35mm 38mm 40mm 46mm waste gate whats the difference?

[2geclipse565]

I understand that you can change the internal spring to make the gate open and close at different psi's. But what is the real difference in the different MM of the wastegate? What are the positives and negatives to going with a bigger wastegate such as a 46mm? My situation in particular Im doing a 20g swap and have found a good deal on a recirculated o2 housing with an external wastegate like such

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Im not getting the ebay one for the record. But it does have the 4bolt hole design, and it looks like this design only comes in 46mm? At least thats all iv seen. So would this set up be ok for my 20g setup? but more importantly what is the difference between wastegate MM sizes?

 

[turbo98eclipse]

You would need a bigger one if you are running less boost as there will be more exhaust gas that needs to be bypassed from the turbine

 

[1990AWD]

the bigger the wastegate, the more exhaust it can move. not much too it.

 

[2geclipse565]

Has anyone seen a 4 bolt style wastegate that is smaller then a 46mm? So a 46mm wouldn't really be sufficient for a 20g? Even with proper springs.

 

[LiquidX]

Most people are sufficent with a 38mm. The larger sizes cost more but as said above, move more exhaust. Those tuners out there that run large turbos and little to no boost would be running a large gate to rid themselves of boost creep at that low of psi.