I'm about ready to try this mod, but first wanted to know how the "early adopters" were making out. Any troubles keeping the KN 1550 on? Issues with stress on the TB? Happy with the performance and sound? (No data needed, personal impressions are perfectly OK)

I have an '05 MCS with the only engine mod so far being a 15% pulley, and I find it hard to spend $150 or more on some bent sheet metal and a $40 filter. Rather save up for an exhaust.

BTW, can anyone tell me if this KN filter needs to be oiled before use, and if it is the cleanable / re-useable type? Thanks :smile:

 

k&n filters are always reuseable and cleanable.. they have cleaning kits for it can be found at any automotive parts store...

 

All K&N filters I have ever seen come pre oiled and ready to go.
I'm with you on expensive bent sheet metal, so I bent my own before the HAI was shared here by Andy.

 

I swapped my BMP for the HAI quite a while ago (probably a year by now). No issues except for the dent in the soundproofing material on the underside of the bonnet. And getting round to cleaning it.

 

Mine needs cleaning too. I also have never gotten around to doing some chopping and grinding I had planned to wittle down the OEM air box bottom. Oh well some day.

 

As far the operation was concerned, I was happy with it. The sound is subdued from inside the cabin compared to the Alta but I'm sure the noise is being projected forward. Performance wise, I couldn't tell much difference and I don't have comparison numbers. Ryphile experienced power loss but I'm not sure what the specifics were. The HAI was a tie-over for the now available AGS so I have no use for it. I did like the tidy positioning of the K&N location and easy access/removal-installation :smile: There was no problem securing it to the TB. If you're interested in a "slightly" used kit (includes the crankcase filter), PM me:smile:

 

I've had mine on for a while. And I'm still happy, the only candidate I'm thinking of as a replacement is the AGS, but that's because for $600 you can get the bigger TB, and the TB-SC duct. I've been thinking of just cleaning up the duct myself, but have been a little lazy. I just got the Bentley Mini manual, so I may attack it after all. Cost vs performace to the standard CAI fare seems to be pretty good, from where I sit.

And I did manage to clean my K&N once!

Matt

 

I've had mine for a few weeks with no issues. I did the angled 1550, and it came pre-oiled, and with a clamp. I also ordered a small breather, which came with a clamp, and some oil. I've drove through some pretty hard rain the other day. When I got home, I popped the hood to check the filter, and it was dry.

The sound is great. It's a very pure tone, almost siren like.

 

I'm somewhat interested in doing the HAI as well. But I've never been able to find any sort of "before and after" dyno run charts for the HAI versus an otherwise stock car that Andy and others are so keen on. Have any such runs been posted on the site somewhere?

/gary

 

The mother of all HAI threads is called "Operation hot air intake". You can easily find it in a search. On post 27, Andy shows the HAI has a lower pressure drop than the Alta. Around 230, Macncheese shows higher boost pressure vs stock, ranging from 0.5 to 1 psi at rpm > 3500. At about 375, Ryephile shows dyno results indicating the HAI is quite a bit worse than the Alta, probably about the same as stock. So, the evidence is contradictory. My guess is that the HAI flows better than any intake except the AGS, but doesn't get air that is quite as cool. Perhaps a homemade heat shield would help.

Thanks for everyone's input. I'm going to replace the stock intake with MSFITOY's used set-up, and see what happens.

 

As an Alta CAI user, I'm mystified by what gain there could possibly be by pulling hot air into the motor. I'm not knocking anyone who is currently using this system-hey, to each their own. But, this seems as strange as those who install an Alta without installing the cold air "box".

 

With forced induction a true CAI doesn't matter as much. If you think about it the air is being super heated going through the supercharger anyway so whether the intake is pulling air that's 70 degrees or 110 degrees it doesn't really matter much.
Mike

 

Less dense air is less dense air. But remember, the HAI is right behind the hole in the plastic dam. So cold air is running there. I think it's really mixed air that gets in..... But IAT measurments don't really show a 40 degree difference, so it's not like it got it air straight off the header....

remember, it's all about the number or O2 molecules. So if the temp increase over a true cold air intake is less than the percentage pressure drop improvment, it makes power, if not, it loses power.

