I see your point Brian. I wonder if I had broken vains on the turbo fan, either at exhaust end, or air output end, would'nt there be a noticable imballance and vibrate like hell?

So if I bypass the pressure switch, and introduce 12 psi (artificially) to the Alda, there should be an increase of fuel supplied, thus increasing boost, and if not, we can rule out the Alda and the only other possibility can only be the turbo it's self?

Hopefully I will have time this week to try that, I'll report my findings........Steve

Well, if a chunk of either the impeller or the turbine came off one of the blades, the turbo would very quickly kill its bearings, so this is unlikely. However, if the impeller injested some crap and eroded the blades, the unbalance would not change dramatically, however, the performance of the turbo would be affected, even if it reaches its design speeds.

The increase in fuel provided by the ALDA will cause more volume to pass through the turbo. In this case, we should expect to see some improvement of the boost pressure, maybe to 7 or 7.5 or so. I would be shocked if the turbo would magically put out 12 psi and trigger the wastegate, but, that is what this test is all about. If the boost pressure remains at 6 psi, this would definitely confirm a problem with the impeller. It is damaged in some fashion and has too much clearance to the housing. Even if it climbs to 7.5 or so, an ALDA adjustment is not going to get you much of anything. We don't want to start adjusting the ALDA if it is not going to accomplish much.

Don't forget my "proximity regulator" smoke test :D

Thank all of you here on this thread for your help. It pointed me in the right direction. GSXR was instrumental in my finding the real culprit which revealed it's self this morning.

I found the push rod that extends from inside the IP to the Alda to be rusted and siezed. I got it free and lubed it, also had to replace the Alda!

Now I get 11 psi, and a hell of a lot of power it never showed me before. I'm sure I can tweak-out one more pound of boost!

The car is extremely fast and compares easily with any chevy 350-v8, if not more!

Thanks again, Steve............ :D

This is very interesting.

It clearly shows that the turbo cannot achieve full boost without fuel enrichment by the ALDA. There is not enough volume from a naturally aspirated 603 to allow 12 psi boost.

The turbo and the ALDA clearly work in unison. The ALDA requires pressure from the turbo to advance fuel, and the turbo requires that fuel advance to generate enough pressure in the turbine to create higher boost levels.

Very, very interesting.

I'm real glad you found the culprit Steve. The process may have been painful, but, I'm sure the results are worth it.

Interesting stuff, huh! I have NEVER heard of a frozen ALDA shaft - that's a new one on me! :eek:

I have heard from others that if the IP is very low on fuel delivery, good boost pressure will not be produced. I have never had that problem on my cars though, because mine all either had the ALDA's adjusted, or were not low on fuel to begin with - i.e. they were able to make enough to build ~12psi.

On a car with a properly richened ALDA, even with the ALDA boost signal line disconnected, the boost should be 12psi+ and the 0-60 time may drop a little (say, from 11 to 15 seconds) but not drastically (say, 11 to 20 or 25 seconds). If it does, the base fuel quantity is too low. This seems to be age related, perhaps from spring tension weakening, as the pumps get older. (??)

:cool:

One thing more I should note is that now I can feel more acceleration way before even 1500 rpm. Never felt that before! I've been driving this car for 12 thousend miles now at only an aspirated level. I had thought I felt some boost before, but the Alda never worked obviously, never did anything!

Boy, it's fast now! :D :D :D