CO2 cooled inlet manifold
Turbo Mini Forums

Was thinking about this last nite,maybe laughable/might work.....

Would firing a load of co2(welding bottle) through the water cooling passage in the inlet manifold have any effect on performance in terms of lowering the intake temprature.

Full of strange ideas

Brian

Metro turbo weekend driver,Mini turbo in the making again!

i was thinking this a while ago although using a fire extinguisher! much cheaper

through the manifold then onto the intercooler

think it might work to use say a heater matrix a seperate leccy water pump from another car and just plumb it in that way it must work to cool it down but think you would see an advantage?

Dan

nope, water will retain too much heat on a hot day. then try find space for a rad etc

I'm not going to say it'd unlikly have an effect on charge temp, as it definately will lower the temp; How big a benefit i'm not sure however...

The surface area of the inside of the manifold, compared to the volume and velocity of the air going through it is also pretty low... It's be even worse if the manifold was polished (the 'turbo' one is pretty smooth anyway isn't it?).

Another consideration - if the manifold was at 100degrees, and you cooled it to zero (for example), the benefit would be there. In reality, if you go for even a mildly spirited drive in your mini, then pop the bonnet and feel the manifold, it's pretty cool (or it is if your intercooler is working as it should). Therefore, further cooling will not yeild much benefit at all (so long as intake air is less than 30/40 degrees you're doing fine).

Spraying it onto the intercooler mind....

Edited by turbodave16v on 6th Apr, 2005.

"Spraying it onto the intercooler mind.... "

as used by many jap racers...

Alex

AlexF

Just make sure you use a C02 and not a dry-powder extinguisher!

We ran a water spray on the intercooler at avon park last year. Didn't seem to make much difference. Might try a slightly different design this year. The problem last year was trying to hide it, I dont think they like you spraying water on the track!

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

It depends how hot your IC gets I guess!

Have you looked at your Air Charge Temps Ben?

Alex

AlexF

I'm off to the scrap yard on Saturday to hopefully get some air temp sensors. Might not get to fit them before the next event though.

I was thinking of using the megasquirt to switch a spray onto the intercooler. This could be triggered by either inlet temp or boost pressure. Something will be on for Avon as it is a great place to test new parts and do data logging.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

I've thought of this also, my ecu can also do this, my IC are quite low with the new intercooler, lets see what there like when I wind the boost up a little

Team Racing

Ben,
All MPi Rovers have great little air temp sensors. They are green in colur, and screwed into the manifolds along with a black sleeve nut (I guess so the sensor is insulated from the manifold temp).
If you file a curve into the top of this sleeve nut, and punch a hole around 40/50mm from the end of your silicon hoses, you can push the sensor through the hole, and use the sleeve nut to hold it in place (hence why a 25mm radius is applied to the top of the nut).

I've done this on my engine and never had a problem. Great, cheap little sensors.

The problem I have with the temp sensor is that the megasquirt can be a pain in the arse. It supports, in theory, any sensor. Basically you just scale the sensor in the software. We have not had much luck with rescaling sensors however, so I am trying to get a standard GM part that is what megasquirt was designed around. I was planning on getting various ones from the scrap yard, mainly Vauxhals, and see if one matches the GM charateristics. Then I will probably order some new ones. You can get the GM part new, but it is expensive and has a very strange connector that is almost double the price of the sensor its self.

So Dave if you have a sensor what sort of tems have you seen?

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

I tried spraying co2 on my intercooler last year, but had two false starts, so it was a waste really, but I did feel a difference when I pulled off.
This year I'm using a different intercooler this year and intend to set the co2 up properly. The other thing is you only get 20 seconds of c02 from a standard bottle, so it tends to be a bit expencive.

16V project underway

how do you stop the C02 from going in your air intake?

Ben, last year at avon I didn't see any temps above 40 degrees, (apart from idle when I was in fireup lane, then they shot up)

Team Racing

So long as your below about 65 you should be ok in terms of engine safety....

performance is another issue thou!

alex

AlexF

what should it be for max performance?

Team Racing

Double posting...

Edited by Vegard on 8th Apr, 2005.

Wouldn't that be as cold as possible so to speak?? It really depends on what the car is fuelled in at I guess. If you have it RRed at 50degrees, and you use -273,15 degrees I guess it'd run lean... Not to mention carb icing..

I don't think you can say what the optimum is..

From a performance point of view I would say the colder the better. My plan is to do runs down the strip using the spray and not using the spray. Log the temperatures and see how much effect it has. Only worthwhile on a hot day I would have thought though.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

65 is a little too warm methinks...

Over 40/50 degrees CELCIUS air density is starting to change sufficinetly to make a difference according to my thermofluids books...

Up to you though.

Ben, The rover sensor I've used is the usual 2K2@20degreesC if that helps. It's also not linear over 100degrees, but i can post you the correction table (calibrated to a few different sensors on a special testign machine) if you want.
DTA only reads up to 120 degrees on air/water temps - and the sensor is not linear anyway over 100.
Even so, measuring temps leaving the turbo, I recall that at higher RPMs and 14psi+ boost it pegged the scale leaving the compressor (120+). After the intercooler however, it dropped to between 30 and 40 typically. Hottest temps typically are seen on the strip, not the road.
I recall - after Zeroing the temps before a run- it peaked at 42 when I next checked (whilst driving down the return lane).
Interestingly, the RSturbo intercooler previously fitted was exactly the same figures as the higher capacity unit. I guess there is only so much heat you can get out of air (in a limited time) that is that warm.

Edited by turbodave16v on 8th Apr, 2005.

When we first buit the turbo I put some probes before and after the intercooler (this was the GT 5 one we had tucked away) I seem to remember air temp in was 95 and out around 35 to 40.

I'd like to think that the new cooler is a bit better, it relieved 20bhp in any case.

Wil

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

65 degrees C is a typical temp most OEM maps begin to retard ign timing to protect the engine.

I'm not saying thats best, just what ford use!

Alex

AlexF

So it's not ideal is it.
If OEM's have decided that 65.1 degrees is a point that control needs to be bought in, then 65 is not a figure to aim for.

I must say, I'm surprised current factory ECU's don't have a full scale control (correction) for air temp, right from -40 through to 65+, rather than a simple 'hit' at 65 degrees?

The GM sensor is
Degrees C/Ohms
-40, 100700
-18, 25000
-7, 13500
4, 7500
21, 3400
38, 1800
71, 450
99, 185

Not quite the same as the rover part. I don't think that there can be that many different types of thermistor material so it can't be that hard to find something similar.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.