 

I have the impression that the main idea behind the HAI (aside from being inexpensive) was trading less air restriction for warmer intake temps.

If you think about, the stock intake is pretty much a cold air intake when the car is moving. The problem is that the air has to go through two long tubes before reaching the throttle body. The Alta, et. al., designs eliminate one of those tubes.* The HAI eliminates the other. It seems to me the results are still inconclusive. Dyno tests with air intakes are especially tricky, because it's very difficult to re-create the airflow through and around the car and the underhood temps you'd have when the car is moving. (It's been a long time since I read the thread, so I don't know how closely the tests mentioned above tried to model real-world airflow.)

* The CAI designs seem to be assuming the cowl vent is a high pressure zone. (And it would seem logical to assume the stock intake, inside the grille is also a high pressure zone.) But has there been any evidence to show that this is actually the case? Not trying to be argumentative here, just wondering.

 

As Andy and Cheese have proven with the HAI, taking little snapshots of data don't necessarily correlate to power output. I have a feeling they've never posted dyno graphs because they've found the same thing I have; it's not what they were hoping.

 

im happy with the price versus the output of sound and performance.

alas it is time to move on..

the full AGS setup is going on in two weeks.

the HAI served me wonderfully, and i recommend it to all who are on a budget.

 

Neither of them have dyno'd it...have you? Just curious as I've never seen before and after dyno's for it
Mike

 

A lot of this is discussed in the big momma thread but I'll reiterate a few points.

No cold air intake makes air cold.

The HAI makes its power by eliminating most pumping losses upstream of the throttle body. There is a complete disregard for inlet temps. No heat shield, no fancy tubes to relocate the filter, nada. Just the biggest honkin filter I could get to fit there. Fortunately, the filter ends up in a position that is frequented by the air inlet from stock intake system.

Intercooled engines dont really benefit (as much) from cooler air. The reason is because the intercooler isnt removing a predetermined number of degrees, its operating at a effieciency (%). The efficiency is a measurement of how close an intercooler can get the fluid being cooled to the temperature of the fluid being used for cooling. Think about it this way.... if an intercooler was 100% efficient, it wouldnt matter how hot the air being ingested was, because the intercooler would always make that air be the temp of the air flowing over the intercooler. The stock intercooler isnt 100% but its pretty efficient by most calculations and it pulls out a big chunk of the air intake temp increase from there being no heat shield.

Despire Ryephile's cheapshot, I never made a HP claim on the HAI because I never dyno'd the intake. My MINI was lemon lawed before that happened and my intake development came to a hault. I handed over the K&N filter to Andy shortly after picking up my xB after discussing my initial findings with him. I'd be interested to see a HAI dyno but that said, I dont think that dynos accurately reflect the benefit of upgrades that heavily rely on airflow because airflow isnt accurately produced in most dyno situations. I feel the same way about intercooler dynos.

I have absolutley nothing to gain by decieving you folks about the HAI. I dont sell the parts, I dont sell the plans, and I dont own any K&N stock.

 

what treat to read a rational, well written discusssion of this topic instead of the current vitriol!

and yes, ryephile's dyno comment was a pyschologizing cheap shot.......

i want to add another comment (that perhaps i'll make in a separate thread: the emperor has no ram air): the HAI hasn't really "lost" any ram air effect because i suspect there isn't any for the stock inlet location. the air inlet trapezoid slot doesn't "see" clean impinging air like the ic slot. i think the grill air is essentially stopped by the radiators and the "ram" air pressure is nil at the location of the stock intake slot. and even if you had perfect "ram" air, the ram air pressure is much less than 0.1 psi.

getting rid of the losses from bending the airflow, whether by the hai or by the ags, is a good thing. it would be interesting to compare the calculated / estimated power gains (or losses) with dyno numbers. these preliminary estimates / calculations are straightforward (not some elaborate cfd model) and would always be done BEFORE hardware was built on a "real" engineering project...
alas, all too many, and you know who you are, think "math, we don't need no stinkin' math...."

i would love to talk to mini engineers to see if they ran the numbers for the mcs intake design compared the cooper "hai" style. so if you guys are lurking, pm me!!

