Building my F201 Renault R25

[DeeMiller 1]

Last saturday we visted a modelshow in Lingen (Germany) and we saw three F201 (4WD), an offer we couldn't resist: € 59,- each...

So we bought them.

This chassis is just amazing!

Double wishbones and pushrods, just like the real thing, excellent![H]

It even comes with full ball bearings, oil shocks and two ball diffs!!!

First pics:

It's going to be a Renault R25...I already got the decals for it (the Ferrari decals are for sale).

I also want it to look like the real thing so that means: rear wheel drive.

To be continued...

 

Dee.

[DJTheo 2]

It's going to be a Renault R25...I already got the decals for it (the Ferrari decals are for sale).

I also want it to look like the real thing so that means: rear wheel drive.

I thought the R25 was FWD? []  (just kidding, I know you reffer to the F1)

Making a 4WD chassis 2WD usually makes it bad handling as they have different mass distribution and suspension setup, so might be better to use a RWD chassis like F103 if you plan to drive it.

Cheers

 

[clarkey 0]

It is a great chassis (to build) i have never driven one. Look forwad to seing what you do with this one

[Corpse Thrower 16]

I smell a custom RWD chassis coming up!!

I had a look at mine, you may be on to something there Dee......

[DeeMiller 1]

Making a 4WD chassis 2WD usually makes it bad handling as they have different mass distribution and suspension setup, so might be better to use a RWD chassis like F103 if you plan to drive it.

Cheers

 

Let me put it in another way: 4WD gives better handling.

RWD on the other hand is more challenging (and more realistic which I prefer over handling, I'm a bad driver anyway []).

Weight distribution is one thing, good tires (A and/or B-compound) another.

Looking at the chassis, the weight distribution is about 60/40 so good front tires are essential.

Also the ride height on the front must be lower than the back (which isn't when building according to the manual).

I also changed the steering set-up because it varies during suspension travel (same issue as the Hummer), now the ball connector is on the underside (at the wheel), case solved.

I had to cut away some plastic of the ball connector joint and added two washers on the steering plate (I also added two ball bearings) to give it some play over the lower wishbone.

I don't use the stabilizer plate because I want to make front and rear stabilizers myself. 

Set-up:

Front: camber -1 deg, toe-in -1 deg.

Rear: camber 0 deg, toe-in 1 deg.

With FWD, the toe-in should be 0 or +1deg.

I love this chassis for it's technic and opportunities to adjust the set-up!

Now that I'm building it I can say: it's a brilliant scale design!

The F103 isn't that realistic...[+o(]

 

Dee.

PS I have understand from another F1-forum the ball diffs are quite tricky (too tight: bolt breaks, too loose: less or no counteraction and the diff could melt in the worst case).

[DJTheo 2]

Let me put it in another way: 4WD gives better handling.

RWD on the other hand is more challenging (and more realistic which I prefer over handling, I'm a bad driver anyway []).

Didn't say anything against that, only that 4WD chassis made to 2WD handle even worse then chassis which were designed for 2WD.

Weight distribution is one thing, good tires (A and/or B-compound) another.

Looking at the chassis, the weight distribution is about 60/40 so good front tires are essential.

Also the ride height on the front must be lower than the back (which isn't when building according to the manual).

As above 60/40 weight distribution isn't great for a 2WD car, look at 2WD buggies and pan cars to see how back the motor is. Also RWD vehicles have usually a  different front caster angle which you can't change easily as camber. Tires aren't a real solution to bad handling or unsuitable weight balance. Also what would ride height affect???

 

I also changed the steering set-up because it varies during suspension travel (same issue as the Hummer), now the ball connector is on the underside (at the wheel), case solved.

I had to cut away some plastic of the ball connector joint and added two washers on the steering plate (I also added two ball bearings) to give it some play over the lower wishbone.

I don't use the stabilizer plate because I want to make front and rear stabilizers myself. 

Set-up:

Front: camber -1 deg, toe-in -1 deg.

Rear: camber 0 deg, toe-in 1 deg.

With FWD, the toe-in should be 0 or +1deg.

I love this chassis for it's technic and opportunities to adjust the set-up!

Problem is setting up needs knowledge, experience and alot of testing, so such a-priori changes don't lead anywhere unless you have alot racing experience and knowledge, so would better recommend start from the factory setup (even if its for 4WD) and start with one change at a time, as with many changes you can drift quickly far away from the "optimal working point"

Cheers 

[irenL 0]

diff setting is critical with 2wd, yes..

and while you're at it, run the smallest spur and biggest pinion you can find. Just found a 37T 48dp pinion sometime ago.. I'll probably throw it onto some 2wd pan chassie...

