Manta Ray Build

Hey everyone!

My next rebuild is gong to be a fast one – both in build time and top speed.

As much as I love my vintage 2wd buggies, the time has come to build one to keep up with the other weapons at the track – all brushless Top Forces, Evos and Terras.

My car of choice is a Manta Ray the first chassis of the pedigree. I’m going to do this as a performance rebuild on a budget.

First I sourced a local dog of a car on ebay for $50 as a base.

Now it looks like this…

I was quite happy as car was complete with only a few broken parts – cracked chassis being the only dissapointment

But I was happy at the spares that were in a plastic bag at the bottom of the box

Sourced a chassis so I’m ready to rebuild.

The car will be running all low cost electronic parts from China to show they can keep up with the big boys. I will list all parts used as I go through the build over the coming weeks.

So far the cost is:
Manta Ray – ebay – $50.00
New Chassis – $29.00
Packet of biscuits – $2.99
Coffee – $5.00

Next step gearbox. A Tamiya #50529 4WD Touring Rally Car Plastic Gear Set, Yeah Racing prop shaft and alloy motor mount.
Rear box stripped

Think the alloy idler may have had its day? and possibly a new pinion required

All new gears and shaft end in. Bearings all round. Using bevel diff with AW grease instead of ball diff. Ceramic grease used everywhere else.

Next was an angled rear gearcover brace (you will need to make this part from an angled section of aluminium). This prevents the top gear case cracking. Big thanks to TA Mark on Tamiya Club for this tip.


Additional costs:
Bearings – $20.00
Plastic gear set – $15.00
Yeah alloy prop shaft $20.00
Yeah alloy motor mount $20.00
Pat Benetar CD to keep that 80s feeling while I build – Kmart – $12.00

Front gearbox rebuilt same as rear. The original plastic end dog bones look ok so I’ll re-use them until they break then upgrade to DF-03 ones.

Rear end ready to bolt up as well. I’ve used original 10mm self tap screws as per the manual. I’m going to keep an eye on them after every run to see if they undo at all. If they do start to loosen I’ll change over to metric threads. I’m trying to keep this as close to manual built stock as possible – apart from modern electrics

Moving onto the shocks… Apart from the dirt and grime they are in pretty good nick. Were even full of whiffy old oil in them. Gave them a good clean and filled with 250 Yeah Racing silicone oil.
Half done…

Additional costs:
Yeah Racing shock oil – $10.00
1 pair of soft ear plugs – to stick in my nose to block the smell of old shock oil – $2.00

Chassis assembled ready for electrics


I put the stock vintage sanwa 101 servo in but it was seriously slow.

Have since upgraded to a Bluebird BMS-621 High Speed Servo. Specs at are torque:6.4kg, Speed:0.13sec Weight: 41g

Also noticed the back end sagged quite badly while the front end was way too high until it was pointed out the front and rear shocks are different and I had them on back to front in this picture. You’ll notice the next time I post a picture the shocks with less turns are the stiffer springs for the rear.

This and moving the bottom of the front shock to the outside hole, dropped the front ride height to a better level.

Off to drop in some power!!

Additional costs:
Servo – $25.00
Nail polish remover – to unglue my fingers after touching step screws – $6.00

Here are the photos with the ride height fixed, suspension the right way round and electrics fitted

I’ve chosen a 9t Hobbywing combo for price, performance and proven reliability. Changed the Tamiya plug to a deans style plug.
Unsure with the gearing yet so starting with the 16t pinion to not work the new motor too hard and work my way up if the top speed is lacking.
Radio gear is 2.4ghz Eurgle – This has been my radio of choice for nearly a year and very happy with it – especially when extra receivers are $15 each.

Additional costs:
Hobbywing 9t Brushless Combo – $95.00
Eurgle 2.4ghz radio gear – $70.00
Robinson Racing 16t pinion – RRP1116 – $10.00
Deans style T plug $1.00 (well they are $10.00 for a pack of 10)
Aloe vera cream to sooth the solder burn on my finger $6.00

Off to try and make the body one piece again

Body is now back in one piece thanks to some sheet ally and “Shoe Goo” – best lexan repair product ever

its not the prettiest shell but at the speeds I’m trying to achieve I have a feeling there are going to be some battle scars

Just about finished and noticed I don’t have a rear body mount or battery stop. Luckily my local hobby shop has some tamiya spares so I ordered in an E parts tree.

Wanted a new set of wide studs to the original speed discs. Not sure how these will go but really wanted to start wit an as close to stock car then make one change at a time to see what is absolutely critical for good performance.

Gearing will be the first thing, wheels and tyres will be next.

Here are a couple of pics of the finished product

Now I just have to wait for the track to dry out to have a test run.

Additional costs:
E Parts – $18.00
Wide stud tyres – $30.00
4 pack of JD & Cola for a job well done – $19.00 – Man our alcohol tax here is nasty!

Last of all is the battery – Probably as critical as the ESC/motor choice.

After researching a number of batteries – there are only so many lipos that fit in a Manta Ray chassis hole  – The best value for money I found was the Eurgle 4400mah 35c 2 cell lipo. These are a “wrapped” soft pack. Similar to the Venom packs but with and extra 10% capacity and cheaper too. They are a perfect fit into the oval hole with no modification required.

Off with the Tamiya style plug an on with the deans style plug.

All I have to do is proram the ESC. I have started with the factory settings to see how they go.

