Induction temperatures

[Anonymous]

I was going to post on the current induction thread, but I didn't want to confuse the situation.

So this is something I've been watching recently with the PFC and there does seem a big difference in temperatures using the standard set-up (Markiii pipe & K&N panel filter) and the Apexi / PPE or whom ever -replacement induction systems is used.

As Nic said in the other thread he is seeing temps between 40 & 45 C normally going up to 50 when the ambient temp increases - and that's using Apexi, yesterday and today the highest running temps I had was 23 C (the lowest was 13 C in the hills yesterday) and when I stopped for a break today - 1 hour - the MAF temp had soaked to 29 C but after a short drive it was back down to 22C, so is the standard / slightly modified system more efficent in delivering cool air which means a better running engine ??

Rob  s:idea: :idea: s:idea:

[ChrisGB]

I was going to post on the current induction thread, but I didn't want to confuse the situation.

So this is something I've been watching recently with the PFC and there does seem a big difference in temperatures using the standard set-up (Markiii pipe & K&N panel filter) and the Apexi / PPE or whom ever -replacement induction systems is used.

As Nic said in the other thread he is seeing temps between 40 & 45 C normally going up to 50 when the ambient temp increases - and that's using Apexi, yesterday and today the highest running temps I had was 23 C (the lowest was 13 C in the hills yesterday) and when I stopped for a break today - 1 hour - the MAF temp had soaked to 29 C but after a short drive it was back down to 22C, so is the standard / slightly modified system more efficent in delivering cool air which means a better running engine ??

Rob  s:idea: :idea: s:idea:

Hi Rob

Just like we always expected, picking up air from just inside the vent is better than picking it up from other under bonnet areas. Probably see some power loss for most intakes, but it is possible that an intake that is well tuned (resonantly) could give slightly better top end. Ideal combination of course is to have right resonant tuning and low air temp.

Has anyone ever seen a power increase with an induction kit? Would filling in the bottom of the air box, reducing it's volume, move the peak torque up the rev range? May try this once I finalise my setup as the PPE manifold works best at the top end.

Chris

[Tem]

I always thought the best intake would be one that just went down from the throttlebody and got fresh air from the bottom.  s8) s8)  

Or do it like Beanie did, get the air from the side intake. Search for his thread on SC, if you wanna see details.

[cclarke99]

20deg C increase means that the density of the intake air will be about 7% lower, thats a big power loss. Plus the high temp will be much more likely to cuase knocking, which will retard the ignition, loosing more power. It would have to be a good intake to recover that loss. Regarding the airbox, reducing the volume will almost definately loose you mid range, with no gain elsewhere. The box provides a smoothing effect and the injection will not like any reduction of that, plus the momentum of air in the box is quite significant. There's a good website with more info on inlet tuning, but I've lost the link - sorry. I worked out the optimum volume for a 1300cc Golf using that data and in fact the standard car was about as good as you could get - maybe they're better at these things than we think?

[tom_deas]

I'm a nerd, so...

Assumptions - dew point 15C, air pressure 1000mb

Temperature          Density (kg/m3)
13C                       1.2096
22C                       1.1727
23C                       1.1687
29C                       1.1455
40C                       1.1053
45C                       1.0879
50C                       1.0711

So if you went there from best case to worst case scenario in the above intake temperatures, you'd see a 11.45% decrease in density of intake air (assuming that theres no form of natural forced induction due to movement of vehicle).

Assuming a temperature of, say, 21C, compared to the 50C stated...

21C                       1.1767
50C                       1.0711

You see an 8.97% decrease in intake density.

*ahem*

[Tem]

Assuming a temperature of, say, 21C, compared to the 50C stated...

21C                       1.1767
50C                       1.0711

You see an 8.97% decrease in intake density.

*ahem*

10% less air = 10% less power.  s:? :? s:?

Not to mention ECU starts to pull up timing with hot air. I'm not sure how much though, but it means even more lost power.

[aaronjb]

Not to mention ECU starts to pull up timing with hot air. I'm not sure how much though, but it means even more lost power.

I'd guess similar to the stock retard on the PFC, which is 4° at 60°C - quite a bit of retard..

[Wabbitkilla]

Well i never reach 60c (yet  s:shock: :shock: s:shock:  )

I'm wondering if i should get some kind of cowling around the filter and pipe air in from the old inlet duct over the arch and maybe scooped up from under the car.

What d'you reckon?

[aaronjb]

Well i never reach 60c (yet  s:shock: :shock: s:shock:  )

Yes but don't forget the PFC (and stock ECU, I imagine) extrapolates the retard based on temperature.  It isn't 0° until 59.999999°C, then 4° as soon as you hit 60°C - it makes a smooth curve between set points.  By default those are:

0 at 40C
2 at 50C
4 at 60C

So anywhere between 0 & 2° ignition retard, along with less fuel to match the lower air density..

