Something I've noticed and posted about (as well as many others on the board) since getting my 2003 CL-S MT is the amazing pull & strength the engine has in ambient temps. below 72/73 degr.F. . Today it is 65 this morning here in NYC and damn the car just feels so much better. Now I know the physics involved but what Im interested in hearing now is how (or if...) anything can be done to make the warmer temps. not effect the engine sooo much. I've had many cars over the years but it seems this one was designed and tested without the account for higher ambient temps.

 

the CLS ECU is SO VERY CONSERVATIVE. Could install a mugen T-stat but that'll only help once the engine is heat soaked. Makes the engine stay cooler but that won't help when the humidity and temp is high.

 

Cooler and drier = more air molecules inside each cylinder for combustion.

 

ok - can/does the CT Icebox (or any of the intake systems) help ??

 

no

 

I saw up 20 WHP difference or 8%. I have 2 dynos. Check my sig and look for the actual uncorrectednumbers

 

Let's hear from you guys down in FL GA SC TX LA etc...have you addressed this problem ??? I am saying "problem" because it seems way too extreme and maybe something about the '03 six speed MT ?

 

oh yeah Nashua Nighthawk since you are in NH it might not be as big of an issue in your particular case. But since the theory behind all of the CAI systems is basially the same do you notice big difference in warm weather performance (compared to before you had the CAI installed ?? )

 

out of all the cars i have driven the cl-s is most sensitive to the humid heat, i think when its 90 deg and humid out compared to when its under 60 deg i make 20 more whp when its cooler

 

The obvious answer is the change in air density. Hot Humid Air contains noticeably less O2 than cool dry air. Temperature change alone can account for around a 5% power change. Add to this changes in water vapor and this amount can easily double.

But what is less obvious is the ECU changes. With warmer air, less timing is run which further reduces power. Warmer air will also make you run the AC which, although it disengages at WOT, heat soaks the entire engine quicker. Running a lower temp T-Stat and fan switch will help offset some of the drastic changes but not eliminate it.

I would expect that a combination of hot humid air compared to cold dry air could amount to as high as a 15% change in power. But that is in the most drastic differences.

 

Or is it a matter of having more power to begin with; I don't know what you previously drove?? In my experience with forums, the current vehicle is always the worst in this case but I feel it is mainly due to people watching it more.

In my case my old Typhoon was the most sensitive. That thing would seem to lose over 50 HP and sometimes felt like 80+ HP loss.

 

ok I'm not as up to speed as you scalbert with the engine mods so the fan switch will bring the fan on 'earlier' ( alower temp. threshold) than the stock ?? BTW - '96 Camaro - '99 BMW 330 - '03 Miata (wife's...hahah)

 

Probably not... I think at high speed, the CLS stock intake will be as good as CAI less the added free flow from the K&N filter.

 

Yes, the cooling fans will turn on at a lower temp. When used in conjunction with the T-Stat you can keep the coolant temperatures 20 degrees cooler. This amounts to about 5 - 7 WHP more.

'99 330i?? The '99 3-Series sedans were the first year of the E46 chassis. There was no 330i in that year, the 330i didn't come out until the '01 model year. For '99 and '00 the top 3-Series motor was the 2.8 liter in the 328i.

 

Now you guys know why my 1/4 mile times are so bad. Its always hot and always humid here.

 

Cant you use nitrous to cool the air into the intake/throtle body kinda like when you use nitrous on a intercooled turbo/supercharger application?

 

Hey scalbert how would i wire up my fans to come on earlier did you use just a simple on/off switch or did you change the temp setting to when they come on..... and how hard is it to change the thermostat what one is in ther now and what did you put in there?

Thanks

Kevin

 

Yes, but you had better add fuel too or else...

 

Our cars have a simple temperature switch (or switches if automatic) to control the fan speed. There is no ECU control of the fans. So it was simply a matter of swapping out the fan switch for a lower temp Mugen unit. This is located on the T-Stat housing.

The T-Stat its self is easy to swap. It is located just below the throttle body. You will lose about a quart or two of coolant.

 

Pretty sure the VQ35DE is just as bad. My Altima feels like a 4 cyllinder vehicle in the Texas heat.

 

Care to elaborate for me ... my apologies I'm not all that familiar with NOS

 

Are you saying I'm going to need another switch. I only bought one. :o

 

scalbert owns you

 

No, only one is needed. There are three switches on the automatic versions and one on the manual. But the same one ,which exists in both, are used for primary fan control.

The other two in the automatics are supplemental.

 

If you introduce nitrous only to your intake tract you O2 content will go up to about 37% versus 21% normally. This will cause you to go lean and burn up the motor unless you add additional fuel.

That is the use for nitrous in cars.

 

So then is it just a matter of an upgraded FP? I would really like to install a fogger system somewhere down the line and I guess nows as good a time as any for a little research