 

Quite right. Since PV=nRT for an ideal gas, the number of O2 molecules (n) is PV/(RT). R is the gas constant, and V is also a constant, equal to the volume of all the plumbing between the SC outlet and cylinder inlet. So, the true measure of intake performance should be P/T, measured anywhere along the SC outlet to cyinder inlet path. Whether the engine actually turns the given amount of O2 into the maximum Hp is not really relevant to measuring intake performance, since there may be some other limiting factor (like fuel flow).

This brings up, at least for me, a different way of thinking about air temp. Since the volume is fixed, cooling the air with an IC doesn't in itself increase the number of O2 molecules. Pressure drops as temp decreases, so n remains constant. The only reason I can see that an IC helps is that having lower pressure (by virtue of lower temp) air downstream of the SC increases SC efficiency. If, for example, the SC were not a centrifugal pump but a positive displacement pump like a syringe pump, then an IC wouldn't be needed.

Decreasing inlet air temp to the SC also increases SC efficiency, since each scoop of the spinning rotor takes more O2 molecules. As Dr Obnxs notes, the inefficiency from high temp air to the filter can't be offset simply by cooling the air downstream of the SC, since at this point the volume is fixed.

Anyways, I'm still guessing the HAI is better than stock. Presumably, the AGS designers agree, since they apparently feel that locating the filter in a cooler region (farther from the TB) is not worth the associated pressure drop.

 

I always remember this as Perv-Nert.

 

Cheap shot? If it didn't lose power, it would've stayed on my car

 

innimini,
By eliminating restriction upstream of the throttle body, we've lowered the vacuum upstream of the supercharger. This is allowing the blower to ingest more air per revolution so your ratios arent valid as n is not constant from one intake to the other. You can only hold them constant when comparing different situations for the same system.

The value of air intake temp isnt as simple as the ideal gas law. The temperature of the intake charge plays a big part in it's volitility and that plays a big part in engine timing and that plays a big part in how many ponies make it to the wheels.

The overly rich state of the stock factory tuning is probably a good example of this. The pig rich levels that most have seen at higher RPMS are most likely a rudimentary form of active cooling. Think of them as an intercooler sprayer for your cylinders, the extra fuel is just there to soak up heat.

--
Cheese

 

Agreed, it is a good idea to lower the pressure drop across the filter and the associated plumbing (or as Cheese puts it, to reduce the vacuum upstream of the SC). Raising the P/T ratio of the air feeding the SC will allow it to scoop up more O2 molecules with every rev. But this doesn't change the fact that the volume of the intake path from the SC to the cylinders is fixed, and that the number of O2 molecules in there at any time scales with P/T (which is proportional to n). Therefore, n (or P/T) will in fact vary for every intake, and should be an absolute measure of intake performance (larger P/T is better). Note that both P and T should be in absolute units, like psia and K.

Also agree that the air temp entering the cylinder influences how the fuel vaporizes and burns. But this is not an intake issue per se. The best intake from a P/T standpoint might also deliver the hottest air, but this could be brought back into line with a bigger IC or hood scoop ...

 

Ryephile he didn't actually use a dyno. He used an Auterra PDA program that by his own admission:

"I was pretty surprised to see such a huge variation in outputs (up to 20Lb-Ft and 10HP!), as I was keeping a close eye on my IAT and ECT, keeping them at 90F and 190F (+/- 2 F) respectively, prior to each run."

https://www.northamericanmotoring.com/forums/showthread.php?t=27311