck on it this time.

Gotta swap out my axles (bent one today) with my new Traxxas steel ones and clean up the truck for tomorrow. I'm hoping I can get things going good, I will make a video if I'm still having issues.

Thanks for the quick reply!

 

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I may have found another cause for the problems....When I installed the Integy clutch it did not sit as far down on the shaft as the 3.3 flywheel did although, it did still fit the spur but was a little offset. Well with the smaller spur that offset made a big difference.

When I went to take the flywheel nut off the flywheel just fell of with it. Seeing as I obviously did not have it tight enough it could have possibly been slipping all day today. That could explain the sparratic shifting differences today. Ok so back to re-fitting the flywheel, I ended up taking a small precision file and started taking a little off of the inside bevel at a time until it fit like I wanted it to. The CB and Spur line up correctly now and the flywheel is tight as hell.

So hoping that a combination of flywheel not fitted properly and smaller spur gear plus clean and resealed motor/carb will make my day full of fantastic bashing!

 

[bgbdwlf2500]

if the flywheel was slipping, that would be impossible to fix with tuning...lol my guess is that was the issue the whole time

 

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I'd like to start off by saying the 36t spur gear helped alot but the LHS owner said I could go back up to the 38t with no problems. Aswell I think the flywheel was another issue, so thats fixed now too.

So I took the truck out this afternoon and started trying to tune, except this time I was following Robins guide from ERCM. That is a really good guide as he explains pretty good about what you need to listen to. I got the tune pretty dang close and was keeping my temps withing the 260 range with the body off. Still a little on the lean side but looking much better, then all of a sudden my throttle servo just died. Well loaded everything up and started for the LHS. Get there and buy a metal gear 85 oz/.15 sec made by JC? ( can't remember right now)

Long story short, I get there install the new servo, and figure you know why I am here I may as well get him to tune my truck for me and explain to me what I am doing wrong. This guy takes about 5 minutes and a few WOT passes and he has this truck running perfectly, I mean perfect! He gave me some advice and I picked up a few other small things and headed home.

Excited to go bash I stop off at the football field and shoot a video of it running flawlessly (this motor rips) and then take it over to the sand pile and start jumping. Second landing the truck dies and I now have either a blown rear diff or a messed up tranny. VERY DISAPPOINTING

 

[2revo1maxx]

No reason to be discouraged, it sounds like the original problem is fixed and truck is doing what these things do.....getting used, abused, and broken!

 

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http://www.youtube.com/user/dpgoverride#p/a/u/0/RyBo-s_h9Uo

Video finally finished uploading...Like I said this thing rips!

@2revo1maxx thanks for the uplifting words...I'm going to the LHS tomorrow for the last time hopefully for awhile. Tranny is ok, the rear diff is having issues. It needs to be shimmed but not from the inside from the outside. I know that doesn't make much sense, either way its messed up.

I think the next thing I'm gonna upgrade is aluminum diff cases and FLM diff cup/modified gears.

 

[2revo1maxx]

She's running good! Your diff most likely failed due to a bad pinion bearing. I wouldn't spend all the extra cash on shiny parts, you can get a whole new stock diff for 15 bucks....but that's just me.

 

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Those parts will come later, for now I do plan to go with just a stock one. Those were the ones that came on the truck and the rear already had a previous problem that I fixed, just didn't last as long as I hoped it would.

 

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Well turns out the rear diff was not the cause of my issues. It infact was a cracked rear rim and it was allowing it to slip on the hex nut which ofcourse by the time I got to it was round. So problem fixed, been bashing for about and hour and half with no more issues. THANK GAWD!