need help with a Kyosho ST-R truggy

xrc10racer · Jul 20, 2009

I'm new to the site and would like to say hello to everyone! I have been in the RC hobby for a long time. I have not raced in the last 5-10 years though. Just bashed around the yard and at the motox track. Recently I found a nice local outdoor track. So I got the itch and decided to build something for racing only. I was looking at an AE RC8T then I found a Kyosho Inferno 777 ST-R. Yeah....it's a little old. But the kit is brand new(un-assembled in the box)and the price was excellent. The only other 1/8 scale Kyosho that I owned was a USA-1 nitro back in the 90's. So I really know nothing about Kyosho kits. After seeing the availability of the ST-R parts....I'm kinda thinking I should have bought the RC8T. But I'm going to stick with my plan. Plus it is cool working on something completely new to me. So now I have many questions!
1)Can I put a pull/roto-start engine in this chassis?
2)I have read that these trucks are not so durable. What parts should be upgraded to aluminum that are know to break?. What parts should I have extras of in the tool box?
3)Any ideas on a set of big bore shocks-not Kyosho?
4)Ideas on diff oil weight?...hard packed medium size track.
5)Will most 1/8 scale exhaust manifolds fit this truck? I already have an almost new JP-2 pipe but there is no manifold. What company sells just a manifold? I was thinking of OFNA or ?
6)I plan on getting a LRP .28 engine. What are you guys running for truggy engines? I understand Novarossi, RB and etc are nice. But I'm trying to stay on a budget with this project....for now at least!!!!hahaha
7) What is a good store on-line to buy stock and aftermarket ST-R parts?
8) Besides the chassis and shocks. What was changed on the new ST-RR compared to the old ST-R?
I would appreciate your input and help!!!!

robmob · Jul 21, 2009

1)Can I put a pull/roto-start engine in this chassis? Yes you can. Chassis really has nothing to do with whether you can use a roto or pull start.

2)I have read that these trucks are not so durable. What parts should be upgraded to aluminum that are know to break?. What parts should I have extras of in the tool box? They can take a fair amount of abuse and while aluminum parts tend not to break, they do bend or cause what they are attached to to bend. Stick with the plastic arms and get some spared for your pit box. About the only part I was not happy with was the silver cast aluminum carrier that came with the kit. I upgraded to a machined aluminum ones by King Headz. I also used a set of King Headz rear hub carriers.

3)Any ideas on a set of big bore shocks-not Kyosho? I would just get Kyosho.

4)Ideas on diff oil weight?...hard packed medium size track. Check the manual and start with the neutral setup. You will need to adjust from there depending on your driving style.

5)Will most 1/8 scale exhaust manifolds fit this truck? I already have an almost new JP-2 pipe but there is no manifold. What company sells just a manifold? I was thinking of OFNA or ? Any 1/8 scale manifold will fit. I always got a manifold by the same manufacturer as the pipe I was using.

6)I plan on getting a LRP .28 engine. What are you guys running for truggy engines? I understand Novarossi, RB and etc are nice. But I'm trying to stay on a budget with this project....for now at least!!!!hahaha I have a Ninja .21 in mine along with a Ninja pipe and manifold. This is the original Italian version and not the current Japanese version.

7) What is a good store on-line to buy stock and aftermarket ST-R parts?See below.

http://www.amainhobbies.com/advanced_search_result.php?keywords=st-r&x=0&y=0

http://www.stormerhobbies.com/cgi-b...&mterm=Kyosho&oterm=&uterm=&sthumb=on&smode=0

8) Besides the chassis and shocks. What was changed on the new ST-RR compared to the old ST-R? You got the main changes. I believe it's also a little wider. The rest are just some minor tweaks that probably don't mean much to the average driver.

The stock width of the ST-R is a little narrow. You may want to pick up some wider offset wheel hubs to help stabilize the rig.

You have a great truggy that will treat you right. About the only thing I would change on mine is to add the ST-RR chassis so it matches today's truggy lengths.

Tmaxx96 · Jul 21, 2009

:goodpost:

MotoGod · Jul 21, 2009

I'm running an LRP 28 in my XRay Truggy, and I can tell you this...you won't crave any additional power that's for sure! It's an ANIMAL in a Truggy. It doesn't sip gas though...it chugs it. I run a 7.5mm restrictor on mine and it helps a little bit....but it likes some fuel for sure.

d8 rider · Jul 21, 2009

xrc10racer · Jul 23, 2009

Thanks for all your replies!
I had some extra time and found tons of parts and info on this kit.
I was looking at Kyosho offset wheel hubs. Are these any good?? They are just so cheap $$ compared to other brands.
I found a ST-RR chassis, rear brace and universal shaft for around $100 brand new. Kyosho made a high priced ST-RR conversion kit but it did not include big bore shocks and other parts :\. The track I race at is not too big. Plus I need to keep this on a budget. I think I would benefit the most from the shock upgrade. Plus I have read stories about bladder problems on the ST-R shocks. My overall goal, for now... is to make it durable. All of my parts will be coming in the mail. The new chassis only gives you handling improvements. And it's not like the stock chassis will fail... lets hope not!!
What do you think I should do first?.. chassis or shocks?
I plan on getting stainless hardware, aluminum steering knuckles, al. rear hub carriers and offset hubs right away. thanks again

robmob · Jul 23, 2009

I would skip the chassis and shocks for now and get the other upgrades you mentioned.

