Lotus Carlton

VXR8

 

 

Exhaust

Changing Hydraulic Clutch Fluid

Bonnet Vents

LS9 Clutch

Intercooler Reservoir Tank

Intercooler Pump

 

 

 

 

VE Tank

 

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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.

 

 Represents only tank connection.......consider doing away with the plastic de-gass fill point altogether ??

 

 

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 :)

 

 That's not going to flow well......so need to look to bend the tube.

 

 Love a good reason to buy new tools :)

 

 

 

Much better !

 

 

Mmmm...chemical black stainless hardware.

 

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 :)