Guys - found this today whilst researching some aero work on mine.
http://www.autospeed.com/cms/search/ind ... ys&x=0&y=0
I think it will answer your questions on the vents and airflow.
Updated Project /Stability control
Picture looks great but I think there is a lot of work to be done in studying this before you start building it. The transition angle seems to be of utmost importance in preventing separation of airflows in particular in that the air needs to follow the angle of the diffuser but will generally only do this if less than a 10 degree angle.
The flat box section at the start also appears to be a restriction that would start to create a reason for air turbulence.
Does anyone have access to a wind tunnel ?
The flat box section at the start also appears to be a restriction that would start to create a reason for air turbulence.
Does anyone have access to a wind tunnel ?
dynamix wrote:Picture looks great but I think there is a lot of work to be done in studying this before you start building it. The transition angle seems to be of utmost importance in preventing separation of airflows in particular in that the air needs to follow the angle of the diffuser but will generally only do this if less than a 10 degree angle.
The flat box section at the start also appears to be a restriction that would start to create a reason for air turbulence.
Does anyone have access to a wind tunnel ?
you have made some very good points there mate. i done this design only using paint so not really the best soft wear
the rear part will not have a direct angle coming up it will rolled round as you have said air needs to flow.
as for the start of it again good point but hope clarify this up, infront of that is all the axle, diff, drive shafts etc
and this cover about a foot long gap between the end of the floor pan to the start of the defuser so this may
cause turbulance and if so ill have to find a way to clean the air up
i carnt wait to start this project as its going to be a challange and a half as they say nothing ventured nothing gained :-D
V8 supercars the greatest show on wheels
When we first started messing about with the set up of the car we found ourselves with a big problem 
. Even though both me and Alan love sierra's and are happy with the back end stepping out, with the track car we had different preferences.
I like the car to feel stable under heavy breaking
Alan preferes the back end to be slightly loose and able to move about under breaking. In a controlled manner.
This year we intend to do a fair bit of work on the set up of the car. With the focus being to get the car set up more to suit Alans driving style than mine initially.
. Even though both me and Alan love sierra's and are happy with the back end stepping out, with the track car we had different preferences.I like the car to feel stable under heavy breaking
Alan preferes the back end to be slightly loose and able to move about under breaking. In a controlled manner.
This year we intend to do a fair bit of work on the set up of the car. With the focus being to get the car set up more to suit Alans driving style than mine initially.
Is the front undertray flat and complete under the engine and the front splitter?
From reading those articles on autospeed, it is important to be able to draw air out of the engine bay through the use of undercar ducting/vents to create low pressure in the engine bay behind radiators and intercoolers but also to stop hot air going under the car. Not entirely sure how this is to be done as it sounds like this would be exactly the result.
It will be fun to watch the progress on this :thumb:
From reading those articles on autospeed, it is important to be able to draw air out of the engine bay through the use of undercar ducting/vents to create low pressure in the engine bay behind radiators and intercoolers but also to stop hot air going under the car. Not entirely sure how this is to be done as it sounds like this would be exactly the result.
It will be fun to watch the progress on this :thumb:
We don't have a front undertray at the moment. The undertray wil not cover the whole bottom of the engine bay, as there were ares that we didn't want to restrict any air flow. The front driveshafts, transfer box, exhaust or any part of the drivetrain.
Having read those articles my thoughts are as follows;
1. The hot air that is pulled through the rad will now be drawn out through the vents. This should hopefully reduce under bonnet temps. As the air flowing into the enginebay is met by lower pressures in the enigine bay then air flow through the rad should also be improved.
2. The part of the undertray that will be towards the back of the engine will have a gap between it and the floor of the car to allow airflow from the engine.
We believe that with the size of the bonnet vents we should see a noticeable drop in temperatures. Plus lower underbonnet temperatures should mean lower pressure also.
Having read those articles my thoughts are as follows;
1. The hot air that is pulled through the rad will now be drawn out through the vents. This should hopefully reduce under bonnet temps. As the air flowing into the enginebay is met by lower pressures in the enigine bay then air flow through the rad should also be improved.
2. The part of the undertray that will be towards the back of the engine will have a gap between it and the floor of the car to allow airflow from the engine.
We believe that with the size of the bonnet vents we should see a noticeable drop in temperatures. Plus lower underbonnet temperatures should mean lower pressure also.