I would also skip the stainless hardware and get alloy steel screws from either Tony's Screws or Hexcrews. Either one will sell a conversion kit.

Stainless screws are crap because the heads easily strip.

Gee · Jul 23, 2009

Man you got some good help already. I get my screws from Tonys also. I stock up on the individual packs of common ones vs buy kits just because the differnt RCs I have.

Not knocking the LRP Z.28R but it is discontinued. You may find parts down the road pretty hard to come by. Other then the engines already linked to earlier there is the LRP 30 out but haven't heard a lot on it. Axials are good engines for the budget minded for under 200. I've tried the .28 and .32 and haven't got any complaints. I only bash though.

The STRR does have stronger differentials in it. The ST-R is missing two of the smaller gears and a cross member is all. It has the two big sun gears and two small gears with a one cross member where the STRR has the two big ones and 4 small gears with two cross members.

The STRR Bellcrank/servo saver is a good upgrade for the st-r. It was an improvement on mine.

When I was converting my ST-R to the STRR I got a pair of the OFNA Jamming XT (I think) Big Bores for the rear and Kyosho STRR Big bores on the front. The OFNA were less expensive and were easier to get a hold of at the time. They also have the threaded adjustments on them. I haven't had any problems with the bladder on the Kyosho Big Bores up front.

I think the shocks made the most noticable difference when I did mine as far as upgrades. The improved handling of the longer chassis wasn't as noticable to me. Once again a basher.

Mine has held up really well. The only parts that have broken on mine were the front arms due cutting the corner to close and clipping poles. Haven't broken the rear arms. I have had the Bevel gear strip on mine also but once again I think it was more due to user error on a reinstall then the actual part giving out. I believe robmob also mention the carrier are worth upgrading.

xrc10racer · Jul 26, 2009

Gee said:
Man you got some good help already. I get my screws from Tonys also. I stock up on the individual packs of common ones vs buy kits just because the differnt RCs I have.

Not knocking the LRP Z.28R but it is discontinued. You may find parts down the road pretty hard to come by. Other then the engines already linked to earlier there is the LRP 30 out but haven't heard a lot on it. Axials are good engines for the budget minded for under 200. I've tried the .28 and .32 and haven't got any complaints. I only bash though.

The STRR does have stronger differentials in it. The ST-R is missing two of the smaller gears and a cross member is all. It has the two big sun gears and two small gears with a one cross member where the STRR has the two big ones and 4 small gears with two cross members.

The STRR Bellcrank/servo saver is a good upgrade for the st-r. It was an improvement on mine.

When I was converting my ST-R to the STRR I got a pair of the OFNA Jamming XT (I think) Big Bores for the rear and Kyosho STRR Big bores on the front. The OFNA were less expensive and were easier to get a hold of at the time. They also have the threaded adjustments on them. I haven't had any problems with the bladder on the Kyosho Big Bores up front.

I think the shocks made the most noticable difference when I did mine as far as upgrades. The improved handling of the longer chassis wasn't as noticable to me. Once again a basher.

Mine has held up really well. The only parts that have broken on mine were the front arms due cutting the corner to close and clipping poles. Haven't broken the rear arms. I have had the Bevel gear strip on mine also but once again I think it was more due to user error on a reinstall then the actual part giving out. I believe robmob also mention the carrier are worth upgrading.

Did you ever use your stock ST-R shocks? These are the ones I was questioning.
I like OFNA shocks too. But everyone in the forums seems to like the Kyosho Big Bore shocks the most.
I thought the difference between the STRR and STR diffs were the bevel and pinion gears. They are now made of chromoly steel. I do not have the kit yet(will be here on the 29th from the brown santa truck!). I already got a pdf manual and the diffs show four smaller bevel style gears on two cross members in each diff. I think the ST Sports Ready edtion has a 2 gear set-up NOT the ST-R. I'm I correct?? I think if I keep them shimmed and maintained good, I will be fine for now in that department. Besides it has been years since I've raced. I doubt I could even run long enuf to finish the Main. I'm picturing a wildly out of control cart wheel with a broken a-arm :hehe:

Gee · Jul 26, 2009

LOL. Yeah, it's like spinning donuts and fishtailing all over the place and everyone thinks your are doing it on purpose. "Man you sure are a good driver!"

