1.6L Miata M45 JRSC, MS2, No Intercooler, No coolant reroute, E85
Ambient Air: 75* F
With a full warm engine (and SC) Putt'n around town:
Intake Air Temp (Cruise): 150*F
Intake Air Temp (Boost @5psi for 3 seconds): 195* F
I have never rebuild my SC before and I have had it for 22,000 miles. Bought it at 90K and I'm not sure if that SC had ever been worked on before I bought it.
Are these normal intake temps for everyone else running a JRSC m45? Does it sound like my SC is beat?
I feel like my SC would make a better conventional oven than any means of making power.
I wonder if I reroute some of those intake temps to a cookie sheet that I could have some fresh baked chocolate chip cookies by the time I make it to work.

 

Well are you enjoying your M45 experience?

 

p = rho x R x T

 

Intercool

oh, and how many turbos do you see that aren't intercooled?

 

 

Nothing like boosting lava.

 

I would actually expect a positive displacement supercharger to make less heat as it gets worn out.

 

Well there you go. That detonation just means your stupidcharger is healthy!

 

How effective is a heat exchanger/ water to air setup on one of these things? Worth piecing something together or just try and plumb in an air to air? My dummy throttle body has had an outlet welded facing across the front of the engine (absolutely wrong way for an A/A, perfect for w/a) and it is literally a straight shot and a 90 bend from plumbing an exchanger across the front. Yes, I know the correct answer is turbo, just want my **** to live til I am in a position to change over.

 

extraordinary effective, and makes the whole superchargers are inefficient conversation pretty much moot. But don't let anybody around here know that

edit: if done properly, and A/ A is usually a better way to go.

 

Any intercooler is better than no intercooler, IMO.

 

I was running an A/A with my M45. Cruising was whatever ambient was and a good long 3rd gear pull would only gain 20-30f or so. And I was running 170kpa (about 10psi of boost).

 

I bet you'll end up with several more horses if you drop it by 60*F in boost.

 

*150 at cruise is still 30+ I would accept on a warm/hot day while just puttin' around. I wouldn't even drive my car until there is an Intercooler. It will make a worlds of a difference. Just make sure to get a well known good flowing unit.

 

It says 150 in cruise. Which, depending where the air filter is. Isn't unusual. With a hot air intake by the exhaust and headlights down, I see numbers like that naturally aspirated.

 

I would just like to add my experience in here.

I have a mp62 kit on my car that was originally non-intercooled. It pulled well, but I had to retard timing mid/top end on normal days, and a significant amount on hot days to prevent knocking. Once I put an intercooler I was absolutely amazed at how much harder it pulled. Several people drove it before and after and noticed the big difference. I was also able to add around 8° of timing mid range, and I never have to worry if it's hot outside or not. Not to mention, that's with 2psi less than I was non-intercooled! (10psi peak before, 8 now).

 

For an ideal gas:

PV = Constant, so if you double the pressure, you halve the volume of a given mass of air.

V/T = Constant, so if you double the temperature, you double the volume.

This assumes you're working in kelvin; going from 40C to 80C is not doubling, because in kelvin it's going from 313.15 to 353.15, a 15% increase.

So, if you increase the pressure 10 psi, which is about 70% over atmospheric, the mass of air in the cylinder increases proportionately (ignoring changes in flow restriction due to increased mass flow rate).

However, if the temperature goes from 90F to 200F, you then reduce the mass of air in the cylinder by 17%, so the net gain is only 53%, or roughly equivalent to 7.8 psi boost.

Hence, intercoolers.