ATP/Garrett Hate - failure GTX3076

[Dano]

holy shitstorm of conflicting information batman!

Garratt says use a restrictor..but only if you are under 40PSI
ATP says..do not use one.
some guys use them
some guys dont

has anyone actually measured oil pressure at the feed line in the upper RPMs?

edit: I see that Garrett wants pressure at least 40-45PSI if lower then the restrictor will increase said pressure in the CHRA.

This may be the same source @rfinkle2 quoted

Ball Bearing Turbo "An oil restrictor is recommended for optimal performance with ball bearing turbochargers. Oil pressure of 40 - 45 psi at maximum engine speed is recommended to prevent damage to the turbocharger's internals. In order to achieve this pressure, a restrictor with a 0.040' orifice will normally suffice, but you should always verify the oil pressure entering the turbo after the restrictor in insure that the components are functioning properly. Recommended oil feed is -3AN or -4AN line or hose/tubing with a similar ID. As always, use an oil filter that meets or exceeds the OEM specifications. "

http://www.turbobygarrett.com/turbob...il_water_lines

[Lex]

Originally Posted by Dano holy shitstorm of conflicting information batman! Garratt says use a restrictor..but only if you are under 40PSI ATP says..do not use one. some guys use them some guys dont has anyone actually measured oil pressure at the feed line in the upper RPMs? edit: I see that Garrett wants pressure at least 40-45PSI if lower then the restrictor will increase said pressure in the CHRA. This may be the same source @rfinkle2 quoted Oil & Water Lines | Turbobygarrett

I think there's a misunderstanding here. The restrictor in the feed will lower the pressure at the turbo since it causes a pressure drop. What they meant is that if you have above 40-45psi oil pressure coming from the block, use a restrictor. Not below.

Another note in here - if the oil feed is so large that pressure drops way low and the CHRA is not enough of a restriction, a restrictor may be needed since too much oil volume will pass through the turbo.

Oil pressure at the relief valve is probably around 70-80psi on our cars and its riding the relief at 3500 RPM and above. Someone check this in the manual. When oil passes through any passage some of that pressure drops, eventually dropping to zero as it return to the oil pan. The main bearings are fed first, then oil works its way up the block and into the head. I suspect the turbo feed to be between the main bearings and head.

I should add, more viscous oil increases pressure, and as the engine wears and bearings wear down/passages open up, pressure drops.

[Dano]

O I C,

I guess I was thinking a restrictor would INCREASE pressure/lower volume...place finger over garden hose pressure goes up.

my head hurts....