i know the GT guys intake makes alot of power
Really?
We have a pretty educated crowd here on this forum - one of the things that differentiates this forum from all others, IMO.
There are at least a couple of mods out there with a lot of subjective HP improvement claims but where there is a complete lack of objective data to back up the claims. Does it mean that these mods are NOT producing the claimed HP benefits? Absolutely not. It only means that; 1) I've just missed any posting of objective or conclusive measurement or; 2) those objectives tests have just not yet been performed.
The mods that are somewhat routinely associated with HP gains are modified intakes and big cams. I've witnessed big cams causing hard-starting issues and I've also witnessed big cams producing a "to die for" lopey, menacing idle. However, I've never seen any objective measurement of HP before/after test results where there is an definitive advantage shown for the cams.
As for the air intake mods, I know that we have dyno'd 7-10 different twin-turbo cars ourselves - each of them at approximately 1,000 RWHP. ALL of these cars have used the stock airbox - with roughly half using K&N filters and half using stock filter elements. We've done a LOT of changes and diagnosed many anomolies and never once have we found a flow issue with the OEM intake. Granted, these were turbo cars. To get the equivalent 1,000 RWHP on a SC car, the motor is going to have to generate about 1200 HP (oversimplifying that 1000HP is going to the rear wheels and 200HP to drive the pulley). The jist is that a SC car may need to ingest more air and could hit air restriction limitations earlier. However, for an 800RWHP SC car, the air intake requirements are not going to be greater than a 1000RWHP turbo car - so once again I don't "get it" when it comes to a modified intake.
Further, testing of an intake on a dyno and comparing it to the OEM intake is virtually impossible. As an example, ALL the dyno tests that we have done as well as all the ones we have seen, are done with the clamshell open. The reality is that on the road with the clamshell closed down and sealed around the OEM airbox intakes - the car is going to enjoy a very nice dosage of ambient air and at a good velocity as the forward motion of the car is pushing the air into the OEM airbox. Compared to this, aftermarket air intakes can conceptually be OK on the dyno (as large fans are typically blowing against a propped-up clamshell) but on the road an aftermarket intake can position the intake filters is an absolute measureable "dead zone" for air. So, in the case of several of the aftermarket air intakes not only has there been no objective performance data to reflect their presumed benefit, there is obvious physical hinderances which are not present with the OEM air path.
