K&N Air Filters Added to Stock Air Boxes??

Sh0velMan · 04-17-2013, 08:59 AM

Quote:

Originally Posted by 280z/300zx

The NISMO exhaust is only worth about 7-8hp over stock. It costs only a few hundred less than fast intentions but doesn't give the same 15-18hp that fast intentions does. Again, this has been discussed and dyno proven in the past. I'm not saying the NISMO exhaust is horrible; it's well made and does perform better than stock. What I am saying is that for the money spent there are better options. My stock NISMO exhaust is hanging in my garage while my fast intentions is on my car. Sounds better, lighter, and performs better.

Remember, the NISMO exhaust isn't the only thing giving the NISMO extra power, there is also a better tune and higher rev limit. Those who did the swap but in 2009 when the car first came out only say 7-8hp gains on a stock regular 370z.

This is all pretty much false.

Rev limit identical, tune has slightly different base fuel table data that is tuned out as soon as the car learns fuel data. The exhaust is the only mechanical (engine) difference between the 332hp base Z and the 350hp Nismo Z. The exhaust is good for over 15+ WHP, if tuned or given time for the engine to adjust.

The exhaust is a great option if you don't want to spend too much money.

Buying it NEW is dumb, buying it used for cheap, is very very smart.

Chuck33079 · 04-17-2013, 09:15 AM

If you're going to buy intakes later, why spend the money on new filters now? What's the point?

Jordo! · 04-17-2013, 09:31 AM

Yes, worth it. Agreed on the smooth tubes to compliment, but you will still see gains without them.

From two different 370's of mine: first is a 2010 comparing K&N vs paper filter only; second is a 2011 comparing K&N+Cobb tubes vs paper filter.

Eventually I will be trying a set of the pop chargers, which have nice built in velocity stacks -- HOWEVER, this will be in conjunction with custom made fiberglass airboxes. This will be a late summer project, so expect no updates before mid July.

There's nothing wrong with the Nismo exhaust as an upgrade from OEM IF you can pick it up on the cheap (say < $550 shipped; < $350 picked up)

Jordo! · 04-17-2013, 09:53 AM

Quote:

Originally Posted by Sh0velMan

This is all pretty much false.

Rev limit identical, tune has slightly different base fuel table data that is tuned out as soon as the car learns fuel data. The exhaust is the only mechanical (engine) difference between the 332hp base Z and the 350hp Nismo Z. The exhaust is good for over 15+ WHP, if tuned or given time for the engine to adjust.

The exhaust is a great option if you don't want to spend too much money.

Buying it NEW is dumb, buying it used for cheap, is very very smart.

First part isn't quite right, at least based on about a dozen or so Nismo vs comparably modded/tuned non-nismo Z's I've seen dynos for. The fueling and spark profile will not adapt to match the Nismo's without tuning.

Also, I thought the Nismo does have a slightly higher rev limit as well -- I could be wrong on that one.

I also remain convinced that the Nismo has slightly different VVEL tuning as well -- although that is yet to be confirmed (hello, GTM?) -- after viewing these dynos I've been accumulating from various folks (all dynojet, BTW).

However, I agree 100% that picking up any Nismo exhaust new is not needed -- get one used for modest gains and good sound without any unexpected rasp or fitment issues.

Sh0velMan · 04-17-2013, 09:59 AM

Quote:

Originally Posted by Jordo!

First part isn't quite right, at least based on about a dozen or so Nismo vs comparably modded/tuned non-nismo Z's I've seen dynos for. The fueling and spark profile will not adapt to match the Nismo's without tuning.

Yes, it will. It takes time and a willingness to actually go to redline @ WOT a number of times over a few days to get the ECU to re-learn. Can be sped up by clearing the learned fuel data at time of install. My baselines with drop ins and the Nismo CBE were well over 295 WHP with AFR's right in line with factory specs. That's not possible if the ECU hadn't re-learned fuel data sufficiently. This is before I had an UpRev license installed.

Also, I thought the Nismo does have a slightly higher rev limit as well -- I could be wrong on that one.

