A discussion among a few friends has led to some needed 'testing' of the cause of some vacuum on our cars, and one common denominator we all complain about is the K&N FIPK - it's shape does not seem conducive to great flow. The question is, has anybody actually tested to see if it is a source of vacuum, and has anybody ditched it in favor of a simpler solution and seen gains?

Post pics of your set-up if you have something different (not another marketed CAI either).

 

This might be what you are looking for.

DYNORUN.022 is exhaust closed
DYNORUN.023 is exhaust dumped after the headers before the cats
DYNORUN.024 is with the K&N FIPK disconnected from the MAF.

Intake manifold is ported LT4
58mm throttle body
Vortech intake elbow.

Removing the K&N FIPK made no difference.
I've also tried running in SD mode to eliminate the MAF. Still shows the same vacuum. So that leaves the 58mm TB and the intake itself.

 

How about a meanass Home Depot 3" PVC setup?


(I have a LPE SuperTube so I was just sayin'...)

 

If ya got it, post it!

 

Disconnecting my whole intake elbow(running the FIPK) from the TB while on the dyno netted less then 2hp to the wheels on back to back runs. I'm sure that was due to the dirty filter, not the CAI.

It is more then enough flow to feed most LT1s, and there cannot be any more power found in the intake side - no difference from an open TB!

My car is MAFless speed density, so any MAF restriction(how little it is anyway) was not a factor.

If you need the info, the basics relating to airflow would be:
-Stock cubes
-Ported stock Heads
-Ported stock intake
-58mm AS&M Tb
-1LE elbow
-K&N FIPK

 

I think it will flow more cfm than you will need NA


I used to have a 1000 cfm k&n filter on the end of the TB. I did away with MAF

 

Good point, I forgot to mention my build was NA.

I thought about the filter right off the TB, like what was common with the L98's, but decided the heatsoak may become a bigger issue at the track. Either way, it seems the K&N FIPK is more then adequet as it is.

 

So much for LT1 intakes being a restriction.

 

https://www.camaroz28.com/forums/sho...ghlight=Amsoil

Here are my subjective results from changing away from a K&N Conical to a significantly MUCH larger amsoil one Zero issues with driving this in heavy rain, puddling isn't too big of an issue here to begin with I think the ducting for the FIPK is pretty decent, they did a good job of working around the radiator with the bulge it has on the top bend.

 

If there aren't any viable alternatives, I would make sure you have the biggest filter you can fit on there. Choices are limited due to our hood clearence.