TRF502X, things to improve
 

Dear all,

When building the TRF 502X I have found some things that Tamiya or an aftermarket company could improve:

- the shock tower attachment on the front upper gearbox cover does have a wrong angle. This should be the same angle as the front kick-up. The result is binding of the front shocks when mounted according the manual. It can be solved by use of a double shock tower, but the shocks won't be square with the lower arms. The TRF 511 doesn't have this problem.

-The slots in the diff joints are too large, in this way dust can easily enter the "sealed" gearbox. To prevent this i used a piece of heat shrink to cover the slots. (only covering the slot that's inside the gearbox)

Some minor things:

-Where is the angled steering system from the TRF 511? I for the best steering characteristics the steering system should be parallel to the steering uprights, like was done on the TRF 511 and 501X.

-The rear shocks are not reversible like on the TRF 511. Shocks can only mounted on the front side of the suspension arms. BTW: I didn't like driving the rear mounted option on the TRF 511.

-The gear box housings are not fully sealed like on the TRF 201. A sealing edge is missing. The gearboxes are very stiff and secured with 6 screws, so hopefully there is no need for sealing edges.

-accessing the motor screws is not easy, an improved motor mount like on the B44.1 should be nice.

- a double slipper clutch, I like this option very much on the TRF 511

So hopefully tamiya releases soon an updated front gear box cover and improved diff joints.

The front steering has to be turned round 180 degrees so that the car steers better you have to dremel gear box housing.It makes akaman same as 511.

True, but you can also use 6 mm spacers to achive the same geometry

Steering
 

Hi to all,

...and its got some bumb steer ( neagtive ) in the last few bits of inboard travel on the front, which " opens " the outside steering angle. Still have no idea to shim that, because of not enough place...

After driving 501 ( orig and AC GTO ) and 511, i am a bit dissapointed:
- the front whishbones start to wobble after 6 Packs inddor
- still no parts availible here


Greetings from Switzerland
Maurice

seems like 502x was released too early

not funny....
 

it seems like Tamiya has lowerd the quality to Schuey, durango and co, if the official price of the 502 would be the same as the others, i would say okay, but for more money i want more quality...like Fiat vs. Porsche...

We will see...

Ive run my 502 now at 6 meetings and love it. Its kit standard and ive had no issues. Its certainly not a "bad" car, although you need to make a few tweaks, which you would do with any car you buy.

502 is not bad
 

i am not saying the 502 is a bad car:
As you said, you have to do with a few minor tweaks.
The 502 is faster than the 511, at my opinion...which is not representiv, exept fo me
i owned the
- Durango
- every Lazer exept FS
- Cat SX, the older ones too
- xxx4
- B4
on these cars you need the dremel, on 501/511 not, which was outstanding, unique selling proposition, what ever ou wanna call that...

I just hope tamiya will come back to the " old " quality, as for me the problem is time, not money. ( sorry to say that in that way, i know no other words ), i would by an upgrade at an instant...

You dont need to dremel the 502 either? At least ive never felt the need to anyways.lol

Dremel
 

if you do change the steering to get enough lock on the outside, you have to.
Otherwise it bends, or you have to drive around like an old Lazer...steeringwise

I disagree, it's a great car. But there is room for improvement!

I would like to hear from someone that had both cars which is faster or better and in what areas...as I am not convinced the 502 is faster than 511...but I have not driven or even seen both cars on track!
...anyone???:confused:

511 vs 502
 

indoors both cars are fast, 511 seems calmer, the 502 better if you have to change direction fast, for me 502 is faster, because its more direct in the drivtrain. ( Indoors on carpet )
I think you should try, then yo will know wats faster for you...

The problem is that on carpet you have so much traction that some problems are "hidden". When you have a slippery surface like dirt or clay, then the problems are magnified.
An advantage on carpet can be a disadvantage on dirt....
That is why I try to understand the 502's "character".

My 502 was really nice yesterday at Worksop. Very easy to drive, it was my first time out so I'm sure it will get better aswell With a bit of help.
Went from Durango to the 502! Love it!

what differences did you notice compared to the DEX?
is the steering as good as the DEX?

The DEX feels like a truck, the 502 is more agile,more sensitive for me

The DEX is great indoors when you dont have loads of grip however go outdoors in the dry and the car is a nightmare to stop grip rolling. I had mine for a while and tried loads of things to settle it but just couldnt manage, maybe im not good enough??

The 502X was instantly smoother and calmer than the DEX and that means that i can push if i need to without getting bit!

I loved the Durango branding and the team are a very helpfull bunch however the 502X does seem to me to be the better car for a medium ability driver.

I made the Lee Martin steering mod, which only took 20 mins and the car had no probs with a lack of steering.

Hope that helps!

I do not understnd the discussions about the quality of the 502. I owned the 501 first and didn't recogize any decrease of the quality. The only thing I really don't like are the screws which are still far too soft.
The issue with the front damper stay, btw, were solved with some spcers, as discribed at trfracing.co.uk.
Some noticed that the steering is not angeled any more, so there is a bit bump steer. I don't think that this is bad as it reduces the slip angel on the front wheels when the car understeers. So that may be useful to improve the handling.
I think the 502 is really awsome and I'm looking foward to drive it outdoors.

Yes, it is nice to hear this! I can understand the comparison and was very helpfull!
Thanks!:thumbsup:

maybe one should write, the car is not finished, compared to 501 and 511?
We are complaining on an very high level, if you compare the 502 to other brands?
The bumb steer thing is exremly driving style related some like it, some don't.
As i am having a lot of experience with real cars ( fwd), slip angle is varied with steering, so i don't like bumb steer, "classic" rc drive style seems to be the same? Most common setups wont work for me.

