Why is it that a Tial 38mm gate is rated to 400-450 HP and a Turbonetics 42mm Racegate is rated to 900 HP? The opening size difference is only 4mm which shouldnt make such a huge difference between the two. I have had both of these in my hands the last few days and the only real difference I can see (besides the 4mm size difference) is the size of the chamber behind the valve. Both gates have the same valving configuration.

Any theories or ideas on this??

 

First, wastegates should not be rated for hp. Not sure why the manufacture does this. They should be rated for amount of CFM the valve can discharge effectively. With that being said, essentially either gate will do the job if your going to run higher boost. The lower the boost you run the larger the gate needs to be. Both units are plenty capable.

Jose

 

So a Deltagate would be better at 14# boost then at 4#boost? When you add more air doesnt that also make more exhaust especialy once the air is heated by detonation? so if you hit full boost at 4500 rpm any additional exhaust after that (4500 to 6500) has to be passed via the wastegate right? Sorry for all the questions but I am relatively new to FI and reference material is scarce. I am trying to get a good understanding of all of the basics.

 

The wastegate only opens to divert exhaust away from the turbine of the turbo.

trying to run lower boost forces the gate to bypass more exhaust. If you have a big turbo and want to run low boost you need a big gate. If the gate flow is too small to keep the turbine speed down, you will experience boost creep.