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NathanUK NathanUK is offline
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Join Date: Nov 2006
Location: UK
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Originally Posted by hobieboy View Post
Nathan, not sure if I understand this completely: "if the smaller turbo is restricting the exhaust getting out of the engine as the bigger turbo will open up the wastegate more than the smaller turbo which needs all the exhaust it can get to maintain turbo speed and therefore cold side flow."

Bigger turbo tends to need more exhaust pressure/velocity to spin up than smaller ones I thought?

If bigger turbo can flow waaayy more air in same amount of time given a static volume to fill, then it will cause more pressure hence opens up the WG more/longer.

But neither directly relates to how more air actually got into the chamber at same pressure & time, unless (as I "discover" now - not sure if its right) that the small turbo didn't really fill the chamber as full as the big one before the valve closes.
You quote in red was my point. If the WG is open then the turbos hot side is not strangling the engines out flow?
Unlike the smaller turbo which will have WG tightly shut.

This comes back to the air pump, getting air in & out of the engine = power.
1981 UK 930. G50/01 shortened, 964 3.8RS Fibreglass Body Kit, 18" Alloys 8.5" F & 10" R, 225's F & 285's R, Special Colour Metallic Blue Paint, FIA Sparco Evo's, A/C and Air Pump removed, Electronic Boost Controller, GHL Headers, Tial46 WG.
Fitting - New service kit.
Needs Fitting - Innovate XD-16 Kit, Kokeln IC. Stephen's K27 HFS, EVO Intake Assy & his Modded USA Fuel Head.

1983 UK 911 3.2 Carrera Sport Coupe. Black, Black Leather with Red Piping, Black Alloy Gear Knob, K&N Air Filter Element, Turbo Tie rods.
Needs Fitting - K&N CO Sensor, Round A/F Dial Gauge, Factory Short Shift Kit.

Last edited by NathanUK; 07-17-2008 at 02:16 PM..
Old 07-17-2008, 02:13 PM
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