Period racing mods and spares for Frog (astroturf)?

[Mad Ax 9329]

Bit of a random one here - and don't think I'm taking this all too seriously, because I'm really not, I just like preparing things properly

I've entered my SRB in this years Iconic Revival, but it looks like I'm the only SRB entry.  Since there's a few other Frog entries in the '77 - '83 class, I'm considering swapping my entry to my Frog so I can play with the other Frogs.  I can't find much about good, functional mods make to a Frog for racing.

Way back in the day I made a new upright front shock mount for my Frog which kinda works, but I need to tune the shocks with softer springs.  Other than that, is there anything worth doing?  I'm prepared to go totally mental, I haven't run the Frog in stock trim in a very long time and found it to be way too tail-happy with a Super Stock BZ installed.

It's a re-re and it suffers the famous issue of the front stub axles popping out.  Besides carrying a drawer full of spares, is there a known fix?

Any other fragile areas worth taking spares for?

I'm guessing spike tyres will be best on astroturf.  Not sure what fronts to run.  For aesthetic purposes I'd love to run Brat wheels and tyres and a Brat shell (it's actually technically a Brat, but I used the shell for something else and always ran it with Scorcher tyres and Baja body) but I guess the Brat tyres will be wrong for an astro track.

Again - don't think I'm taking it seriously, I just want it to be as well-behaved as possible, we tried to run the SRB on astro with the Rough Rider tyres for last year's enduro and it was almost undriveable until we switched to spikes.

[Backlash 481]

Frog hop-ups..

Steel Pinion and Ballraces..

You have the MIP Ball diff designed for the Monster Beetle..

The re-re Frog already uses a dog bone style drive shaft thus correcting the issue with the original hex drive axles..

I really think that the Frog would benefit from a rear shock upgrade to a coil over shock that actually works and is adjustable..

2.2 inch wheels may be something else you might consider if the rules allow.. If not maybe look at cutting down some 2.2 inch tyres to fit the some 1.5 or 1.7 inch Tamiya wheels..

Upgrading the servo saver and steering rods to something more durable may also be an idea.. 

CRP made quite a few upgrades for the Frog.. I found the adjustable motor mount quite good to allow a greater range of gear ratios.. I also used to use the CRP front bumper and nerf (side intrusion) bar that went under the battery plate as well.. There was a CRP bushing kit for the rear swing arms that removed some slop and also helped stop them from ejecting the drive shafts in a crash.. CRP also did an oil shock conversion for the front of the frog using 2 small shocks similar to those on the rear of the SRB buggies (Rough Rider, Scorcher).. You also had the option to use coil over springs on the front shocks..

Have a look at some of the CRP upgrades for yourself..  http://www.rcchopshop.com/crp/team_crp_tamiya_frog_rc_parts.html

Parma (I think) and maybe some others, did a rear sway bar kit for the ORV buggies..
 

[Mad Ax 9329]

Thanks Backlash, very useful info there  I need to revisit my front shock mod and possibly replace all four shocks for better adjustability, and look at that issue with the front knuckles.  The rules allow for "period-correct upgrades" so I'm assuming 2.2s and modern tyres are out for the 77-83 class.  I can always take some alternative rubber along in case others are running modern wheels and tyres.  I've got hex adaptors and plenty of spare wheels and tyres.

Home-brew mods seem to be fine as long as they're not taking the mickey - I guess lots of racers back in '83 used to run home-brew mods.

The MIP ball diff looks like an awesome bit of kit and as it's a re-release of an old part, I'm guessing it's period-correct, more or less..?  I'll try to get some good hard testing days on 2.2s with modern tyres before the event so I can see if I'll have an issue with the stock diff and my chosen power source (modern motors and batteries are allowed).

[Backlash 481]

For the knuckle issue you have, why not look on eBay (or put an ad on here) for set of original knuckles that don't have the problem..  In addition to the Frog Brat and Lancia, the SRB's also used the same knuckles.. The one advantage the SRB knuckles had was that the ball end for the steering linkage was screw in, so you could easily upgrade the steering linkages to any ball end that used a 2mm screw like Du-Bro.. https://dubro.com/collections/ball-links

Also keep in mind that with many RC companies bringing out re-releases, you have had a few smaller companies (like J Concepts) releasing better tyres for them, like these tyres that suit a 1.7 inch wheel.. http://www.jconcepts.net/shop/double-dees-17-rc10

If the organisers are really going to stick with the vintage rules, then a set of Wild One rear shocks and from memory a set of coil overs and collars from an RC10 will give you some softer rear shocks.. Even a set of Monster beetle rear CVA's (with the MB shock mounts if needed) wouldn't be too bad, and springs shouldn't be an issue with CVA's..

OH, and if you are allowed to use Tamiya re-release cars to race, then why shouldn't you be allowed to use a MIP re-release ball diff in your Frog? ;-)

[Mad Ax 9329]

Thanks - I was intending to go thru my parts bin and see what other knuckles I had that could be made to fit.  The screw-together nature of the ORV front-end even lends itself to having knuckles from a totally different car fitted - although that might not strictly be period-correct  

I think I have a Monster Beetle rear shock mount - I acquired a collection of MB parts a very long time ago - that should give a nicer back-end.  I'm sure I've got some Tamiya CVAs lying around, or can get some more.

The rules are not actually super-strict - using modern shocks in place of vintage ones is fine, provided they're not of a totally modern design (like big-bore shocks, piggy-backs, low-friction coatings etc).  I don't think anyone would complain if I used any kind of Tamiya plastic shock.

Like I said in post 1, this isn't about me taking it seriously and trying to win - I'm not that good - I just want something that's not going to be a real nightmare to drive.  My memories of driving the ORV with Grasshopper wheels and tyres and a Super Stock BZ is of a car that basically goes round and round in circles and won't hold a straight line over any kind of bump

[Mad Ax 9329]

Hmm, so it appears the Double Dee 1.7s aren't a direct fit on the Brat wheels...  they're quite loose and floppy around the inner rims and aren't locked in place like the stock tyres are.  I'll have to investigate how best to glue them - possibly direct to the inner part of the wheel, rather than the locking rims...