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A comparison of a recent before and after an aFe CAI (no tune) install.
Testing info: Dynojet in ground dyno with 48 inch rollers, 7 speed manual transmission.
As you can see the numbers for RWHP and TQ both went up just under 30 for each.
Absolutely true! That's why I always quote SAE CORRECTED. It keeps the numbers quoted as close as possible to a standard, no matter the DA or temp.
BUT... That's why I always say "Your results may vary, please check that the mods haven't made your car's tune unsafe."
I check my car on a dyno with a wideband and HPTuners after every mod. I suggest all do the same.
Point is, actual air density, not corrected density, is what the sensors actually read. So at high altitude, the sensors may not need to pull timing, like at sea level on a cold day, since the engine is not getting "overly-aired" so to speak. A z making over 650 rwhp corrected, may be making only 528 rwhp in Albuquerque, which is less than stock---
Less than stock = less demand for air= less need to pull timing....
A comparison of a recent before and after an aFe CAI (no tune) install.
Testing info: Dynojet in ground dyno with 48 inch rollers, 7 speed manual transmission.
As you can see the numbers for RWHP and TQ both went up just under 30 for each.
Point is, actual air density, not corrected density, is what the sensors actually read. So at high altitude, the sensors may not need to pull timing, like at sea level on a cold day, since the engine is not getting "overly-aired" so to speak. A z making over 650 rwhp corrected, may be making only 528 rwhp in Albuquerque, which is less than stock---
Less than stock = less demand for air= less need to pull timing....
Yes, it may react differently at this altitude. YRMV.
Vegas Panton: Did you record the A/F stock and with the AFE?
I believe that the HP gains are because the Hall system is less restrictive than the stock. More air in equals more hp and more air to be compressed so more boost.
Yes, it may react differently at this altitude. YRMV.
Vegas Panton: Did you record the A/F stock and with the AFE?
Yes we did. Sorry I did not take a photo of that. I will go back to the shop an get that info. As I recall the AFR's were pretty close to the same with both going very rich when the cat protection kicked in around 4500 rpm. The AFR's did not make a big jump to the lean side like some folks have experienced when they installed the new CAI's. I will find out for sure and report back.
Last edited by Vegas Panton; 12-01-2015 at 07:54 PM.
Point is, actual air density, not corrected density, is what the sensors actually read. So at high altitude, the sensors may not need to pull timing, like at sea level on a cold day, since the engine is not getting "overly-aired" so to speak. A z making over 650 rwhp corrected, may be making only 528 rwhp in Albuquerque, which is less than stock---
Less than stock = less demand for air= less need to pull timing....
Not sure I understand you logic here.
How does sea level correlate to pulling timing?
The PCM knows what the DA is and the MAF knows how much air is going into the engine. So it meters fuel accordingly.
So why would one expect to pull timing at sea level in a properly tuned PCM?
In the case you mention above at sea level the PCM wont pull timing it would add fuel instead. This would keep the afr from going lean, and in effect take advantage of the denser air at sea level and produce more power.
Keep in mind as long as the afr is close to what the engineers intended, there will be little to no knock and the PCM shouldn't have to pull timing. Again as long as the PCM is within its ability and the fuel injection systems ability to add more fuel.
That having been said the PCM makes slight adjustments to timing in the normal course of business. This is generally due to variations in the quality of fuel (octane) which varies the threshold of knock at a given afr.
Yes we did. Sorry I did take a photo of that. I will go back to the shop an get that info. As I recall the AFR's were pretty close to the same with both going very rich when the cat protection kicked in around 4500 rpm. The AFR's did not make a big jump to the lean side like some folks have experienced when they installed the new CAI's. I will find out for sure and report back.
"The AFR's did not make a big jump to the lean side like some folks have experienced when they installed the new CAI's. I will find out for sure and report back."
Exactly as expected and what 6 Speeder and others have found with both the AFE and the Halltech. These systems are properly designed and when properly installed are not leaning the afr to dangerous levels.
I used to work for AEM, and we designed intakes...was there for 5 years... I have forgotten more about designing that stuff than you will ever know. It's o.k., you can believe whatever you like. I write Engine control strategy for a living, and I fully understand how GM's code works, and what happens. No matter how much you like your intake (i don't care what brand it is), the simple fact remains, the gains aren't from some wiz bang rocket science thousands of hours design in making a tube that houses a filter and directs air to a throttle body, it's from leaning out the mixture, and adding timing, and then from the lack of restriction from the air filter, and larger tube (secondary in this case). If I take the stock intake tube, put a better air filter on it, and retune and get most all of the gains back.
