Thread: HAI vs CAI. CAI wins

Originally Posted by Mike Kopstain

The extra boost isn't what gives you knock; the extra heat is. This is why you can change nothing other than adding an intercooler, drop pulley sizes and see no knock. So yes, that's an accurate statement. All things equal, denser, cooler air is more desirable.

Otherwise we'd have to up pulley sizes in the winter when the air is cooler/ denser but we don't because the accompanying temperature change offsets the increase in air density (and more).

Actually, many people DO up pulley sizes in winter to combat knock. Hotter air means LESS dense air, which means LESS knock. Reason why I was able to get away with a 3.0" in the summer with no intercooler, meth, pump gas...dumb amounts of timing...and then we had to richen up the AFR and up to a 3.1" in the winter...yeahhhhh buddy.

That's proven.

Also proven that as soon as you are moving, the ambient air temps are the same on an open cone as they are on a superawesomecoldairfenderwell intake setup...and the ONLY time this would benefit...is at the track.

90% of the cars here don't even see the track...and the ones that do are basic 3.4"~ setups that will gain nothing from running an intake setup that is supposed to have "colder" air.

Also, you do know the GenIII M90 is probably one of the worst, heat soaking, parasitic roots blowers out there? I'd be willing to bet...if we are being accurate...and measuring the air temps that matter, say...post blower? The superawesomecoldair intake...will have the same post blower temps as the open cone...because...the pre-blower air temps aren't gonna get into dat injenz...its dat retarded hot post blower air. So, like you said...unless there is an intercooler, or say...a methanol injection setup...COOLING the intake charge, POST blower...it's all worthless...

So basically just read: $50 HomeDepotRacing Intake > $3934985743095204587204 K&N CAI, MSP CAI, JMB FWI, SLP CAI, ZZP Intake...etc...etc.

I see a 80-90* differential between summer and winter.

20-30* to 110* in ambient air -- with the differential in intake temps being even more extreme.

My CAI cost $55 total. Build your own.

Yay, a V6 Mustang.

On a Grand Prix forum.

m90 is about right for it.

Originally Posted by szalajka05

Well the guy is trying to say that a m112 is to big for a 3.8...

There happens to be a section titled..

"Other Cars".

And I've seen an M112 3.8 Mustang.

Had ported heads, suspension, DR's...ran 13.30's.

Did not impress me...especially the part where you have to have like a 30" cowl hood...

Originally Posted by bluegtp91

Actually, many people DO up pulley sizes in winter to combat knock. Hotter air means LESS dense air, which means LESS knock. Reason why I was able to get away with a 3.0" in the summer with no intercooler, meth, pump gas...dumb amounts of timing...and then we had to richen up the AFR and up to a 3.1" in the winter...yeahhhhh buddy.

You really have to be on the cusp of your setup to need to pulley up during the winter. Even on my most extreme setup I never had to pulley up in the winter.

Less dense, superheated air is never preferred over cooler, denser air, never, especially before the supercharger. You just won't find any performance company claiming that to be beneficial. You also reach a point of diminishing returns with the M90 and the hotter the intake charge, the quicker you reach this. Back in the day when testing intakes we could loose boost by dropping pulley sizes and just pick up a few degrees heat on the outlet side. If you're putting hot air into the supercharger you're handicapping your own setup and just making everything work harder for no real gains.

This is stuff that we tested in spades back in the day as did ZZP as did Intense as have countless other performance parts companies. You won't find anyone out there that tells you inlet temperatures (pre-supercharger) on a supercharged setup don't matter because they absolutely do. Now if you guys want to debate the temperature differences between various styles of intakes, good for you but don't do yourself the dis-service of thinking that inlet temperatures don't matter. They matter way more than you think.

Also, you do know the GenIII M90 is probably one of the worst, heat soaking, parasitic roots blowers out there? I'd be willing to bet...if we are being accurate...and measuring the air temps that matter, say...post blower? The superawesomecoldair intake...will have the same post blower temps as the open cone...because...the pre-blower air temps aren't gonna get into dat injenz...its dat retarded hot post blower air. So, like you said...unless there is an intercooler, or say...a methanol injection setup...COOLING the intake charge, POST blower...it's all worthless...

See you post this as a reason for it to just not matter but the M90's inefficiency is precisely why it does matter and why it matters so much. This is why people put on larger throttle bodies too and why we see the gains we do from ported housings (more specifically ported inlets). Anything you can do before the rotors that can either a. introduce more air to the inlet and/ or b. lower the temperature of that air, is going to make a substantial difference.

I have nothing to gain here either. I'm not a fool. I know for every person that buys one of our intakes there's 20 people making their own and that's fine. I'm all for people making their own stuff but don't minimalize the need for proper design, even if you're making something yourself.

Originally Posted by bluegtp91

There happens to be a section titled..

"Other Cars".

And I've seen an M112 3.8 Mustang.

Had ported heads, suspension, DR's...ran 13.30's.

Did not impress me...especially the part where you have to have like a 30" cowl hood...

You're a moderator here? The guy was called out about the blower on his dad's setup being too big (something NOBODY could know without knowing other details about his setup) and retorted with facts. It followed the conversation thread. Geez, I was lead to believe this forum was laid back.

Laid back...well yeah, that's why I told him there is a section called "other cars" so he can talk about it all he wants...and technically the thread topic is about intakes...

Just trying to keep it on the OP's track.

even if you have to reduce timing or reduce blower speed.

Originally Posted by matt5112

What facts?

Putting it together does not prove its the ideal sized blower for the job.

You can't possibly know whether that blower is too big or too small for the engine without knowing other aspects of the build yet without asking just toss out arbitrary "facts" without having nearly enough information to draw anything even close to resembling an accurate conclusion.

None of this test data has been shared.

If you have a desire to know, it's all out there. Some of this stuff is just basic operation of a roots type blower though.