Aircooled VW South Africa

Hallo Gentlemen, I need some info on my project. I'm new to your blog found it while looking for air cooled turbo projects. I'm running a suck/pull through configaration with a GT1549 Garrett turbo, the ones you buy from Importers. I damaged 2 of them, on the third one now. After some research I'm sure the problem is with the type of seals in the turbo. Most of the new turbos use piston ring type seal but pull through applications need a mechanical face seal. Can anyone help with some info or suggestions if I'm on the right track?

Robby.. Intro will be in order.. Check your welcome mail
Suck through turbo's require a carbon seal due to oil being pulled through the seals when the carb throttle close. a Turbo house can install.. quite pricy though
Su carbs have a vacuum release valve on the throttle that is a life safer in long runs,, if you have a side draft you will benefit fitting one of these made up between the carb and intake manifold

Johan

[quote="johanb"]Robby.. Intro will be in order.. Check your welcome mail
Suck through turbo's require a carbon seal due to oil being pulled through the seals when the carb throttle close. a Turbo house can install.. quite pricy though
Su carbs have a vacuum release valve on the throttle that is a life safer in long runs,, if you have a side draft you will benefit fitting one of these made up between the carb and intake manifold

Johan[/Hi Johan, still trying to find my feet,and the welcome mail for a intoduction. Please supply more detail on the vacum release valve as I'm using a side draft. ]

Robby

The best is to have a look on on a SU carb to explain how they did it.. basicly what it boils down to if you close your throttle to change gears, the turbo is still spinning at eg 22 000 refs and at that speed push all the air in the head, now here is where the problems start
1. Becuase of the vacuum the oil gets sucked through your seals (Turbo running dry and turbo failures- A possitive carbon seal will resolve this - The problem you currently have)
2. In very rare cases because of the vacuum air gets pulled out of head and cause the turbo (Intake side) to reverse while the exhaust side is still running is the oppisite direction with the normal rotation -- breaking turbo shafts -- like I said very rare but it already happened to me

The vacuum release valve is a small valve with a spring that opens up as soon as there is vacuum to ease the reverse effect and keep less vacuum for the turbo seal to leak oil.. (In a nut shell) You don't drop instant revs when closing the throttle but the turbo will last for ever. There might be better methods of doing these things nowadays, but I'm from the old school and that is how we did it those days

My garage is in schambles with kombi spares blokking everything, will se if I can get a SU and will take a photo so you can have a idea what I'm talking about,, don't worry I read better with pictures as well

Don't lose hope in your turbo setup,, a few mods and you will enjoy the turbo for years to come