Sprintex Inlet Temperature
Discussion
Yes I have, bear in mind that I have no airbox like Oz adam.
I checked the temp with a thermocouple in the air at the short rubber pipe between the blower and the plenum inlet.
When under full load it was around 60-70C? Roughly from memory. However when you list off after acceleration it jumps up to 90-100C. Although there is of course hardly any air being passed through when you lift off, and no power being generated (comparatively).
I had initially thought of an intercooler, but then realised that any cooling of the air between the blower and the engine is going to dump energy out of the system. This is energy that has been stolen from the engine and very expensively transferred by the blower to the intake air! Unlike with a turbocharged system, we have been stealing this energy from the crank so it's very precious.
So I think there are two sensible upgrades:
1) Ozzy Adam's air box. This will get the air sucking in from outside rather than engine bay/outside mix. Should reduce intake and therefore compressed temperatures by 10C or more (see Adam's post about this - I just bumped it).
2) Water injection. This will cool the air by evaporation. Use distilled/deionised/soft water only to avoid crud building up gradually in the cylinder heads (I have a dehumidifier that makes this almost for free). I was thinking to spray into the blower intake where it will get mashed by the blower too, and cool the vanes, where I suspect some of the temperature rise is happening. I have bought an old peugeot washer tank with integral pump to try this out. I need to lash together a circuit to turn on the pump at over 3/4 throttle. But not got around tuit yet...
I checked the temp with a thermocouple in the air at the short rubber pipe between the blower and the plenum inlet.
When under full load it was around 60-70C? Roughly from memory. However when you list off after acceleration it jumps up to 90-100C. Although there is of course hardly any air being passed through when you lift off, and no power being generated (comparatively).
I had initially thought of an intercooler, but then realised that any cooling of the air between the blower and the engine is going to dump energy out of the system. This is energy that has been stolen from the engine and very expensively transferred by the blower to the intake air! Unlike with a turbocharged system, we have been stealing this energy from the crank so it's very precious.
So I think there are two sensible upgrades:
1) Ozzy Adam's air box. This will get the air sucking in from outside rather than engine bay/outside mix. Should reduce intake and therefore compressed temperatures by 10C or more (see Adam's post about this - I just bumped it).
2) Water injection. This will cool the air by evaporation. Use distilled/deionised/soft water only to avoid crud building up gradually in the cylinder heads (I have a dehumidifier that makes this almost for free). I was thinking to spray into the blower intake where it will get mashed by the blower too, and cool the vanes, where I suspect some of the temperature rise is happening. I have bought an old peugeot washer tank with integral pump to try this out. I need to lash together a circuit to turn on the pump at over 3/4 throttle. But not got around tuit yet...
Hi Martin...As Adam say's..When the guy with the same set up on his sierra as i have on mine had the inlet temperature measured it too was 90c at idle..I was thinking of a refridgerant on a jet nozzle fitted into the airbox and then linked up to full throttle..It wont bring idle temp down but when you boot it ice cold air is being injected into the system..I think it would work but water is definitely cheaper..Realistically i dont think its a major issue..
Then theres always NOS...
Then theres always NOS...
Thanks for the info guys, the reason i asked is because in WOT the inlet temp climbs to 107 degress!! So i will have to find a way of bringing the temperature back down to an acceptable level....I've not decided on which route i will take yet but will keep you posted....But i'm not sure if it will be done before the Fest...
Yeah so that's where I was measuring mine too - the compressed air.
I do recall it was very high just after a burnout when returning to idle, but my memory of the WOT temperature is vague now, and I couldn't find any PH articles where I wrote it down.
Just from Boyle's law (PV/t is constant) you would expect a significant temp rise.
E.g. if you start at 20C that's 293 Kelvin. P(pressure) rises from 1 bar to 1.43 bar. V(volume) will drop as the air is squeezed. To find out how much we must look at the blower specs (from SX Technical Data):
One rev of the engine = 2l.
Blower sucks in 2.75l of air at atmospheric.
So now we have
1bar * 2.75l / 293K = 1.43 bar * 2l / T_plenum
This makes T_plenum = 335K = 63C
Note this is from the compression effects alone - it ignores the heating effects caused by turbulence in the blower and friction between the vanes etc. No wonder we are getting hot under the collar!
I do recall it was very high just after a burnout when returning to idle, but my memory of the WOT temperature is vague now, and I couldn't find any PH articles where I wrote it down.
Just from Boyle's law (PV/t is constant) you would expect a significant temp rise.
E.g. if you start at 20C that's 293 Kelvin. P(pressure) rises from 1 bar to 1.43 bar. V(volume) will drop as the air is squeezed. To find out how much we must look at the blower specs (from SX Technical Data):
One rev of the engine = 2l.
Blower sucks in 2.75l of air at atmospheric.
So now we have
1bar * 2.75l / 293K = 1.43 bar * 2l / T_plenum
This makes T_plenum = 335K = 63C
Note this is from the compression effects alone - it ignores the heating effects caused by turbulence in the blower and friction between the vanes etc. No wonder we are getting hot under the collar!
Hi Adam i've been reading through some data on the Sprintex, the artical was very interesting !! It said the measured temperture inside the sprintex unite when running at max rev it sucks near as dam it 500 cubic foot of air per minute and at max revs inside the compressor the temperture reaches 140°c !!!
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