That must be the difference. I traded a Losi XXXNT for the Kyosho ST US Sport truggy. So that's what I was referencing. That good the diffs are beefed up. Actually I never had any problems with the internal differential gears. I only added the other gears becuase I had some sitting in front of me when I was doing the diff fluid. The US Sport did have the spiral bevel gears on it. They weren't made of any special material as far as I could tell. Finding the differences when upgrading from the rtr to the strr has been a bit of a challange. I may still not have the strr differential gears if that is the case.

Which PDF are you looking at. I went to download a ST-R manual/exploded view but don't see one here.

http://www.kyoshoamerica.com/manuals.php?category_id=1

Just the STRR, ST 2 US SPORTS, and then US Sports. I was going to see if the ST-R has the same stock shocks as the sports one.

This is what the stock shocks were on the US Sport next the the Kyo Big bores on the front and then next to the OFNAs on the back.

I had a hard time swollowing the 150.00 price tag on 4 Kyosho Big Bores. So I used the stockers and a set off the Raze St for long time. I kept getting sniped on ebay when ever I bid on a set. The OFNAs came first and a month or so later the front Kyoshos. They seem to be pretty evenly matched in my expereince. The ofnas have the adjusting ring and all the treads to catch the dirt and grime the Kyosho use the spacer method. Made spacers out of some PVC pipe for the Kyoshos.

I found this picture. I don't remember the exact details but I got the ofna shocks off ebay and either the wrong retainers were included for the springs or maybe it was no big bore springs themselves. I wanted to try them out real bad cuz the shocks I had been using were leak prone even after a rebuild. Anyway I came up with a way to use them and they actually were pretty good this way. Better then the ones I had on it. I got some rustler springs to take over the duty until the right parts got here.

xrc10racer · Jul 26, 2009

I'm 99% positive the ST-R shocks are different than the RTR. The pictured you showed looks like they have plastic bodies and caps...the ST-R are aluminum. I found a complete list of parts are needed to convert a ST-R to a ST-RR.http://www.infernosonly.com/Convert_your_ST_R_to_an_ST_RR_s/400.htm
Here is the ST-R manual so you can check was is different on a RTR...http://www.infernosonly.com/Download_Kyosho_Inferno_Lazer_and_Ultima_Kit_Manuals_s/25.htm
This is a great store with tons of info and an awesome stock of Kyosho parts!

xrc10racer · Jul 30, 2009

Well I got my kit and started the build

So far I'm very impressed with the fit and quality of the parts.... except for the diff ring gear and pinion. The spiral cut teeth seem extremely thin, I can see why these often fail. I shimmed them tight and used some Amsoil synthetic grease. Next year I plan on upgrading to the ST-RR ring+pinion gears. The internal parts are the same as a ST-RR.
I did come across a problem I was worried about. The engine will not fit into the chassis correctly. The roto-start backplate is hitting the chassis before the motor mounts are flush/square. The rear of the motor is tilted up and the mounts are not sitting flat on the chassis. There is over a 2mm gap between the motor mounts and chassis. The chassis is countersunk for the engine case and not the roto-start. On the engine: the roto-start is over 4mm lower than the case. I already had to grind some material off the motor mounts just to bolt to them to the case. Those also did not clear the roto-start. That was an easy fix but the motor needs to be level or the gear mesh will be shot. If I put spacers in...that would also change the gear mesh. So I thought about just grinding a spot in the chassis for the roto-start to clear. But going 4-5mm into a narrow section of the chassis... prolly not wise. I'm using all stock Kyosho parts and a Sirio S30 engine.
The engine is brand new and I don't want to convert to a starter box. And I really shouldn't spend more money right now. So I'm trying to make what I have work.
Any ideas for a fix?
Are they any aftermarket mounts that are taller?

Scrogg · Aug 5, 2009

See if the RTR engine mounts will fix the problem. Most RTR engine mounts are for roto or pullstart type engines.
Me personally I'd buy a starterbox.

Gee · Aug 6, 2009

I've had the same problem your having with the mounts. PIA they are. I've used spacers to lift the whole mount up. Then it hits the drive line so had to grind one side down. Also ground away as much of the back plate on the bottom of a couple of engines to help also. I got some engine mounts along with some other stuff from some guys that converted their truggies/buggies to brushless. All the parts got mixed together but I think the engine mounts that I am using now are from the Hot Bodies D8. It sits up higher and is actually easier to install/remove the engine. The mounting screws were larger to attach it to the chassis. So I found some in the junk drawer and got it working. At one time I also saw that they (Kyosho) has a single piece motor mount for the STRR.

Something like this one. http://www.amainhobbies.com/product_info.php/products_id/27458/n/Kyosho-One-Piece-Engine-Mount-Sirio

The more I looked the more I wonder what mounts I have installed on mine. They may be these ones.
http://www.amainhobbies.com/product_info.php/products_id/13618/n/OFNA-Engine-Mount

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