To come to an end, i will stick with the 502, and redesign the steeringrack a bit.

The word "quality" has many meanings so I do not know how each person translates it...

The quality of the materials and parts is there for sure... what I do not understand is why some small flaws (damperstay angle, soft screws, steering bellcrank) were not corrected from the factory.... and the owner/racer must modify to make it work at it's best!? if it is easy for me and you to see these flaws, then I am sure it was easier for Tamiya!

Also when you have such a good base (TRF511) people expect the new car to be a big improvement from the box.... is it????:confused:

@floudas103: yep.

You could not have said it better! That is how I feel exactly... I think a 512 is on it's way!;)

I am an owner of a 501 and thinking of what to buy: 511 or 502 I just can't convince myself to buy the 502! The biggest plus is the support it will get (from Lee and other sponsored) in setups and the 511 (which I think is the safest bet) is already not supported as much...

The TRF range of offroad cars are not for everyone. If you're on a budget, stay away (you'd be better of with a B44 then), but if you're serious about your racing and expect results, this is the car for you. The easiest solution to overcome the spares issues are buying two kits, but its obviously also the most expensive.

Once the steering mod is done, the car should feel like the 511 since the suspension is the same.

Couple of points:

1. The spacers on the front shock tower do not fix the angle issue, they stop the shock binding but do it by making the shock a different angle to the front kick up, which is not ideal, you still don't get linear movement. I believe the 511 had an angled front shock tower?

2. The steering mod does not turn it into a 511. The weight distribution, steering (again due to the kick up etc, and the massive flex built into the steering mechanism), and flex all remain different on the new car. I also don't think it's possible to match camber link angles between the 2, though may be wrong.

3. Therefore the "shaft drive version of the 511" blurb is misleading really, it's more different than that!

Personally, I find the 502 a better jumper, and smoother, but with less grip than the 511. Also not convinced yet that the steering mod is an improvement speed wise...

It also feels to me like a car designed and sold, with the key testing bit missin from the middle. As someone else said feels like obvious bits are missed on it!

Shame, as I am a total Tamiya fan boy, and I will be sticking with the 502, but to be honest, I'd recommend the 511 instead!!

I know where a good 511 that has you name is Amish!!! I have a present for you this weekend:)

me too!! he has one beauty!

are you serious?

tamiya release a car that is not geometrically correct from an engineering standpoint and you still disagree with the car being released too early.

I hope tamiya release their mistake with this problem. I personally would be very wary of future releases. I mean I love their cars, but the newer ones, including the 201 has had a few teething issues.

funny how most of the pros are going backwards since running this car

agree;)

Well, I do agree in most points. Above all, the screws are a big issue in my eyes as this problem is known for a long time.
I can't say anything about the steering problem by now as we only have an outdoor track here which is still being renewed and, most of all, the wether is, lets say, quite bad :-)

Really...

Please name one........

I think with any car it takes a bit of time to get the set up right. Tweaking a few bits etc. I got a 511 late on, by that time I had a list of things I needed to get, hubs, steerting brace, weight kit, springs....

The 502 is still a new car, most drivers have had very little time to run the car properly on all surfaces, I would say it's too early to say if the top boys will be going back to the 511.

I'm waiting for the TRF512:D:D:D

Sounds a little like the classic bullshit on that always go with a new car.
The car is just a few months old and it has not even had a chance at the track yet. Give this car a bit more time to prove its worth before you talk shit about it. Then I have difficulty understanding me in some who are discussing how bad the car is when it in fact they not even have the car.
I just bought a 502 and do not hesitate one second on it. The only negative is the spare parts availability. Have just changed from Durango to this car.

A bit gutted to read this, im not the best with car setups etc and sometimes all of this shizzle really confuses me!!

On the other hand, if the car is crap and not designed right im sure Lee Martin/Tamyia will fix it, let us all know what to do with it then it will be even quicker cos mine was awesome last weekend!


Actually, im over the moon its got problems as i will be quicker again when its sorted!!:thumbsup:

Nobody said the 502 is crap or shit...:o
we just discuss if it is better than the 511! a step forward!
and as mentioned we all agree that both cars are at the top of our list for 4wd buggy.
we just don't understand why some small flaws were not corrected so it can be "perfect"!

We are all in this thread because we have chosen Tamiya and most definite will buy again Tamiya!:thumbsup:

Yeah agree with the last post, I don't see a problem with discussing it's flaws, I can't stand threads where everyone has to either claim perfection, or it's rubbish, and nothing in-between! I haven't said it's slower than a 511 either, not convinced either way yet!

For myself, a wishlist of hopups/changes would be:

1. Someone to design a wedge system for the front tower to angle it with the kickup (probably need a new tower too for that!)?

2. Aluminium steering, the 511 Ali steering arm had a better bearing fit which meant slop could be reduced. The 502 steering slop is horrific! If possible angle it too!

3. Carbon thinner camber link mounts to enable lower inner positions!

4. Diff height option (not sure it's doable)

5. Gear diffs!

6. Bigbores for bling!!

i think Viktor, Marc and lee's results on the FIRST outing with the car at the petit speak for themselves! 3 in the top ten of a very competitive meeting.
My only issue with the car is parts availability (some bits) at the moment. this is being sorted by a few people.
i think lee winning a few rounds at the reedy race against the best in the world shows the cars pace:thumbsup:

Amish, the alloy steering linkage has been done and angled forward;) speak nicely to who i pm you and i'm sure he might help you out:thumbsup: