Intake, Header, HFC, CBE = Too Lean?

LateralG'z · 03-23-2010, 11:28 PM

I am betting they make a justifiable difference if you run the car at a track where the engine bay is hotter than normal driving conditions and they are actually pulling colder out from in the front of the car instead of in the engine bay. Basing things from a dyno is only a small part in the initial performance gains while getting things tuned to help have the motor run at better conditions because everything there is suppose to be in near perfect conditions. Not to mention a fan blowing air at 15 mph is not same as the car moving faster than 15 mph. A fan to keep the car from over heating from a 15 second pull is not a great test to base off of for intakes. If you do a couple of consecutive pulls, you will watch the horse go down as car generate heats. Add these long intakes and I bet you see better gains than stock ones once the car is a more severe condition than perfect dyno temps. I know you can prove that and are aware of it F.I. Inc. and I know it is true because I was an intern for Dynojet in Belgrade, MT when I was in college in Bozeman. I have seen more than a enough dyno runs and pulls and data to say if you run the car for more than 60 seconds hard and get the car hot that any sort of descent CAI that can bring in colder air to the engine helps teh performance. Thus the point of an intercooler on a S/C or Turbo set-up. Kind of common sense if anyone thinks about it, and yes the stock intakes are great for OEM but things can always be better than OEM to help squeeze extra juice out of NA motor.

m4a1mustang · 03-23-2010, 11:53 PM

Quote:

Originally Posted by LateralG'z

I am betting they make a justifiable difference if you run the car at a track where the engine bay is hotter than normal driving conditions and they are actually pulling colder out from in the front of the car instead of in the engine bay. Basing things from a dyno is only a small part in the initial performance gains while getting things tuned to help have the motor run at better conditions because everything there is suppose to be in near perfect conditions. Not to mention a fan blowing air at 15 mph is not same as the car moving faster than 15 mph. A fan to keep the car from over heating from a 15 second pull is not a great test to base off of for intakes. If you do a couple of consecutive pulls, you will watch the horse go down as car generate heats. Add these long intakes and I bet you see better gains than stock ones once the car is a more severe condition than perfect dyno temps. I know you can prove that and are aware of it F.I. Inc. and I know it is true because I was an intern for Dynojet in Belgrade, MT when I was in college in Bozeman. I have seen more than a enough dyno runs and pulls and data to say if you run the car for more than 60 seconds hard and get the car hot that any sort of descent CAI that can bring in colder air to the engine helps teh performance. Thus the point of an intercooler on a S/C or Turbo set-up. Kind of common sense if anyone thinks about it, and yes the stock intakes are great for OEM but things can always be better than OEM to help squeeze extra juice out of NA motor.

The stock air boxes are cold air intakes. They isolate the filters from the heat of the engine bay and source cold air from outside... the same air that the Injens and G3s breathe.

The reason the Injens and G3s gain at the very end of the range is because the stock system becomes slightly restrictive beyond ~7k RPM.

Temperature wise, the G3s/Injens/Stock should all be very similar as they are all sourcing air from the same place.

BOLIO 671 · 03-24-2010, 07:46 AM

Quote:

Originally Posted by m4a1mustang

The stock air boxes are cold air intakes. They isolate the filters from the heat of the engine bay and source cold air from outside... the same air that the Injens and G3s breathe.

The reason the Injens and G3s gain at the very end of the range is because the stock system becomes slightly restrictive beyond ~7k RPM.

Temperature wise, the G3s/Injens/Stock should all be very similar as they are all sourcing air from the same place.

Very good counter response m4a1mustang....

I don't have a CAI...I was initially planning to get one, but after reading all of the posts here and dyno results, I totally changed my mind about it...In one thread, I recalled seeing similar results in reference to the CAI gains...Tony was right, most of the gains are seen at 7k and above....and like "Matt" said in another thread, I don't think any of us are planning to run our Z's at 7K plus majority of the time....

I just don't feel that the minimal gain of horsepower up top, is worth the loss of torque and power in the midrange....

Smallywood · 03-24-2010, 04:56 AM

My understanding is that the issue really has the potential to show when headers and HFCs are used together. Add in CBE & CAIs and then you run the risk of knock and/or engine damage...

Vegitto-kun · 03-24-2010, 06:09 AM

what is running lean? I probably know it in other terms but does it mean that the engine isn't pumping enough fuel and air in the cilinders?

