Intercooler Pump |
VE Tank
Some rough flow numbers
Bosch 1150 LPH pump, so 19 LPM (without restrictions ?)
With circuit restrictions, ltrs say 18LPM
Mile run flat out takes 30secs, so pump will flow 9L in that time.
Charge cooler std capacity 3L, tank capacity 5.25L, total 8.25L.
So very roughly, could say charge cooler total capacity would do 1 circuit during a mile run with tank.
Without tank it would circuit at least 2 1/2 times.
Remove the red hatch area of plastic
Cut out required for pipework
Fill point added to the input pipe, accessible when trim is in place.
Dims for reference.
Hacking into the car air box marks a point of no return !
Flat patterns and cad drawings proven out for tank body.
Filler cap neck shoulder removed and extension piece added.
Mount plate to be welded to tank top, reinstates strength lost from making the cutout for pipes.
Siphon tube.......don't like it :)
Much better !
mmmm.......spooky...spot on 1.8kg with all the junk.
Slow progress today, couldn't release the saw because it was setup for another job which I had to
get finished first !
Pressure test to 20psi
Final tank capacity 5L
Keep the little expansion (degass) tank or not ??....I think yes.....
Lets make some guestimate assumptions.....
1. The total average change in temperature for the entire volume 35degC
2. Standard volume of coolant ~2.8L (and 50% glycol mix)
Now if we add in the 5L of reservoir coolant, we get:-
So, I've decided to keep the little degass bottle, if only for the safety of having the 5psi relief valve
in the cap, so worse case it will vent air/coolant if pressure rise above 5psi.
First thing I did was syphon as much coolant from the degass bottle and system
by stuffing a small bore plastic tube into and down the hose as far as it would go,
drained abou 1/2 litre.
Next removed the outlet hose from the degass bottle and make a cut as shown, the 90deg
piece is not required.
Using some sticky backed foam, stick some around the cut out aperture inside
to stop hot engine bay air entering into the cabin air.
Connect Hoses to tank
Connect inlet hose to tank direct to the degass bottle outlet.
Connect the tank outlet hose to the top radiator inlet hose.
The 2 polycarbonate tubes are just to check that coolant is flowing properly without air locks.
I found it easier to fill the tank with 5L of coolant before placing into the heater plenum.
Tank fitted in place
Scuttle re-fitted
Job done.
The charge cooler pump runs with ignition on, so I left the pump to run for a few minutes to clear all the air.
YouTube video here:-
So, time for a dyno run and retune to accommodate a smaller supercharger pulley :)
This gave an increase of ~2psi overall.
So, how did it perform ?..........
First, some reference material:-
http://www.departmentofboost.com/tech/intake_air_temp_tech.htm
- Twin Screw blowers are the most thermally efficient of the blowers.
This is because they’re actual compressors where everything else is a “blower” to one degree or another.
You’ll see about 12deg/psi of temp gain with a Twin Screw.
- A correctly sized Twin Screw making 10psi will get you a temp rise of about 120deg. But then you have to
add that to the outside air temp (ambient), which we’ll say is 80deg. That is a total discharge temp of 200deg.
So, bottom line lets say for every 1psi boost, the charger outlet temperature will rise 6.7degC
Looking back to the last dyno runs:-
Ambient temps 18degC
Pull 1
Pull 2
This years dyno and re-tune:-
Pull 1
Pull 2
Remembering that for every 1psi rise in boost, supercharger outlet (prior charge cooler rads) temps will rise 6.7degC
2017
Theoretical supercharger outlet max temp = ambient 18degC + (9 x 6.7degC) = 78.3degC
Pull 1 Ambient temp 18degC boost of 9psi should have seen temp rise of 60.3degC, actual rise 6degC (38-44)
Pull 2 Ambient temp 18degC boost of 9psi should have seen temp rise of 60.3degC, actual rise 8degC (37-45)
2018
Theoretical supercharger outlet max temp = ambient 13degC + (11 x 6.7degC) = 86.7degC
Pull 1 Ambient temp 13degC boost of 11psi should have seen temp rise of 73.7degC, actual rise 11degC (32-43)
Pull 2 Ambient temp 13degC boost of 11psi should have seen temp rise of 73.7degC, actual rise 11degC (34-45)
Conclusion
Considering that the extra 2psi would have raised supercharger outlet temps by around 13.4degC, even if you decrease this
by the difference in ambient temps ie 5degC, then outlet temps should have been 8.4 deg more, and therefore (possibly) post
intercooler temps should be ~44degC + 8.4degC = 52.4degC......but what was actually observed was pretty much same IAT as before,
so maybe the tank has helped....certainly it has not hindered temperatures and recovery and stabalisation after a pull is still very good.
I guess the acid test will be how the AIT behave during a flat out mile event :)