Hello.

I just purchased a new turbo, and i have been told that i should use a 44mm wastegate with it to keep from spiking in the high rpm's. Currently my manifold is fitted with a 38mm. Would it be ok to just cut off the 38mm 2 bolt flange, and weld the 44mm vband flange in its place? Would this make use of the 44mm capacity, or does it need a larger feed tube to really work properly. right now i think the tube feeding the WG is larger than the hole in the flange, and that is why i think i could "getaway" with this until my new manifold is finished.

some quick specs to help make the judgement.

Ls/Vtec 2.0L
9.0:1 CR
Equal length Ramhorn
3" Down Pipe and exhaust
Full Race Spec Garrett GT3567R

planned boost level: what ever it takes to make 600+WHP

 

i believe they make a adaplter plate to make a 44mm fit

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by komat &raquo;</TD></TR><TR><TD CLASS="quote">i believe they make a adaplter plate to make a 44mm fit</TD></TR></TABLE>

o rly?! any more info on this? or just say who "they" are and i will look for myself

 

the reason for it to spike is due to the fact it can´t control low boost, if u wanna go for 600 whp u shouldnt have a problem with the 38 gate.

 

check with http://www.atpturbo.com

 

Big turbo + low boost = big wastegate

Big turbo + high boost = small wastegate

 

i would cut off the 38mm flange and get the vband welded on there...the tubing is most likely 1.6" ID and 1.9" OD and 44mm ~ 1.7" so it would be a perfect fit

this is all of course if you decide to go with the bigger wg which they have already discussed

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tchleung &raquo;</TD></TR><TR><TD CLASS="quote">Big turbo + low boost = big wastegate

Big turbo + high boost = small wastegate</TD></TR></TABLE>

Big turbo + low boost and then high boost = big wastegate(s)

 

You don't need a big wastegate for high boost.. On my 2.0L GSR with GT30R It holds low boost fine at 14psi, and 28 psi just fine as well. This is all with a 38mm wastegate. And I don't know anybody with a big turbo trying to bosot under 10.. If that was the case, then a alrge wastegate is needed. I find anything over 12-14 with a big turbo and engine, it doesn't creep even with a small wastegate.

 

unless your tryin to keep the boost below 10lbs you shouldnt have a problem with the smaller gate. Is this car gonna be drag racing with a multistage boost controller? if so then u might want to get the larger gate that way you can limit yourself to 6-12 lbs off the line to try to get traction then up the boost from 2nd to 4th gear.