Modshack · 03-24-2010, 07:49 AM

Quote:

Originally Posted by Vegitto-kun

what is running lean? I probably know it in other terms but does it mean that the engine isn't pumping enough fuel and air in the cilinders?

Ideal Air/Fuel ratios for a N/A car are in the 12.5 to 12.8:1 range. Too lean would be in the mid 13:1 range.

Turbo cars like to run richer in the mid 11's as more fuel is used to cool the combustion and keep detonation under boost controlled.

F.I. Inc. · 03-24-2010, 09:51 AM

Quote:

Originally Posted by Modshack

Ideal Air/Fuel ratios for a N/A car are in the 12.5 to 12.8:1 range. Too lean would be in the mid 13:1 range.

Turbo cars like to run richer in the mid 11's as more fuel is used to cool the combustion and keep detonation under boost controlled.

I totally agree. On my TT mustang @ 25PSI we are at 1000 RWH! My A/F throughout the entire curve is 11:4-11:7. Keep in mind, I am also running unleaded 109 octance VP race fuel in order to achieve this.

Tony

semtex · 03-24-2010, 07:54 AM

Quote:

Originally Posted by Vegitto-kun

what is running lean? I probably know it in other terms but does it mean that the engine isn't pumping enough fuel and air in the cilinders?

In simple terms -- too much air, not enough fuel. Running rich would be the opposite.

Vegitto-kun · 03-24-2010, 07:53 AM

damnit so if I get HFC + exhaust I would have to find somebody that can tune the ECU up.

horray for more money to spend

F.I. Inc. · 03-24-2010, 10:06 AM

Quote:

Originally Posted by Vegitto-kun

damnit so if I get HFC + exhaust I would have to find somebody that can tune the ECU up.

horray for more money to spend

No you do not. If you run the HFC's and CBE your car will not become too lean. The ECU will correct and do it's job. Here is why the intakes change the A/F ratio's so much more than the exhaust system.

Inside your stock intake tube is a MAF (Mass Air Meter) As the air rushes by it, it samples that air. It works directly with the ECU and is calibrated specifically for the car. If you change altitude your cars A/F ratio will change. Meaning being at sea level opposed to driving in the mountains. In the higher altitude your car will actually be richer. Here is why, the air is thinner up there, your car naturally will take in less air. It naturally wants to lean out due to this and in most cases the ECU will compensate by dumping too much fuel and make the car rich. The MAF and ECU are designed from the factory to do this. However, they only work to a certain extent being that the elements from one place to the next are too different. If it worked perfectly your A/F would be optimum wherever you drove.

Now if you put an aftermarket CAI on the car that changes the location of the MAF or the tubing diameter it will change everything. The car is not calibrated for it. In the case of the Stillen Gen III intakes with exhaust & headers the intakes are causing the car to run way too lean. This is why you need a re tune so at the least amount you can bring the A/F ratios back to where they need to be. I know this how you may ask, over the past two days I dynoed a car that had Stillen Gen III intakes with our exhaust components and the car was borderline unsafe in terms of A/F. We re tuned the car, picked up alot of mid range power and low end torque just be getting the A/F back in the 12's. To be continued I am sure...

Thanks, Tony

chris410 · 03-26-2010, 01:19 PM

Quote:

Originally Posted by F.I. Inc.

No you do not. If you run the HFC's and CBE your car will not become too lean. The ECU will correct and do it's job. Here is why the intakes change the A/F ratio's so much more than the exhaust system.

Inside your stock intake tube is a MAF (Mass Air Meter) As the air rushes by it, it samples that air. It works directly with the ECU and is calibrated specifically for the car. If you change altitude your cars A/F ratio will change. Meaning being at sea level opposed to driving in the mountains. In the higher altitude your car will actually be richer. Here is why, the air is thinner up there, your car naturally will take in less air. It naturally wants to lean out due to this and in most cases the ECU will compensate by dumping too much fuel and make the car rich. The MAF and ECU are designed from the factory to do this. However, they only work to a certain extent being that the elements from one place to the next are too different. If it worked perfectly your A/F would be optimum wherever you drove.

