MattODoom

iTrader: (1)

I've got a turbo here with the following measurements:

Compressor - 56trim
-60.3mm inducer
-80.5mm exducer

Turbine - 74trim
-74mm inducer
-63.5mm exducer

The compressor housing has a 4" inlet with a 2.5" outlet (t04s?)

The turbine has a t3 flange with a 3" outlet

I don't know the A/R's, could someone explain to me how to measure them?

Any ideas what it is and if it'll work on a stock 305tpi in a single setup?

Pictures:
http://www.mattodoom.com/turbogta/turboid/IMG_1295.JPG
http://www.mattodoom.com/turbogta/turboid/IMG_1296.JPG
http://www.mattodoom.com/turbogta/turboid/IMG_1297.JPG
http://www.mattodoom.com/turbogta/turboid/IMG_1298.JPG

askulte

Here's a good link:
http://www.moddedmustangs.com/forums...rim-vt730.html

and the z28tt page where I calc'd my turbos...
http://www.skulte.com/z28tt/archives...harger_sp.html

junkcltr

iTrader: (1)

Your 90% VolE is extremely optimistic at 6000 RPM. Must be a huge cam to get the VE at 90% at 6000 RPM. What is the duration and LCA?

I would have expected about 80 - 82% VE max. at 6000 RPM with most V8 turbo cams.

It seems with the high VE and low IAT estimates your lb/min is much higher than actual. Did you do the VE calcs to see where you are at after you had the engine running or is it really at over 600 FWHP at 5 PSI?

junkcltr

iTrader: (1)

It looks like a T4 compressor and T4 turbine to me. Why do you think it has a T3 flange? What is the spacing between the flange bolt holes (on bolt centers)?

A/R = area/radius. Measure the area of the two turbine inlet holes. Then measure from the exhaust wheel center to the turbine inlet center to get the radius. Divide the two numbers.

With that compressor and a T4 turbine with a decent A/R it should work great on a stock 305 TPI.

askulte

I'll need to re-visit the calcs when I get a chance. I think the temp drop may have come from the intercooler core specs from Spearco - they had a chart w/ charge airflow vs efficiency with a few curves depending on the velocity of the ambient airflow. Good chance the VE was optimistic. Looking back on the dyno results (http://www.skulte.com/z28tt/archives/engine/) I see 520 rwhp @ 6psi. I wish I had a chance to instrument everything, get turbo shaft speeds, before/after temps, before/after egt's, etc. Cam is 236/230 on a 113 LS with AFR 210 heads and 399 cid, so it's not too wild, but has a bit of a lope. My aim was to keep the sky high backpressure from reverting the charge.

junkcltr

iTrader: (1)

With the good heads, a mid-230's cam, and 399ci it probably was up around 85% VE at 6000 RPM. That is a bigger cam than I was expecting. I figured it had a 21X to 22X duration cam with a 110 - 114 LCA.

With a properly sized Spearco you will have IATs down around 110* F. Overall, I would say that your calcs are pretty good. Maybe only 5% high on VE which doesn't change things a whole bunch. That is a nice setup you have there.