Scorpio FE was miserable!

DHABHAR.BEHRAM · 12th September 2008, 09:43

Dear Headers - not ncessarily - there is a certain mass flow and a design pressure drop of XX mm of water column which must be met, otherwise performance will drop. This is the exact reason why periodic cleaning and replacement of the element is compulsory.

Best regards,

Behram Dhabhar

headers · 12th September 2008, 11:53

Sir, agreed, but is not the ECU self learning to understand the increase in air flow. My understanding is that in most modern ECU cars [the non carburettor non electronic ones], the ECU gets inputs based on a battery of sensors.

So, if the air filter is changed to a high performance one such as the K&N Universal, then the air mass flow into the intake is higher than normally required, this should recalibrate the ECU to give more fuel to get better response which translates to an increase in power.

Most ECUs learn this and gradually change the A/F ratio to this. Also, the exhaust emission is monitored using the EGR and some partial unburnt gases are sent into the chamber again. If the EGR value is not desirable, then too, the A/F ratio will not change due to increase in air flow. This may lead to loss of power / FE.

So correct tampering of the ECU codes is also required to effectively install an aftermarket performance part.

moleculez · 12th September 2008, 18:13

Behram Dhabhar

Here are the pics of the K&N.

DirtyDan · 13th September 2008, 02:36

Quote:

Originally Posted by DHABHAR.BEHRAM

For this vehicle, the production air cleaner must go back as there is a pressure sensor in the "clean air" hose which if disturbed in any way will vary the signal that the ECU will recieve.

K&N has a decent, if not spectacular, reputation. I have seen film of dyno tests showing "before" and "after" results. The "after" results showed a 3% gain in hp in the application I saw. The filter does still remove impurities as effectively as the original and it is washable and reusable, for awhile.

What Behram, Headers and I suspect is that perhaps the installation was done badly and/or the sensor was displaced, whacked, damaged or fooled. The ECU receiving data from the sensor may be reacting to the bad data it is getting or, perhaps, going into "limp" mode. "Limp" mode is an average default setting the ECU resorts to when it can not make sense of the info it is getting. "Limp" mode is not efficient and may be giving you the bad FE. You may try unplugging the battery cables for 20 minutes or so. This will force the ECU to reboot itself and reset itself when you hook the battery back up. SOmetimes this works, and sometimes it does not. Cheap fix though and worth a try. Else, better listen to Behram.

ramkya1 · 13th September 2008, 22:38

Quote:

Originally Posted by DirtyDan

Else, better listen to Behram.

Moleculez,

Would suggest you PM Behram or do as he suggests. This horse knows what it's speaking

--Ramky

headers · 14th September 2008, 07:37

well, but there are scorpios running K&N with an increase in performance!

gd1418 · 14th September 2008, 20:32

With reference to my post #:6 & 15 here I would like to report that the 5th tankfull that I did sometime back, returned the following figures:

Diesel Filled to tank-up: 36.24 ltrs

Kms done: 380.5

FE: 10.50. (city driving with AC)

Rest all parameters remained the same as during the other previous 4 tank-fulls.

Now, will somebody explain this? I'm now due for the 6th tank-full and this time I'm going to use premium fuel and check the results.

DirtyDan · 14th September 2008, 20:44

Quote:

Originally Posted by gd1418

Over the last 4 tank top-ups I've consistently got a FE of 9.88kmpl in city driving with AC. Since all parameters of my car are working 'purr'fectly and no changes have been done as such, I presume it is the upsize that is giving me heartburns..

Yup! It takes away power and falsifies your odometer/speedometer. This last also messes up your FE calculations a little bit. There is some stuff around the site on it if you want to search for it.