[miramar 4]

Dee, I'd like to add that even though you discovered the F201's features a few days ago, it has actually been on the market for about five years. Accordingly, a lot of very skilled racers have collected a lot of experience and knowledge about it, not only by "table-top" testing and guessing, but by running countless laps on many different tracks. So why try to "re-invent the wheel"? I appreciate that you want to set it up as 2WD, so a few of the setup tips provided by the expert racers may not apply, but are surely better suited as a basic setup than pure guessing.

At the time the F201 was hot (relatively), David Jun was one of the most successful F201 drivers. His setup proved to work very well and was copied by many other drivers. It was based on a lot of knowledge about handling and setup of RC cars in general and actual testing and racing of the F201, and can't really be easily dismissed:

 http://www.formula1-rc.com/Default.aspx?tabid=151

 

 

[DeeMiller 1]

Guys, guys, guys, I'm not trying to re-invent the wheel, it's just that I bought a (cheap) fantastic car which I never looked at until now.

I like it for it's scale look and no, I don't want to be a good driver but enjoying the building and share the pics with you guys.

I want to drive it just for fun, not to be a top racer but thanks for your concern.[:S]

Anyway, the car is equiped with a 15t VRX Modified Corally with a Jamara ESC.

Here are the first pics of the chassis:

This is how it looks when unpainted.

I think that's a shame because all those lovely details don't come out that way.

Painted the shocks and some parts of the chassis (gun metal).

Standard unpainted rear end.

Much better, don't you think?

This is the standard connection of the rear wing.

Cut off the two bars and drilled holes in them.

Much better.[<)]

To be continued.

 

Dee.

[DeeMiller 1]

Adjustable rear wing...lovely![<)]

 

Dee.

[DeeMiller 1]

Also what would ride height affect???

As you can't adjust the front wing (it's fixed), I'll lower the front (and/or raise the back end) and set the rear wing to "speed" (top hole) instead of "downforce" (lower hole).

But I don't think it will provide that much more downforce to the front wheels though...

 

Dee.

[DeeMiller 1]

Making of the rear stabilizer:

I used a 1,5mm stainless steel rod.

Moved the ball connector to the other side to create a hole for the rod.

About 1mm clearance between the axle and the pushrod...

And it works lovely![]

Now I have to figure out how to do the same thing at the front...[^o)]

To be continued.

 

Dee.

[Zjor76 0]

You know what Dee??

Just do it!! [Y]

I was only looking at getting myself one of these F201's last week and doing the same thing.. (you know... accidentaly on purpose forgetting to put the front ball diff, bones and centre shaft in...[:$])

 I have F102 and F103RS, so to get an F201 is getting all the more closer to a complete F1 chassis line up.

Love the special painted bits!!

 

[Glitch 0]

Marty Lee Peterson has made a full time business of adapting and developing the basic F201, creating a range of 2WD and 4WD versions: some shaft driven, some belt driven, and now a direct drive version. Dee, maybe you should have a look at his site for some idea as to how far the F201 can be modded!

http://www.mlpmotorsports.net/ 

 

Enjoy the F201. Sure, its a complex and fussy beast, but its great fun... 

[DeeMiller 1]

Marty Lee Peterson has made a full time business of adapting and developing the basic F201, creating a range of 2WD and 4WD versions: some shaft driven, some belt driven, and now a direct drive version. Dee, maybe you should have a look at his site for some idea as to how far the F201 can be modded!

http://www.mlpmotorsports.net/ 

 

Enjoy the F201. Sure, its a complex and fussy beast, but its great fun... 

Indeed, a great site with gorgues bodies and modifications!

I can recall he's a TC member too, right?

Thx for the link, I already saw that site and I am already thinking of making a direct drive version (more realism) with custom chassis plates and a closed underside for "ground effect".

That way, I can add my Novak GTB 5,5t brushless in (more room for the ESC).

But that is something for the future.

If you understand RL race car physics, it's not a complex chassis but a real joy to set it up!

I love this chassis!

I'm glad I didn't sold it (my first intention)...[:$]

 

Dee.

[Glitch 0]

...If you understand RL race car physics, it's not a complex chassis but a real joy to set it up!...[:$]

 

I know you are not planning to race it, but anyone who has raced these cars know they are "complex" in the sense that often the smallest repair ends up requiring a major strip and rebuild (and recheck on the setup station). The aftermarket chassis's (3racing, MLP Cross etc) you get are much better in this regard, in that they are more "modular" and make working on the car easier. So ja, from a theoretical point of view they might be a 'real joy', but to race them take a certain enthusiasm for openwheel classes...

And yes, seems Marty is still a member here: "Dakota2763"

[cardesigner 0]

I love this build already, I can't wait to see the next steps!  I love the painted parts as well.

I agree with you, the 4WD aspect of this car bothered me.  I like how you are making yours RWD- I convert some of my TA02 touring cars to RWD and love how they drive.  Quick, light and responsive.  Sure they are a handful to drive but makes it more fun and challenging I say.

