R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 02-12-2007, 06:06 PM   #1
Tech Rookie
 
Join Date: Feb 2007
Location: Virginia
Posts: 16
Default Bringing Grandpa out of retirement: Yokomo YR-4M2 Pro

I understand that the 1998 Yokomo YR-4M2 Pro touring car is practically a decade old, but how does it stack up to the super rc cars of today? I.e. X-ray, TC5, Mi3, TRF 415, Cyclones, etc...
How much have 1:10 4wd graphite touring cars progressed in the way of technology really? Is the 9 year old Yokomo really out dated? In stock form it came with upper and lower carbon fiber chassis decks, full ball bearings, 4wd, a front diff, adjustable camber, adjustable toe, ajdustable shock mounts, Yok caster adjustment options, and still has some aftermarket support today, supplying titanium hinge pins, titanium turnbuckles, front and rear sway bar kit, CNC anodized aluminum lower A arms front and rear, etc...etc...

Yes, the car is a grandpa, but can it still slug it out with the latest state of the art offerings from Tamiya, Associated, HPI, etc...? Perhaps giving it an update of Lipo saddle packs, Novak Brushless motor and ESC set-up, and the stickiest rubber, the decade old YR-4M2 could keep up? Once upon a time in '98, "at the NORRCA Road Course Nationals, Yokomo M2s dominated the event by taking first through third in the Modified Sedan class." -RC Car Action, 1998.

So what do you think? [BTW, the YR-4M2 is a pic I found on the internet.]
Attached Thumbnails
Bringing Grandpa out of retirement: Yokomo YR-4M2 Pro-yr-4m2-pro-naked.jpg  
PseudoScience is offline   Reply With Quote
Old 02-12-2007, 06:51 PM   #2
Tech Regular
 
daveaustin5's Avatar
 
Join Date: Feb 2007
Location: UK
Posts: 464
Trader Rating: 1 (100%+)
Default

In the right hands it'll be do fine. It wont be as quick as other cars around a corner because it appears to have a much higher center of gravity. My brother used to race a version of this chassis many years ago and he loved it. If nothing else I'm sure you'll have fun with it.
daveaustin5 is offline   Reply With Quote
Old 02-12-2007, 07:38 PM   #3
Tech Initiate
 
Th3NinjaPenguin's Avatar
 
Join Date: Feb 2007
Location: Redford, Mi
Posts: 28
Default

Wow.. i remember that car winning many titles back in the day.

I think its all a matter of drivestyle. At the local track, you'll see people buy the new XRay what seems to be every 5 months. Does it help? Well, someone shaved .02 seconds off of their lap, but maybe its something they did a little different in a corner or something.

Get out and race for a few weekends before deciding to change. That was an excellent car, and still is.
Th3NinjaPenguin is offline   Reply With Quote
Old 02-12-2007, 10:45 PM   #4
Tech Addict
 
AngryAsian's Avatar
 
Join Date: Oct 2005
Location: Melbourne, Australia
Posts: 550
Trader Rating: 4 (100%+)
Default

Save it!! save it!!

I'd just go and buy whatever latest chassis you can get your hands on (cheaply of course), and run whatever has the best parts support.

I think there merits of the new cars are relative. But principally these are:
1) Better balance (Newer cells are heavier and larger)
2) Better durability (Newer motors and the battery tech have raised the power levels. Most mod cars now have been built and refined along with the newer generation of cells. Things like diffs, and outdrives are much stronger/thicker than older cars. This is one of THE biggest differences. You can see the evolution of these cars fairly quickly. Invariably it's always, thicker CVD's, thicker outdrives, Stronger diff screws etc.!!)
3) Lower CG (This is one of those "fad" things right now. Low CG is marketed as the big ticket to race wins..)
4) Easier access and maintenance. (Some old cars are a nightmare to maintain. So many overlapping parts to take out. The newer cars are very simple and quick to work on.)

Are they really faster? I wouldn't have a clue. But if you start breaking things.. then at least the parts are plentiful, and there's tuning help around.
AngryAsian is offline   Reply With Quote
Old 02-13-2007, 09:46 AM   #5
Tech Champion
 
Join Date: Oct 2004
Location: Long Island, NY
Posts: 7,211
Trader Rating: 2 (100%+)
Default

I had a YR-4M2. It sucked!!! I got the kit when it first came out but then got out of racing for a year. When I went back to racing the car had no corner speed. I even talked to the racers that recommended the car in the first place and even they said the HPI RS-4 was a better car all the way around. That was the hot car. The TC3 wasn't released yet. I should point out my car had the tiny shocks. The big shocks (what is considered normal today) made a big difference.

So you are probably better off with a newer car. Lots of things are different and you will end up chasing your tail with an older car.