.anshuman · 14th September 2008, 21:25

I easily manage 11kmpl Gurgaon traffic with some spirited driving,i drive a 2.2 mhawk.

moleculez · 14th September 2008, 23:02

mhawk is suppose to give a better FE than cRDE due to engine changes and also a 200 CC drop in the engine.

talking back abour cRDE i fear to even test my FE in traffic. If the highway running is so poor i dont expect anything more than 9 in city driving.

raj_5004 · 14th September 2008, 23:31

hey anshuman, pls do post the pics of your scorpio in the thread "all scorpio owners with pics of their SUV" in the SUV/MUV section. let us have a look of your car.

pramods · 14th September 2008, 23:37

I got an average of 11kmpl with 100% AC and with speed in excess of 110kmph for 75% time, this is mHawk 2.2 VLX. I have done 1.3K since 3rd sep, all most 90 % highway driving.

-Pramod

gd1418 · 15th September 2008, 11:14

It seems, I could not explain properly what I wanted to know..

In the 4 tank fulls I did I got a FE of 9.88 kmpl but in the 5th tank-full the vehicle returned a FE of 10.50 kmpl.

All the driving parameters were same for all of the tankfulls and no changes or servicing of the vehicle has been done.

All I wanted to know was due to what the FE showed an increase? The fuel was and is always filled from the same bunk.

Quote:

Originally Posted by DirtyDan

Yup! It takes away power and falsifies your odometer/speedometer. This last also messes up your FE calculations a little bit. There is some stuff around the site on it if you want to search for it.

Quote:

Originally Posted by .anshuman

I easily manage 11kmpl Gurgaon traffic with some spirited driving,i drive a 2.2 mhawk.

Quote:

Originally Posted by pramods

I got an average of 11kmpl with 100% AC and with speed in excess of 110kmph for 75% time, this is mHawk 2.2 VLX. I have done 1.3K since 3rd sep, all most 90 % highway driving.

-Pramod

Roshun · 15th September 2008, 15:51

GD, probably a lighter foot, or lesser traffic situation in the last one week? Hard to explain what could have increased your FE this time.

As for me, I've been getting between 10.25 to 10.78 over the weeks on IOC Xtramile and depending on traffic conditions (always full-time AC use). However, last week, I filled the tank with regular as Xtramile was out of stock at that pump that day. This week's average 10.52, right in the middle of my average band.

I guess not much of difference between the two diesels - except that Xtramile has more 'soapy' properties in terms of keeping the injectors and filters cleaner. I doubt if there's any change in the cetane number of both diesels.

Similarly, when I use STP diesel fuel treatment once in 4 tankfuls - I do get mileage in the upper part of my average band but not a very significant difference. I guess, I can stay satisfied with the consistency.

Cheers,

moleculez · 16th September 2008, 14:18

Does the Tyre pressure make a difference. I maintain 32 in all 4 tyres!

12th September 2008, 09:43	#31
DHABHAR.BEHRAM Distinguished - BHPian Join Date: Jul 2007 Location: MUMBAI Posts: 3,059 Thanked: 5,408 Times	Dear Headers - not ncessarily - there is a certain mass flow and a design pressure drop of XX mm of water column which must be met, otherwise performance will drop. This is the exact reason why periodic cleaning and replacement of the element is compulsory. Best regards, Behram Dhabhar
	() Thanks

12th September 2008, 11:53	#32
headers Senior - BHPian Join Date: May 2006 Location: Greater Chennai Posts: 4,667 Thanked: 564 Times	Sir, agreed, but is not the ECU self learning to understand the increase in air flow. My understanding is that in most modern ECU cars [the non carburettor non electronic ones], the ECU gets inputs based on a battery of sensors. So, if the air filter is changed to a high performance one such as the K&N Universal, then the air mass flow into the intake is higher than normally required, this should recalibrate the ECU to give more fuel to get better response which translates to an increase in power. Most ECUs learn this and gradually change the A/F ratio to this. Also, the exhaust emission is monitored using the EGR and some partial unburnt gases are sent into the chamber again. If the EGR value is not desirable, then too, the A/F ratio will not change due to increase in air flow. This may lead to loss of power / FE. So correct tampering of the ECU codes is also required to effectively install an aftermarket performance part.
	() Thanks

