calculated geometric cr for hybrid

[greg donovan]

using this site:
http://www.kb-silvolite.com/calc.php?action=comp
i got 11.644:1 w/the thick gasket and 13.187:1 w/the thin gasket and i used th right number of zeros this time

now i just need to find out rod length and Intake Closing Point (degrees) so i can calculate effective CR.

it looks like if i use the thick gasket i may be safe but thin would require some extra stuff done to the ecu. of course i will measure my stuff first before assembly.

[vrg3]

This thread might help you with rod length:

http://bbs.legacycentral.org/viewtopic.php?t=15294

And this with valve timing:

http://bbs.legacycentral.org/viewtopic.php?t=14770

[greg donovan]

thanks alot for all your help.

here is the efective that i got:
10.086:1 w/thick gasket
and
12.421:1 w/thin gasket

lookin more and more in favor of doing this project w/thick gasket.

[greg donovan]

is this the adjustable FPR i would want?
http://shop.store.yahoo.com/racingsuper ... igpre.html

what is stock FP on a n/a ej22?
the stock injectors flow at ~270 cc/min, is that the max flow rate?
is it true the turbo pump flows @39.6 gallons per hour (gph) or about 149 liters per hour (lph). what does the N/A pump flow @?
would the walbro 255lph pump over power the injectors?
would the stock injectors be capable of flowing enough for a 11.5:1 CR motor w/the AFPR and the walbro pump?

[vrg3]

I don't know if an adjustable FPR is the way to handle engine management for this hybrid engine...

This thread contains various OEM Subaru fuel pump flow capabilities:
http://bbs.legacycentral.org/viewtopic.php?t=14461

There isn't any concern of overpowering injectors; the only problem would be if the FPR can flow enough to keep fuel pressures correct at low load.

Do have have a good resource explaining how engine management has to change when compression ratio increases? I kind of suspect that you won't really need to do much with fuel, and that it'll be the spark timing that will be the big issue.

[THAWA]

I dont think I'd trust my engine to an afpr named "desert storm"

[greg donovan]

I dont think I'd trust my engine to an afpr named "desert storm"

not sure why aeromotive named it that but it is one slick looking piece. actually i dont even think that thats its name the aeromotive sit just refers to it by part#.

i have no good resource other than the tech that is helping me do it and you guys. jason grahn was the one that brought up the AFPR and the need for more fuel. he also reccomended the greddy emanage for ignition timing. will the stock ecu retard timing at all if it detects detonation? im guessing no.

looking at that pump thread would lead me to believe that the na pump is woefully inadequate and the walbro one would be a good idea. that can be used w/my stock injectors and fpr.

i use the search function and somhow miss the threads you point me too how do you do it? i realize im in strange yet familiar territory here as no one want to us NA power. but i dont want/cant afford turbo power in my sedan. i just want a little bump. 20 free hp is well worth the time and energy.

[vrg3]

I think Jason just brought up the adjustable FPR as an alternative to an RRFPR...

Your stock engine management might do fine for fuel.

If you go to RC Engineering's injector worksheet page (http://www.rceng.com/technical.htm) and enter in the following numbers:

160 desired hp
4 injectors
0.47 BSFC
0.80 maximum duty cycle
36.3 psi rail pressure

And you come up with needing 271cc/min injectors. Aren't the stock EJ22 non-turbo injectors 270cc?

You might be concerned about the stock ECU not being well mapped for the kind of flow required for 160 hp. That may or may not be a valid concern; I don't have a non-turbo car to play with. Maybe you could try out the scan tool I posted in the Electrical forum and let us know how high the load numbers get and then I can extract the maps from an ECU the same year as yours and we can take a look.

It certainly couldn't be much worse than us turbo people running higher-than-stock boost, I think.

An e-Manage should be able to give you some control over both timing and fueling, so that might make sense to try.

The stock ECU will retard timing if it detects detonation, but that's not really the best way to go, since it'll be a purely reactive system. What you want is to retard timing a little even when detonation isn't happening, to make detonation less likely.

About the threads, I just remembered each thread each time and searched for a string I knew would be in it.