R9 Body

[mattsedgley]

So the R9s been out for a good while now - those of you who have tried it - what's your thoughts particularly in comparison to the Stratos 3 and Speed 6.


Matt

[MonkeyNuts]

I still prefer the Dodge 3 over the R9, but i found the R9 alot better than the Mazda

None of them are as good as the Tamiya Ebbro 350R thou , ashame it only works on the TA05-IFS and TB-03.

Liam

[keitheroonie]

The R9 bodyshell is apparently a copy of the Audi R8, I was talking to Wayne Shaw (very fast racer) a couple of months ago and he swears by them.

[TryHard]

R9-R is ment to be very very front endy, especially if it the original version (not to be confused with the -F, thats the foam version) with the larger splitter. A friend of mine tried it, and likened it to driving a 12th scale, where it just turns, stops, goes...

Mazda 6 or Speed6 get my vote for sure, preferably the Protoform versions (never really got on with the HB versions...). Dodge is just too neutral/numb for my liking, although it does rotate reasonably well mid corner.

HiH
Ed

[mattsedgley]

Cheers Ed,

I've picked myself up an R9 - i thought it was an Audi R8 - the lights seem to give it that Audi look -

It felt good yesturday - quite grippy - plenty of turn in which is allways nice - It is however an F - I presume that this means it's higher down force or is there more to it than that Ed/guys??

Matt

[yellowshark]

Protoform Speed 6 for us at Bashley ; turn in outweighs the alleged instability. Like the Alfa on the less twisty tracks like Cotswolds

[keitheroonie]

Jan 2, 2009 23:25:55 GMT MonkeyNuts said:

I still prefer the Dodge 3 over the R9, but i found the R9 alot better than the Mazda

None of them are as good as the Tamiya Ebbro 350R thou , ashame it only works on the TA05-IFS and TB-03.

Liam

Unfortunately the Ebbro is a GT shell rather than a tourer, so it doesn't really count as it's not permitted in competitions, other than the Tamiya cup of course

[TryHard]

F actually means it's lower downforce... Hence it doesn't have a particularly prominent splitter.

Main reason is that over in the US, Foam tyre racing on carpet is still huge, and the cars produce huge amounts of grip. Downforce from the shell isn't really a massive requirement (at least front end isn't), so they have different treaments (smoother fronts, no splitters, lower rear decks) etc, all aimed mainly at streamlining the shells best as poss. Have a look at the R9-F and R9-R overlay below. Orange is the R, silver is the F.



Thats not to say they don't work on rubber, but thats just what their optimised for.

As for the shell... well, it's and Audi grille, but with Jag XF headlights

Ed

[lesbaldry]

For what its worth

I tried the R9 as far back as the Cotswolds, west London and at Bashley on the 008 and TF5 Shin

For me the shell had tremendous initial off power bite into corners but seemed to wash out on high speed corners when back to backed with the speed 6...it felt a little unstable too on the faster tracks.
It may be a shell that needs a little tweaking with the set up to get the best feel?...rear wing style/shape might be the key for various tracks?

I have yet to find a shell that beats the speed 6 for all round performance...Dodge 3,nice and stable but "soft"!

[mattsedgley]

cheers for the information guys! I've got a more fundamental handling problem at the minute me thinks.. however the shell was pleasing again today - This setup stuff is addictive! - Matt ;D

[TryHard]

Les, was it the F or the R version you were using? I have feeling (from recaling what you ran then) it was the F version... which would probably explain the front end washing out.

[lesbaldry]

Jan 3, 2009 18:28:54 GMT TryHard said:

Les, was it the F or the R version you were using? I have feeling (from recaling what you ran then) it was the F version... which would probably explain the front end washing out.

It was the F version....But even in this varient it "looked" as if it should of had more high speed steering than the speed 6 .....I thought I may have been running a too steeper wing?(Hot Bodies low down force should have worked!!)

[TryHard]

Steering is aided by the splitter more than anything else. It's why the latest versions of the R have a 2mm shorter splitter than before, to help reduce the amount of steering generated. The wing change will probably help change the balance a bit, but then your also just reducing your overall downforce.

HiH
Ed

[lesbaldry]

Jan 4, 2009 8:48:44 GMT TryHard said:

The wing change will probably help change the balance a bit, but then your also just reducing your overall downforce.

HiH
Ed

..A steeper rear wing should increase high speed rear down force and decrease high speed steering...overall down force : body shape/angle of attack

I have played a lot with splitters in 1/8th circuit and found them to be not too effective??,the important part of the shell for steering was the angle/shape of the front including the position/angle of the front screen (depending apon class) The critical position and angle of the rear wing was used to fine tune high speed steering..moving a rear wing/Gurney flap 3mm could make the difference of taking a fast bend flat out or backing off.

[TryHard]

Erm... if you change the wing to a less steep one on the rear of the car, you will reduce the downforce on the rear, ergo, reduce the overall downforce avaliable... same front + less rear = lower overall...

I did play around with wings quite a bit a while back, but always ended up back on the steepest one I could run, and then tuned the car otherwise. Making the car high speed stable by aero was a given. Bear in mind though this was with correctly cut down BRCA spec wings (25x40mm endplate, 40mm chord), which generally are a fair bit smaller than the out-of-box wings. That's not to say wings and there position don't have an effect (just look at all the cars at the euros running the wings as far back as possible), but with the restrictions we have on size, steepest wing, and as far back as the rules allow seems to be the best option.

I would hazard a guess that the 8th shells your talking about are pretty different in terms of shape generally comapred to touring car.... more wedge shaped. Hence why the splitter probably didn't work so well compared to changing the shape of the front body sections, mainly asthe front is guiding air over the top of the shell, in total acting like a giant air plow.

On a full scale car, the splitter acts to help generate low pressure under the car, mainly by stopping dirty air from the body flowing underneath the car.
In RC the splitter acts differently, simply as a) theres the scale effect (you can shrink the car, but not the air molecules) and b) we don't run smooth undersides... Hence why the splitters are fairly thick in section. However, they are working by simply guiding the air better around the body. Hence a bigger front splitter on our RC's works to help give more front end.
On the 8th, the wedge front is already doing some of splitters work already, whilst on the 10th tourer, theres a fairly blunt front end with lots of nasty flow..

I ran a DNA1 and a DNA2 a few times back to back a while, and the difference in the level of steering was pretty impressive, if you look at the front of the DNA's, you'll see the main difference being the addition of the splitter.... I'll let you work out your own conclusions on that.

I'll agree that the R9 should have a lot of front end compared to a mazda speed6, especially given the lower front end, and in -R format it certainly seems the case.

My last thought is why bother debating this when we both know the Speed 6 is best... hehe

[lesbaldry]

Ed have you ever been involved (hands on testing)in the development and homologation of shells including the efectivness of shapes,wings,so called splitters etc etc?

At national level 1/8th circuit used to run three classes..F1,Group C and....saloon

[TryHard]

Les, I can honestly say I haven't.

However, I know what I feel on the track, and I have experiemented with different wings etc on bodies, so I do know the effects of what occurs.

I still stand by my view that you whilst you may be able to get the balance better by changing the wing...you would be sacrificing some downforce to do so. Hence why, IMO, the -R version, with the front end splitter, would be a better bet.