Help me understand HP potential of S vs TT

Originally Posted by TopgunZ

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I inquired into the GTM stage 2 twin turbo kit. The sales rep shot me back an email stating that at 550whp I would be maxing that kit out, the GT28's with the .84.

So I am just confused as to how you can have a single turbo, that isnt all THAT much smaller than a GT28, making the same power #'s as TWO turbos of a slightly smaller size, on larger engine. Has it got all to do with the fact that they really do just drop off in efficiency at such a lower psi?

I would like for there to be room in my system for growth and I also wouldnt want to be pushing my turbo's super hard all the time.