I spent $129 on a March Performance Ram Air Kit on another car and the K & N filter cone came with the kit. It definitely helped on another car (Not a Corvette) I did notice changing and cleaning the oil filter was a bit more troublesome compared to paper (factory stock). I also noticed that I was picking up all kinds of garbage but that's probably due to the scoop being under front bumper.
I don't know if I would do this on a C-6 using those other popular brands for Corvettes which are expensive i.e blackwing, varanam.

 

I've got a 2006 Z06. How much more air does your product flow compared to the stock unit @ 50mph? 75mph? 100mph? 125mph? 150mph? 175mph?
I know the computer will require 50 "on/off" start cycles to relearn the new algorythims for maximum performance.
Thanks

 

Is that really true? I thought it was just a few hundred miles along with a few start cycles maybe?

 

I believe one WILL in fact notice a 2/10ths+ reduction in ET and a 2mph+ gain in trap speeds especially out on the highway, even if it's not in SOTP feel what's the difference, improved performance is improved performance.
If one can't feel that kind of performance gain than one probably can't feel the difference between a Corvette and say a Mazda Miata either so it likely doesn't matter to them.

 

if the start cycles help that much i better get starting it so far i only started it 13 times

 

 

That's great at least you guys listen I wonder if GM is listening?

 

Well I found a good deal on a Vararam so I pulled the trigger. Should have it in about a week. I'll post before and after HP Tuners logs.

 

Soooo, the best thing to do is plan all your mods and install them all at the sametime then get a good tune so so mods will really be used.

 

This is kind of misleading and I'm not sure everyone understands fully what is meant be "learning" so I'm going to try and explain.

Learning refers to fuel trim learning. Fuel trims are the PCM's way of keeping track of whether the air/fuel mixture is rich or lean at a particular cell. A cell being defined as a point in a table where the current manifold pressure and RPM meet. A positive fuel trim means that the PCM had to add more fuel than called for by the VE table and/or MAF and a negative fuel trim means it had to take fuel out in order to maintain the commanded air fuel ratio. The PCM uses short term fuel trims to adapt quickly to required changes and when the short term fuel trim goes too high or too low the PCM adds or subracts to the long term fuel trim. It takes a while for these long term trims to be "re-learned" because lets say you had a -3 long term fuel trim in a particular cell before adding a cold air intake and your flow characteristics have now changed, the air is flowing through the MAF differently, and the PCM is now having to add more fuel at that cell instead of subtract fuel so the STFTs need to gradually decrement the LTFT +3 to say -3.

Here is a screenshot of my fuel trims from a recent log. The numbers are the percentage of fuel that needed to be added or subracted from each cell.


Here is the kicker; the fuel trims only change when in closed loop. When you go WOT PE (power enrich) mode kicks in as well as open loop and changes to the fuel trims lock out. Closed loop is typically <25% throttle where the O2 sensors give the PCM feedback as to whether the mixture is rich or lean. When WOT you are in open loop and the O2 sensor feedback is ignored and the PCM is determining fuel requirements based solely on the amount of flow the MAF is reading. Remember how I said fuel trims lock out in open loop/PE mode? Well if the cell you were in before entering PE mode had a positive fuel trim then that percentage is locked in throughout the PE mode. So if you left closed loop in a +5% LTFT cell then 5% would be added to your WOT fueling. If your LTFT is negative then the LTFT's on the PE cells is locked at 0 which is what we want.

So that explains learning but note that this learning is not doing anything to make the PCM "take advantage" of the extra air at WOT. All it is doing is making part throttle fueling more accurate. What a good tune will do is calibrate your MAF and/or VE table so that when the PCM is commanding 13:1 AFR it is really resulting in 31:1. Whether or not you have positive or negative fuel trims you may not be achieving your target ARF. I have heard of bone stock C5 Z06's dipping into the 11:1 range which costs horsepower. Changing intake and exhaust components, particularly the airbox which is right in front of the MAF will throw the MAF clibration off to where it is reporting an incorrect flow and thus incorrect fueling results.

HTH

 

but isnt it good to keep getting tunes because the tables keep changing from different driving conditions

 

Not sure I follow this completely......are you saying that the PCM learns nothing at WOT by adding a CAI, only LTFT are affected and that LTFT have nothing to do with WOT? If that is the case then by adding a CAI without a tune, at WOT you will always get a leaner mixture than at stock? Is a CAI wothless without a tune? Still trying to learn.........

 

The PCM will adapt to different environmentals, particularly a MAF vehicle. There are two ways to calculate the airflow, VE; which is a table much like the fuel trim table that says at x RPM and y manifold pressure add z fuel. Then there is the MAF which just measures how much the hot wire is cooled by the air moving across it and looks up that frequency change on another table to determine airflow.

The PCM uses the MAF the majority of the time and uses the VE table as a sanity check. It also defaults to the VE table during throttle transitions where the MAF cannot keep up with the quickly changing airflow. Once the MAF is calibrated it is not affected by environmentals very much. If it's colder, the colder air will cool off the hot wire more and add more fuel, if the air is thinner (when you go to high altitude) the less dense air will not cool the wire as much and less fuel will be added. Speed Density tunes that some FI guys go to, also called MAFless, only uses the VE table values and is more affected by climate changes.

 

Correct, the PCM learns nothing at WOT. It only learns in closed loop and the only time the learning affects WOT is if you have positive LTFTs.

Adding CAI will allow more and colder air to enter the motor and the MAF will account for that extra colder air but by changing the characteristics of the intake tract ahead of the MAF the MAF may not be reporting exactly the right airflow, heck the MAF may not have been reporting exactly the right airflow in the stock configuration. Now these discrepancies may not be much but you may be leaving horsepower on the table. A tune (with a wideband O2 sensor) will allow you to calibrate the MAF table so that you get the commanded AFR.

Now a tune also entails playing with timing, torque management, shift pressure and points, fans, etc. but for the purposes of this discussion they are moot.

I may be over-complicating things. The point I'm trying to make is no amount of ignition cycles is going to result in the PCM getting more out of the CAI at WOT.

 

Thanks for taking the time.........I understand a little better now. I see that you are in Houston, as am I. I am looking to get maybe a CAI and a catback, but probably not much more for now.(warranty) Any recommendations? Good place to buy, install....etc? Sorry for the hijack.

 

Mine came with the Corsas on it when I got it and I just ordered my Vararam from Cajundude. http://www.gulfcoastperformance.com/

Since you're in Houston you should come check out our new club, http://www.spacecitycorvettes.com/. We just started up.

 

Thanks I'll do that. Are you happy with the Corsa's? All I've heard is internet clips. Don't really like the extra weight, but they seem to be what I'm looking for.

 

Well I got around to installing the Vararam last night. Install went fairly easy. I also got the smooth silicone couplers from Extreme PSI. SOTP gain is definitely there. I'll post up the HPTuners logs from before and after but the roads were wet and it was kind of hard to get a WOT run logged without getting squirrely. I will say that I immediately noticed a large drop in IAT but in a cursory comparison of the logs I did not notice any difference in MAF or MAP max values. I'll post some screenshots of the logs by this evening.

 

I am interested to see what you come up with.

 

Started a new thread.

http://forums.corvetteforum.com/show...post1558940065