Chip

iTrader: (3)

Not to the discussion at hand about turbine pressures really no.

But knock yourself out with posting what you want, im not getting into another one of these gay arguments with the passionford WI contingent cause they dont like how someone worded something, I tried my best to nudge the thread back on topic but if people want to drift off a tangent thats up to them at the end of the day, so I wont mention it again.

Lloyd

.thanks mate.

yrkesman

I think one reason for the backpressure is my 3" catalytic converter. I'll have to measure the pressure after the turbo when I have time.

yrkesman

I measured today that the maximum exhaust backpressure (was measured from the downpipe) was 0.3bar, so it seems that the catalytic converter doesn't limit the flow as much as I first tought. I think I need to get bigger exhaust housing somewhere and see how it works.

Fiecos Dan

Have you tried measureing @ different boost's? say 1 bar, and 2.2bar?

yrkesman

No, but I could try that also when I have time. But there's no point for me to run more boost than there is now (about 1.6bar) since the preturbo backpressure is that high, but I could try to lower the boost. Even though, lowering the boost doesn't sound too good

Fiecos Dan

have you tried more boost on a dyno?

yrkesman

No, we did just few pulls with the current boost level.

Fiecos Dan

IMO, i would try higher boost's on a dyno, recording backpressure, boost, egt's, act's and power/torque @ the wheels
before deciding your next direction.



My cossie will be up and running in a month or so, and i'll be putting it on a DD RR, to test the above.

rapidcossie

AVA measure back pressure in the ex manifold, exh housing and downpipe in my car.

I cant give away figs but I can say its amazing how much of a differance in power can be had.

Look at the downpipe on my car for one thing....its not the size it is for no reason.

yrkesman

I think I'll try removing the catalytic converter and do few pulls again to see how it affects and I think I should check also pressure from the compressor outlet to see if there is pressure drop between it and inlet plenum.

yrkesman

I measured today pressure from the compressor outlet. It was 0.2-0.3bar more than from the inlet plenum. So when inlet plenum had 1.6bar, compressor outlet had 1.9bar and preturbo backpressure was 2.2bar. I didn't have time to try without catalytic converter, but I hope I can check that next weekend.

Fiecos Dan

What intercooler are you running?

Mine = 26psi (1.8 bar) inlet boost @ 7500 rpm, I see about 2-3psi drop from turbo to plenum, (yours is 2.9 - 4.4 psi)

Thats on a AH Fab's inter, and a RS500 inlet.

yrkesman

The intercooler is as big as we could fit tho the escort front. It was made by one of the local guys that does them for a living.

http://kotisivu.dnainternet.net/jtuo...o/Cooleri1.JPG
http://kotisivu.dnainternet.net/jtuo...o/Cooleri2.JPG

The inlet plenum is 4wd model with modified elbow.

Fiecos Dan

Have you tested after intercooler but before throttle, and @ plenum?

mine has no drop on that test

yrkesman

No I haven't.

yardy2186

ive never understood on rs500 type intercoolers why the endtanks are designed that way
what i mean i imagine the air coming out of the compressor outlet and hitting a wall
before it can make the turn ive always though having a 90 bend situated on top of the
end tank would work better s the air is moving smoothly and yes i understand the fact
that you get more cooling when the air is moving slower but it just seems strange to me
sorry for rant jus wanted to know

Fiecos Dan

Even tho i dont think it's not ideal, boost will make its way to where its got to go due to its nature, or going to the lowest pressure area (ie engine)

I take it, that means you have a Jap style end tanks? which is better for flow, like you said.

yrkesman

I have done some more testing. I compared the VDO pressure sensor with my ecus pressure sensor and VDO showed about 0.15-0.2bar more than the actual pressure was, so that means that the backpressure was less than I tought. With catalytic converter it was about 2bar with 1.6bar boost and with catalytic converter removed it dropped ~0.2bar.

Fiecos Dan

Have you checked the map sensor/ecu reading with a calibrated gauge?

yrkesman

No, but I doubt it reads wrong.

yrkesman

How's your car? Have you tested it yet?

Fiecos Dan

No touched it mate, got all the parts to finish the rebuild, just no time for my own cars at the moment.