Originally Posted by Tripleblk6spd
Any of you guys that have put intakes on your cars without a tune and "no issues" have you been back to the dyno, or the track? This isn't something that starts throwing lights, goes in to limp mode...you just start losing power as you drive the car on pump gas. Go back to the dyno and dyno the car again... Tell us what you see.
Originally Posted by Tripleblk6spd
Alot depends on how you drive it, buy yes! If you baby it all the time, no. If your relatively aggressive with the car and put it under boost. Then that's when everything starts to move. But yeah...bring it down, we can certainly take a look!
Originally Posted by Tripleblk6spd
...EVERY car I have seen has done the same thing. If you have an intake, and no tune, you aren't making the same power you did when you first put it on.
Your drag results were also a first time deal...he went back in better conditions and went slower....proving the point.
Originally Posted by Tripleblk6spd
It's more complicated than that. when you make the pipe bigger, the Air flow meter calculates the air incorrectly, leans out the mixture, AND adds more timing. Which is why you see such huge initial gains. Problem is... pump gas can't support the additional timing and leaner mixture...so it knocks, then the knock sensors start pulling the timing numbers down toward the low octane numbers...that's where the loss in power comes from.
Originally Posted by Tripleblk6spd
There is PLENTY of proof...you just KEEP IGNORING IT! Ask 1QUICKZ...you know the one you keep posting his E.T. change from the intake. He lost 5 mph the next time out with MUCH better air.... you can't just choose to pay attention to the results that benefit you and ignore the ones that don't!
Ask 1QUICKZ...you know the one you keep posting his E.T. change from the intake. He lost 5 mph the next time out with MUCH better air
Maybe if I say it twice in one post...it will sink in! :smas h:
I would be very curious as to what tool you were using. The car 100% stock has knock events.... so this really doesn't make any sense. This is a log of my car when it was 100% stock. Notice the 5 degrees of timing being pulled due to knock around 4krpm, and another degree at 6200, and this is completely stock. Unless you are running race gas all the time, I don't see how you could NOT have knock retard on the intake unless your total timing has already been learned down to the mid teens for timing. This log shows 25.5 degrees of timing on top with 91 octane after timing is put back in from knock
These threads can be VERY useful and informative if every stops the Rah Rah stuff and just look at things systematically. No one is bashing anyone or anything. It's just facts....I have over 200 pulls testing things on my personal C7 Z, in FACT, last week was the first time in 3500 miles that I have put a tank of gas in my car that hasn't had dyno pulls on it or track time.
There is more informative data in that thread.
I tend to enjoy Tripleblk6spd's posts because he seems to know what he's talking about at a very high level relative to ECU calibration and mods (aside from being the founder of ProEFI).
S.
" Originally Posted by Tripleblk6spd View Post
Any of you guys that have put intakes on your cars without a tune and "no issues" have you been back to the dyno, or the track? This isn't something that starts throwing lights, goes in to limp mode...you just start losing power as you drive the car on pump gas. Go back to the dyno and dyno the car again... Tell us what you see."
Yes I have, both the dyno and the dragstrip.
My timing is the same before and after the CAI, the A/F is (nearly) the same. It hasn't lost power on the dyno, and I went quicker and faster on the dragstrip. This is after thousands of miles and months of having the CAI in place. The ECM is NOT pulling timing and as the LTFT's are the same as stock, it's NOT adding or reducing fuel.
I tend to enjoy Tripleblk6spd's posts because he seems to know what he's talking about at a very high level relative to ECU calibration and mods (aside from being the founder of ProEFI).
S.
And, he was exactly right in what my car started to do at the track. Big power gains at first (in the heat of the summer), but after the CAI sat on the car for a few thousand miles and conditions got MUCH better, I lost tons of power at the track. As I previously stated, my car was stuck in the low octane table and was pulling tons of timing and seeing way too much knock. Put the stock intake on with a little more octane and bam, all better! You guys do what you want, but I saw it first hand.
Yes we did. Sorry I did not take a photo of that. I will go back to the shop an get that info. As I recall the AFR's were pretty close to the same with both going very rich when the cat protection kicked in around 4500 rpm. The AFR's did not make a big jump to the lean side like some folks have experienced when they installed the new CAI's. I will find out for sure and report back.
These are the same dyno runs with the air fuel ratios included. The air fuel ratio actually went richer with the new aFe CAI. As you can see, once the cat protection kicks in, the AFR's go very rich. Run 1 (blue) is the original pull and run 3 (red)is after the aFe CAI installed. Drove the car several hundred miles after the install before I put it back on the dyno. So yes--different days on the dyno with different STD CF's. Kind of difficult to put a few hundred miles on the car so that the ECU can adjust to the new CAI on the same day. The original run had a 1.08 STD CF and the aFe run had a 1.04 STD CF. The car has 14542 miles on the odometer.
