RowJ

Lowers EGT's because each turbo is running 50-75% of full rpm....lots of cool compressed air...not worked hard and hot like our singles!
RJ

wannadiesel

Also some systems have a wastegate that bypasses some exhaust around the small turbo and into the big turbo to reduse the restriction.

SmokinFive9 4x4

I've seen the external wastegate on most twin turbo systems, is this regulated somehow or is it always open just restricted to a certain amount? And if so, to what amount? And if not, what regulates it?
Secondly, by "larger turbo" are you talking about exhaust housing size like using a 12mm vs a 16mm? and/or the compressor volume?

Been interested in this for awhile, but never really knew how to set it up, so figured I'd ask a few more questions to get a good start :-)

wgingg

50 - 75 % that helps me some and the waste gate dumping more to the second turbo helps alot. the reduction in egt's i was talking about is the 300 or so degrees diff from pre to post turbo readings

HOHN

Most twins setup have the external w/g set to pop open at around 20psi. This keeps the small turbo in its operating range and shifts more work to the big turbo.

It also relieves the restriction that the small charger becomes as boost gets higher.

Justin