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Discussion Starter #1
I'm running a Roush M90 Supercharger on my 07 GT. It came with the stock air cleaner setup, which I found curious. I'm wondering now:

1. what HP and torque could I gain with a CAI (cone filter with air dam isolating from engine bay) vs the stock panel filter and air box
2. how much re-tuning would be necessary?

I've done some google searching to try and answer these questions, with no luck so far. Can anyone here point me to answers?

Thanks and happy hooning!
 

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I'm running a Roush M90 Supercharger on my 07 GT. It came with the stock air cleaner setup, which I found curious. I'm wondering now:

1. what HP and torque could I gain with a CAI (cone filter with air dam isolating from engine bay) vs the stock panel filter and air box
2. how much re-tuning would be necessary?

I've done some google searching to try and answer these questions, with no luck so far. Can anyone here point me to answers?

Thanks and happy hooning!
The blower is your best source of added hp and adding a Roush CAI or CAI period will compliment it nicely. Average hp on a bone stock 4.6L GT with stock air box is 300 at the crank. Average hp on a SC'd GT, 4.6L with a CAI is about 427 hp at the crank. With a good performance tune and changing out the SC pulley you can boost that up to near 500 hp, at the crank. So, adding a CAI will help, but keep in mind, this all will require a tune adjustment...which is a good thing. Shop around, find some mustang tuners in your area, find out who's the better, i.e. reputation, numbers of tunes done, results, customer feedback, etc....
 

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Do I remember correctly that the intake is relocated to the left hand side of the engine compartment with the M90 supercharger? (looking from the front)

If so, then a "normal" CAI probably won't work; seems like you would need one that is designed to be mounted over there?
 

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or, if you want to keep it all Roush: These 3 components will enhance the Supercharger and pull from it some good performance. The Idler Pulley is the HD version, used on the Roush P51 Mustangs and will stand up to lots of abuse. These are what I have on mine. You already have the long inlet tube going from TB to cone filter. The cone filters Roush sells are top notch. Get 2, that way when you clean one, you have the backup to go to.


https://www.roushperformance.com/parts/mustang-parts-category/mustang-cold-air-intakes-category.html?p=3
https://www.roushperformance.com/mustang-belt-tensioner-heavy-duty-4-6l-3v-2005-2010.html
https://www.roushperformance.com/blog/2006/05/roush-gt-pulley-kit-speeds-up-an-already-quick-supercar/
 

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Well, it's all based upon the laws of physics, not PR material that you read about all the time! Here's the science in a short to the point formula....


1st you need to calculate the CFM the engine with the blower is actually sucking/taking in...... next, you need to calculate what th current filter is capable of flowing......


The formula which is used by every air filter manufacturerin the world to determine the CFM for flat panel filters is...
Flat Panel CM= Length x Width x 6


So let's look at a stock 2013 Mustang V8 and assume 6,800 max rpm & 90% volumetric efficiency (note that 90% VE is race carspec and likely higher than reality) can only suck in a maximum of 535 CFM, and the OEM flat panel filter (12.375鈥 x 9.675鈥) will flow 718 cfm, so the engine is sucking in everything it already can.


Standard atmospheric pressure is 14.7 psi.......so let's say that your blower is set for 7 psi......that's about an increase of 49% CFM into the engine....... so if we assume this is on the same 2013 mustang, we would do the following math....


535 CFM multiply by .49= 262 cfm


535 + 262= 797 cfm


Max flow on the oem panel filter is 718 cfm


797 cfm - 718 cfm= 79 cfm


meaning at 100% throttle and at 100% of the peak RPM power available, the engine at that point is absent of 79 cfm (ie about 9%).


However, at 500 rpm lower, I bet if you ran the calcs you would find that the engine is getting all the air if needs...... meaning, if you're racing, yes, you need the CFM, however, if your running in all other rpm ranges, the engine is getting plenty of air........ if you shift just a hair sooner, I doubt there would be any impact in street type performance that one could see........ So once you figure really what where you are at in terms of actual CFM needs, then you can decide if it's worth the $ for an aftermarket CAI.
 

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don't forget to include pressure drop in that fancy math; all fluid flow is driven by pressure differentials so pressure drop is very important . . . no measure of fluid flow is meaningful without the pressure drop that goes with it


For practical purposes: I don't think you are going to be able to put numbers on any of this, and it doesn't really matter. Pikapp has the same setup on his car, and he races it on a track where laps are timed and actual performance matters . . . so I doubt you are going to get any better advice, especially for free on an internet board! :)
 
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Discussion Starter #9
thanks for all your input! I realize that I can maximize potential with the Roush pulley / CAI kit. I don't think I want to increase boost just yet, I want to take an iterative approach. I'm interested in the difference from just the CAI.

Beechkid, thanks for the math, it makes sense even without the specific data needed for an accurate evaluation. What I'm really getting at here is the difference between the stock panel filter setup and a cone - type. The variables seem to be surface area and flow capacity per area, temperature and as you point out, flow demand. Is the current temperature adversely affecting power? Is current air supply < demand?

Re: tuning - shouldn't the computer be able to adjust for airflow and temp already? I realize that adding boost is outside the parameters of the original tune, but once tuned for boost, I would expect the computer setup to be able to adjust significantly to those variables. I obviously don't know much about engine control programs.

