New bests THROUGH THE MUFFLERS! AND CAI thoughts

[3X00-Modified]

154*f... yeah that sounds about right... I pulled my sensor out of my intake when I was at Charlotte and the sensor was reading 150+ since it was just in the bay.

As long as you don’t have a spark reduction vs air temp table then the temp doesn't really matter that much. I have a stock box on the red car and the temps stay stable just as you noted... but even with my CAI around town I get temps up in the 90's to 100's and I think that’s because most of the air that gets in that cubby comes directly through the radiator when the fan is on... SO basically its 100% useless to me.

I need to evaluate what couplers I need and I'll be scrapping the CAI setup I have.

[Asylum]

Here are some thoughts that come to mind at least as it is unfolding on my application, and I suspect alot of others.

No one can argue that cold, or at least cooler air is not a benefit to engine performance and efficiency.

The problem it seems is finding a way to deliver it, and in sufficient quantity, to satisfy the performance requirements of some of the modified/larger engines we are now using.

The current thinking and design of the CAI that has been popularized for our cars is obviously somewhat wanting.

In fact the ONLY testing that I have ever seen was done years ago on a Quad and a 2.8/3.1, one siginifcantly smaller and the other a very poorly "flowing" engine.

We now have engines that flow freely, at least relative to the earlier design, and are making significantly more power and therefore require alot more air flow.

That doesn't seem to be available with the current CAI design that is being offered.

Hell some of us are using throttle bodies almost 20% larger than were tested.

So the problem is, how do you get enough cool air to the engine?

The fact a short unrestrictive 12" tube delivering admittedly warmer air can trigger a rather dramatic change on wideband readings indicates it is really pulling in more air.

The timeslips don't lie, and MPH is the true indication of HP. I picked up over 2 mph by taking the CAI off!

I will be very interested in seeing how other cars react in real and honest comparisons with a CAI and just something totally unrestricted.

If it comes back as I suspect then the problem is the design, not the idea of cooler air.

More to come I suspect.

[Barry]

154*f... yeah that sounds about right... I pulled my sensor out of my intake when I was at Charlotte and the sensor was reading 150+ since it was just in the bay.

As long as you don’t have a spark reduction vs air temp table then the temp doesn't really matter that much.

I do have that, but its not active.

What i dont have is a air temp v.s. fuel enrichment table. The whole thing is based off the gas equation and while thats perfect in the text book, its not perfect in a car. Once I put th msII chip in it I will have that table though.

[woody90gtz]

This CAI business is all very interesting to me. Would have been nice to test while Geoff was on the dyno in Charlotte.

With my 95Z, I made my own duct work that sealed the lower lip of the bumper to the bottom of the radiator support and brought a lot of air into the fender well where the CAI resides. The 91 will use the same setup and should be a good test to see if it is the location (vacuum in the fenderwell) or the bends (restriction) that choke power.

Edit: I almost forgot to mention my findings during the winter time. Even with closed exhaust, mine felt very quick in cold weather, and according to my iPod Touch and Dynolicious it trapped 93.9mph. I realize the iPod may not be 100% accurate, but the best I could muster with closed exhaust at Lebanon was a bunch of 89-90 traps, and those were on good runs with summer tires. During my winter 1/4 runs I had studded snows that would spin all the way through 2nd gear if I wasnt easy on the throttle.

Basically what I'm saying is cold air makes a HUGE difference. There has to be a way to supply enough to keep the engine happy. Perhaps I'm just lucky because I have a smaller TB and cylinder heads that are not as efficient... and at that point no headers either.

There's one way to find out!

[3X00-Modified]

Never an argument that cold air didn't make a difference... Its more of the fact your killing the benefits by having to suck it up like a vacuum... The issue has been and always will be, HOW do you supply a car with cold air without making a NY subway out of the intake tube. Ram air is about as close as your gonna get, so I would say to run a duct work over to a shielded area by the battery from the front grill or down in the Z04 intake area, You will still get a lack of air there due to it being shielded but it should prevent the temps from rising quickly.

Oh and Dynolicious is null and void if you spin tire. Accelerometers can't detect that very well and get all confused.

I will say, a stock airbox as restrictive as it is, does a good job at keeping the air temps stable... I've noticed that on my daily car.

[Asylum]

Jon is absolutely right!

And as I argued/attested to.

The current CAI offerings for our cars are NOT the performance Mother-Lode they are purported to be.

And in actual fact may be a compromise in a drag race application.

An unrestricted flow of any air is better than a restricted flow of better air!!

FWIW!

[woody90gtz]

Dynolicious measures g-forces over a period of time. It doesnt matter if the tire is spinning or not, it is accurate. It's not like it thinks the car is going faster like the speedo does spinning at 20mph and reading 40... FWIW, it is always VERY close if not perfectly in sync with the speedo on a WOT run. I forgot to set it up in the Subaru in NC when I was at the strip. I wanted to see how it compared to the real slip.

I'll test with & without my CAI, but hopefully the way I set up my duct work I dont have any lack of air issues.

[3X00-Modified]

I know how dynolicious works, I have it too... But its not 100% in sync when you spin tire.

[Barry]

I dont disagree with you, but I cant grasp the physics behind what your saying... I dont see why.

[3X00-Modified]

What physics can't you grasp? The fact that it's a restriction to have bends in an intake system? What's the best flowing exhaust system? Straight shot and if there has to be bends, make them a smooth as possible and same diameter. It's the same idea with an intake system and even more so when your sucking up the air.

[Barry]

Nothing related to that... Im talking about the dynolicious thing.

When tires break loose they are pulling the car using kenitic friction vs static friction if they were hooking up. Obviously you accelerate and decelerate faster when the tires are rolling or abs would not be popular.

I dont see how spinning a tire throws it off. It dosent pull as hard when they spin and it will read a lesser acceleration value...

[3X00-Modified]

Trust me, when you grab for a sec then start to spin what do you think the accelerometer does? it feels g's then they are gone, then the come back... Dynolicious is not the best thing to get a MPH from... maybe a good estimate on HP, but I think once your break your tires free the sensors provided in an Iphone or Ipod just aren't enough to get a good solid reading.

[Asylum]

Dynolicious??

What is that some new flavor of JELLO?

Get all your computer sugary junk out of my drag racing thread or I'm going to hold my breath stop my feet and have a Hissy-Fit!

By the way went a 1.99 60' through the mufflers and a 14.22!!


OK back to the JELLO you two!

[woody90gtz]

I'm with Barry on this one. But I am not a rocket scientist either. I'll test it out at the track and compare increments to my slip.

[Barry]

Damn thats a good 60'