BTW if anyone in interested in collecting I still have that car with the original box and directions, and a couple spare parts. I'm raising money for a TC5!
jiml is offline   Reply With Quote
Old 02-13-2007, 12:22 PM   #6
Tech Addict
 
MrBlack's Avatar
 
Join Date: Jul 2006
Location: OC
Posts: 746
Default

One of the biggest reasons a new car seems faster is all the parts are new.

If you take a kit from last year and build it new it will most likely be faster in your hands then your current used car.

Also from my experience it seems like this:

On a scale of one to 10, 1 being first time running and 10 being World Champs like Andy Moore or Spashett it seems from 1-3 equipment makes a big difference then from 4-7 the equipment makes very little them from 8-10 it makes a huge difference yet again.

I am run Li-Po's and I am thinking of going back to my 414 because I can put the battery across the center and run the car super light out weighing any advantage of the lower CG of my 415 which requires me to run MUCH heavier to get proper weight balance.
__________________
TEAM ORION - AVIONICS - KYOSHO - KO PROPO - PEAK

"Racing is about the journey not the destination if it wasn't it would simply be called Arriving"

"The solution is people need to spend more of their efforts on promoting and finding more people to race with, rather then a personal quest to form a class that they can win at."
MrBlack is offline   Reply With Quote
Old 02-13-2007, 12:39 PM   #7
Tech Regular
 
sinisterRC's Avatar
 
Join Date: Dec 2004
Location: Miami
Posts: 444
Trader Rating: 7 (100%+)
Default

Quote:
Originally Posted by Th3NinjaPenguin
Wow.. i remember that car winning many titles back in the day.

I think its all a matter of drivestyle. At the local track, you'll see people buy the new XRay what seems to be every 5 months. Does it help? Well, someone shaved .02 seconds off of their lap, but maybe its something they did a little different in a corner or something.
broken record...broken record... broken record.....

XRAY HATERS!!!!!!!!!!!!!!
__________________
MUGEN Tekno - MBX6TE TEKIN
Custom Nitro Pro Mod
MRX6 under construction..
sinisterRC - High Performance R/C
sinisterRC is offline   Reply With Quote
Old 02-13-2007, 08:44 PM   #8
Tech Rookie
 
Join Date: Feb 2007
Location: Virginia
Posts: 16
Default

The YR-4M2 has a high center of gravity? My car sits about 9mm off of the ground, and the cells, ECS, radio and laid down servo are sitting on the bottom deck. If I needed to lower it any further, I could always shorten the shock lengths and add a little positive camber to offset the gained negative camber from reducing the ride height. When I was looking at the Yok MR4, HPI RS4, Tam 415 and so on, there appears to be a marginal difference (if any) between C.G.
Perhaps situating the 6 cells in the battery slot cutouts, thus allowing the cells to sit lower than the bottom of the chassis, could assist in lowering the C.G.

Yes, I agree too that new cars have new parts and thus unworn parts, but the YR-4M2 Pro I just picked up was ran about 5 times, and then sat in it's box in a closet for the rest of it's life. So it's practically a "newish" old car. (No scratched on the underbody, and the original tires look like they've gone about 10 feet.)

Odd how some think the car sucks. Didn't Masami Hirosaka win a bunch of Pro International races with this car? There must have been some sound engineering in the car considering it was $500 for the rolling chassis in 1998.

In terms of hard to find parts--well yes, parts aren't as easily around the corner like that of a TC3, or RS4, but I just picked up a spare rear drive belt from Tower hobbies today, and Integy and GPM Racing Products still have hop-up parts for sale, and ephobbies.com has titanium hinge pins and center shafts should I need them. (And complete YR-4M2 rollings chassis to serve as a parts car, can be had for $60 or so.)

Okay, I'll stop defending my ancient car now.

Cheers!
PseudoScience is offline   Reply With Quote
Old 02-13-2007, 10:06 PM   #9
Tech Champion
 
robk's Avatar
 
Join Date: Aug 2001
Location: Macho Business Donkey Wrestler
Posts: 7,587
Trader Rating: 22 (100%+)
Default

You will not have the roll center adjustability as far as hinge pin heights. Not sure how much you can do with the kickup. The belts probably wont be as free as never cars. Outside of that, I'm sure it will be fine. The biggest thing is that cars are now WAY more optimized to run on roadcourses. The YR4 cars were based on the offroad cars Yokomo made.

I think it will be cool to see how it runs against the newer cars.
__________________
A mutually re-enforcing cascade of failure

"Failior [sic] crowns enterprise." Robert Goddard

I-Lap Scoring Systems http://www.rclapcounter.com/
robk is offline   Reply With Quote
Old 02-13-2007, 11:02 PM   #10
Tech Addict
 
AngryAsian's Avatar
 
Join Date: Oct 2005
Location: Melbourne, Australia
Posts: 550
Trader Rating: 4 (100%+)
Default

PseudoScience..