Last edited by Vegas Panton; 12-01-2015 at 07:55 PM.
Reason: more info
I tend to enjoy Tripleblk6spd's posts because he seems to know what he's talking about at a very high level relative to ECU calibration and mods (aside from being the founder of ProEFI).
S.
I would not buy into a lot of stuff he puts out he was still thinking the A8
and the M7 dyno the same even with different mods.
he knows some stuff but something he puts out is BS!!
I tend to enjoy Tripleblk6spd's posts because he seems to know what he's talking about at a very high level relative to ECU calibration and mods (aside from being the founder of ProEFI).
S.
I understand your logic in respecting what he says.
I was monitoring that original thread as it unfolded.
It got to the point so many "not totally correct" statements about PCM function were being thrown around I just left it alone.
Not my nature to challenge his findings.
But before I took anyone's word as gospel I would ask for an explanation of how the PCM "learns" at WOT and in turn applies what it learned without a feedback loop?
Because unless it can do this (all other things remaining the same) there is no way for the car to lose power days, weeks or months later.
With a hall tech cai and high octane fuel I have a faster speed at half mile and standing mile events than any stock z06. Money well spent if you want to go faster. All of my speeds after installing cai have been higher. Throw high octane fuel and even better.
But before I took anyone's word as gospel I would ask for an explanation of how the PCM "learns" at WOT and in turn applies what it learned without a feedback loop?
It's simply a matter of the PCM detecting KR. That's what this is all about. At a certain level the PCM moves to a low octane table and reduces timing, and thus power.
I'm not sure the fact that the PCM has low and high octane tables is in dispute, is it?
S.
Absolutely true! That's why I always quote SAE CORRECTED. It keeps the numbers quoted as close as possible to a standard, no matter the DA or temp.
BUT... That's why I always say "Your results may vary, please check that the mods haven't made your car's tune unsafe."
I check my car on a dyno with a wideband and HPTuners after every mod. I suggest all do the same.
To 6Speeder; have your gains from the 2 mods, CAI and pulley, of 72hp and 71tq stay consistent from day1 til present, Jan 28th? Also, with this much increase, the car must feel much stronger, correct? And you see a few tenths improvement it ET if you ran it at the drags. Are you planning to get a tune to see if makes further gains? Will you use Diablo, maybe their custom version which only adds about $100 if get the part from the tuner.
Originally Posted by Snorman What I'd like to see is a pull a couple of weeks from now. From reading various threads on this topic (no tune CAI's), after a number of drive cycles, the factory ECU will start to adjust for the CAI and the car will make the same or less power than when stock.
As the car detects knock, it will start to pull timing down to the low octane tables and eventually, I think you'll see that horsepower gain disappear.
S.
I'll say this...
A friend took his A8 Z06 back to Orlando Speedworld a few weeks ago. Previously, the car ran close to 130-131 mph bone stock on DR's in decent air (60-70*). This time out he ran 10.7 at 127-128 mph. The car now has a Halltech on it. If the car was truly making that much more horsepower (based on initial Halltech customer dyno figures), it should have ran 133-134 mph. Granted, he said the car didn't get much cooldown, but that wouldn't account for a 6-7 mph delta.
S.
And I just found out that he is at the track right now cooling the car off to run at a rental.
If the Halltech gains are real, and sustained as many claim, it should run 133-134 mph today. It is in the 50's outside right now.
S.
Last edited by Steve Garrett; 01-29-2016 at 02:54 PM.
Reason: Merged Posts
To 6Speeder; have your gains from the 2 mods, CAI and pulley, of 72hp and 71tq stay consistent from day1 til present, Jan 28th? Also, with this much increase, the car must feel much stronger, correct? And you see a few tenths improvement it ET if you ran it at the drags. Are you planning to get a tune to see if makes further gains? Will you use Diablo, maybe their custom version which only adds about $100 if get the part from the tuner.
Hey there Conmax: I have not re'dyno'd since. I did run it at the strip before and after the mods. BUT, when stock it had a bad early tune and went into limp mode after a burnout. I actually got one clean run (no I won't give times or MPH, I'm tired of the responses I get from people who don't understand the affects of 6,000+ feet DA.)
Comparing the one clean run stock to the six I made with the mods, stock was 4 tenths slower and 6 mph slower than with the mods. Also the drag strip runs were MONTHS after the mods were installed, so I don't feel it lost performance with time.
A friend just bought a stock Z, we'll race and compare soon.
12-01-2015, 11:10 AM
aFe CAI Dyno Numbers
I actually got one clean run (no I won't give times or MPH, I'm tired of the responses I get from people who don't understand the affects of 6,000+ feet DA.)