Turbo/Kit Crossroads...

[redtop91]

I've come to a crossroad as regards what turbo setup I'm going to use for my SR. My power goals are right at or even just below 500whp.

The GT3076R is rated at 54 lb/min flow according to Garrett. So, with that in mind, I placed my flywheel HP goals at 520HP which is probably below 500whp but I'm just trying to get an idea of how it will perform. I want my air/fuel ratio to end up at right around 11.5. My brake specific fuel consumption as calculated by the turbo calculator a member here made (I forget the thread or even his name sorry) is .55/60 or .009167 lbs/HPxhour. Soooooo what I'm getting at is....

According to Garrett, the Ambient manifold pressure required to get to my 520HP (At the flywheel remember...) by 8000 RPM you can use this equation:

((turbo flow rate) X 639.6 X [460 + 130 degree temp in the intake manifold])

all divided by:

([Volumetric efficiency of the engine or VE] X(engine RPM/2) X Engine displacement in CI (SR20DET =122 CI))

So for the GT3076R I did

(54 X 639.6 X 590)/(.95 for VE (built head, greater VE) X (8000rpm (what I want to rev to most of the time)/2) X 122CI)

Which equals 45.0947 as the ambient Manifold pressure. Because boost pressure measures pressure above atmospheric, which is 14.7. So 45.0947 - 14.7=30.3947 PSI required to push my engine to 520 flywheel horsepower? WTF? The GT3076R isn't even good for that kind of boost is it?

Well I'm going to proceed assuming it is.

A Garrett T3/TO4E 57 Trim w/ .63 A/R Turbocharger is my other option on the peakboost turbo kit here:http://phase2motorsports.store....html

which is only $2400 but will lag a bit. My question in all of this is, is it even worth the extra $1000 for the Full-Race turbo kit which according to Garrett is pretty far outside it's peak efficiency to meet my goals?

Cliff Notes:http://phase2motorsports.store....html

Orhttp://www.full-race.com/catal...7}222

?

[david200095367]

i have the peakboost setup. I should have mine running this week.

[grenade180sx]

you know what you do...

ever heard of holset turbos?

big in the diesel world.

the hx35 flows the same cfm as a gt35r from garrett and has a twin scroll setup

these turbos are amazing. lagg is pretty minial depending on how crazy you get

ebayholset turbos-$200-500top mount maniwaste gate

a guy is making 550whp on his rb25 which is internally stock at 22psi.these turbos dont start getting crazy until 18psi and up!

this can get you into 500 whp quick

research them here

best of luck on your boost needs