It wasn't meant to be an attack. Just so we're clear.

But have you had a look at the current crop of cars.. the X-ray 007, the HB Cyclone... ?
Their topdecks are LOWER than the height of the motor. Usually reaching only 3/4 of the height of a 540 sized can.
Their layshafts are located lower down, spur gears requiring a cutout in the bottom of the chassis. Their diffs are very much lower as are their bulkheads. The bulkheads no not reach higher than the motor shaft level. (Rough measurement)
Even the bottom chassis plate is machined out to mount the motor "in" the chassis.
On these cars, the topdeck and bulkheads barely reach higher than the height of a servo that has been laid down on the bottom deck.

Have a look at the height of the steering assemblies. Cars like the TB EVO V have theirs barely 1mm off the bottom deck.

Have a look at the width of the new chassis. The cells now side barely off the centreline and the motor can hangs off by 1/4 of its length. This reduces the polar moment of inertia during cornering.
It's not much.. only a few MM here or there, but when the car is pulling 4G's on a carpet track every little bit helps.

Other things to look at:
Not so much how "new" the parts are, but their more robust construction
Pulleys - the newer cars have large pulleys and more belt wrap for greater efficiency.


To be honest - I'm not a good enough driver that the choice of chassis greatly reduces/enhances my chance of winning any race. But the newer chassis are indeed faster on track. I'm sure the Yokomo would still be fine.
But a newer car does make things eaiser. And really.. it's all part of the fun! Who doesn't like a new kit to play with
AngryAsian is offline   Reply With Quote
Old 02-14-2007, 03:42 PM   #11
Tech Champion
 
robk's Avatar
 
Join Date: Aug 2001
Location: Macho Business Donkey Wrestler
Posts: 7,587
Trader Rating: 22 (100%+)
Default

I wouldn't be worried about the cg. A lot of companies make a big deal that they lowered the top deck 3mm on the "new" car. The majority of the car's weight is motor batteries and servo.

Also, the FK04 is still probably better than 3/4 of the current cars with it's layshaft way up in the air.
__________________
A mutually re-enforcing cascade of failure

"Failior [sic] crowns enterprise." Robert Goddard

I-Lap Scoring Systems http://www.rclapcounter.com/
robk is offline   Reply With Quote
Old 02-14-2007, 06:31 PM   #12
Tech Adept
 
Join Date: Jun 2005
Posts: 182
Default

LOL...and I still have my YR-4M...the version before yours.
chumanji is offline   Reply With Quote
Old 02-14-2007, 11:46 PM   #13
Tech Apprentice
 
Teddygoat's Avatar
 
Join Date: Nov 2005
Location: Eston,South Africa
Posts: 89
Trader Rating: 4 (100%+)
Default YR4-M2

I bought a 2nd hand YR4-M2 and having started racing it again, I have found it to be awesome and very light compared to some newer models. I'm beating guys with newer Pro 4's and TC4's, I think at club level it's all about your driving.
Teddygoat is offline   Reply With Quote
Old 02-15-2007, 12:04 AM   #14
Tech Addict
 
clinehobbies's Avatar
 
Join Date: Sep 2005
Location: Maricopa, Arizona
Posts: 626
Trader Rating: 3 (100%+)
Default

It really does not matter what car you run if it is set up correctly and you are a good driver. Owning a high dollar current TC car does not make you a good driver half the guys that talk about setups for their cars blame their poor driving on the setup or their 2 month old chassis saying if they only had the 2 week old car they would have TQ'd. You can't buy your way to SKILL.
In most club races you will do fine with a old car if you really know how to set it up and are a good driver. My 0.02 cents
clinehobbies is offline   Reply With Quote
Old 02-15-2007, 08:50 AM   #15
Tech Regular
 
nagatahawk's Avatar
 
Join Date: Sep 2005
Posts: 349
Default

i used to have that very same model mr4, and ran it successfully against tc3's. but finally went to the tc3 which I still have today.

The tc3 was a lot more stable and durable. it also had the shaft drive which gave it punch in the infield.

I think with a few updates the old mr4 would will be a good club car today,
New batteries, maybe a 19t motor or a hot stock motor like a cobalt, new tires rp30's and a strutus body of course. an LRP esc, I still have mine today it's over 8 yrs old.

have a blast.
nagatahawk is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Temporary Retirement Racer_Chick Florida Racing 40 08-05-2008 09:44 PM
Bringing the hobby mainstream TomBlaze Electric Off-Road 177 04-17-2008 11:03 AM
Grumpy Comes Out of Retirement!!!!!!! skipstr Nitro On-Road 13 08-01-2006 11:42 AM
Bringing vintage RC up to date mikethemachinis Electric On-Road 3 03-28-2006 10:06 AM
GP Bringing Out 3600's NR Electric On-Road 167 12-28-2004 09:35 AM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 05:49 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net