Home
Up

 

 

Ram Air

Sealing airbox to intake ducts through the frame to make the most of the Ram Air efffect involves removing the foam and lip from the airbox intakes, this should be beveled on the inside to ensure smoth airflow and no increased turbulance. Then, I used 2x 80mm lengths of Tesco's value washing up liquid bottles :>) and 2x 30mm lengths of 4.00x8 wheelbarrow innertube.


The nose cone needs to be removed, the rubber innertube put onto the box inlets and doubled back out of the way, then remove the intake ducts and slide INSIDE the Value tubes about 1". then slide back through the frame, and OVER the box intakes, then, wriggle the rubber over the top, align the fixing holes and reinstall everything! Easy.
This makes the pressurization of the box more and quicker.

Problem that you must be aware of is that to refit the box at anytime needs the same procedure to be implemented.


Some of the testing I did to learn more is as follows...


of course the following is from theoretical modelling.. (thanks Busa@11K)

MPH -- PSI -- --mbar
0 -- ----0.0000 -- 0.0
25 -- --0.0107 -- 0.7
50 -- --0.0426 -- 2.9
75 -- --0.0959 -- 6.6
100 -- 0.1704 -- 11.8
125 -- 0.2663 -- 18.4
150 -- 0.3835 -- 26.4
175 -- 0.5220 -- 36.0
180 -- 0.5522 -- 38.1
185 -- 0.5833 -- 40.2
190 -- 0.6153 -- 42.4
195 -- 0.6481 -- 44.7
200 -- 0.6818 -- 47.0


while the following is ACTUAL tested data I got (pressures in mbar)


TMH = full box mod, sealed ram air and screens removed
S-S = stock box, stock filter, screens removed
S-B = Stock box, BMC filter, screens removed
SM-S = Small mod, stock filter, screens removed
SM-B = Small mod, BMC filter, Screens removed



MPH TMH S-S S-B SM-S SM-B
0...........0........0......0........0..........0
10.........0........0......0........0..........0
20.........0........0......0........0..........0
30.........1........0......0........0..........0
40.........2........0......0........0..........1
50.........3........1......1........1..........2
60.........4........1......1........2..........3
70.........5........2......2........4..........5
80.........8........4......4........5..........7
90.........9........5......7........7..........8
100......11.......7.....11......11........11
110......14......11....14......14........14
120......17........-.......-........17........17

I have still to go a tad quicker and get some more data 8>) but it ties in nicely with the max available pressure data posted above with the fully sealed box.

 

200mph.org.uk