Originally Posted by shiv@vishnu

Your hot air induction system is only 20 degrees warmer than a fully sealed, cold air ducted airbox? Don't you think that is a bit optimistic when underhood temps can easily approach 200 degrees (or more when the radiator fans kick on)? I've measured turbo inlet temps of over 200 degrees on cars with aftermarket intakes.

Yes, intercooler does remove 80-90% of the heat generated through compression. But post IC temps will always be colder if turbo inlet temps are colder. And when there is no measureable vacuum in the turbo inlet tube, I think its safe to say that there is no power to be gained through "opening it up." So what you have in the end is a hotter intake charge, with a MAF that doesn't read airflow as well as it should and no measurable reduction in intake restriction.

With bigger turbos that move a lot more air, inlet restrictions may come into play. But with stock turbos that can only flow so much air, talking oneself into upgrading the intake is like trying to fix a problem that isn't there.

Just my 2c,
shiv

Originally Posted by Precision Dyno

EVO 9's in japan often see huge differences in part throttle preboost A/F ratios when they change the intakes to an aftermarket unit.
The new ECU program has a lean spool map that will actually be detramental to the engine when this happens. The A/F target from mitsu is about 13.5:1. When the aftermarket intake is installed they are almost stoich.
Many blown manifolds are the result.
Whenever you increase the pressure differential you will see an increase or decrease in induction volume. Depending of course on the size of the inlet and the pathway.
So no offense but I don't agree with your post
I also don't understand the comment about the MAF having difficulty reading airflow. Could you please explain...

Originally Posted by Spec'd

That sounded very intelligent. But are you saying that an aftermarket unit
is good or bad ?


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