Ben

iTrader: (33)

agreed. with Scott's formula, core performance is theoretically decreased with increased depth.

Braineack

iTrader: (62)

pretty sure that was the formula out of corky's book.

if you think about it, I have twice the amount of runners with a 12" tall core than a 6" tall core, so even if it's not as long, I have more internal flow, just because there's so many runners to go through.

but yeah, guess you're right, maybe I copied it down wrong. I'll take another look at it when I get home.

Atlanta93LE

iTrader: (5)

The length of the runner determines how much heat can be dissipated. Internal flow area basically determines how much air can effectively enter/exit the intercooler, in effect setting limits on horsepower.

I don't think Corky would disagree...his website FAQs essentially say the same.

Braineack

iTrader: (62)

yeah it looks like i kinda combined two formulas somehow...i always read that damn thing too late at night.

the correct formula is: Internal flow area = channel length x channel width x number of channels

then you divide that number by .45, as 45% is the average of the face area.

THEN divide it by your width....only to determine how wide of a core you need.

the problem with this formula is that it's setup for vertical runners like the old BEGi kits....let me see if I can't move some numbers around and come up with something for horizontal runners.

Atlanta93LE

iTrader: (5)

Whoah, I just noticed how many posts I had made before actually experiencing boost. I am a sad, pathetic individual.

Braineack

iTrader: (62)

ha badass just downloaded his book in DOC format....


too much effort....ill just wait till August when his second revision comes out and has all the forumlas for horizontal runners. :gay:

Braineack

iTrader: (62)

ok, had a chance to skim back through corky's book.

first off, bar & plates are .125" wide, not 1/4"

So Rob, your intercooler would be 17 in² of flow area.

If 6 in² is good for every 100BHP then yours would be good for around 17/.06 = 283BHP

Mine, 22 in², 366BHP.

I was dividing by the depth of the core, which I shouldn't have done and screwed the pooch.

y8s

iTrader: (8)

more pics of the big phat intake pipe at this thread.

no dataz yet.

m2cupcar

iTrader: (5)

283hp looks about right given my 250whp. I might have/had another 5-10hp if AIT compensation were less aggressive.

Looks like your IC is safe.

Just checked my dyno sheet datalog- IGN retard from compensation starts at 6k rpm (40c). By 7k rpm AIT is 50c and advance is 7*.

so big it has it's own area code :gay: That's gotta help

Atlanta93LE

iTrader: (5)

Seems like it's be 17 sq. in. of frontal area, but not internal flow area. Using the 6 sq. in. per 100 bhp rule-of-thumb makes no claims about cooling capacity, only flow capability (if you're looking at internal flow area :gay

Braineack

iTrader: (62)

yeah true... this is where it's hard to follow, as all his calcs. determine how big of a frontal surface area you want with vertical runners.

y8s

iTrader: (8)

Got data.



I'm beginning to wonder if my sensor is just heatsoaking from the radiator. It's just plain silly. Note complete lack of change from boost. Note my coolant temp drops 6 or 7 degrees.

Braineack

iTrader: (62)

yeah...I'd say that intercooler is at least doing it's job....

I wonder if a heatsink on the IAT sensor similar to the one Innvoative suggests for the WBO2 would help.

y8s

iTrader: (8)

heatsinks can work both ways. a heatsink would probably make the problem worse.

Braineack

iTrader: (62)

yeah i guess you're right....maybe shield/heatwrap would be more in order.

m2cupcar

iTrader: (5)

I agree- something is up with AIT starting at 50c (and at only 9psi) and not moving...hardly. I wonder if the peak at the end is an actually rise, or a rise in the heat that might be causing the soak. That puts you in fuel and ign compensatons too.

My sensor is inside a pipe that comes off the coldside IC pipe, right near the tb. So it well shielded- and opposite the rad. Where is your sensor? The back side of that fat cold side IC pipe would be a good spot- sheild from the rad.

Is the drop in the AFR curve at the beginning of each gear intentional (for peak torque)?

y8s

iTrader: (8)

the sensor is directly under the throttle body. you can see it here, in the inside of the throttle body inlet pipe's curve:
http://gallery.y8s.com/miata/turbo/D...geViewsIndex=1
it's wrapped in some foil backed fiberglass tape and that's what the datalogs are based on.

Sadly I didn't get to datalog the car before starting because my gf was in the passenger seat and already had tons of my crap on her lap.

I'd like to keep the sensor in the section of pipe before the TB but if this is the result of sensor heatsoak, well... I wont keep it where it is.

the drop in AFR is... I need tuning time and a perfect map by which to set my enrichments. I can do TPSdot and MAPdot based throttle pump enrichment as well as "dynamic enrichment" based on how fast RPM rises. it also has a dynamic enleanment for rpm decreases. you can see that's too high too.

m2cupcar

iTrader: (5)

still trying to erase that image from my mind :gay:

My sensor is about opposite of that, but I still can't see yours getting "that" heat soaked. I wonder if your wrap is acting more like an insulator? I just can't believe your air temps are that high with that IC.

Braineack

iTrader: (62)

take out your headlight and see how it reacts.

y8s

iTrader: (8)

I use my headlights!

I dunno what's causing my hot air but I'll find it eventually! Even if it takes til winter!