So I am running the Greddy SOHC kit, custom 2" DP, stock Greddy elbow, no boost controller or anything like that. The place who rebuilt the turbo "set" the wastegate for 8psi. Strange thing to me is that it has NO threads showing on the shaft, none. I've always seen external wastegates with at least some threads showing. Anyways, boost is spiking to 8psi, then it settles down to 4-5psi by the time I am at 7,000rpms. I have a feeling this has something to do with the wastegate adjustment. I've read that moving the rod doesn't actually change the amount of boost the car is capable of, but it adjusts the sensativity. What I need to know is can anyone confirm this and clarify what tightening or loosening the rod might do? I know if its too loose then spool time would greatly suffer. Right now, this thing doesn't even have full boost till almost 4,000rpms which just doesn't seem right for a litle TD04H.

 

the length of the rod has alot to do with it. the shorter the rod the more boost it has.

 

from my experience, you are basically adjusting a flapper, that covers a hole. If that is loose on there, it will cause you to have later boost. I just made mine tight, then went a couple more turns on it, and had to pull it out a little to make it fit onto the flapper. Not sure yours is setup the same way. But this ensured it was nice and tight. Also, I've read that depending on where you take your vacuum reading from, it will affect the waste gate.

 

RPM's sound about right. My stock TD03 on my Audi A4 hits full boost around 3300-3500rpm and its a 1.8.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostedcivicsir &raquo;</TD></TR><TR><TD CLASS="quote">the length of the rod has alot to do with it. the shorter the rod the more boost it has.</TD></TR></TABLE>

Yeah, I was able to do some more research and find this out. I went to check my wastegate and it was as tight as it could go. Could this cause spiking? I adjusted it 5 turns looser and will try it later on tonight.

Would anyone here happen to know how to hook up the dual SBC spec S (I think) solenoid valve? I tried every possible combination I could think of and always wound up hitting the boost cut in the ECU even when it shouldn't have been boosting more then 9psi.

 

the tighter it is, the less it opens, therefore increasing boost, if it cant open then it will cause a spike.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostedcivicsir &raquo;</TD></TR><TR><TD CLASS="quote">the tighter it is, the less it opens, therefore increasing boost, if it cant open then it will cause a spike.</TD></TR></TABLE>

Alright, then help me understand this... Why would it spike down low and then around 7,000rpms settle to around 4psi? Slow reaction?