373 replies to this topic

[38bfast]

Eric is sampling at the AFM same place that the ECU is sampling. 

[Jim Drago]

new 1.6 exhaust

 

[chris haldeman]

We may need too send that exhaust to the same person who studied all of our heads so it can be studied.

[chris haldeman]

I recommend it be studied in his living room

[MPR22]

I recommend it be studied in his living room

with the windows shut to more closely replicated the environment under the hood? 

[chris haldeman]

Yes agreed

[Tom Hampton]

We're not F1 Tom. And we aren't looking to solve the issue of heat picked up along the way through the intake plumbing (though it may be greater than the NBs given location). At the moment all we really need is reliable data to show the delta between ambient and the air temp just inside the filter adapter, with and without the turn indicator mod, while racing under various conditions. Our first goal is to establish that delta and calculate the theoretical benefit of a simple rules change to give the 1.6 a more consistent IAT similar to other models. Then it would be nice to determine whether the temps at the manifold actually drop the same amount, of if the benefit is largely negated by other factors. But if we require research lab quality process and data or get caught up in too many other variables, nothing will ever happen.

 

I sure hope what I wrote above doesn't amount to F1 quality collection and analysis.  If it does, then I would be sorely dissapointed. 

 

 

 

The suggesting above doesn't only serve to collect data on the heat pickup through the intake plumbing.  It actually serves to collect data on the boundary conditions that affect the temperature of the air entering the manifold.  It still leaves in question heat pickup from the throttle body to the combustion chamber.  The data points above are enough to:

 

1.  Determine the heat rise from outside air to air filter inlet.

2.  Determine the heat gain through the filter, intake pipe, and AFM.

3.  Determine any heat soak relationship over time.

4.  Determien the heat gain through the intake tubing (plastic parts).

5.  thermal conductivity of each of the above parts. 

6.  Sensitivity of most of the above variables to both OAT, and filter inlet air temp. 

7.  Sensitivity of filter inlet air temp to OAT.

 

As I'm sure you know, thermal systems like this can be a bit tricky---its not that complicated, but there are some interdependancies.  A simple reduction in inlet temperature does not necessarily translate into a reduction in manifold temperature.  Some understanding of the heat transfer of the entire system is necessary to acurately predict the decrease in manifold temperature.  The above data, along with a rudamentary analysis (basic spreadsheet) would be sufficient to determine the sensitivity of manifold temperature (more accurately throttle-body inlet temperature) to inlet air temp. 

 

Besides, I don't agree that we AREN'T looking to solve the "heat-pickup along the intake track" issue. We have been asked for any and all ideas that could improve the 1.6 performance.  If removing the turn signal has merit (by postulating that it will reduce IAT), then any other method that reduces IAT is also worrthy of consideration.  if simply painting the plastic white, or wrapping it in a thermal barrier has merit, and potentially MORE merit than removing the turn signal, then why dismiss it? 

 

Bench's data is far from complete or even reliable.  But, its enough to make a fella say "hmmm...there's a lot of temperature gain there to play with."  

 

Its also possible that letting more air into the engine compartment reduces the average ambient temperaure along the entire intake track, thus reducing heat pickup throughout the entire track.  In other words, the reduction in filter inlet temperature may only be part of the gain. 

 

Again, this is hardly rocket science, and I sure hope doesn't measure up to anything that an F1 team is doing. The hardest part of it is getting the temp sensors into a data system.  Nevertheless, Bench doesn't have the data system to do this job.  So, its largely moot, unless someone else does (I don't at the moment, but could). 

[Johnny D]

Just some fuel for the fire.
I'm sure our brightest are on it.

http://www.revlimite.../pix/scoop1.jpg
https://www.flyinmia...od-louvers.html

And after you look at getting it in, maybe look at getting it out,
cowl induction, maybe play with the seal on the back of the hood by the firewall.

carry on.
J~

[Tom Scheifler]

If you pull the turn indicator assembly and look in you will see that the flow is still largely obstructed. Disappointing to learn that pulling it was no help, but I would suggest a retest with the headlight bulb removed. May still be negligible but worth a try. Not sure venting (out) at the windshield as some have suggested will help either, but pulling the rubber desk off for a test is easy enough.

Any more ideas for reducing IAT?

Steve, reread Danny's post. I think he is using negligible to mean it is beneficial.

[Steve Scheifler]

Riiiight, after the indicator was pulled the change in temp [relative to ambient] was negligible. Excellent, I found the opposite hard to believe but thought maybe cage headlight bulb deflected what could get through. Thanks to Eric for doing this!

[Bench Racer]

Any more ideas for reducing IAT?

 

Install a MegaSquirt, no need for AFM/AFM temp sensor. Along with eliminating the plastic inlet tube, use wrapped aluminum tube to air in to filter location of choice on drivers side. Maybe fab and install a spacer to raise the thermostat housing for aluminum tube to pass under the thermo to radiator hose. $$$$ compared to other two posted choices and a likely harder sell to SMAC. 

[Tom Hampton]

bench asked me to post pictures of his cold air intake solution.  i created a gallery album for the pix, the album description is text from dave.

 

http://mazdaracers.c...hurst-cool-air/

[Bench Racer]

Thanks Tom. 

[SaulSpeedwell]

Unfortunately, CR vs. efficiency isn't linear.  See FIgure 24 below.  I've got MIT/Taylor's text in front of me, and I'm getting 1.7% THEORETICAL gain going from 9.4 to 9.9 CR.

 

http://naca.central....-report-205.pdf

 

With every automaker willing to kill their Mom and bolt on turbos and 9-speed transmissions to try to meet the new 54.5 MPG bogey, I can assure you if there was a 5% efficiency gain in CR just laying there for the taking, there would be no 87 octaine.  We'd all be running 93+ and getting 5% better MPG?

 

In contrast, see Fig 3 in the below.  It's a little complicated, but it is a FIAT tech paper that basically shows  that 50 degrees F of intake air temperature is worth ~3.5%.  It also indicates that the SAE dyno correction factor we know/love is a bit harsher than reality, compared to actual vehicle testing.  (I'm a skeptic, though, so I'm assuming FIAT's engines just make crappy numbers on SAE dynos and this whole thing was a trumped up study commissioned by the Pope).

 

http://www.scielo.br.../v25n3/a10v25n3

 

FIAT's bias aside, the point here is that the SAE Correction factor itself is a somewhat valid indicator how much intake air temperature matters.  Plus, "we" already have data showing that the 1.6 is sucking 50+ degrees hotter air than the NBs.  Don't take my word for it,

 

The voting should go like this:

Joe 1.6 Frontrunner (does this guy stiull exist, lol?):  Vote for ITA engine rules, make a custom intake to lower IAT under today's rules

Joe Engine Builder:  Vote to scrap existing heads and make ITA engine rules legal

Joe Cheapskate/Lazyass:  Vote for weight and RP changes, and a cold air intake provision

 

I have no plans whatsoever to profit from any of the above. 

 Bump because I'm trying to link someone to the links in this post and it isn't working ....