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This is my version of a Tamiya Astute. I set out with a few goals in mind, the main one was it being a replica of Jamie Booths works astute, so battery down the length of the chassis, madcap arms and hubs, I went a bit further too in terms of madcap bits, i got the madcap front bulkhead on there which presented its own problems, the astute bulkhead uses press nuts which i wanted to avoid, but they sit flush on the bulkhead, so I had to space the steering up a few mm so it would clear the locknuts which on the madcap sit above the bulkhead, the other reason for the extra use of madcap components is the weight, no more bushes or bearings in any pivot point on the car.

The madcap rear bulkhead is also on there, again, it presented its own problems, i had to make an adapter plate out of perspex to make it fit the astute mounts, this also doubled as the battery hold down which sits further forward than standard as i planned to have the battery sit more forward in the chassis than usual.

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I also retained the madcap bumper, after being knocked out of a race 2 years prior by marshal who was over eager to get to his teams car, the front clipped his shoe and the front arm fell apart a few laps later I knew it was worth doing whatever I could to project the front arms of this machine

The car was built with its main purpose being it had to withstand the stress of a 6 hour vintage enduro, Mabuchi 540 motor, one car, 4 drivers. With that in mind, you'll notice a lot of locknuts where it was possible to run longer screws through parts and a lot of washers and spacers to spread the load as much as possible during hits etc. The enduro is an annual event held using our current vintage rules which allow vehicles on sale up to Dec 1990 to compete.

One thing I've read about these cars is terminal understeer is a problem, our track consists of a lot of tight corners including several hairpins so the aim was to move the weight balance a bit forward. To move the battery forward on the chassis which seems like a reasonably short wheelbase, I bolted in a low profile servo, then used some spacers on the servo mounts to move the servo forward a few more mm, then put the ball stud on the backside of the servo horn so the turnbuckle lined up, it all just fits without any binding etc, then I drilled holes in the chassis for the battery holder with the holder butted up against the servo, I ended up with a bit over 1cm of travel that I can slide the battery fore and aft to alter the balance of the car. I tested it with the battery forward, middle and back, all had their benefits, back and the car was more planted and stable, forward – the car turned in very positively and the rear was holding on so that's where I based the setup on

Transmission. Originally I had planned to run an avante gear diff in the standard gearbox as I had read with a little modification to the plastic parts, you can get one to squeeze in, which did work, the avante gear diff is one tooth smaller than the astute one, so there's a potential for the gear to strip as the mesh wouldn't be very tight, however I ended up breaking teeth on the gear on the back of the spur, they were old used gears which could have been part of the problem, however within short succession I broke 2 gears on the back of the spur so I gave up on the idea of running the gear diff in the standard astute tranny as I figured the slip with the ball diff was what was saving the internal gears from breaking normally. The only other route I could think of was the lethal weapon tranny from A & L, this was out in 1990 and came with the adapter to fit onto the astute chassis, so I ordered one. It is a great piece of kit, it seals extremely well, when I opened it after running it for about 2.5 hours, it was clean inside, with just a little of the original grease in the bearings having seeped out, I gave them a spray, rebuilt the diff and put it back together. The A & L ran faultlessly for 6 hours straight and I have since run the car in some 5 minute racing without problem. I had to make my own tranny brace as without one, the rear flexed very badly, so I made one using the same Perspex I used to make the rear bulkhead adapter. I flattened off an area on the rear bulkhead, carefully drilled some holes, lined up the brace, got it all to work though it's a pain to install or remove as I used locknuts, as with everywhere else, I used washers to even out the load a bit, it worked perfectly, reduced the flex massively and held up for the whole race, I'd semi expected it to break in its first test, or stress the bulkhead into failure

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In the rear, the hole in the hub where the ballstud screws in got dremelled flush with the hub which stopped the turnbuckle fouling on the shock springs and also brought the turnbuckle into alignment with the pivot point on the rear bulkhead which was further rearward as it's the madcap item

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One of the other things that would be noticeable on the car is the use of DF03 rims on the front as well as the rear, the reason for this was mainly looks, the astute original had black rims, the DF03 ones look most similar in my mind and are a perfect 2.2 inch fit. To do this, I originally planned on using DF01 front carriers and hubs but it would have sent the front track too wide so TA03 items had to suffice, I could have achieved the same results with period kyosho pieces but I wanted to keep it Tamiya, the 4wd front tyres provide good front grip and I used to put 4wd front tyres on the front of my madcap to counter the huge understeer but if I need to run 2wd tyres I can trim off the inner ring of the rim and glue 2wd fronts to it

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The shocks are Tamiya ones from my spare DB01R, spruced up with some gold accessories made for the on road shocks but they fit the off road shocks perfectly too. Our racing allows newer shocks to be used as at the time hi-caps had not been released and I'd have needed to take out a mortgage to buy a set, now the rere hicaps are out I have bought a set so now I can run period shocks too. The springs I had to go losi in the rear, Tamiya simply don't make a heavy enough spring to keep the rear end of the astute off the ground, in the end I went losi orange in the rear which is the stiffest spring I've ever run in the back of a car and Tamiya springs were good enough to keep the front end working well, though it was a hard spring also.

