XM Intake Manifold and s90 TB Dyno...

[familyMAN]

I don't think your new intake pipes and filters will be great either. I had 3" pipes to each turbo with a 3" by 5" AEM filter on each. I would have gone even bigger filters if I could.

[Chris@Rvengeperformance]

This was GTPro's dyno from an old 2008 thread on the other forum:

"well here are the results. i only dynoed it on one car as it was a pain in the ass with this prototype to swap intakes so i figured id do it on a 16g car right off the bat.
mod list:
stock engine 720cc injectors with gtpro fuel system
arc2 big mas
full exhaust/16g internal wg kit
FMIC
at 12.5psi on pump gas with stock intake the car put down 355awhp, i dont have a torque reading because our tacho pickup is being funky for some reason.
with just swapping the intake leaving the boost alone i had to richen up the car 2 clicks on high and she put down this:"

why is the humidity on that graph 28% for the green run and 18 for the red? Also, the red pull is clearly started earlier. No boost logging? Are we to believe eyeballing the gauge or posting what a boost controller showed as peak is okay?

Had to change the tune two clicks, but no af plotting?

There's so many issues with this I could go on for a while. For one thing, with 720s and ~350 AWHP you are looking at 50% idc or so. Richening it up is going to raise that and could've done all sorts of things to what load cells he was hitting. It may have actually been overtimed in the beginning. I wouldn't be surprised to learn it was knocking in the first run on cali gas.

[NOMIEZVR4]

I don't think your new intake pipes and filters will be great either. I had 3" pipes to each turbo with a 3" by 5" AEM filter on each. I would have gone even bigger filters if I could.

I got a second set of pipes and filters...but damn..3" intake pipes?? Its gonna be hard for the front turbo pipe to clear because the coolant reservoir is right in the way..

[fastfalcon94]

why is the humidity on that graph 28% for the green run and 18 for the red? Also, the red pull is clearly started earlier. No boost logging? Are we to believe eyeballing the gauge or posting what a boost controller showed as peak is okay?

Had to change the tune two clicks, but no af plotting?

I noticed the humidity difference as well. IDK if it was done all in the same day or not. I think there are 2 threads on the other forum involving this and one is 42 pages long. I haven't gone back and read it all. Hopefully some people over there asked the same questions.

[Chris@Rvengeperformance]

I noticed the humidity difference as well. IDK if it was done all in the same day or not. I think there are 2 threads on the other forum involving this and one is 42 pages long. I haven't gone back and read it all. Hopefully some people over there asked the same questions.

The graph claims its within an hour or so of each other. Given the source I hope you can understand my skepticism. It just wasn't very scientific IMO.

[AdamVR4]

Curious as to why? *It is proven to not be worth it for 500whp but, I would think it a huge waste of investment to limit a 3.5L build to 500whp.

Holy faulty logic. We've got data here suggesting NO GAINS @ 500 whp. You're simply assuming this combination will separate itself from the stock parts as the air flow increases. It might. It might not.


Further, you're ignoring years of real-world evidence suggesting that the stock TB and manifold don't EVER present a hard limit. I've made over 600 whp through these parts on my 3.0L and you're trying to suggest that there's a limit at 500 whp. LOL

I suspect there are gains to be had from this setup north of 600whp. Just because this testing was never pushed hard enough to realize the restriction it will cause north of 600 doesn't mean it won't.

Or it could still show negligible gains or stock could prove to be better as air flow increases. You don't know.

I was seeing a 3psi difference through my 3.5" maf and the stock tb at mid 600's whp. *Some of that was the sensor but, i bet some was the tb. *Make more power than that and the gains will only increase.

Was there a bend between the MAF and the TB or do you have the 3.5" MAF directly mated to the TB? Any bend or coupler in that section of tubing will cause pressure drop. 3 psi measured by what? What's the accuracy of the 2 pressure sensors you're using?


If your measurement is valid, you can approximate the air flow at your data point and using the pressure drop equations, estimate the pressure drop at higher and lower power levels. That should be a trivial task for someone aggressively speculating about the performance of intake manifolds.


Thanks again to Nomie for attempting to create a valid experiment so the rest of us can use the data to draw whatever conclusions we want to

[fastfalcon94]

I really like the link someone posted on your other forum thread: Intake manifold dyno tests and facts only.

That guy seems to indicate that he can tell right away if an intake will be good or not based on it creating lean conditions. Did fixing your boost leak bring it back to normal or was it still rich afterwards? He also mentioned that balanced runner CFM didn't seem to make a difference. I bet that would vary though as the engine is not looking for air in all cylinders at the same time. I'm not sure if he blocked off ports to simulate this when measuring CFM in a runner or if he was just measuring all the runners simultaneously while pumping air through the TB opening.

[NOMIEZVR4]

I really like the link someone posted on your other forum thread: Intake manifold dyno tests and facts only.

That guy seems to indicate that he can tell right away if an intake will be good or not based on it creating lean conditions. Did fixing your boost leak bring it back to normal or was it still rich afterwards? He also mentioned that balanced runner CFM didn't seem to make a difference. I bet that would vary though as the engine is not looking for air in all cylinders at the same time. I'm not sure if he blocked off ports to simulate this when measuring CFM in a runner or if he was just measuring all the runners simultaneously while pumping air through the TB opening.

I read that article before too...The leaks were minor and did not make the AFR change anything worth noting...I mentioned in my conversations with Jeff and Eric that I would probably have to add fuel up top because from all the tests that I've seen on Intake Manifolds...they usually ended up resulting in more air..hence a leaner AFR. Unfortunately for me, locating parts and R&D of the plenum took some time...on top of that I don't have a flex fuel sensor either..so I cant be sure if the e85 content is the same or different from before...or if its solely the plenum which is causing the richer AFR...which I do find hard to believe because this thing dwarfs the stock plenum by quite a bit in every regard...bigger TB, MUCH larger tank, larger (and ported on top of that) runners...IDK. I'm hitting myself on the head for not doing a pull with wbo2 readings on the initial tests...

...the only thing I can say for sure is that is that ~2 months ago in about May in chicago when I did the initial baseline pulls..we were still at the very end of a very long winded record setting winter season...we were in the 50's in MAY...so it was definitely still cold...who knows what the e85 content was...who knows what it is now and how much/if it has changed...while fueling up the other day..i decided to smell the pump and see if the gas smelled like e85...surprisingly it did not...it smelled like straight gas and Ive had e85 in gasoline containers at the shop before and e85 has a distinct smell not only when running on a car but also when just sitting...I'm going to try a different pump next time and see what happens..can't think of anything else to do...unless you guys have any ideas.

The other issue is that despite having a much richer AFR...power is still the exact same...? I don't know how to explain that either..

[Chris@Rvengeperformance]

You can get the glass ethanol content testers for like $5 on eBay. I don't start changing fueling until I test what's in the tank.

Afr alone just doesn't impact power that much unless you get way off.

The maf should pickup any additional airflow, so im always curious when people say better flowing parts made the afr change a lot. If anything you are hitting different loads and the ecu is setup a little different there or your maf is not scaling properly.

[NOMIEZVR4]

Something interesting i found out..the station where I get my e85 has a sticker that now says MINIMUM 50% ETHANOL...i drove by a different station and it said 70%..hmm