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Lunchbox Front End Conversion

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I'm using the same dampers, Short CVA yellow ones (they are the discontinued versions). Raided from the Blazing Star after I fitted DF03 rear dampers all round to it. I have mine limited in length too with o-rings inside the body on the shaft under the piston. I didn't use the Blazing Star shafts though. I fitted shafts (no idea what from) that I could fit 3 hole piston and light oil to rear and 1 hole piston and medium oil to front. My front springs are heavier gauge than the rear. 3rd damper is same settings as the front except limited in length more.

Mine sits level. Under power, when the diff rolls, it's nose up slightly.

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great.thanks for the info and links.

cant wait to get started.

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Those Ansmann shocks look alright Ben but fourth jump off a ramp the other day (long plank on a tyre) snapped one of the fronts on the lower plastic connector. Going to to fix it and see how they go but still got those big yellow CVA's I bought off you so might be digging them out.

Mind you, I was trying to keep up with my dad/brother's truggies and might have been treating her a bit too rough...

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Those Ansmann shocks look alright Ben but fourth jump off a ramp the other day (long plank on a tyre) snapped one of the fronts on the lower plastic connector. Going to to fix it and see how they go but still got those big yellow CVA's I bought off you so might be digging them out.

Mind you, I was trying to keep up with my dad/brother's truggies and might have been treating her a bit too rough...

i was thinking of getting some monster beetle cva's now.watching a few on ebay.if i dont win them,ill get the ansmann ones

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OK, it's all back together now, the upper links aren't quite parallel to the arms (intentionally), so it has a little neg camber at full compression. There's virtually no bump steer, certainly not enough to have much effect with those huge flabby tyres on the front.

Nothing's binding & steering geometry looks excellent. My existing tie rods were long enough, they were wound fully in before this mod, but assembling the ball studs on the correct side of the servo saver helps too :):) .

Damping looks perfect too - Yellow CVA's with the smaller 2 hole piston head & yellow 400 oil.

I had to rebuild one shock as it has obviously leaked a little, the oil was badly aerated & a mucky brown colour, the o-rings were so loose you could see daylight round the piston shaft !!

I need to do something about the rear shocks, it's way too bouncy & the springs are so stiff, the dampers barely move.

Thanks to Aconsola, TA-Mark, and everyone else who's contributed - this is a great mod.

Ben, if you took default shipping, expect 2-3 weeks wait for your parts :)

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I need to do something about the rear shocks, it's way too bouncy & the springs are so stiff, the dampers barely move.

There's no weight in the rear of the chassis, it's all in unsprung weight in the gearbox. I added weights to the rear so the suspension would work and made the dampers/springs as light as I could. Did the same thing to the rear of the Grasshopper which has the same suspension setup front and rear as a Lunchbox.

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My NiMh packs weigh about 400g which helps, but the springs are far too stiff, I borrowed a pair of my Top Force, the Black Durga ones & they're better, (11 turns, 1.2mm wire, 65mm free length) but I still need to drive it & see how it behaves dynamically.

But yeah, you're right, it's all unsprung mass.

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I was using a 520 gram Ni-MH. Still had weights added. When I changed to Li-Po I added another 250 grams of lead. In the base of the chassis where the rear pivots screw in to keep the weight low.

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No wonder it was too stiff, the springs that came off are monsters; 1.4mm, 15t, 72mm FL ;)

I swapped the rear springs for 10 turn, 1.0mm, 54mm FL. They needed 1 x 8mm spring spacer to support the weight of the rear properly.

I also fitted the same spring to the centre gearbox damper, again with the 8mm spacer.

The rear still bounces on the tyres, but at least the springs are doing a little of the work now.

It's still over damped, but I'm not rebuilding the shocks tonight.

Is it worth putting foams in the tyres ?

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Is it worth putting foams in the tyres ?

I feel it is. Made them much less bouncy for me. I also put some material tape around the inside of the tyres to stop them ballooning so badly with the high rpm of the 5700Kv.

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As it's now in a very usable state, I'm not going to pull it about any more before Sunday's bash, I'll just see how it performs.

I have some suitable foams, but I'm not going to try & unglue the tyres for now.

The rear dampers need new piston heads with more holes before I worry about foams, that will alleviate much of the bounciness & let the rear end work properly.

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All that work and you will drown it within 10 mins.........oh hold on no wait , that was me.

im going to be having a look mate as i think my Battle box is more dangerous than it should be to bystanders

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Well front end conversion is complete and I have to say its made a welcome improvement to the wheelie landing, cornering and general bouncing about ;)

Its got a newer Sport Tuned in it now and it goes well - just waiting for pay day before I order a Superstock TZ for it.

Here are some pics...

The conversion - everso slightly different to everyone elses - but then that seems to be the way to go! Centred the servo at the same time to. Had to play around with the springs, oils and damper rates though as I set it way to soft initially - I used 4 hole things with red shock oil and the least springy springs - felt great off the truck but as soon as I fitted a battery and the body it was obvious it was way to soft. Ended up with 2 hole things with 40cwt oil and Monster Beetle springs which is just about right.