Also the chassis and shock towers are fibre lyte items, anyone who has seen the front shock tower on the website will know that it normally comes with a big brace across the top and the tower is a fair bit taller. To keep the car more authentic , I cut out the brace and trimmed off a couple of the top mounting points, also it needed a little dremelling on the bottom as it fouled on the bulkhead

Problems: not too many to report, the madcap arms flex so badly that castor would be in a constant state of flux for both front and rear, the lack of upper bracing on the chassis (corrected by the dynastorm) means the whole car flexes mid chassis, even with the battery in the most forward position the front end bounces around which I attribute to the flex, under braking it's a little noticeable as well as when carrying speed in corners, the car still holds good lines despite the front end not being perfect

Result: The car turned out better than I'd hoped, the A&L tranny proved to be very smooth and efficient, the car had excellent acceleration and top speed and it did not miss a beat. One of my fellow racers described it as being a bit of overkill on the build with regards to my attempts to ensure the car survived a 6 hour race, this could be true but I guess we'll never know, however in the enduro, one of the teams ran a madcap with the standard gearbox and the car was a bit more standard overall and it ran reliably for the whole race.

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Pic thanks to Jak Rizzo, he took some really nice action shots of the astute too

The Race: A small but quality field had entered for the race, the encouraging thing was it was a varied field in terms of manufacturers, there was an RC10 Worlds, a Losi Jrx pro, Kyosho Maxxum FF and a Tamiya Madcap as well as my astute. I figured the main competition would come from the RC10 and the kyosho, the RC10 got fastest qualifier and I qualified the astute in second, the gearing I'd chosen was for the black endbell motor, the motor handed out on the day was a grey endbell Johnson so a quick gamble decision to go up by one tooth proved to be a lucky choice. Early on I was able to stick to the back of the rc10 and any time lost in the infield I was able to claw back a bit of it down the straight. The setup turned out to be a bit stiff and I'd taken a little too much droop out of it so as the track dried up and broke up a little and car had to be driven very accurately to get the lap time out of it, the car burned through a set of tyres by the 4 hour mark so tyres were changed. The car remained consistent though and we were able to just stay ahead for the duration of the race which ended up coming down to the cars efficiency allowing us to do less battery changes than the RC10, also the guys steering my car did a fantastic job all day in some tough conditions, making smart decisions and keeping the car on its wheels and lapping consistently.

The Competitors

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The top 3

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Future: Our neighbouring state has a slightly different rule set for vintage with the cutoff being end of 1991 thus the Super Astute is legal, so I will be rebuilding the car with super astute arms all round and SA rear hubs with a view to attending some of their events. I've also got a new chassis that's 3mm thick as opposed to 2.4mm which will hopefully cure some of the flex issues. I'm going to mount up the rere hi caps for the more authentic look and while doing that I'll give the car more droop back and soften the setup so it's a little easier to drive overall.

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A couple of vids of the car in action thanks to Ed who films a lot of the vintage action

Enduro footage

5 min race vs Losi Jrx pro

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Nice post and vids Jesse. Looked quick in the 5min race, was that still using the standard silver can motor??

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Nice post and vids Jesse. Looked quick in the 5min race, was that still using the standard silver can motor??

Hi Sheriff, yeah still the silvercan and actually the enduro motor and gearing, i could have gone up 2 or 3 pinions but it was a hot day so i left it. We are loving the silver can with the lipos, its a great speed to race the cars at, the A & L tranny has a lot to do with it too, the belt drive is very efficient, in saying that, the losi aint no slouch in a straight line either lol

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Well done JJ. I really enjoyed reading your post. Good stuff M8. :)

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Thanks guys. Glad you enjoyed the read. The great thing is the car isnt a one trick pony, we've been having regular vintage classes at our club meets so its been getting plenty of running since the enduro

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Hey guys, a bit of an update, last weekend i was able spend some time building what i call version 3.0 of the astute.

The car is now built as more of a super astute, it featurs super astute arms and rear hubs, which should help solve a lot of the flex issues cause by the madcap arms. The main feature of this new version is the chassis, custom made by fibre lyte (who do great work) this is a 3mm thick chassis, they were also kind enough to remove every screw hole i didnt need, so the battery mount holes are gone etc, as well as that, you'll notice on the pic of the underside of the chassis, they didnt cut the gearbox hatch where the diff would normally come out of as i only intended on running A & L lethal weapon in ths car, so i drilled the holes for the gearbox using the old adapter plate as my template and used the old chassis as the template for drilling holes for the super astute battery holder

While i was pulling the car apart to put it onto the new chassis, the transmission got a rebuild, after the 6 hour enduro plus a few club meetings running, it was very clean inside,belt still looks great, i gave the diff a good clean, put it back together and it feels great. The shocks also got a good clean out and some new oil, i also pulled the internal spacers so the car will have more droop again and a drop in oil weights so make it a little lighter damped

The super astute front arms are more swept back than the madcap items, as detailed in kontemax's guide to building an astute, this hasnt presnted much of a drama other than the camber links are on a bit of an angle

normally i'd have put a 540 back in the car and be done with it but this time i have opted for a 17.5 motor as i plan on running the car in some stock class racing, we'll see how it goes against the modern cars!! I did a quick blast up the driveway, transmission handles it just fine, it pulled some small wheels stands which i like, it should be fun to drive

thanks

Jesse

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Holy Moly Mikey.

