interesting data; keep it coming

Andy, what happened to the efficiency after 100mph-was that the boost/efficiency contributing? Seems like it is impossible to control/display all the variables at once: road speed, boost, rpm. how about a 3-D plot of efficency, boost, road speed?

A simple request...can you keep all your temp measurments is Farenheit, since that is how most of us Yanks read the ambient and motor water temps? thx

 

I really didn't take many data points after 100 mph. What I plan to do at some later date is do 500 rpm intervals in each gear so I can fill in the data a little better.

I've finally begun to think in Metric - no way am I switching back to English units.

 

I did some testing on Saturday, still with the stock intercooler. Surprisingly, the efficiency percentages haven't gotten worse in the heat, and appear to have improved slightly compared to the runs done in much colder weather.

Here's the data:



ambient= 18.5 C,ic in= 46.2 C,ic out= 27.2 C,RPM= 3100 ,Speed= 42 mph Gear= 3 Boost= 0 psi
ambient= 21 C,ic in= 57.5 C,ic out= 31 C,RPM= 3200 ,Speed= 80 mph Gear= 6 Boost= 0 psi
ambient= 21 C,ic in= 103.1 C,ic out= 43 C,RPM= 5000 ,Speed= 100 mph Gear= 5 Boost= 14 psi
ambient= 22 C,ic in= 87.3 C,ic out= 34.9 C,RPM= 4000 ,Speed= 100 mph Gear= 6 Boost= 12.5 psi
ambient= 21 C,ic in= 100.3 C,ic out= 41.1 C,RPM= 4500 ,Speed= 90 mph Gear= 5 Boost= 13.5 psi
ambient= 21 C,ic in= 48.7 C,ic out= 26.9 C,RPM= 3200 ,Speed= 80 mph Gear= 6 Boost= 0 psi
ambient= 20 C,ic in= 100.3 C,ic out= 41.1 C,RPM= 4700 ,Speed= 87 mph Gear= 5 Boost= 13.5 psi
ambient= 21 C,ic in= 47.6 C,ic out= 41.1 C,RPM= 5000 ,Speed= 110 mph Gear= 5 Boost= 14 psi

_________________
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I'm looking forward to getting hold of a larger air/air intercooler to do some comparison testing.

 

from my understanding, the current larger intercoolers are not that great, but there is one coming by unichip / webbmotorsports and one by a london company(i cant remember at the moment) that are looking more promising, from what i have tested "currently" water air is the way to go, those two front mount may change that....

 

oh, by the way the reason for the not so great peformance is that little temp change, and alot of pressure drop, if the temp was significant the pressure drop wouldnt be that big a deal, but to have little to no change in temps from the stock AND a 1-2psi drop is only a loss in power anyway you look at it...

 

Did one ever come your way?

 

Yep, two of them.

 

Awesome. :-) Keep us posted.

 

If you have a 100% tempurature efficient IC, but drop boost due to flow restrictions, you may or may not have more dense air charge. To do the full charecterization of the IC, you also have to look at pressure.

Matt

 

Good point. Much like the temperature/pressure balance from aftermarket intakes, it seems that one of the two factors could dominate the other one. For instance, with intakes, it is more important to raise pressure than it is to lower temperature since the air is cooled by the IC anyway. With the IC, it may be more important to lower temperature rather than raise pressure, since the cooler charge's resistance to detonation may be a more significant effect than the increase in performance from additional air molecules in the combustion chamber. Obviously, lower temperature AND higher pressure would be ideal, but that may not always be achievable.

 

i like the molecular/momentum explantion: the sc whacks molecules with the rotors, imparting a velocity in the direction of the intake manifold. the molecules there are already moving around with enough heat induced random direction velocity to oppose (collide with) the incoming. An equilibrium is reached when as many are getting out as in. Another factor is the removal of molecules as they get into the combusion chamber. now if the temp drops, the random velocity drops, and, being less opposed, more get in. eventually, the whacked molecules and the re-directed and slowed down molecules start to build density until the number of molecules per second trying to get out (a function of density) opposing those trying to get in...etc.