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Günter

V8 turbo 'calibration'

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Hey folks,

as some of you know i have 'reworked' my 918 engine , bud still use the old wastegates (for now). Those have got a manual set-up by hand for the first start. Bud as it was coming out they need some real adjustment.

So my thought was i need to do it on the engine. What i have left over from the engine rebuild is a magnetic-bracket/mount for a measuring gage & a measuring gage tool. Alternatively i could use a sheet/strip of metall mounted onto the wastegate fixing , and mark the right amount of 'mm'-rod movement. Sounds good, bud without a exactly to regulate pressure signal/pump there is no way to calibrate it.

My evil thought was: I have the hand-pump ball from the seat-support/lumbar support -this should have the right diameter opening to use it with a *T-piece* hose connector between the BARO-sensor port & wastegate pipe connector nipple. Sounds simple, bud should gave a good pressure reference !? Together with the magnetic bracket it sounds like the way for perfect calibration. I will try out this in the next time, bud would also like to read what you all think about this 'idea' --and sorry if this is a 'reinvention' of something that was posted before, never heared of something like that so far... ?

Oh..and finally: My OBD system can read out the extended data (like BARO reading), bud it is measured in Lbs -in opposite to the kPa-reading of the MAP. So what BARO reference signal should i read on the right 'mm-distance' of actuator lever movement ?

update: first step of the experiment was to test both old actuators by pressure applied manually. It was fine on RH, bud on LH I've got this annoying sound of a porous/leaking membrane. So it's definitely time to swap this stuff for my new alloy ones.. .

Funny thing after all: the improvisation made for the internal spring (a cover , to protect the membrane from the broken old spring and made out of an old film-capsule) still works !

Bud without an actuator body it is useless from now on... :lol:BILD0479.JPG

wastegates fit in, some minor rework on the turbo for the studs -no problems so far. BARO port does have nearly the same dimension as the wastegate connector -just perfect!

...so for now all i can say -I was a little wrong: the manual was spelling of *lb* -and the extended screen reads it in *PSI*. OK, now i understand it is simply the same ! What means nothing else as it has to show 0.4mm on the gage in the same time I can read 20PSI on the extended screen -Is that right !? Think 0.4mm is not that much, bud i hope it is no mistyping on the document and means 0.4cm ??

Oh, yes -some pictures: BILD0482.JPGBILD0481.JPG

Edited by G

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to name the things if I see them, that's what I call integrity..

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Hi G


1996 Esprit V8, 1998 Esprit V8 GT, 1999 Esprit S350 #002 (Esprit GT1 replica project), 1996 Esprit V8 GT1 (chassis 114-001), 1992 Lotus Omega (927E), 1999 Esprit V8SE, 1999 Esprit S350 #032, 1995 Esprit S4s, 1999 Esprit V8 GT (ex-5th Gear project), 1999 Esprit V8SE ('02 rear)

1999 S350 #002 Esprit GT1 replica

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the experiment failed, ..for now -Maybe you're right on the baro-range. It was not possible to get an reading above 15.7 PSI. Even if i fit the pump directly with one pipe on the sensor (I've chosen not to use one of the lumbar-support pumps with 'no-return valve', instead of that i used an ordinary ball pump..)

So the next option was the MAP-sensor. Bud that failed simply on the fact that i don't want to undo it from its mount or use different connectors/pipes to fit it in the line . I've got some fault codes from there on my first runs and now it worked -so i don't want to disturb the functinality... . Anyway, the necessary 135kPa would be more easy to see on that sensor.

Third part of the experiment was to use the MAP-sensor fitted on the Scorpio instead. It is mounted next to the engine, and not directly on the engine! So it does have a pipe on it , where i could fit my pressure signal from the wastegates too.. .

OBD was set on *read one* -so the time of actualizing was fast. Bud not fast enough. I've got varying reading on the screen and an stable reading on the measuring gauge. Or vice versa an static 101kPa pressure signal on the screen and in the same time i could vary the dial from 0.1mm-1.2mm .... simply annoying so far.. .

It was just a dream -what i need is an manually actuated pressure pump like it is shown in the manual. With pressure dial, and non return valve.... . Don't know where i can get one -or borrow one.

Final decision was to 'calibrate' the wastegates manually -based on the fact that i have chosen the yellow springs:

close the lever/flap on the turbo and turn the actuator/rod just to the point where both match up... . Looks nice so far ! An real road test will show the results !!

BILD0483.JPG

Edited by G

*********************************************************************

to name the things if I see them, that's what I call integrity..

*********************************************************************

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side note: Mike was right -I've got an *Baro out of performance range/unlogic MAP difference* code two times in the ECM.

Both are erased now. No *limp home* or anything -the car runs like hell and peak boost was 0.99bar as documented in the Vehicle-explorer Log/scan file... . The ECM tried to solve the over-boost heat by dumping fuel, or at least that should be the case as we expect that from an stock ECM ..interestingly on the long distance the mpg/fuel consumption was as god as in the last years. Around 10L/100km.

So the fuel dumping is not an massive problem for now. On the long term I will downgrade to green springs, just to be on the save side... .


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to name the things if I see them, that's what I call integrity..

*********************************************************************

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