I've never heard of this, would like to see evidence from UpRev to support. (Screen shot of stock ROM)

I also remain convinced that the Nismo has slightly different VVEL tuning as well -- although that is yet to be confirmed (hello, GTM?) -- after viewing these dynos I've been accumulating from various folks (all dynojet, BTW).

Unless you (or anyone) can provide UpRev traces showing VVEL actuator behavior that is different, I'm gonna say it's all the exhaust you're seeing. The H-Pipe design absolutely causes the high end of the curve to take on a different shape, as compared to the stock Y pipe. That shape is visible even in my own dynos with longtube race headers + the Nismo OEM CBE.

However, I agree 100% that picking up any Nismo exhaust new is not needed -- get one used for modest gains and good sound without any unexpected rasp or fitment issues.

Responses in bold.

gsxr750 · 04-17-2013, 11:00 AM

Quote:

Originally Posted by Jordo!

Yes, worth it. Agreed on the smooth tubes to compliment, but you will still see gains without them.

From two different 370's of mine: first is a 2010 comparing K&N vs paper filter only; second is a 2011 comparing K&N+Cobb tubes vs paper filter.

Eventually I will be trying a set of the pop chargers, which have nice built in velocity stacks -- HOWEVER, this will be in conjunction with custom made fiberglass airboxes. This will be a late summer project, so expect no updates before mid July.

There's nothing wrong with the Nismo exhaust as an upgrade from OEM IF you can pick it up on the cheap (say < $550 shipped; < $350 picked up)

It looks like your data points are taken at different RPM levels between the 2 dyno charts , if this is so, it will give you a lot different readings if you measure your HP at 4000 rpm compared to 4200 rpm.

Jordo! · 04-17-2013, 04:01 PM

Why would you base it all on one data point?

If you gained 10 whp in the middle and 3 at the peak, would you say the car only gained 3 whp?

7speed · 04-17-2013, 04:22 PM

Quote:

Originally Posted by Jordo!

If you gained 10 whp in the middle and 3 at the peak, would you say the car only gained 3 whp?

Actually you would.

But of course all of us on this forum know...... area under curve counts just as much if not more for driveability.

gsxr750 · 04-17-2013, 04:53 PM

Quote:

Originally Posted by Jordo!

Why would you base it all on one data point?

If you gained 10 whp in the middle and 3 at the peak, would you say the car only gained 3 whp?

Showing a 2 different graphs to represent HP gains, with different data points on each graph does not provide accurate data, unless you were to overlay the 2 graphs or plot the data points on 1 chart.

If a car makes 200 HP at 4000 rpm. in one chart and in another chart it makes 210 HP at 4200 rpm , you can 't say there was a 10 HP gain between to 2 charts.

Data points between the 2 charts must be identical in order to illustrate an accurate comparison.

Jordo! · 04-18-2013, 07:14 PM

Quote:

Originally Posted by gsxr750

Showing a 2 different graphs to represent HP gains, with different data points on each graph does not provide accurate data, unless you were to overlay the 2 graphs or plot the data points on 1 chart.

If a car makes 200 HP at 4000 rpm. in one chart and in another chart it makes 210 HP at 4200 rpm , you can 't say there was a 10 HP gain between to 2 charts.

Data points between the 2 charts must be identical in order to illustrate an accurate comparison.

Those data are from the same car in each graph -- not comparing two different cars. The overlay is before and after a given set of mods. Selected points are just showing where greatest gains were.

I'm not making a case for a mean gain of x at datapoint y, I'm showing that a humble change of a filter does indeed net gains throughout the rev range, as shown on two vehicles for which I have data on hand. There's too many transient variables that may affect the magnitude of change at a specific location in the rev range. That we see gains throughout the rev range -- albeit at different points -- on two units is generally good evidence that high flow filters make a positive improvement. Comparing the same car at the same point before and after still provides useful information.

That car A gained 3 whp at 3500 RPM whereas car B gained 5 is not really the issue -- we have no specific hypotheses about that, and again there are too many transient modifiers that will influence things.

Anyway, one shows gains from filters alone the other shows gains from a combo of filters and tubes. The filters alone netted about a 2% gain at 5252 RPM (or as close to it as I could align the cursor) and with both the gain is about 4% when hp and torque are equal.

Here they are again with a single selected RPM point -- 5252 RPM (or as close to it as I could align the cursor)-- for comparison... same day too.

2011 Z

2009 Z

Interpret these data as you will...

UNKNOWN_370 · 04-19-2013, 06:22 AM

Quote:

Originally Posted by Jordo!

First part isn't quite right, at least based on about a dozen or so Nismo vs comparably modded/tuned non-nismo Z's I've seen dynos for. The fueling and spark profile will not adapt to match the Nismo's without tuning.

Also, I thought the Nismo does have a slightly higher rev limit as well -- I could be wrong on that one.

I also remain convinced that the Nismo has slightly different VVEL tuning as well -- although that is yet to be confirmed (hello, GTM?) -- after viewing these dynos I've been accumulating from various folks (all dynojet, BTW).

However, I agree 100% that picking up any Nismo exhaust new is not needed -- get one used for modest gains and good sound without any unexpected rasp or fitment issues.

It doesn't have a higher rev limit but peak HP expands from the regular Z

Z= 332hp @7,000rpm
Nismo= 350hp 7,400rpm

Buying the exhaust separately from Nismo, they claim 5-8hp gain with their exhaust. Not sure if i can float with Nismo getting all their power solely from an exhaust considering their claims on the independent exhaust

NISMO Exhaust System 370Z - B0100-1EA25 - Nismo

Sh0velMan · 04-19-2013, 07:44 AM

Quote:

Originally Posted by UNKNOWN_370

It doesn't have a higher rev limit but peak HP expands from the regular Z

Z= 332hp @7,000rpm
Nismo= 350hp 7,400rpm

Buying the exhaust separately from Nismo, they claim 5-8hp gain with their exhaust. Not sure if i can float with Nismo getting all their power solely from an exhaust considering their claims on the independent exhaust

NISMO Exhaust System 370Z - B0100-1EA25 - Nismo

That's the shitty 'S-Tune' exhaust system.

We're talking about the Nismo OEM exhaust, which is good for well over 10WHP in most cases.

Quartermaine · 04-19-2013, 11:16 AM

Quote:

Originally Posted by kenchan

dayam.. i heard if you put them in the exhaust it acts like a turbo. can you confirm that?

confirmed!

forza370z · 04-19-2013, 01:02 PM

Quote:

Originally Posted by Quartermaine

confirmed!

Oh sweet! Gotta do this mod ASAP!

Jordo! · 04-20-2013, 11:25 PM

Quote:

Originally Posted by Sh0velMan

That's the shitty 'S-Tune' exhaust system.

We're talking about the Nismo OEM exhaust, which is good for well over 10WHP in most cases.

Hmm. Well, I've had the S-tune previously (about 3-4 whp) and will be bolting on a Nismo take off in July so I'll post before and after results in a few months.

04-17-2013, 09:15 AM	#17 (permalink)
Chuck33079 A True Z Fanatic Join Date: Nov 2011 Location: Houston Posts: 12,265 Drives: 2011 370ztt Rep Power: 29538	If you're going to buy intakes later, why spend the money on new filters now? What's the point? Sh0velMan likes this. __________________ 2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

04-17-2013, 09:31 AM	#18 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 417	Yes, worth it. Agreed on the smooth tubes to compliment, but you will still see gains without them. From two different 370's of mine: first is a 2010 comparing K&N vs paper filter only; second is a 2011 comparing K&N+Cobb tubes vs paper filter. Eventually I will be trying a set of the pop chargers, which have nice built in velocity stacks -- HOWEVER, this will be in conjunction with custom made fiberglass airboxes. This will be a late summer project, so expect no updates before mid July. There's nothing wrong with the Nismo exhaust as an upgrade from OEM IF you can pick it up on the cheap (say < $550 shipped; < $350 picked up) Sh0velMan and LiquidCrewZ like this. __________________ Enjoy it. Destroy it. Last edited by Jordo!; 04-17-2013 at 09:34 AM.

04-17-2013, 04:01 PM	#22 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 417	Why would you base it all on one data point? If you gained 10 whp in the middle and 3 at the peak, would you say the car only gained 3 whp? __________________ Enjoy it. Destroy it.

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