14psi on turbo = 14 psi on supercharger?

[TERRA Operative]

The power figure is total power. I think my formula is underestimating slightly?

The ratio is simply a function of max engine RPM and required supercharger RPM. Ie. if your crank pulley is 100mm in diameter, your SC pulley needs to be 96mm.

[big_zop]

Well, the problem with your calcs is that a factory 1G-GZE puts out 125kW stock and doesnt use an intercooler. I have no idea what the intake temps are either, nor the size of the pulleys used so i cant do my own calcs.

[TERRA Operative]

Hmm, my calculations come to 109Kw @ 6000 RPM for the 1G-GZE.
http://en.wikipedia.org/wiki/Toyota_G_engine#1G-GZE
I'll have to revise my power calcs.

Boost temps at 112deg, at 0.7bar for that engine.

[mullett]

Very different application, but on my setup (4A-GZE with SC14/cams/extractors/ecu etc etc) the standard crank pulley (155 or 165mm?) and the standard SC14 pulley (125mm?) resulted in 12psi (14psi with standard cams), and made about 160-170rwhp. I'd call that ratio (at 7000rpm) pretty much the max that the SC14 can handle happily, as power tapered off markedly after 5500-6000rpm. Nick had a 175mm pulley, and made up to 18psi with it. Low-mid range was incredible, and the noise was insane, but efficiency taperd off badly near higher RPMs.

So a drive ratio of 1.3:1 is ok, but 1:1 is probably ideal, even lower if you're going to run a turbo too.

To my mind, if you ran the SC at 0.8:1, and left it running thru the whole rev range, the turbo would effectivly see an engine of ~3ltrs. So if you used a 320hp GT28 turbo (which would be responsive anyway), the boost would come on very hard and very early, and if you set the wastegate to 16-18psi (reading absolute manifold pressure after the SC), and the power levels would be strong through the whole rev range, but especially the midrange.

All of that said, for the weight and complexity, a small, BB modern turbo (like a 300hp GT25) would be extremely responsive, simple and make much more power than the SC14 could ever dream of.

Just my 2c

-RM.

[IH8TEC]

my experience with bigport ae92 4agze

14psi pulley kit on supercharger, exhaust and pod = 101kw atw on 14psi

on same dyno with a really tiny t3 turbo and 10psi got 125kw atw.

both on same computer, same exhaust etc.

[greenmac80]

can someone do a quick calc for me?? i don't understand it myself.
4age20v silvertop stock compression 10:1 or something like that? + 9 psi SC Killawasps=?????? approx..

[TERRA Operative]

My calcs seem to be out. Anyone got a good formula that takes airflow, compression ratio etc into account?

[oldcorollas]

torque = capacity(L) x manifold absolute pressure(BAR) x 100 x VE of NA version x fudge factor for blower loss

ish.

that is for peak torque.

power depends on cams and blower heat/loss

[Cuzzo]

That rear housing on the turbo you have now looks larger than the front housing.

Downgrade the rear housing to the smallest size you can get and it will be minimal lag. However it will reduce your peak output.

[YLD-16L]

my experience with bigport ae92 4agze

14psi pulley kit on supercharger, exhaust and pod = 101kw atw on 14psi

on same dyno with a really tiny t3 turbo and 10psi got 125kw atw.

both on same computer, same exhaust etc.

Mine was similar, 4AGZE

14 psi SC12 = 98rwkw

Same ECU, same dyno same exhaust, same intercooler but with T28 running 15psi = ~154rwkw

[oldcorollas]

same rpm for peak power?
what was midrange like (after turbo spooled)

[YLD-16L]

same rpm for peak power?
what was midrange like (after turbo spooled)

I'll try and find the old dyno sheets to confirm mid-range change but the rpm for peak power shited to the right by about 1000 - 1500rpm I do believe. Instead of feeling flat from 5500 onward it rapidly swung around to the limiter.

After moving from factory to aftermarket ECU any loss in mid range was swamped by the new setup as it picked up a massive 40+rwkw in the mid range, no doubt a gain made mostly possible by the removal of the restrictive air flow meter.

[oldcorollas]

seems to be fairly common that the simple roots chargers on the toyotas don7t like being spun that fast... perhaps it is just heat generation at around 5500up that makes it feel flat.. combined with the power loss... they were not really designed for a 2:1 pressure ratio

[TERRA Operative]

torque = capacity(L) x manifold absolute pressure(BAR) x 100 x VE of NA version x fudge factor for blower loss

ish.

that is for peak torque.

power depends on cams and blower heat/loss

Sweet, I'll try it out.

Mine was similar, 4AGZE

14 psi SC12 = 98rwkw

Same ECU, same dyno same exhaust, same intercooler but with T28 running 15psi = ~154rwkw

I got 104Kw at 10psi on the dyno with my AE101 4AGZE.

I won't be going turbo though, that's being saved for the 3SGTE.

seems to be fairly common that the simple roots chargers on the toyotas don7t like being spun that fast... perhaps it is just heat generation at around 5500up that makes it feel flat.. combined with the power loss... they were not really designed for a 2:1 pressure ratio

1.8 seems to be the most they'll take continuous.

The MAP 4AGZE's, most prominently the AE101's, are highly prone to a power drop issue after about 5500RPM. It is believed that the knock sensor picks up the supercharger noise and pulls out timing (it is known for sure that timing is pulled).
I have fitted an AE92 MAP ECU which has a less sensitive knock circuit and the power drop is almost unnoticeable.
My 104Kw dyno chart exhibits a flattening off from this point, and I've seen some charts that drop a huge amount then continue almost flat to redline.

The best fix is an aftermarket ECU, or a turbo....

[oldcorollas]

ahh thanks i forgot about the knock thing..

for that formula, it works for turbo cars almost always, but i haven't compared so many SC cars..

basically it is just scaling up the NA torque per litre, with the new absolute pressure.
when modified, some people get to 95 or even 100Nm/L, but it is not that common. some newer cars are up to 1105 or 110, but with direct injection and fairly specific tuning.

for example. 4AG = roughly 150Nm/L multiply by absolute boost = roughly the torque you can expect.
from that, at whatever rpm you can calc power, and then take away blower drive cost..
and then you can fudge for increased outlet temps etc (decreasing VE = decrease torque per L)