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RELAX-iMA-DOCTOR
02-26-2014, 06:17 AM
So, I just recently finished my engine build for a D21 hardbody.

I used a frontier .20 over block, weisco deep dish coated positions, Manley turbo tuff rods, clivette 77 race bearings, 264/264 crawler cams, dual valve springs with aluminum retainers, arp main and head studs, cosmetic mls head gasket, 800cc injectors, walbro 255lph fuel pump, cx racing turbo intercooler, Haltech Sprint 500 standalone. The turbo is a HX35

I'm hoping for 350 to the wheels at 18-20PSI?

What do ya'll estimate? Almost forgot, the trans is frontier, with 300z flywheel, and a 6 puck clutch
Kingtal0n
02-26-2014, 05:57 PM
formula for all engines is

CID X RPM / 3456 = [CFM * .069lb/cubicft * PressureRatio * VolumetricEfficiency] = lb/min airflow

For example, sr20det engine @ 14.5PSI

122 X 7200 / 3456 = [254 * .069 * 2.0 * 1.0] = 35lb/min = 350BHP
Subtract for drivetrain losses,
using 12%:

350BHP * .88 = 308rwhp

Any 2.0L @ 7200rpm running 14.5 PSI with 100%VE puts down around 308rwhp when air weight is .069lb/cubic foot

plotted on a graph:
http://i23.photobucket.com/albums/b378/draglarry/blamekingtal0n_zps6470faf0.jpg
jr_ss
02-26-2014, 06:35 PM
12% is a bit generous of a drive train loss percentage. Id bump that up closer to 15-18%.
Kingtal0n
02-27-2014, 01:32 AM
12% is a bit generous of a drive train loss percentage. Id bump that up closer to 15-18%.

It was just an example, I could have used 50% or 2%.


I laid the equation out like cookies on plate next to milk- take your pick we have chocolate, peanut butter, oatmeal, white frosted, pick any numbers you want.

Every car is different right? We are out of chocolate chip though. Sorry
jr_ss
02-27-2014, 04:32 PM
All I'm saying is if you're going to throw numbers out there, you might as well use something closer to real world, not magical fairy land numbers.

And I prefer white Macadamian nut...
Kingtal0n
02-27-2014, 04:59 PM
All I'm saying is if you're going to throw numbers out there, you might as well use something closer to real world, not magical fairy land numbers.

And I prefer white Macadamian nut...

lol. well those cookies are custom.

12% is not that far off actually. I use 16% for automatic transmission.

I think 12% is reasonable with lightweight parts, stock wheels, etc...
WV_SR20
02-27-2014, 05:04 PM
Put me down for some of those macadamia nut cookies