Si, i'm not going to start saying who's wrong and who's right and where i got my info from etc. etc. as i don't want to get drawn into a great political slanging match...

But - as you well know, Lee's old engine couldn't hold more than 1 bar of boost, he was running a Garrett GT series turbo and ALS.

Having researched it thoroughly as i was buying his engine and wanted to establish whether the fault was in the short block or the turbo i spoke to a number of well established and respected turbo specialists. One of the was even kind enough to send me the roller bearing cartridge out of a GT30 that had been anti lagged. When i took that cartridge into work and inspected it in our NDT lab i carried out the following tests:

Penetrant dye then inspection under a x25 UV microscope
X Ray
Checking spherical dimensions of the bearings

The casing itself showed a large amount of fret on the inside, the ball bearings had compressed slightly into oval dimensions and there was scoring on the outer race part of the bearing case.


Hence me concluding that the shaft load created by ALS posed a risk to the service life of the turbo.

I'm not saying that a 'mild' (i.e vacuum removal) ALS system will pop it straight away, but as i remember Lee's engine, he had done less than 5000 miles with a relatively mild system and his turbo can't hold more than 1 bar...

Therefore personally - i won't be using it