trickd122

iTrader: (3)

I tend to want to disagree with that statement, I would however say that "AIR" cannot be scaled.

robk

iTrader: (22)

F1

rcfoolz

iTrader: (22)

The way that I had done it was using a large box of long straws on each end. Then build the center sections with cardboard or plexi glass. I do it with cardboard and just one side with a sheet of lexan. Then all you have to do is use a fan. I have a floor drier(like used for drying wax on a large floor) that has 3 speeds. I have a radar gun that when you drop stuff into the stream, like foam peanuts, I have a reading of 3 different mph. Then all you have to do is use a setup board with 4 scales built level to the surface going under the car...... This is a very basic tunel, but works.

musti72

Yea but that was without diffuser I only used them before the quals, on friday.

mailboxck

iTrader: (9)

Nice work. Looks similar to the original Tamiya diffuser. I've modified mine a bit too placing end plates to the original Tamiya part. Can you confirm, does this diffuser really work? I can't confirm with my F103GT just yet until I hit the track.

My biggest issue is that there is a large void in the lower chassis for the motor. Reading from technical articles, the "vacuum" is created in front of the diffuser due to the venturi effect it creates. With that large hole for the motor, it defeats the purpose of the diffuser. I'm thinking of covering up that hole a bit to see it there are any improvements.

robk

iTrader: (22)

Here's what I did- I put the part on and hit the track. I went out there thinking it would just be some bling. Basically worthless as a real performance enhancement.

The weird part was that the car was totally stuck to the track, yet it seemed to steer harder(???) I could drive super hard into the corners and just turn the wheel.

When I removed the diffuser, I drove just as I had done before, but now the car would start to break loose at the limits. I could not drive as hard as I had before without getting the car to break the rear end loose.

I didn't have lap time available to me, but the difference was obvious to me as well as a couple other guys who I had drive the car.

rcfoolz

iTrader: (22)

I don't think that the steering changed, you were just able to use the steering you already had, that is why the rear of the car was getting loose.

I've made a diffuser for the front of the car too, but it took too much steering away from the car to be effective, so I am working on that to find the right balance, but so far have had no luck in that area.

itchy b

iTrader: (2)

I wonder if this would work well in my tourer??
I see the DTM cars use these type of rear difuser with side blade wings? on the rear edges of the wheel openings.
Is it worth trying out ?

Just read the whole thread and must say,It does seem to be a good thing!!
When you finalize the design RC Fools, can you post where to get a hold of some from please?
I know of a LHS which would be interested in this sort of thing!
Regarding the tamiya F1 style diffusers, would they work the same way ad could they be fitted to a tourer?

rcfoolz

iTrader: (22)

I have a final design of the diffuser, I have tried many designs and settled on one that stands above all the rest. The one like on the F1 will work to an extent, but no where as good as the design I am using now. I am in the works to having something taken care of and when that is done, I will post and send you a PM.

drfritz

took a trashed gpt body off 10l cut the rear off from kick up back, trimed to fit with in tires spacing. clued on 2nd roll of fins and placed on tc3. bolted it under the rear bumper was running and gave it a try in our sportsman nitro class. we runn non sedan bodys with rubber tires in this class. I found that I was a good second a lap faster than anybody else on the track with this on the car and my car did not fall off the pace like the other rubbers guys car did. took it off for pactice run and car was a drift monster with out it...... its a good size difusser that i'm running good 1" wide and goes from inside tire to inside of the other tire. try to post pics.

drfritz

musti72

Exactly. You had had a lots of steering without diffuser, but that much of steering was causing the rear end to break traction. Diffuser makes the rear end stick more, resulting more corner speed than a car without diffuser and have just enough steering not to break traction. Thats what I felt when I was testing. Hope you get what I wanted to say...

Im going to talk to my race commitee again on 3rd Round of nationals on 17-18th July, I read the efra book again and again, found nothing about diffuser/underbody aerodynamics. I think they confused it with ifmar rules...

rcfoolz

iTrader: (22)

good work. The rear wasn't sliding around so the tires didn't get "greasy"

rcfoolz

iTrader: (22)

make a piece that goes to the bottom edge of the body and call it a bumper support

musti72

I'd rather do this from the right way