Steve Cargill Posted March 23, 2003 Share Posted March 23, 2003 Originally posted by Gordon Flynn A lot of race cars use a high resin content marine plywood known as jabroc as skid blocks. It is also used to make the infamous 'planks' on some F1 and F3000 cars Got the piccies now :- Quote Link to comment Share on other sites More sharing options...
Steve Cargill Posted March 23, 2003 Share Posted March 23, 2003 Getting back OT, I was trying to get info out of Toyotas technical department about downforce. What I came away with was they would not allow the rear wing to be removed from a UK car. No hard figures A closer piccy of the 'Heath Robinson' front Quote Link to comment Share on other sites More sharing options...
lucasl Posted September 30, 2006 Share Posted September 30, 2006 hello just found this old post and wanted to ask a few questions, i was thinking of trying to make a rear diffuser out of aluminium similar to the top secret one and try to make the underside of the car flat using plastic sheeting like ferrari use. my question is as you can see in the picture below the ferrari has two distinct tunnels for directing airflow, why not one single large tunnel or 3 or 4, plus on the f430 what are the purpose of the fins in the rear diffuser cause the 360 doesnt have them http://img89.imageshack.us/img89/6733/speedlabferrari5au3.jpg http://img89.imageshack.us/img89/8830/f430pressrearll0.jpg Quote Link to comment Share on other sites More sharing options...
Alex Posted September 30, 2006 Share Posted September 30, 2006 The Ferraris's have a gap in the middle to accomodate the Rear Diff. The Fins are are conditioners (smoothers) to reduce drag. Quote Link to comment Share on other sites More sharing options...
TLicense Posted September 30, 2006 Share Posted September 30, 2006 Blimey just read through this blast from the past. Firstly, my personal opinion is you really don't want any kind of positive downforce generating device that is ride height dependant on a road car. (Diffuser's etc.) I've said it before in threads about this kind of thing. Basically if you go over a good size bump mid corner at the limit of grip, you're going to suddenly lose a lot of grip and end up with the car in the ditch. The fins on the 430 probably help it to create a higher average negative pressure. They'll have an effect on drag, sure but they might not reduce it. Essentially they help to increase the average negative pressure as the slight changes in pressure in 1 tunnel aren't propogated across the entire floor. They're kinda contained if you like! They're such fickle devices though. Moving them 5mm one way or the other can gain or lose VAST amounts of downforce. You really can't create ANY type of aero component without some kind of flow/flow field visualisation or a device that will show you effective increases or decreases in load. Say with these diffusers. Get the expansion angle off by 3 or 4 degrees, instead of gaining downforce you're now losing it due to seperation. Same deal with all these wings. It takes a LOT of time to set up a wing. Have too large an incidence, then it's just going to create drag, not enough, then it's doin feck all. The nice thing is, the incidence will be different for every wing (even wings made from the same tooling can be different from each other) Also the incidence probably really needs to change along the span. Seperation due to tip loading can propogate along the entire span of a wing. Also the GT wing that was posted that is twin element, causes even more head-ache as if you try to load the flap (2nd element) too highly then you can stall the wing (first element). Again the flap will also probably need incidence change over it's span. Flat bottom floors are another nighmare again. The pressure will change over the span of the floor as much as it will over the length. Saying that they're only good for a max ride height of 50mm isn't strictly true. The outer sides will not create as much downforce above these ride heights but the centre will still be creating a reasonable amount to many multiples of this ride height. Look at rally cars for example. But as I said, I don't think it's really something that you want to rely on in a road car, but then again getting it working effecively enough to get to the point where you're relying on it is pretty unlikely. What would I do? I would leave it well alone. Quote Link to comment Share on other sites More sharing options...
lucasl Posted September 30, 2006 Share Posted September 30, 2006 yea fair enough, but it must make some difference to road going car otherwise they would not put it on the ferrari's. I understand that there could be a loss of control round a corner when something disrupts the airflow like a bump in the road but it can't be that dangerous otherwise as i said before they wouldnt put it on the ferrrari. I have never looked into doing something like this so how hard would it be to set up a car in a wind tunnel providing i could find one to use! Quote Link to comment Share on other sites More sharing options...
TLicense Posted September 30, 2006 Share Posted September 30, 2006 Very. Wind tunnels cost about approx £350/hour We recently did a diffuser survey on our F1 car that lastest 10 days I think it was. (That's 6am till 11pm 6 days a week) Plus wind tunnel testing on a full size car is that expensive that none of the F1 teams do it to any serious extent. (Usually you would just do a full size test check model to full size correlation) The diffuser on the ferrari is probably very benign (ie not particularly ride height dependant, but probably not creating a great deal of downforce) But they're massively in-tolerant to geometry changes, and it would be very easy to get something that just created drag and no downforce at all. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.