Now if you put an aftermarket CAI on the car that changes the location of the MAF or the tubing diameter it will change everything. The car is not calibrated for it. In the case of the Stillen Gen III intakes with exhaust & headers the intakes are causing the car to run way too lean. This is why you need a re tune so at the least amount you can bring the A/F ratios back to where they need to be. I know this how you may ask, over the past two days I dynoed a car that had Stillen Gen III intakes with our exhaust components and the car was borderline unsafe in terms of A/F. We re tuned the car, picked up alot of mid range power and low end torque just be getting the A/F back in the 12's. To be continued I am sure...

Thanks, Tony

Well said Tony, everyone needs to keep in mind that most dyno graphs of the G3 intake show a "peak" gain which means next to nothing for overall performance. The K&N drop-ins are your best route to go with the stock intakes along with a CBE and HFC.

However, like Tony said...if you change the location and process of how the car reads the air ratios, you are at risk of running lean because the car may not be adjusting the fuel ECU map correctly. You have two ways of determining this, either pull your plugs and read them (basically if you are running lean you will see a whiteish plug) or get to a dyno and get an a/f reading. If you are running lean, the car "should" pull timing which means you are losing power. Don't make your mods work against you!

You will not be able to put more power using an intake, HFC, and CBE IF the car can adjust air/fuel correctly. If you go the supercharger/turbo route of course the game changes quite a bit. So, for those of you going with the G3, you should at least get your air/fuel readings to make sure you're not going lean. Better safe than sorry!

semtex · 03-26-2010, 01:38 PM

Quote:

Originally Posted by chris410

You will not be able to put more power using an intake, HFC, and CBE IF the car can adjust air/fuel correctly.

I disagree.

I started off with a CBE and HFC. I never dyno'd before this, only after, so my baseline is with the CBE and HFC.

Baseline: Max = 291.7whp. My only mods were the Stillen cat-back exhaust and the Berk HFCs.

Then I went and added the G3 intakes.
After: Max = 306.4whp.

Net gain = 14.7whp.

Then I added headers.

This first graph shows HP and A/F:

This one shows torque:

So I should be running really lean now, right? And when I get a tune and get my AFR adjusted, my HP should go back down as a result of the AFR correction, right? But it doesn't. And keep in mind that AFR correction is pretty much the only thing a tune is good for right now, because timing adjustments just get bounced back, so it's not like we're offsetting HP loss via AFR correction with HP gain via timing advancement.

Sharif at Forged Performance did my tune, and he made sure the AFR is where it ought to be.

Final number: 318.1

Unless I'm missing something, it does not appear that my gains from the G3 intake were at any point negated by AFR correction, which leads me to conclude that the gain I got from the G3 was legit, and not simply because it caused my engine to run lean.

chris410 · 03-26-2010, 06:20 PM

No, what I meant is that IF your air meter is working properly that even with all the bolt on mods, the car should be able to adjust the fuel so that you do not run lean. In other words, the stock fuel system can keep up with the amount of power you will make with all of those mods. If you relocate or your air meter is NOT reading accurately, you could end up with a lean condition.

I wasn't really talking about the "power" itself rather the power compared to what the ECU can adjust to.

Basically, if you have a G3, you're better off getting the car on the dyno and obtaining your a/f ratios. OR...if you have the software, watch the timing during a pull. If you see timing start to decrease through the run, that means your car is going lean and the ECU is pulling timing to compensate...NOT good!

Nice numbers btw!

Quote:

Originally Posted by semtex

I disagree.

I started off with a CBE and HFC. I never dyno'd before this, only after, so my baseline is with the CBE and HFC.

Baseline: Max = 291.7whp. My only mods were the Stillen cat-back exhaust and the Berk HFCs.

Then I went and added the G3 intakes.
After: Max = 306.4whp.

Net gain = 14.7whp.

Then I added headers.

This first graph shows HP and A/F:

This one shows torque:

So I should be running really lean now, right? And when I get a tune and get my AFR adjusted, my HP should go back down as a result of the AFR correction, right? But it doesn't. And keep in mind that AFR correction is pretty much the only thing a tune is good for right now, because timing adjustments just get bounced back, so it's not like we're offsetting HP loss via AFR correction with HP gain via timing advancement.

Sharif at Forged Performance did my tune, and he made sure the AFR is where it ought to be.

Final number: 318.1

Unless I'm missing something, it does not appear that my gains from the G3 intake were at any point negated by AFR correction, which leads me to conclude that the gain I got from the G3 was legit, and not simply because it caused my engine to run lean.

