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 Post subject: 4wd Mod
PostPosted: Thu Jan 14, 2010 1:46 pm 
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Joined: Mon Aug 11, 2008 11:43 am
Posts: 29
You guys have been busy in here!

Since Daniel is getting into 4wd mod I thought I'd post a few tips that may help. This class is a lot of fun, the cars are really quick and suit our track. Now with Lipos and brushless anyone can have the speed (too much sometimes)!

7.5 motor would be the pick, I use a 6.5 light but turn the endpoint down on the tx to 95%. Its still too quick... Gearing around 19:84. Make sure the vent holes in the body are cut out to get some cooling in, and the standard Novak GTB fans are crap, get a Muchmore one.

I'll talk about the B44 as it is what I run;

1st thing, slipper clutch & diffs. If these are not right you'll be going through diffs petty fast. If setup right they last for ages.

I run the front diff tight (screw all the way in). This helps with getting power down out of the corners.
Rear diff as per the kit settings, maybe a touch tigher - it must not slip - ever!
Slipper clutch. This is the part that is to take the shock out of the drive train when landing of jumps etc. Easy way to set it up is hold the spur gear by your thumb and try to push the car over some carpet. It should be pretty hard to hold the spur, but the slipper should slip and not the diffs. Do this with only the rear wheels on the ground, same again the slipper should slip and not the diff. When set right the slipper should slip for about 1m when you nail the trottle on a grippy surface (not the lounge carpet...)

Setup - I run the B44 kit setup with the following changes;
silver rear sway bar - helps keep the front wheels on the ground when exiting corners.
25wt oil & #2 pistons in the rear - slightly lighter damping than the kit setup in the rear as the lipos are lighter than NiMH.

Well maintained shocks make a big difference in mod, if there is air at the top its time to rebuild them.

Tires holeshots or Jconcepts DD's. Both about the same performance but the DD's last longer. Ones I'm using have done over 15 meetings!

If anyone else has some tips or questions fire away.


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 Post subject: Re: 4wd Mod
PostPosted: Thu Jan 14, 2010 2:28 pm 
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Joined: Mon Aug 31, 2009 11:27 pm
Posts: 149
How about shocks setup? Do you use limiters?

I was looking at replicating some setup sheet found on the net.

- green shocks on the back with 1 limiter with a ride height of say 23mm.
I could not replicate this (too high - more like 32mm).
I probably need limiters.
My shocks are just stock configuration.
I stuck some black springs on the back to bring the ride height down more.
Overall my b44 has been riding way too high anyway, so it should perform better no matter what.

- front shocks silver springs, ride height of say 22mm.
I managed to get this okay.

Looks like I will be ordering rpm limiters amain order? any other options?

Google brings up a ton of information about this but its difficult to decipher sometimes :)

I was thinking of 19T pinion / 81T spur as suggested by google, but I will go with yours (or should I gear for less speed?)


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 Post subject: Re: 4wd Mod
PostPosted: Thu Jan 14, 2010 2:47 pm 
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Joined: Sun Nov 30, 2008 10:13 pm
Posts: 530
I am new to mod and running the Durango with a 6.5 motor but just got a 7.5..was running an 8.5 in a Losi X5 but Durango a little heavier and find the 6.5 to much for Harewood track as it low grip a lot of the time.
With setup I havent done to much from the norm ..did put lighter oil in diffs as it runs geared diffs and did backoff the slipper a bit as was to tight and running the optional brass weights for back as running lipo and soft springs in rear but may go harder as we have some big 8th scale jumps..not really suited to the smaller 10th scale cars.
You need to be very smooth with these cars and very light on the throttle to get out of the corners in one peice and they get affected in the air a lot more than the 8th scale I am used to so again you need to get this right.
just make 1x change at a time from a good base set up and its youre driving that will win the race so be smooth and light on that throttle (y)


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 Post subject: Re: 4wd Mod
PostPosted: Thu Jan 14, 2010 3:42 pm 
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Joined: Mon Aug 11, 2008 11:43 am
Posts: 29
Daniel,

As far as droop limiters, I can't remember. It is whatever is in the kit setup. Do you have a B44 manual? Use the manual setup as a start, there are loads of setups on the net, but the kit one is pretty good especially with the change I've done on the rear shock.

Something does not sound right with your ride height, you should not need to use droop limiters to set ride height. Doing this can pre-load the spring, not good for offroad. With green rear springs on my car I think there is about 3-4mm of gap between the spring adjuster nut to the top of the shock.

I can take some pics tonight if you like.


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 Post subject: Re: 4wd Mod
PostPosted: Thu Jan 14, 2010 3:59 pm 
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Joined: Mon Aug 31, 2009 11:27 pm
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Perry wrote:
I can take some pics tonight if you like.

That would be cool.

I will also take some pictures to show what I am talking about tonight.

thanks for the information so far (y)


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 Post subject: Re: 4wd Mod
PostPosted: Thu Jan 14, 2010 5:27 pm 
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Joined: Fri May 23, 2008 11:28 pm
Posts: 82
I found the kit setup was a good starting point when I ran my B44(literally christening it at the Hawkes Bay Nats in 2008). Oh how the times had changed from back in the 90's though ;)


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 Post subject: Re: 4wd Mod
PostPosted: Thu Jan 14, 2010 7:18 pm 
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Joined: Mon Aug 11, 2008 11:43 am
Posts: 29
Here are some pics of my b44 so you can get an idea of the ride height.


Attachments:
Dsc00564.jpg
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Dsc00562.jpg
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Dsc00561.jpg
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 Post subject: Re: 4wd Mod
PostPosted: Thu Jan 14, 2010 7:41 pm 
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Joined: Sun Nov 30, 2008 10:13 pm
Posts: 530
Nice setup..who painted youre body as looks very similar to a body I had on my X5 I got from Scott Kendall.


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 Post subject: Re: 4wd Mod
PostPosted: Thu Jan 14, 2010 8:00 pm 
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Joined: Mon Aug 31, 2009 11:27 pm
Posts: 149
okay, my ( attempted :) )setup.

black springs only: front ride height 21mm, rear ride height 22mm,
Attachment:
File comment: with the black springs
b44_blackspring.JPG
b44_blackspring.JPG [ 204.93 KiB | Viewed 104 times ]


green springs only: front ride height 20mm, rear ride height 26mm,
Attachment:
File comment: with the green springs
b44_greenspring.JPG
b44_greenspring.JPG [ 189.89 KiB | Viewed 104 times ]


green springs with 5mm spacing: front ride height 19mm, rear ride height 32mm,
Attachment:
File comment: with the green springs and 5mm gap
b44_greenspring_5mmgap.JPG
b44_greenspring_5mmgap.JPG [ 164.75 KiB | Viewed 104 times ]


the setup sheet is was using.
Attachment:
File comment: the setup sheet I chose
b44_tebo_ifmar_2007.pdf [729.44 KiB]
Downloaded 5 times


weight of car is within legal weight limits, has lipo, esc, servo onboard. missing only transponder & rx unit.


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 Post subject: Re: 4wd Mod
PostPosted: Thu Jan 14, 2010 8:16 pm 
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Joined: Mon Aug 11, 2008 11:43 am
Posts: 29
Daniel, I think I know what is going on.

There are two types of spring cup (plastic bit at the bottom of the spring). There are long ones that are used on the front of the b44 only, see my front pic, and normal (like b4) short ones for the rear. It looks to me like you have the long ones on the rear? Look at the bottom of the spring in your photo vs mine.

Malcster, the paint job is by James Dale, he had several X5's so may be the same style. That buggy you have looks like a bit of a weapon!


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 Post subject: Re: 4wd Mod
PostPosted: Thu Jan 14, 2010 8:35 pm 
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Joined: Fri May 23, 2008 11:28 pm
Posts: 82
Would be inclined to trim that wing a bit too, plenty of drag...and I think Perrys right about the spring cup too(very observant)


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 Post subject: Re: 4wd Mod
PostPosted: Thu Jan 14, 2010 8:46 pm 
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Joined: Mon Aug 31, 2009 11:27 pm
Posts: 149
um, yea. that makes a difference :oops:

1mm gap on rear threaded shock, 11mm gap on front threaded shock (sort of dogbones level) and I now have tebos setup (23mm front ride height, 22mm rear ride height) :D

3mm difference between standard kit and actual settings on both F/R shocks.

thanks (y)

hopefully the forecast for the weekend is wrong :wink: because I want to try this baby out :D

for the horsepower I have got a novak 6.5 light & gtb esc.
will also try out that 84T spur and an 18T/19T pinion combo you suggested as well as the diff / slipper ideas.

and yes, the wing will be trimmed ... I just cut out the rough shape, drilled the holes and took a photo. The back wall will be cut out as per normal.


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 Post subject: Re: 4wd Mod
PostPosted: Thu Jan 14, 2010 9:51 pm 
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Joined: Tue Jul 01, 2008 9:01 pm
Posts: 243
Perry

any tips for the b4 mod im running a 12t brush motor std spur but the smallest pinon i could get on was a 20. any setup tips for this aswell would help.


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 Post subject: Re: 4wd Mod
PostPosted: Fri Jan 15, 2010 6:57 am 
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Joined: Sat Apr 19, 2008 10:40 am
Posts: 264
Stay in stock LOL


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 Post subject: Re: 4wd Mod
PostPosted: Fri Jan 15, 2010 7:29 am 
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Joined: Tue Jul 01, 2008 9:01 pm
Posts: 243
gasman wrote:
Stay in stock LOL



why no one can catch me ??? :wink:


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