[DeeMiller 1]

Sure they are a handful to drive but makes it more fun and challenging I say.

That's what it's all about! Thx!

 

I know you are not planning to race it, but anyone who has raced these cars know they are "complex" in the sense that often the smallest repair ends up requiring a major strip and rebuild (and recheck on the setup station).

I think you are refering to the fact that one change (like changing camber) influences other set-ups (like toe-in).

In that way, yes, it's complex but if you understand that one adjustment leads to other changes in set-up, it's not that hard to understand.

I wish I had knowledge AND skill, that way it would be more easy to show some proof (sounds rather haughty, doesn't it?[A]).

But I hope you'll understand what I'm trying to do (not guessing but using RL physics to set-up an RC-car) .

Open wheel racing is not that different from touring cars though.

The major difference is the centre of gravity and air resistance.

In fact, a group C class race car isn't that different from an F1 car.

Aw 'ell, it's "just for fun" as cardesigner said on which I deeply agree upon![]

 

Dee.

[terry.sc 16]

Let me put it in another way: 4WD gives better handling.

4wd does not necessarily handle better. If the grip is high enough a 2wd car can be made to handle better every time. 4wd has the advantage on lower grip surfaces of sharing the traction between front and rear so the handling is more balanced.

Weight distribution is one thing, good tires (A and/or B-compound) another.

Looking at the chassis, the weight distribution is about 60/40 so good front tires are essential.

As the rear tyres have to power the car as well as grip, the 60/40 weight distribution is biased too far forward so you need more rear grip, not more front grip.

Also the ride height on the front must be lower than the back (which isn't when building according to the manual).

Lowering the front ride height will shift more weight to the front when turning in to a corner so increasing the (already high) chance of the car spinning out. It will also means less weight shift onto the rear coming out of the corners so more chance of spinning out when you accelerate. It is a basic setup on a 2wd chassis that the front should never be lower than the rear.

I don't use the stabilizer plate because I want to make front and rear stabilizers myself.

The stabilizer plate is not just an anti roll bar. It also stiffens the suspension (a good thing in a 2wd chassis) and protects the front suspension from damage in an accident.

Set-up:

Front: camber -1 deg, toe-in -1 deg.

Rear: camber 0 deg, toe-in 1 deg.

With FWD, the toe-in should be 0 or +1deg.

 

First as an off the shelf setup that would be very difficult to drive. For a 2wd not enough toe in at either end (you will need at least 2-3 deg at the rear) and zero camber will mean no rear grip at all except in a perfectly straight line.

I love this chassis for it's technic and opportunities to adjust the set-up!

Your setup doesn't include ride height, droop, damper oil and piston, track(you can adjust the car width a little) or spring and spring preload. Plenty to play with there. Unfortunately one thing a 2wd version would benefit from is more front caster but it isn't adjustable

Regarding the rear wing mount changes, the reason the rubber o rings are there is that if you have an accident the wing can flex. Bolting it up solid will mean an accident an easily break the wing.

Anyway, the car is equiped with a 15t VRX Modified Corally with a Jamara ESC.

I hope you've got plenty of space to run it. The gear ratio can't be lowered and being tucked inside the chassis there is no cooling for the motor either.

As you can't adjust the front wing (it's fixed), I'll lower the

front (and/or raise the back end) and set the rear wing to "speed" (top

hole) instead of "downforce" (lower hole).

But I don't think it will provide that much more downforce to the front wheels though...

 

Being 2wd you will need as much downforce as possible on the rear of the car, not the front. You want as little downforce as possible at the front to make it more stable at speed, these wings are tiny and have no downforce at low speeds when cornering. Changing the angle of the chassis (and upsetting the handling) to get more downforce on the front wing will also get more downforce from the rear wing, as that will also be angled more.

 

[terry.sc 16]

To

be effective that anti roll bar wants to be straight between the wing

mount and the wishbone mount. Having the bend in the middle means it

will flex inconsistently. Having straight links means the anti roll bar

will twist correctly.

MLP Motorsports cars are nice, one

fundamental difference of their chassis design is that with the direct

drive setup the battery pack and motor are moved back to give better

weight distribution compared with the standard setup.

Open wheel racing is not that different from touring cars though.

The major difference is the centre of gravity and air resistance.

...and the fact most touring cars are front wheel drive with

strut front suspension and no downforce whatsoever[]

But I hope you'll understand what I'm trying to do (not guessing

but using RL physics to set-up an RC-car) .

Remember that

although the car is smaller the ground is the same and the forces

acting on it are also still full size. Scaled up touring cars would be

able to go round corners at 200mph.

I think you are refering to the fact that one change (like changing camber) influences other set-ups (like toe-in).