I'm planning to try a number of steps:
1. modify the stock airbox to maximize flow and minimize temperature - and see if that makes much difference. (I've done this before on a V6 Chrysler and it made a noticeable improvement)
2. if 1. doesn't seem to help, add a larger, cone style filter
3. re-tune if it seems necessary
4. consider downsizing the pulley / belt and re-tune accordingly

I'll post results as I go - but I don't expect to have any real data (like dyno tests), so it will be based on observation.
 

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Closed air boxes have a bad rap, but there is a reason that manufacturers use them . . . drivability. With some CAIs, the MAF can get "air washed" or have other air turbulence issues causing some negative characteristics. This was common with the JLT in the 2011+ 5.0s.


The CAI in my Kenne Bell on a 4.6 hides behind the front bumper. Problem is, about 60% of it is still exposed to open air. If I attempted to coast at highway speeds (like when you push in the clutch at 55+ MPH as you approach a traffic light), the car would idle hunt to the point of near stall conditions because the MAF was getting completely washed over by turbulent air. I ended up building a shield to go around much of the exposed area of the CAI, and this fixed the problem.
 

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Discussion Starter #12
VERY interesting... I can see how the MAF would be confused. I hadn't thought of such complications. I'll endeavor to limit any "ram air" effect, since I expect it would be redundant with a supercharger anyway.
 

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Discussion Starter #13
Here's another variable to throw in the mix: I just happen to have a Ford Racing 62mm Throttle Body - I wonder how that would affect the overall system? I'm thinking a re-tune will be essential if I go with that...?
 

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I'm running a Roush M90 Supercharger on my 07 GT. It came with the stock air cleaner setup, which I found curious. I'm wondering now:

1. what HP and torque could I gain with a CAI (cone filter with air dam isolating from engine bay) vs the stock panel filter and air box
2. how much re-tuning would be necessary?

I've done some google searching to try and answer these questions, with no luck so far. Can anyone here point me to answers?

Thanks and happy hooning!
The biggest improvements you'll see for the money is going to be a 2013 GT500 HE and pump on an M90. Those M90s are TINY and they all run hot, especially with the factory HE and pump, so you pretty much never run full timing.

You can get the pump for $238 from Rock Auto and take off 2013/2014 GT500 HEs run about $200-300.
 

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Discussion Starter #15
Never thought of that either, thanks for the schooling. I'll look into it. The M90 is really small, so much smaller than the Whipple I had - it makes sense that cooling would be an issue.

Speaking of cooling, I've never seen a "blower-internal" temperature gauge on a supercharged car - only a boost gauge. (I guess the temperature stays pretty consistent with an intercooled system, so little to gain by monitoring?)

I've never experienced detonation with the Roush, I expect it is somewhat "detuned" to make sure of that.
 

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Never thought of that either, thanks for the schooling. I'll look into it. The M90 is really small, so much smaller than the Whipple I had - it makes sense that cooling would be an issue.

Speaking of cooling, I've never seen a "blower-internal" temperature gauge on a supercharged car - only a boost gauge. (I guess the temperature stays pretty consistent with an intercooled system, so little to gain by monitoring?)

I've never experienced detonation with the Roush, I expect it is somewhat "detuned" to make sure of that.
Monitor your IAT2s via the OBDII port. Your IAT connections should be unpinned from your MAF and wired to a temperature sensor in the intake manifold after the compressed intake air leaves the intercooler. Anything over ~128 degrees Fahrenheit is pulling timing on most 93 octane tunes, even sooner on lower octanes.

Your IATs will go up significantly when idle vs at speed and in boost/out of boost. With the 2011 GT500 HE and pump, I was seeing 90-105 degree IAT2s while cruising and up to 140 degrees at WOT and 13psi with a Department of Boost kit. Yours are likely much higher than that.

The factory Roush tune is SOFT. Email Lito and get a real tune. You'll need an SCT handheld, laptop, and wideband with an analog output. He charges $300 for an FI tune and it is well worth it over the canned Roush tune. His email is [email protected]
 

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. . . I've never experienced detonation with the Roush, I expect it is somewhat "detuned" to make sure of that.

The system should be measuring post-blower intake air temp., and it will pull timing to prevent the pinging if the IAT gets too hot. That's why the intercooler is so important; quite likely you are not getting full timing or full power but you don't know it.
 
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Discussion Starter #19
Wow, that's a basically whole new supercharger! It looks like a nice upgrade but oddly enough I still have the full 2.3 Whipple kit off my last car, if I wanted to go to all that effort I'd just swap it out. I'm trying to get the most from the M90 for the least effort / money - just tweaking around the edges, I know I won't get a lot more out of it without going big like this. But that's not my objective. Eventually I'll probably sell the M90 and go with the Whipple. Right now I have too many frikkin projects going on to devote the time needed for the swap.

Thanks for all the info on air temp - great stuff, something else for me to get into to get it done right!
 

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The biggest improvements you'll see for the money is going to be a 2013 GT500 HE and pump on an M90. Those M90s are TINY and they all run hot, especially with the factory HE and pump, so you pretty much never run full timing.

You can get the pump for $238 from Rock Auto and take off 2013/2014 GT500 HEs run about $200-300.

I've also thought about this. Do you know if that HE will bolt right into the existing M90 setup on an 05-09 style mustang? I'm also thinking about doing the FR500S radiator and fan upgrade as well FR500S Radiator and Fan Upgrade: Daily Driven S197 Mustang. Which "pump" are you referring to?
 
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