12th September 2008, 18:13	#33
moleculez BHPian Join Date: Aug 2008 Location: Mumbai Posts: 49 Thanked: 24 Times	Behram Dhabhar Here are the pics of the K&N. Attached Thumbnails
	() Thanks

14th September 2008, 07:37	#36
headers Senior - BHPian Join Date: May 2006 Location: Greater Chennai Posts: 4,667 Thanked: 564 Times	well, but there are scorpios running K&N with an increase in performance!
	() Thanks

14th September 2008, 20:32	#37
gd1418 Senior - BHPian Join Date: May 2006 Location: Gurgaon Posts: 3,577 Thanked: 729 Times View My Garage	With reference to my post #:6 & 15 here I would like to report that the 5th tankfull that I did sometime back, returned the following figures: Diesel Filled to tank-up: 36.24 ltrs Kms done: 380.5 FE: 10.50. (city driving with AC) Rest all parameters remained the same as during the other previous 4 tank-fulls. Now, will somebody explain this? I'm now due for the 6th tank-full and this time I'm going to use premium fuel and check the results.
	() Thanks

14th September 2008, 21:25	#39
.anshuman Distinguished - BHPian Join Date: Dec 2004 Location: Good-Gaon Posts: 7,763 Thanked: 11,126 Times View My Garage	I easily manage 11kmpl Gurgaon traffic with some spirited driving,i drive a 2.2 mhawk.
	() Thanks

14th September 2008, 23:02	#40
moleculez BHPian Join Date: Aug 2008 Location: Mumbai Posts: 49 Thanked: 24 Times	mhawk is suppose to give a better FE than cRDE due to engine changes and also a 200 CC drop in the engine. talking back abour cRDE i fear to even test my FE in traffic. If the highway running is so poor i dont expect anything more than 9 in city driving.
	() Thanks

14th September 2008, 23:31	#41
raj_5004 Senior - BHPian Join Date: Jan 2008 Location: Dubai/Mumbai Posts: 5,238 Thanked: 3,168 Times	hey anshuman, pls do post the pics of your scorpio in the thread "all scorpio owners with pics of their SUV" in the SUV/MUV section. let us have a look of your car.
	() Thanks

14th September 2008, 23:37	#42
pramods BHPian Join Date: May 2005 Location: Nagpur Posts: 993 Thanked: 858 Times	I got an average of 11kmpl with 100% AC and with speed in excess of 110kmph for 75% time, this is mHawk 2.2 VLX. I have done 1.3K since 3rd sep, all most 90 % highway driving. -Pramod
	() Thanks

15th September 2008, 15:51	#44
Roshun BHPian Join Date: Oct 2005 Location: Delhi Posts: 151 Thanked: 41 Times	GD, probably a lighter foot, or lesser traffic situation in the last one week? Hard to explain what could have increased your FE this time. As for me, I've been getting between 10.25 to 10.78 over the weeks on IOC Xtramile and depending on traffic conditions (always full-time AC use). However, last week, I filled the tank with regular as Xtramile was out of stock at that pump that day. This week's average 10.52, right in the middle of my average band. I guess not much of difference between the two diesels - except that Xtramile has more 'soapy' properties in terms of keeping the injectors and filters cleaner. I doubt if there's any change in the cetane number of both diesels. Similarly, when I use STP diesel fuel treatment once in 4 tankfuls - I do get mileage in the upper part of my average band but not a very significant difference. I guess, I can stay satisfied with the consistency. Cheers,
	() Thanks

16th September 2008, 14:18	#45
moleculez BHPian Join Date: Aug 2008 Location: Mumbai Posts: 49 Thanked: 24 Times	Does the Tyre pressure make a difference. I maintain 32 in all 4 tyres!
	() Thanks