Induction Kits lose power - Dyno Results

[Pritchard]

Everybody knows that the induction kits lose power on the 350z. Everyone.

if you dont know that then your clearly not reading through the forums enough

 

I am going to Abbey M/S next week for bits done, and their recommendation too is not to use an aftermarket induction kit but to use the '06 airbox for 'maximum HP'

 

Then reading through post after post from forum members everyone keeps repeating the same answers ''induction kits LOSE you power'', lose is the key word here.

Not worth the money, or dont make as much power as a '06 airbox, etc i could understand. but lose. Lose ??

 

So, i did what any normal person would do - and i searched around the UK forums looking for the dyno that showed that an aftermarket induction kit loses power over OEM.

Found it. here it is: <link>

 

and then I also searched the US forum too. again, found one here too <link>

 

 

 

If you are having trouble opening the links above, its because they dont exist... i cant find these illusive dynos. Anyone know where they are? Many of you do because you keep mentioning this loss of power in your posts

 

 

However, dyno results showing power increases are here, here and here: (these are the before&after dynos)

11whp gain:

http://my350z.com/forum/intake-exhaust/53825-jwt-pop-charger-dyno-results.html

 

5whp gain here

http://www.superstreetonline.com/how-to/engine/0311tur-nissan-350z-aem-cold-air-intake/

 

2whp gain from a K&N panel filter, but loss in torque!!.... 8whp gain from aftermarket system though.

http://my.prostreetonline.com/2014/01/07/faq-vq35de-intake-shootout/

 

 

Quote from 350Z-Tech/wiki. again notice the words used.... but no dynos found.

''Many people prefer the stock design, and it has been dyno proven to be better than many aftermarket CAIs on some cars, particulary the G35.''

which is then followed on the 'Cold Air Intake' link with...

''If you're interested in adding horsepower and torque to your car, as well as giving it a more aggressive engine note, then adding a cold air intake should be your first step.''

got to love a Wiki. worse than a forum for facts sometimes.

http://www.350z-tech.com/wiki/index.php?title=Category:Intake

 

 

 

So yes, can someone point me in the direction of this loss of power dyno please? I have searched (as you can see from the above links!) but i cant see it anywhere. surely it should be a sticky on some forum somewhere, a dyno this important.

 

Pritchard

 

***actually. Anyone have an induction kit they can get to me / Abbey M/S by Tuesday? i'll do a back to back dyno for you all ***

[Tricky-Ricky]

I think the main points you have to remember are firstly those dynos are from the US and likely that they where performed by the same shop that sold the induction kit,

secondly those are US dyno figures

Also since the std ECU is capable of negating any breathing mods, and add to that if you run a Z on the dyno it takes 3 to 5 hard runs for the ECU to sort itself out if you have been driving in normal traffic, just ask Mark at Abbey, so its quite likely that adding an induction kit and doing two or three runs on a dyno will result in an increase even if nothing has been done, so its easy to prove a mod can increase power

I'll see if I can find my old dyno sheet.

[Ricey]

Also it does depend how the CAI is set up. Specifically a Cold Air Intake of the average variety only serves to Hoover up warm air from the engine bay instead of the ducted cold air that a standard box will get.

 

Colder air = bigger bang.

 

If you ducted and shielded a CAI properly and had the ECU set up right to fuel correctly then yes you could get a power increase.

[Wasso]

I have the ARC induction which sounds the best of course. Also my V2 Nismo bumper comes with a Cold Air Feed which is directed at the intake. So if anything this is the ideal solution.

 

 

If you look right hand side the number plate you'll see the part in place.

 

[Mark@Abbey m/s]

The main issue with all CAI is heat soak as they all have alloy pipework that gets heated while standing still heats up the IAT and retards the ignition timing.

 

The stock air box is feed with cold air via the duct in the composite front panel and doesn't suffer heat soak as the pipework is plastic

[chirag1988]

The main issue with all CAI is heat soak as they all have alloy pipework that gets heated while standing still heats up the IAT and retards the ignition timing.

 

The stock air box is feed with cold air via the duct in the composite front panel and doesn't suffer heat soak as the pipework is plastic

 

So if there was a CAI made with plastic pipework instead of alloy, would that give the best overall results would you say?

[Wasso]

So in effect:

 

If you are stopped the CAI gets warm/hot affecting the timing. So if you want to drag race you're performance will be penalised by, well, it's got to be all of 2bhp if you're lucky.

 

If you are driving say 50mph the intake shouldn't suffer from heat soak due to the airflow. Unless you're in Dubai then the outside temps are quite a lot warmer. So you'll probably be back to loosing 2 or maybe even 3 or 4 bhp.

 

If I was to put 5bhp on a switch in your car, turned it on you wouldn't even notice. You'd probably notice more if I blinked!!

 

The problem with a dyno is the air feed isn't exactly realistic. So no Dyno is going to prove if the CAI should be making horsepower, as the wind effect is far from realistic.

 

The fan at Abbey is in a room at the back of the workshop. So the "cold" air has to be drawn in from a further room, of which the ambient air is some 15-20ft away.

 

The dyno at Horsham and the fan is as close to ambient air as possible, some 2ft.

 

For the sake of a CAI I wouldn't fuss if it made me 3bhp or I lost 3. It will never make what the manufacturers claim they do.

 

Look at the published bhp figures for a zed. Brand new off the factory line, whack it on a dyno you'd never see the bhp figures they advertise.

 

 

[Tricky-Ricky]

_{I disagree about the Heat soak issue, as it only affects the intake pipework via radiated heat when the engine bay is hot and the car is stationary, and/or has no cold air feed from outside the car, once there is any appreciable airflow going through the intake system it cannot be affected by heat soak due to the boundary layer effect which prevents the moving air being heated because of the thin layer of near stationary air that's between the pipe/box and the main airflow,}

_{Sure if the IAT sensor is mounted in such a way as to be getting transmitted heat from the pipework, but AFAIK its combined with a AFM and so shouldn't suffer badly, and also AFAIK plastic is just as susceptible as alloy to retaining heat, but that's beside the point anyway.}

 

Surly IAT is not going to have that much effect on timing on an N/A motor as its not going to see vast changes in intake temps unlike an FI motor.

Edited November 29, 2014 by Tricky-Ricky

[Floydbax]

What Mark means isn't what is usually known as the effect of heat sink, which only affects turbo engines. He means the heat sinks into the SENSOR which then tells the ECU the intake air temp is higher so the ECU then retards the ignition timing to compensate which then does not fully utilise any intake mod and the engine does not run at optimum because the information is wrong as the airflow is so great through the intake it doesn't have time to get hot. It's not the heat per se as these engines get pretty hot at the best of times especially the plenum where all that air from the intake go's into, when the engine is running at load the airflow is so great that heat doesn't have time to get hot, but the SENSOR is still telling the ECU it is.

Edited November 29, 2014 by Floydbax

[Wasso]

But the sensor is plastic, and is oem. So that doesn't add up?

[Floydbax]

Engine gets hot, heat soaks into sensor, sensor gets hot, sensor tells engine ECU ambient air temp is hot, ECU retards ignition the compensate, ACTUAL REAL intake air temp is NOT as hot as ECU has compensated for, therefore engine does not run at optimum. - Well that's how I read what Mark meant, I'm sure he will be along to correct me if it's wrong

[Tricky-Ricky]

Not possible as both the AFM and IAT are in the main air stream, so as long as there is moving air past the sensors it cant suffer heat soak, I often read people talking about heat soak, but in reality unless the intake air is already very hot IE taken from engine bay directly, then the moving air will always result in a cooling effect, I have proved this on FI engines again and again using top quality temp sensors, and like I said before apart from the boundary layer effect, N/A engines don't suffer such large intake temp variations.

[Pritchard]

Rather than join in, i'll just say; where is the dyno.

 

If its just a 'heat soak ''issue'' ' then why is this any different to any other car?

its just an age old argument of hot air vs cold air discussed from armchairs, rather than dyno'd intakes.