P1000497Medium.jpg

Close up of the conversion - bent the shock bottoms to allow more clearance - cheers to TA-Mark for the tip ;)

P1000500Medium.jpg

Front view of conversion

P1000496Medium.jpg

Uncompressed

P1000503Medium.jpg

Fully compressed (notice that the wheels are still as they are in the above pic)

P1000504Medium.jpg

A nice clean 'Box (makes a change for me!)

P1000501Medium.jpg

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I've been working on mine, got the front shimmed up a little to get rid of the play around the c-hub.

I've found that getting shocks working up front is a tricky thing. If they are soft enough to keep the font end from just bouncing over bumps then they compress too easily when turning at speed, and the inside rear wheel picks up as the outside front spring fully compresses.

I think I am at about 35wt oil with stock or clodbuster springs, (stiff). I have found that Losi springs seem to fit well and are color coded for weight, so I will probably switch to those when I get ahold of some of the heavier versions

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I've found that getting shocks working up front is a tricky thing. If they are soft enough to keep the font end from just bouncing over bumps then they compress too easily when turning at speed, and the inside rear wheel picks up as the outside front spring fully compresses.

I think I am at about 35wt oil with stock or clodbuster springs, (stiff). I have found that Losi springs seem to fit well and are color coded for weight, so I will probably switch to those when I get ahold of some of the heavier versions

Yup I had loads of trouble with this - Monster Beetle springs seem about right - one of my front tyres is getting old and the rubber doesnt keep its shape too well so I am going to fit a newer one this evening - I think foams would help too. I watched it turning and its definitely a tyre issue - I am happy with the suspension as it is for now. I used Clod springs in its old setup - I think the Monster Beetle ones are stiffer (or at least the ones I have are!)

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A sway bar - pmsl!

Actually it wouldn't be that hard - something like the Thundershot setup could be done quite easily...?! ;)

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got my fx10 kit but no hardware.

what you guys using for the kingpin and lower shock mount shaft?and knuckle lower mount shaft?

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got my fx10 kit but no hardware.

what you guys using for the kingpin and lower shock mount shaft?and knuckle lower mount shaft?

I bought the hardware kit with it - if not I could have used Thundershot axle shaft screws I guess

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I bought the hardware kit with it - if not I could have used Thundershot axle shaft screws I guess

thanks mate

just checked the ebay site ,and theres a hardware kit.should have read the auction when i bought the other parts.

was planning on doing the conversion this weekend.gonna have to wait a few weeks now.

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You can get away with using DF01 (Manta Ray) screws for most of it & as long as you have a few other spares you can just wing it.

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finished mine here

http://www.tamiyaclub.com/showroom_model.a...31&id=10679

did it a bit different though.

instead of heat bending the bottom of the shock,i cut the shock mount of off the lower arms ,pushed the shock forward towards the front of the truck.then put the bit i cut off behind the shock to keep it in place,then put the shaft though the whole lot.clears the steering turnbuckles nicely.

also i used a clod steering turnbuckle for a chassis brace above both shocks.

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Finally finished my front end conversion.

It's soooooooooooo bad. Sloppy at the front and the wheels rub on the body. Fitted MB CVA's all round and hi torque servo saver with the shocks mounted same as Ben's (shock mount cut and placed behind the rear of the shock). Really suprised at how bad it is, thought I'd have done better. Have a couple of changes in mind but the general problem seems to be this: compared to Skip's pic number 4, where the Lunchy in its uncompressed state has the lower arms at an angle, on mine the lower arms are almost horizontal at rest. I'm tempted to stick the Ansmann shocks back on as the longer shaft will push the angle of the lower arms down and away from the body. Everything just seems really loose.

Have got the upper arms mounted to 5mm ball joints facing backwards on the inner side of the triangular chassis piece just behind the bumper, outside end fitted onto an M3 screw through the top of the C Hub. I think changing this to a 5mm ball joint screwed into the top of the C Hub will remove a bit of the slack but the C hub just wobbles about all over the shop. The upper arms are pretty much horizontal with the lower arms as TA Mark suggested. Used the CRP hardware kit too.

Pics below, thoughts welcome...will be giving all and anything a once over on sunday seeing as how the weather over here is forecast to be horrific!

Uncompressed arms at rest are horizontal, upper arms parallel

P8280276.jpg

P8280274.jpg

Upper arm connected to ball joint inner end, M3 screw outer

P8280278.jpg

P8280275.jpg

Oh my

P8280273.jpg

Help!

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Finally finished my front end conversion.

It's soooooooooooo bad.

Help!

I've now done two of these front end conversions, and to me, it just seems like your front shocks are way too short. Try some longer shocks on there and see if it makes a difference. I'd also like to see a better picture of how you mounted the top of the shocks to the chassis.

Steve

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Agreed - I used the same shocks as you but used longer bottom ends which lengthened the whole shock. Also - fit a spacer bit that compresses the spring - this stops it from compressing too much when landing wheelies

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