Proper BLT

[93RS]

Little bit of background:
92 Rs-T only real "mod" is a MBC set at 12 psi. It seems to me that my baby has a boost leak. Irregular idle, sometimes fine, sometimes it surges between 9-15k, other times it just sits there at 1500. Boost leak, yes I just did the TB shaft seals and when reinstalling the TB I stripped the top right threads on the intake. I took some of the washers off and grinded off a little of that plate between the TB and head. I figure that way it will grab more threads.
Now my issue:
I was told in a previous threadhttp://www.dsmtuners.com/forums/turbo-system-tech/424553-higher-boost-after-tb-shaft-seals.htmlthat i need to set the timing to 30* above TDC so the intake valves were closed. The marking on the lower cover dont say TDC... If I remember right it says BTDC not sure what that means and not sure how to set it to 30*. I just want to get a proper BLT done and fix my leak. Ive read all BLT links I can find and none say anything about the 30* thing. Any and all help is appreciated in advanced

 

[mattasi]

No one? I also am wondering.

 

[EGLTAWLN]

depends if the car has run recently and if your lifters are pressureized.
if you just let it cool down and you are about to boost leak test, don't worry about finding any TDC mark, just plug in your tester and test away.
aftermarket cams may make a difference. i don't use them so i don't know.
but when i pressurize my system, the cams move to where the air wants the piston to be anyways.
only time i had a wierd boost leak test was when my car had sat and the lifters bled out and so the valves were not seated properly.

i test post turbo to get out the bad leaks to 15-20psi.
then i test pre turbo to finish at 10-15 psi. otherwise air pressure can leak past the turbo seals and cause pressurized air in the crankcase which sucks for your engine oil seals.

i think the 30 degree thing is overkill, but may be nessecary for cam upgrades. i dont know.

 

[agentorange313]

Little bit of background:
92 Rs-T only real "mod" is a MBC set at 12 psi. It seems to me that my baby has a boost leak. Irregular idle, sometimes fine, sometimes it surges between 9-15k, other times it just sits there at 1500. Boost leak, yes I just did the TB shaft seals and when reinstalling the TB I stripped the top right threads on the intake. I took some of the washers off and grinded off a little of that plate between the TB and head. I figure that way it will grab more threads.
Now my issue:
I was told in a previous threadhttp://www.dsmtuners.com/forums/turbo-system-tech/424553-higher-boost-after-tb-shaft-seals.htmlthat i need to set the timing to 30* above TDC so the intake valves were closed. The marking on the lower cover dont say TDC... If I remember right it says BTDC not sure what that means and not sure how to set it to 30*. I just want to get a proper BLT done and fix my leak. Ive read all BLT links I can find and none say anything about the 30* thing. Any and all help is appreciated in advanced

9-15k means 9000-15000

Sounds like you are on the right path. Idle problems can occur due to vacuum leaks and will be come boost leaks when pressurized.

I would set timing to 40* BTDC so that all the intake valves are closed.
http://www.dsmtuners.com/forums/art...st-how-boostpro-net-tester.html#post152554139

If you cant find the leaks, use soapy water, or if you are lucky enough use a smoke machine. Common leaks are: injector seals, TB seals/gaskets, loose couplers, turbo outlet gasket, TB ports on top, BOV, BOV gasket, etc.

depends if the car has run recently and if your lifters are pressureized.
if you just let it cool down and you are about to boost leak test, don't worry about finding any TDC mark, just plug in your tester and test away.
aftermarket cams may make a difference. i don't use them so i don't know.
but when i pressurize my system, the cams move to where the air wants the piston to be anyways.
only time i had a wierd boost leak test was when my car had sat and the lifters bled out and so the valves were not seated properly.

i test post turbo to get out the bad leaks to 15-20psi.
then i test pre turbo to finish at 10-15 psi. otherwise air pressure can leak past the turbo seals and cause pressurized air in the crankcase which sucks for your engine oil seals.

i think the 30 degree thing is overkill, but may be nessecary for cam upgrades. i dont know.

I dont think the text above in bold is correct. ATDC, BTDC, ATC is important when doing a boost leak test. You dont want to have open intake valves when you are doing the test. Air can leak from between the TB and head (mainly intake manifold), leaks can occur between the PCV system, FPR, BOV, brake booster.,anything that runs off of vacuum.

Why would air force the cams to move to where the air wants the piston to be? If the camshaft is moving then the crank needs to move, if its in running condition. Maybe I don't understand what you are trying to say, but it doesnt make sense for the cams to move when you pressurize the system.

30-40* is not over kill, its a proper boost leak test. Whats the point in doing the test if you aren't doing it correctly to verify that there are no leaks?