Aditionl costs:
Eurgle 4400 25c 7.4v lipo – $60
Deans style plug $0 – used the other half of the pair from the ESC

THE REASULTS


Absolutely fantastic!!!! This car was awsome around the track both in handling and speed. I was turning faster laps than a fully hopped up Top Force Spec Terra Conquorrer running a 5.5t Brushless (same batteries). He was faster on the straights but could not take the corners as well.

Track was slightly muddy to dry – low grip

Motor only just cracked 50 degrees C which means I could go up a tooth ot two on the pinion for more top speed but for now I couldn’t be happier with the reasult.

Factory ESC settings were spot on – again with the motor running just warm I could have advanced the timing for some more speed.

Got 3 flat out runs of 5-10 mins each with the battery before I realised the factory ESC settings don’t have lipo cut set – oops. Dropped one of the cells to 2.95V but straight on the charger and it is fine – you can drop a cell to 2.85 before any permanent damage happens.

Other casualties were:
– lost front wheel – I used the original wheel nuts which obviously weren’t up to the task
– 2 empty shocks – I re-used all shock seals so will go through and rebuild with new before the next run.

Anyone that wants a fast 4wd vintage racer, the old Ray is a definate low cost alternative.

I will do the math and list all the parts and costs to build a budget vintage Brushless weapon.

Total cost of this build was $536.98 – BUT if you take out all the extras including car repairs and self medication it boils down to this:

Bearings  – $20.00
Plastic gear set  – $15.00
Yeah alloy prop shaft – $20.00
Yeah alloy motor mount – $20.00
Hobbywing 9t Brushless Combo – $95.00
Eurgle 2.4ghz radio gear – $70.00
Robinson Racing 16t pinion – RRP1116 – $10.00
Deans style T plug $1.00

Real total: $251 – Seriously, 2 years ago you couldn’t buy aBrushless combo for much less! Again, this is AU$ so you northern hemisphere people will do it for a lot less than that.

All of these parts can be purchased in my store www.vintagercspeedsupplies.com

If the item isn’t listed, email me as I will usually have it within a week if it is sold out.


Happy bashing!!!! 


Comments

Manta Ray Build — 14 Comments

  1. Hmm, good question. I’ll ask Mark (the author, who’s name I realised I Ieft off). Although I suspect at the time he built these he may not have had all parts in stock. Also to be fair we was also quoting average prices on the net.

    Apart from that, did you find the article informative?

  2. Hi Luke!

    I have edited the article to make more sense. Doing these builds is how I started my store a few years ago as there was no one doing this sort of thing in the vintage scene – and to be honest, there still aren’t many guys doing it today.

    Is ther a particular car you are wanting to upgrade or any electronics you wanted reviews or advice on?

    • I’m more of an old school rc guy so I’m not really interested in running brushless motors.

      Where do you guys usually meet up aside from the places you listed or is it just those two places you run?

  3. Hi Luke,
    we run where ever really. There is a large water reserve at Springwood that is great for road cars. I have run my Martini Renault Mk 22 out there, and will probably run my Celica LB Turbo and some other cars I am working on once restored. We’ve also done the odd run at night at Capabala at the shopping centre carparks. Plus parks at Thornlands, Redlands and other places. I’ve only been to Boondall once myself. Boondall seems to be over run with guys with insanely fast cars that have no respect for the older cars, so I tend to stay away. Mark and myself are also into the older cars. Mark is trying to get together the Tamiya top 100, but I am just after a few of the cars I wanted as a kid, plus some of the older aluminium chassis cars like Renault and Celica (or a porsche if I get lucky!).

    We set up this site to try and organise the runs a little better, but time is an issue for both of us, so its a work in progress.

    What cars are you into Luke? Also you local to Brisbane you are welcome to join us if you are.

    • I live at Ormeau at the moment. I have an assortment of off-road cars (hornet, hotshot, clod buster and a few others). I have an old road wizard as well. I did see some really cool pics on tamiya club a couple of weeks ago of a run you guys had at a place with dirt jumps (at least I think it was you guys). Is it just you and mark who meet up?

  4. Hi Luke,
    if its the “any aussie keen for a bash” thread – http://www.tamiyaclub.com/forum/index.php?showtopic=51935&st=400
    then thats us. Not just us two either, usually at least one or two other guys, sometimes more. Those jumps look like the bike park at Redlands. There is also a fairly good area at Thornlands, which has a good park (good if you have to bring kids along like me).

    Ormeau is a nice area, I work out that way in Blanck Street!

    I also have the hornet (my original one and a re-re) and hotshot. Most of my cars are listed here, http://www.tamiyaclub.com/showroom.asp?id=35302. 21 cars so far, plus a plane, but will probably not go too crazy, getting a whole lot more. I am mainly focusing now in upgrades and improvements. Current project is making pop-up headlights for my Pantera racing car.

    • Yeah those are the pics. Looks like that was mad fun and great job catching them in full flight! Might have to try and make it to along to a run in the future.

  5. Hi Luke,
    it looks like some of the guys are going for a run this Sunday arvo in the cleveland area, plus a run on the 4/11, plus a beach run north of Brisbane somewhere yet to be decided. I’ll posted on the calendar here once I get some more info.

  6. Hi Luke,
    not entirely sure of location, most likely a park with a dirt track. I’ll update as soon as I know. I think they guys are running from 1 til about 4 though.

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