What a awesome Astute. Geee I'm not racing Vintage 2wd stock now LOL.

Love your work & R&D. Don't think there is much left to do except work on your set up now.

Best of all it's a Tamiya. :) :) :)

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Thats a cool build, hadn't heard of that belt drive transmission before.

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I think phase 3 just left us and Jamie behind ! That's the benchmark for an Astute racer right there.

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I think phase 3 just left us and Jamie behind ! That's the benchmark for an Astute racer right there.

I was thinking the exact same thing! Cannot wait to hear how it fares in stock class!

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Thanks for all the nice comments chaps. I'll report back about how it goes.

Setup-wise it was pretty close, with the rebuild of the track it'll be interesting to see if I need to change it much and to see if the stronger chassis and arms have made a difference.

Lol Mark, I'll gear it down a few pinions and put the turbo on and run mod then!! Lol

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So I gave it a run with the 17.5 in it. Went really well in practice however the super astute hubs seem to give the unis more plunge into the diff outdrive so as the car came off the drop off on our track the angle proved too much and broke the outdrive. So I had to fix that, went back to the madcap hubs and ordered some unis that are a few mm shorter. In the mean time I put a bunch of o rings on the rear shock shafts to limit up travel.

The other problem ive now had twice is the super astute rear battery hold cracks at the screw holes where it bolts to the chassis and where it bolts to the adapter plate. So I went back to the standard astute metal posts which should hold up to the punishment and fashioned a battery hold at the back out of a switch box from jaycar. Ran the car last weekend with a sport tuned motor in it in preparation for a race im heading to next weekend. Car ran perfectly. Had a mixed bag of top forces, an avante, a dyna storm, a manta ray and an astute in our vintage class at our local Club meet. The car was able to match lap times with all the other cars out there which I was pleased with.

Next Sunday will be the big test. Big field of good 2wds, trx1s, rc10 graphites, ultimas. Looking forward to it!

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Hey all.

A little update. To protect the nice fibrelyte chassis I put on a ***** undertray and with the thick chassis the car ended up a bit on the beach side so I moved the battery holder rearward so it would nicely hold a shorty pack. This brought the car back down to a better weight and I've got the rere hicap dampers close to sorted

Last weekend we had our annual vintage festival

Heres a vid of the black astute in the first final of 2wd 540

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I am loving this thread, It is almost completely different to the normal threads you see on TC. The car looks awesome. Have you any more shots of it or does it still look like it did in the previous pics? Excellent work

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Well done Mikey and thanks for posting some footage from the vintage festival. Conditions and track looked great and I really dig seeing the Astute out in front.

How have you set up the re re Hi-Cap dampers please ? Oh and what motors are being used in 540 ? Anyone using Torque Tuned or mostly Johnson cans or what ? Cheers.

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Hey thommo

540 motors must all be the silvercan 540J (kit motor)I think it is or the 540 Johnson motors. No torque tuned or sport tuned. The racing over the weekend was great. In the top four of the 2wd 540 class we had the astute, a losi jrx pro (white car), an rc10 graphite (mainly blue car) and a cougar (blue and green) so we had most brands covered.

Hi caps I use losi front springs all round, blue on the front, green on the rear. Smallest pistons (2hole?) And I think 35wt front 30 rear

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Hey madmat. Thanks for the compliments! The car still looks basically the same but now with hicaps and the battery holder moved and it's dirtier now that I've raced it a fair bit. It's a bit of a testament to how I built it. People thought it was over engineered but it lasted the 6 hour enduro race, and now its been through a couple of big vintage events plus many club days and the thing keeps coming back for more. Ive had a couple of nuts loosen on the front bulkhead which will need threadlock despite me using nylock nuts other than that it's been fine and quick. I'd say in that vid I posted above that would be the best the car had ever run

Its funny though, now it's done and been successful, it might be time to rest it as I'm moving onto a bear hawk. Though I don't think I'll ever do another car up to the level of the astute

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this buggy is awesome, you put in some work there mate and it came out great by the sounds of it, even thinking to order the A & L myself now. even if it is only for the different look !

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Ha zooter yeah the blue A&L stands out for sure and runs great. Belt drive is smooth and no doubt it makes run times longer and the motor tends to run cooler. A couple of guys here got them because they've seen it do well in my astute. Its just so cool that daryl still sells the stuff! !

Its hard with the vintage cars, I want to run so many of them! My next projects are the bear hawk and a kyosho triumph

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