Red370 · 03-24-2010, 08:05 AM

Self admittedly, I know jack squat about A/F ratios, but i'm curious... my AP says that i'm running an avg. of 14.2-14.4 at idle, is that a normal idle ratio? is it only considered running lean at a specific RPM?

F.I. Inc. · 03-24-2010, 09:48 AM

Quote:

Originally Posted by Red370

Self admittedly, I know jack squat about A/F ratios, but i'm curious... my AP says that i'm running an avg. of 14.2-14.4 at idle, is that a normal idle ratio? is it only considered running lean at a specific RPM?

You are fine! Optimum A/F ratio at idol is 14:7! Now WOT (Wide Open Throttle) You reallly want to be in the high to mid 12 range once you get above 4-5000 RPM. At the lower RPM's the A/F being leaner will not be catastrophic to the engine. However if you run it the high 13's low 14's in the upper RPM range you can cause serious damage to the engine. Detonation will occur inside of the engine and you can actually hear it if it is real bad. Bottom line, it is not enough fuel.

Thanks, Tony

03-23-2010, 11:28 PM	#1 (permalink)
LateralG'z Track Member Join Date: Nov 2009 Location: Oklahoma Posts: 876 Drives: 370z Rep Power: 18	I am betting they make a justifiable difference if you run the car at a track where the engine bay is hotter than normal driving conditions and they are actually pulling colder out from in the front of the car instead of in the engine bay. Basing things from a dyno is only a small part in the initial performance gains while getting things tuned to help have the motor run at better conditions because everything there is suppose to be in near perfect conditions. Not to mention a fan blowing air at 15 mph is not same as the car moving faster than 15 mph. A fan to keep the car from over heating from a 15 second pull is not a great test to base off of for intakes. If you do a couple of consecutive pulls, you will watch the horse go down as car generate heats. Add these long intakes and I bet you see better gains than stock ones once the car is a more severe condition than perfect dyno temps. I know you can prove that and are aware of it F.I. Inc. and I know it is true because I was an intern for Dynojet in Belgrade, MT when I was in college in Bozeman. I have seen more than a enough dyno runs and pulls and data to say if you run the car for more than 60 seconds hard and get the car hot that any sort of descent CAI that can bring in colder air to the engine helps teh performance. Thus the point of an intercooler on a S/C or Turbo set-up. Kind of common sense if anyone thinks about it, and yes the stock intakes are great for OEM but things can always be better than OEM to help squeeze extra juice out of NA motor. __________________ 2010 Mag Black, 6MT,

03-24-2010, 04:56 AM	#4 (permalink)
Smallywood Track Member Join Date: Jul 2009 Location: Central Ohio Posts: 501 Drives: 12 GT-R BlackEdition Rep Power: 18	My understanding is that the issue really has the potential to show when headers and HFCs are used together. Add in CBE & CAIs and then you run the risk of knock and/or engine damage... __________________

03-24-2010, 08:05 AM	#14 (permalink)
Red370 A True Z Fanatic Join Date: Jul 2009 Location: Kaiserslautern, Germany Posts: 4,391 Drives: your mom to church Rep Power: 297	Self admittedly, I know jack squat about A/F ratios, but i'm curious... my AP says that i'm running an avg. of 14.2-14.4 at idle, is that a normal idle ratio? is it only considered running lean at a specific RPM? __________________ 2011 Mustang 5.0 \| 3.55's \| Lethal Performance off road H-Pipe \| Magnaflow Muffler Delete \| JLT CAI/Bama tuned 417whp/ 404 ft/lbs

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03-24-2010, 06:09 AM	#5 (permalink)
Vegitto-kun A True Z Fanatic Join Date: Feb 2010 Location: USA Posts: 2,011 Drives: 09 370Z Rep Power: 264	what is running lean? I probably know it in other terms but does it mean that the engine isn't pumping enough fuel and air in the cilinders?

03-24-2010, 07:53 AM	#9 (permalink)
Vegitto-kun A True Z Fanatic Join Date: Feb 2010 Location: USA Posts: 2,011 Drives: 09 370Z Rep Power: 264	damnit so if I get HFC + exhaust I would have to find somebody that can tune the ECU up. horray for more money to spend