Miller PSIK

[LJ851]

if i had a stock car i'd be all over the PSIK and would do back to back testing.

digger, i am doing just that. I've already been to the dyno once to do a back to back but my car could not handle the added HP (seriously) and i was unable to get a full power run with the psik. It will happen though and i will make a thread as i promised.

[BavBeater85]

yeah, for the cost I dont see the advantage of upping air flow...everything in the induction system seems designed to take an exact amount of airflow unless you just cram it in there (aka forced induction)...and it seems like youd spend almost as much as a good turbo setup to just pull in more air all the way to the cylinders ($900 maf setup, $600 extruded head, $1200 port and polish, and i dont even know where to get a bigger tb)

[BavBeater85]

correction, extruded/honed intake manifold, not head

[nando]

60mm will support a ton of flow. without going into math, I have memorized that a 65mm TB will flow 440cfm, only because we use them a lot on 60v6.

It's easy to see if the throttle plate is a restriction. Measure vacuum just before/after the plate and anything more than 2" difference equals restriction.

I have measured it. I lose 10-15kpa (3-4") through the throttle plate at 6500-7000+rpm. if I put the stock airbox on, I start to lose that at 6000rpm. engine makes about 220bhp at 6200rpm.

[ForcedFirebird]

Just did the math. 60mm TB flows just under 375cfm. You would benefit from a 65mm tb.

[nando]

I know, and I bought a TB that was advertised as a "BBTB" (wanted a 65mm plate). But in reality, it's a 60mm plate with the bore ground out a little bit. So I basically gave up on that.

[ForcedFirebird]

We make TB adapters for the 60v6's that allows us to use a GM throttle from another car and since the sensor values/size etc are the same, it's a bolt on deal.

Imagine their 175bhp engine uses a 62mm TB and the 205bhp engine uses a 65mm in factory form.

[digger]

Take One For The Team

it is worth noting that there are more to intakes than whether or not they pose a restriction. The intake is essentially a tube with size and length and therefore volume which influences how the waves that are generated as the intake valve opens and closes will travel, these pressure waves can have positive and negative benefits if tuned correctly.

i recently did some dyno testing where i removed my large airbox and piping which was proven to add some good gains over the stock airbox setup.

i replaced with 3" K&N cone filter on the end of the TB and then added varying lengths of pipe upto a length similar to what the Miller did. I didnt see any meaningful gains (over my custom setup). the shortest length gave a few whp more on the topend but i dont think it is repeatable enough to be 100% conclusive but there would be nice gains over a stock airbox and elbow.

Anyway a nice flowing tube and cone filter shielded from air a winner over stock, add a custom tune and your away, not likely 30ish hp like claimed but better none the less

[nando]

I saw the same, about a 5-10 HP increase after 6000rpm over the stock airbox. But not 30..

[bastianshaw]

Im surprised no one has done back to back before and after pulls w the PSIK esp. considering brody has offered to pay for the dyno time

[e30trooper]

The miller kit claims not to make 25peak whp but within the rpm rang (thus more midrange) I had the 19lb tune miller maf on my past vert. It made great midrange power but fell off after 6k. I went back to my adjusted afm/chip and made more power up top but missed that super mid. This was all on a butt dyno. Id love to go ms on my 2.7i po

[LJ851]

Im surprised no one has done back to back before and after pulls w the PSIK esp. considering brody has offered to pay for the dyno time

I did like i said i would, but ran into complications on the dyno and was unable to get conclusive results. i'll probably go back to the dyno and do it again.