In

that way, yes, it's complex but if you understand that one adjustment

leads to other changes in set-up, it's not that hard to

understand.

One change alters the handling in its own unique way

and does

not necessarily affect the other setups, but usually does. The handling

is sorted by adjusting every different change and learning how they all

interact is something that takes some time to understand. Make notes of

every setup change and what it does so you can build up your knowledge.

It does take time to learn and having many years experience I do

impress people whose car isn't handling well when I can tell them

several changes to make to their car at once, which transforms their

car. You might find this interesting, read at your leisure.

[8-|] http://home.tiscali.be/be067749/58/

 

[DJTheo 2]

If you understand RL race car physics, it's not a complex chassis but a real joy to set it up!

I am not sure what you mean with RL race car (as you have used this term several times before too) but if you mean real car racing physics, they might give some understanding about what effects what, but won't give you working initial designs and setups, as not all factors can be 1:10 scaled down, so you need alot of RC racing experience as others wrote. Also I doubt anyone of us really understands in depth modern racing car setups, aerodynamics etc except if he is doing it professionally, almost everyone else has just "google and TV program knowledge" as it can be seen also by the several corrections in this and the older Alpine M02 thread.

Cheers 

[Glitch 0]

Open wheel racing is not that different from touring cars though.

Dee, i know for you this is a theoretical exercise in car physics (summink i am not qualified to discuss) but from a racers point of view there is a world of difference in the experience of openwheel vs closed body racing. When the racing line is full of cars, open wheelers require much more caution and careful attention to line selection than touring cars. What would be harmless "paint swapping" between 2 cars in TCs would be likely disaster for both cars in open wheel racing.

I think you are refering to the fact that one change (like changing camber) influences other set-ups (like toe-in).

 

My point about the complexity of the cars relates not to setup but to engineering. For example, the integrated gearbox/suspension mount means that a slight blow to the suspension often damages a gearbox casing,  resulting in an almost complete suspension rebuild (and setup check). Even replacing an upright takes more work than a touring car. The drivetrain has more transfer gears than most touring cars, requiring careful work to get it free and smooth. Simply changing gear ratios requires either modding, or aftermarket components. As mentioned above, motor and ESC cooling is always a challenge.

Sure, i appreciate that you are approaching this car from a non-racers perspective... but i stand by my description of the F201 as fussy and complex.

Dont get me wrong, i enjoy the F201, faults and all. And i am enjoying your thread, and your enthusiasm for the chassis... Enjoy the build, whatever your goals are...

[DeeMiller 1]

Dont get me wrong, i enjoy the F201, faults and all. And i am enjoying your thread, and your enthusiasm for the chassis... Enjoy the build, whatever your goals are...

Yes, I enjoy this discussion as much as you do (don't get me wrong) and often lead to new perspective (thx for your extensive explanation Terry!).

That's also the intension of this thread: you got to start somewhere.

I just set it up and work from there (the hard part).

It would be silly to set it up like a 4WD when you want RWD though.

As for my knowledge, I base this on the game GTR(2) and my experience with the M02 Alpine with the Novak Brushless: it's rock stable (due to the modifications I added) and with these B-compound tires, it handles great (as far as I can judge because I don't have much RC race experience).

Much better when I used the standard F201 tires (completely worn out after less than an hour...).

So with this F1 chassis, I can take it one step higher due to the lower center of gravity and downforce (which I forgot to mention in the difference with open wheel race cars [] although Formula Ford, V-class don't have wings).

When looking at real F1 cars, I think this F201 has the same (or slightly less) weight distribution to the rear.

Anyway, thx for taking the strain to put up all the info/experience here (also very informative for others).[]

 

Dee.

 

[DeeMiller 1]

http://home.tiscali.be/be067749/58/

Thx Terry, nice guide (indeed, 90% there when using the right tires).

 

Dee.

[DeeMiller 1]

If you understand RL race car physics, it's not a complex chassis but a real joy to set it up!

I am not sure what you mean with RL race car (as you have used this term several times before too) but if you mean real car racing physics, they might give some understanding about what effects what, but won't give you working initial designs and setups, as not all factors can be 1:10 scaled down, so you need alot of RC racing experience as others wrote. Also I doubt anyone of us really understands in depth modern racing car setups, aerodynamics etc except if he is doing it professionally, almost everyone else has just "google and TV program knowledge" as it can be seen also by the several corrections in this and the older Alpine M02 thread.

Cheers 

You don't seem to have a lot of faith in other people's knowledge and I don't think your replies are very helpfull either (unlike Terry's and others).

It's not about who is right or wrong and it would be even more stupid not to discuss these things on a forum.

You can learn from each other instead of pointing people to their "faults".

Critics are welcome when constructive.

Thx.

 

Dee.