[Anonymous]

Well i never reach 60c (yet  s:shock: :shock: s:shock:  )

I'm wondering if i should get some kind of cowling around the filter and pipe air in from the old inlet duct over the arch and maybe scooped up from under the car.

What d'you reckon?

It's got to be worth a try Nic, I think that pipe over the rear arch must act as a cooler as well hence the speed the air cools when driving.

Rob.

[DannyN]

Are you just recording the air intake temperature on the commander?

If so I will keep an eye on mine and post up with finding.  That will give us a nice cross sectional spread as I have the AEM which puts the filter down under the rear light

[northernalex]

I'll have a go with mine tonight too.. PPE intake (will log it from the ODB2)

Alex

[Wabbitkilla]

That's right Danny, it will prove interesting to compare.

I found an air cowl produced by K&N for one of their kits, don't know if it would fit the Apexi, but it gives me ideas.

[DannyN]

ooo, shiny !

[Anonymous]

Are you just recording the air intake temperature on the commander?

If so I will keep an eye on mine and post up with finding.  That will give us a nice cross sectional spread as I have the AEM which puts the filter down under the rear light

Yep

[Wabbitkilla]

What about this?



Meant for a jetex filter, but surely something like that would fit an Apexi and the external ducting to handy locations?

[DannyN]

What about this?Meant for a jetex filter, but surely something like that would fit an Apexi and the external ducting to handy locations?

Maybe for your apexi but I dont think it wold fit around my AEM

[ChrisGB]

Regarding the airbox, reducing the volume will almost definately loose you mid range, with no gain elsewhere. The box provides a smoothing effect and the injection will not like any reduction of that, plus the momentum of air in the box is quite significant. There's a good website with more info on inlet tuning, but I've lost the link - sorry. I worked out the optimum volume for a 1300cc Golf using that data and in fact the standard car was about as good as you could get - maybe they're better at these things than we think?

I have done a fair bit of this sort of thing in the past. The airbox (as part of the inlet system) acts like a resonator and will be optimised for a certain engine speed. As my PPE manifold is optimised for a higher engine speed than the original engines peak torque, it may be possible to reduce the airbox volume by a small amount and move the resonance up nearer peak power to fall into line with the PPE manifold.

I would expect to possibly lose a little mid range, but possibly gain some top end. I don't expect large gains though and a drop in midrange would not be good. If the drop is only at the bottom end, that would be ideal. Manufacturers do tend to work these things out well. I have had a couple of Vauxhall 6 cylinder cars with variable volume inlet systems, big for midrange, small for high revs.

Chris

[northernalex]

15 degrees celcius at 70mph
22 degrees ceclius at 30mph (pootling about)
38 degrees celcius at 0mph (sitting in pub carpark for 5 mins).

PPE intake.
Have the maf air mass readings and temperature readings graphed.. I'll put them up later  s:) s:)

[Wabbitkilla]

I suppose i should attach my datalogit now eh?

Caan someone answer this for me...

If i attach my datalogit and boot up the pc, will it affect the setup of the pfc?

[aaronjb]

Not unless you 'accidentally' run FC-Edit, click Read All, then Tools->Initialize PFC..

Which I think is unlikely  s:lol: :lol: s:lol:

[Wabbitkilla]

Not unless you 'accidentally' run FC-Edit, click Read All, then Tools->Initialize PFC..

Which I think is unlikely  s:lol: :lol: s:lol:

Now you've told me how - it's scared the bejesus out of me  s:oops: :oops: s:oops:    s:lol: :lol: s:lol:  

Tomorrow methinks, gotta start working again in a bit through the night.
Work (cough) from home tomorrow  s:wink: :wink: s:wink:

[Anonymous]

15 degrees celcius at 70mph
22 degrees ceclius at 30mph (pootling about)
38 degrees celcius at 0mph (sitting in pub carpark for 5 mins).

PPE intake.
Have the maf air mass readings and temperature readings graphed.. I'll put them up later  s:) s:)

Alex

What did the temp go down too after you run from the pub, also what was the ambient temp.

Rob

[northernalex]

rob, i dont know what the ambient temperature was.. around 15-18 degrees I guess.. but i dont know.

Make sure you zoom in on putfile

Alex

[aaronjb]

Pah, you all think you have it hard.. I regularly see 65C+.

I really should sort that chargecooler out (if they'd hurry up and deliver the silicone hose!)  s:oops: :oops: s:oops: