Invasion1 Posted February 25, 2004 Report Share Posted February 25, 2004 ' Quote Link to comment Share on other sites More sharing options...
SleeperRed90TGp Posted February 25, 2004 Report Share Posted February 25, 2004 I hope you use 800 numbers Davis. Good info. Turbochargers didn't like my cracks at all. there was 1/3 to 1/2 of the wast gate seat that was black from leaking. Yea, the cracks don't mater if there flat cracks. If your housing has warped do to these cracks and you have a offset from side to side of the crack it will effect how much boost you can get out of the t2 small turbo. And you don't know if the cracks will get worse and seperate. I had like .020 offset so I junked it. and bought a monster. Welding, I don't know. They have come a long way in welding cast iron in the last few years. In the past the cast iron usually cracked on each side of the weld. I wouldn't trust it due to the record of our turbos cracking. Don't think there is an un-cracked one out there. Jud Quote Link to comment Share on other sites More sharing options...
Jeff M Posted February 25, 2004 Report Share Posted February 25, 2004 I agree with all this totally, nice wrap up of info!!! I want to add since its common to the TGP turbo for sure and not the norm of understanding for it but the wastegate hole leaking from raised area cause by the cracks is not really a problem. The spring in the wastegate actuator will never allow the wastegate to close at full boost, the highest boost most will get is 12 psi past 4,000 rpms, even if you unhook the hoses to the actuator, it will never get close to being closed (UNLESS the turbo is not clocked properly and the actuator spring is pre-loaded/over-loaded!). I have threaded wastegate rods to pre-load and get higher boost, and it took a lot to get it to close near totally closed but at that point, I was hitting 18 to 20 psi, NOT what you want with this little turbo anyways, but all just test to give me the info of value I can also share here! So, no worries WE now know, but maybe some education to those rebuilder shops is in order. I have seen TGP turbos with cranks nearly 3 inches long, going in all 4 directions (noon, 3 o-clock, 6 and 9 and these turbos were still holding together and allow everything to operate and boost properly….all in all nice to find this casting material flaw is not a main problem for us. As for getting a new turbo, not from GM, big maybe Garrett still has these, maybe from their plant in France where these were made. As for welding, I so agree with you here too, it’s a real skill to do it and not have it crack soon as the weld cools, Caterpillar is one of the companies I know of that can do it proper, back the shit out of the housing to get the carbon out of the pours, then keep it above a certain temp while welding, keeping it above that temp so the weld will take, all this will end up having the repair a bit costly, but like I said, so far we are surviving to boost another day! Davis, email me for a xover pipe install doc, it uncludes the turbo R&R and has tricks and tips from me doing literally dozens of pipe installs, and honed by owners and any tips or tricks they found, valuable tool for someone doing work in this area 8) ! Jeff M Quote Link to comment Share on other sites More sharing options...
tgpguy21 Posted February 26, 2004 Report Share Posted February 26, 2004 Hey davis if you need your turbo back pretty quick I would think twice about sending it to cheapturbo.com. Theyve had mine since last wed, and still havent even got me a estimate back yet. Ive talked to the guy and he says their backed up pretty good. so if its something that you really need i would hold of for alittle or send it somewhere else. Quote Link to comment Share on other sites More sharing options...
Jeff M Posted February 26, 2004 Report Share Posted February 26, 2004 and those cracks still bug the shit out of me..... wish i never looked.... Dave You mean to tell me after posting here and on the other message board, and getting some excellent replies you are still hanging on to this small issue, you sound more like my wife fussin about such trivial things Jeff M Quote Link to comment Share on other sites More sharing options...
SleeperRed90TGp Posted February 27, 2004 Report Share Posted February 27, 2004 20 psi humm, I could never get over 15 with my waste gate wired closed. I wonder why? Jud Quote Link to comment Share on other sites More sharing options...
Aaron Posted March 7, 2004 Report Share Posted March 7, 2004 Do the turbos in the cars need to be rebuilt often? Like after 137k on a stock turbo running stock boost and a aftermarket blowoff valve should it be replaced? Thanks!!! Quote Link to comment Share on other sites More sharing options...
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