Just a basic question. Could a car run lean after installing a intercooler? Example in the summer with the intercooler the car wasnt lean at all, now in the winter the car is running lean? Any help is appreciated, thanks

 

The colder air is more dense, meaning more air molecules are being put into the engine per psi. If the fuel isnt there, then it will result in a lean condition...my 2 cents, even though Im prolly talkin out my ****...

 

The colder air is more dense, meaning more air molecules are being put into the engine per psi. If the fuel isnt there, then it will result in a lean condition...

sounds logical to me.

Blaze

 

yes that information is correct. however, the AIT sensor comes into play and if configured correctly (with a super cool standalone ), it can counter act for the "leaner" conditions caused by lower intake temps

 

So...I changed majors before I got to thermodynamics...can someone (who actually knows for a FACT) explain how two different volumes of air with the same pressure can have different densities? I realize this should be simple (Boyle's law kinda thing, maybe?) but it befuddles me...could you also explain it in terms of temperature...ie. how lower temp air at Xpsi can have more air in it than higher temp air at Xpsi...an equation would be appreciated

 

hmm...no equations, but I think I have an analogy:
a tire is set at 40psi in 80 degrees...
now if you lower the temp to 30 degrees, the psi will have decreased dramatically;however, no air has escaped. The only thing that has changed is the activity in the air molecules, not the quantity of molecules...
I think I touched the topic...Im tired, and lack the energy of explaining myself more thoroughly...

 

different air temperature, will = different density.

PV=nrt

EDIT:does anyone know what the r = to for air? from my understanding the R will differe depending on what type of gas you are dealing with. In our case this is air (oxygen).

copy and paste that equation and paste it onto the search feature on http://www.yahoo.com




[Modified by BlueShadow, 10:40 PM 1/11/2003]

 

yea i always thought the cooler the intake charge , you would need more fuel to keep it from leaning out. . . i dunno if im explaining the way im thinking it . but Eric, i would suggest more fuel on that thing , your pushing it with no fuel mods and no tuning at all . ill let you get in for a few bucks, me and DC2R714 were going to rent the dyno for a day in POttstown , thats a great chance to check your **** outm.

 

although not turbo yet, but even with stock ecu my car ran more lean in the winter on the dyno, i turned the fuel pressure up a little since my car was tuned in the summer. In future I plan to re-dyno for both winter and summer, or if it don't make difference, just turn the fuel pressure up.

 

I was wondering the same thing... I always had a feeling but I guess now I know. I have a D16z6 with a greddy turbo and big type 31( i believe ) intercooler, Colderplugs, and the rest is pretty much stock. I am currently experiencing detonation due to outside temperaures. I went through summer at 90+ degrees fine now that its 20 out I can easily hear detonation....... blah blah blah....

What I wondering was. Could a simple fuel pressure regulator be able to solve this problem; simply turn up the pressure a couple psi to compensate for the air density. Will this effect the Greddy blue box in any way? Will i just have to run rich/richer throughout the entire rpm band? Basically I was just wondering what kind of effect this would have on the blue box. Any advice would be helpful.

P.S. I am only currently running 5 psi and need to have this fixed before I get my exhaust and turn it up to 7.

 

Only thing you could do is try? Shouldnt hurt to run more fuel...if anything, more fuel=good thing. Blue box should be fine...just do a few psi of fuel however...
peace,
Cody

 

BigD+Itsuki I am running just about the same setup as you but on a ZC.

Pete I will have to get ahold of you about the dyno run, Im very interested

 

Blueshadow: r equals the gasses no matter if your looking for just oxygen it's just the total gasses. To find the oxygen you use the avaeraeg temperate of the exhaust with the average percentage of oxygen in the air. That's a seperate equation.

PV=nrt As in different pressures for volume can have different ratios of gasses in different densities. The ratio of different gasses is calculated to find the value n. Then you find the density and calculate the amount of any specific gas your looking for. I hope that makes sense in english. If I'm wrong please correct me.
P=Pressure, kPa
V=total volume, m*3
n=Polytropic exponent/ variable of gasses
r=compression ratio
t=Time, s


[Modified by tzsir, 9:14 AM 1/13/2003]

 

Anyone else out there with the Greddy kit with a IC running lean in cold weather also? Maybe we can email Greddy and ask them about this.

 

You will need to richen your fuel mixture to accomodate the colder air. The same thing happened to me last winter with a 97 EX and Greddy turbo/IC. Your IAT will not adjust enough to get you the extra fuel you need, especially if you put your IAT in the charge pipe right before the throttle body and not in the intake pipe that registers the incoming (and not turbocharged) air. But it really doesn't matter where you have the IAT with the above setup, it won't compensate enough to give you enough fuel in very cold conditions.

 

Yep my Talon hits fuel cut when its cold out. You have to either turn down the boost or add some fuel to compensate.

 

this is why i added a GM Intake Air Temp sensor to my charge pipe, so I can tune the AEM EMS accurately to add fuel for colder temps.

I am thinking of moving it to the outlet of the intercooler (when i get one) so it has an accurate measurment of the air temp going into the engine.

I used a GM IAT cause its nice and threaded and a fitting can be welded onto a charge pipe.

 

This seems to be a common problem. Why not just convert to MAF. Except it'll only work if you use a standalone I guess.

Falcon: Have you experienced any surging problems with your EMS at all?
Do you use yours to control the boost? I just keep hearing problems from people that have them, and curious to if it's their set-up or what.

 

i've worked out most major issues with the EMS. the firmware is still steadily improving. the car is daily drivable at this point. are you referring to idle surging? mine behaves pretty well overall...the rpms drop when the fans come on, but i havent tried to compensate for that although there are ways to do so. i hear the latest firmware has a much improved idle algorithm. but i havent tried it yet. that release has some other issues still. and i dont like being a guinea pig. version 0.89 is good though.

i do not use boost control yet since i dont want to boost any more than my default boost level at this point. i have the boost solenoid installed already though.

i am mulling the GM IAT sensor location over on a supra mailing list. i think it's the ticket for ems users.

 

Thanks for the info.