Turbo spooling, or the lack of it

[RickDLance]

I'd like to share some things I think I've learned over the last few years and possibly learn more about the dreaded turbo lag.

We all know it can be caused by too big a turbo. I found out a year or so ago that the manifolds / headers and up pipes sizes can affect it also.

I know tuning plays a big role too, but the biggest surprise to me was the CAC and it's plumbing.

Yes, you heard me right. A bigger CAC / intercooler and/or it's piping can in fact effect throttle response.

Building too much "storage" capacity anywhere in the system is like having a "storage tank" in the system. You have to fill the "storage tank" to the desired pressure BEFORE the engine will see that pressure.

In time I think the manufactures will see this also and offer CAC's based on flow number's and not just on cooling or pressure rating.

Anyone have any opinions, different conclusions, or just good old fashioned discussion?

[James Hess]

Ok what is a CAC, i know what a intercooler and all its piping is but are they the same thing?

[RickDLance]

Basically. A cac is a charge air cooler. From the dictionary;

A charge air cooler (also known as an intercooler) is used to cool engine air after it has passed through a turbocharger, but before it enters the engine. The idea is to return the air to a lower temperature, for the optimum power for the combustion process within the engine.

[madmaxdmax]

I'd like to share some things I think I've learned over the last few years and possibly learn more about the dreaded turbo lag.

We all know it can be caused by too big a turbo. I found out a year or so ago that the manifolds / headers and up pipes sizes can affect it also.

I know tuning plays a big role too, but the biggest surprise to me was the CAC and it's plumbing.

Yes, you heard me right. A bigger CAC / intercooler and/or it's piping can in fact effect throttle response.

Building too much "storage" capacity anywhere in the system is like having a "storage tank" in the system. You have to fill the "storage tank" to the desired pressure BEFORE the engine will see that pressure.

In time I think the manufactures will see this also and offer CAC's based on flow number's and not just on cooling or pressure rating.

Anyone have any opinions, different conclusions, or just good old fashioned discussion?


Seems like the GM engineers are more likely to base the CAC on reliability rather than peak performance. I wish they would offer other power upgrade options like larger turbos etc with the tow package. IMO the consumer should be able to choose what they want since everyone has a different use for these rigs. Too bad that GM and the others only give us a sneek peak from the assembly line as to what these trucks are capable of doing. If you think about it, what would this scenario do to all the aftermarket companies out there? All I want from GM to date is a solid fix for my LB7 injectors (fingers crossed).

[hondarider552]

and the racer option comes with a built motor and trans, efilive sold separatly ):h