It's the turbine wheel which will affect your spool time. So, if you're going with 92mm turbine as Stock48 recommends, you might as well get the the 80mm compressor. Just a thought.

 

Iv been told the 76 spools faster.

 

the 76 will spool faster than the 80. more mass=slower spool.

 

I wonder how much faster the 76 over the 80 spools.
100-200-300 rpms?

 

I guess in that case you would have to compared apples to apples. The 76 I was looking into has all the bells and whistle.

 

Correct.
That's what I was thinking but wow talk about time consuming and funds chewing up to do a comparison like that.
Would have to on an engine Dyno.
To limit all the other variables.

 

I never liked that "spools by this rpm" nomenclature. What really matters is the temperature of the exhaust (including pipes, turbine housing, and downpipe). A turbo will spool faster after youve been driving for a while than it will when its first started (even if the engine is full temp).

Also time is important... lets say you are at a dead idle (and have been for a few minutes), the lag to get into boost may be 2-3 seconds. Now lets say you are cruising down the highway and punch it, now the lag may only be 1 second when you nail it.

My point is, turbo lag is not something as easy as "this size turbo will spool by this rpm on this engine". Even what fuel you use makes a huge difference. With that said, most of the mass is in the exhaust wheel, and also the smaller the wheel the more pressure (and heat) it will cause between the turbine and engine and therefor the faster it will spool. More heat + less mass = much faster spool time.

 

lol i've said that myself i don't know how many times. using rpm alone to explain turbo lag is not*sufficient.

 

One of those things that has like 10 variables and each depends on the other ones....its not an easy question to answer, but no one likes anything but the easy answer.

 

this is anything but easy i can tell you that lol

me and Stock48 have PMed each other alot talking about which turbo/size motor/intake/cam/header pipe... you name it. so its not that im just picking one out of a hat. the more we talk the more we narrow it down on the best setup.