simonsi
Joined: 14 Oct 2007
Location: Leicester
Posts: 668
 
|
10forcash wrote:stapldm wrote:Although the EGR blanking instructions are brilliant  I'm confused about removal of the butterfly plate; isn't this part of the engine braking mechanism?
yes it is - especially on auto boxed versions, the butterfly also forces the engine to suck in exhaust gases when the throttle is closed
Gareth - 100% on the 300tdi & TD5
Eh?? Engine braking comes from compressing air, as I see it the butterfly valve is there to close when the EGRs are open to force the engine to intake more exhaust via the open EGR valves, ie create a slight vacuum at the EGR that results in exhaust induction. With the EGRs blanked off the butterfly valve will only restrict the amount of air drawn into the engine - bad for creating turbo lag!
Wild theory number 1: The action of the EGR/butterfly valve is responsible for the pickup hesitation common to TDV6s, personally Iīm keen to experiment and get mine blanked off/removed asap to see if it improves this "feature".
As for the MOT, well the MOT diesel test etc involves lots of revs to the diesels max speed as per the warning leaflets so under MOT conditions the EGRs will be shut wonīt they? So blanking off may make no difference at all.
j moore - thanks for taking the trouble to post these - fantastic pics Did the mod remove/reduce the pickup hesitation you can sometimes get say exiting roundabouts?? Cheers
Simon
TDV6 S Auto - Zambezi Silver - JE Tune - RRS 19" - Sidesteps - Roof Rails
Body Side Strips - Xenons - Bright Pack - Cold Pack - Premium Stereo
Alpine Roof - Towpack - Alpine Touchscreen Satnav - Veba Rear DVD changer
Alpine Roof Monitor - Webasto FBH Timer - Awesome Brembo Frt & S/C Rr Brakes
|
 Wed Mar 19 2008 11:19pm |
|
|
j,moore
Joined: 26 Nov 2007
Location: n.lincs
Posts: 106
|
hi, i removed the butterfly valve because when the engine ecu opens the egr valves it also closes the butterfly valve to cause the engine to induct the exhaust gasses by creating a vacum on the egr inlet pipes, but when you blank off the egr valves the engine ecu still closes the butterfly valve to restrict the air flow, but because the egr valves are blanked off the air flow is cut down and so it efectivly starves the engine of air. you could try just blanking off the egr valves and see how the engine performs, im not sure because i did both mods at the same time. the emissions produced after the mods were almost the same as before so i dont see any problems from mot's. the main reason i did this mod was to eliminate any costly maitenence costs from failing egr components. the advantages in regards to performance are nominal, it does eliminate some flat spots and the throtle responce is improved (in my opinion) and it starts up better on cold mornings but i think that if you pump sooty exhaust fumes back into a perfectly good engine you are going to cause un needed extra wear. i supose none of this matters if you only intend to keep the vehicle for a short period of time,and so it wouldnt be worth the hassle.
hope this helps, jim.
Last edited by j,moore on Wed Mar 19 2008 11:33pm; edited 1 time in total
|
| Wed Mar 19 2008 11:20pm |
|
|
blue meanie
Joined: 04 Aug 2005
Location: quizzically indifferent
Posts: 2630
|
excellnt info and pics! thanks Jim I am sure ths will be one of the most visited threads in the months and years to come as warranties expire global warming my ars...!!!
Last edited by blue meanie on Wed Mar 19 2008 11:28pm; edited 1 time in total
|
| Wed Mar 19 2008 11:24pm |
|
|
simonsi
Joined: 14 Oct 2007
Location: Leicester
Posts: 668
|
blue meanie wrote:excellnt ifo and pics! thanks Jim I am sure ths will be one of the most visited threads in the months and years to come as warranties expire
Mines out already - yippee!!  Cheers
Simon
TDV6 S Auto - Zambezi Silver - JE Tune - RRS 19" - Sidesteps - Roof Rails
Body Side Strips - Xenons - Bright Pack - Cold Pack - Premium Stereo
Alpine Roof - Towpack - Alpine Touchscreen Satnav - Veba Rear DVD changer
Alpine Roof Monitor - Webasto FBH Timer - Awesome Brembo Frt & S/C Rr Brakes
|
| Wed Mar 19 2008 11:26pm |
|
|
10forcash
Site Sponsor
Joined: 09 Jun 2005
Location: In the naughty corner.... eligible for parole 2025
Posts: 13960
|
Engine braking comes from compressing gases if the gases are mainly exhaust and therefore have a low oxygen content, the engine braking will be greater as there is little combustion effect from the diesel injected at 0% throttle, the butterfly (as mentioned above) causes more exhaust gases to be introduced due to the depression created within the induction manifold  for Freelander 2 Diesel, Discovery 3 / RR Sport TDV6 & RR Sport TDV8, Defender (TD5 & Puma) - available Now!
Vehicle modifications, preparation, training and equipment also available 
|
| Wed Mar 19 2008 11:26pm |
|
|
Gareth
Site Moderator
Joined: 07 Dec 2004
Location: Bob the Builders 'ere
Posts: 9577
|
How is vacuum generated for the brake servo?
On older D1 there was a separate vacuum pump, but on even older Series 2 & 3 deisels there was a butterfly valve very similar to the D3 arrangement in the inlet tract to create a depression when the throttle was closed to power the servo brakes (when fitted).
I presume because Jmoore has already done this, it does not affect the brake servo?
Interesting theory about the turbo lag. Silver TDV6 HSE
Pepper White Cooper S Convertible
Old English White MGB GT
Ex Military 109 Series 2a Soft Top
|
| Wed Mar 19 2008 11:26pm |
|
|
simonsi
Joined: 14 Oct 2007
Location: Leicester
Posts: 668
|
10forcash wrote:Engine braking comes from compressing gases if the gases are mainly exhaust and therefore have a low oxygen content, the engine braking will be greater as there is little combustion effect from the diesel injected at 0% throttle, the butterfly (as mentioned above) causes more exhaust gases to be introduced due to the depression created within the induction manifold
I disagree, on a trailing throttle very little if any fuel is being injected, hence the engine braking is coming from compressing whatever gas is in there, it makes no matter what it is as little or no combustion is taking place...as j moore states the butterfly is there to create vacuum where none would normally exist in order for the EGR system to work, hence with no exhaust to draw in if the EGRs are blanked off the butterfly valve will just starve the engine of air in the same way a petrol engine is throttled back. A functioning butterfly with blanked EGRs must leave the engine with less gas to compress and hence less engine braking in any case so removal canīt be a bad thing un der any circumstances as far as I can see.
Best thing about this I can see is that all the systems still think they will work so hence no fault codes Cheers
Simon
TDV6 S Auto - Zambezi Silver - JE Tune - RRS 19" - Sidesteps - Roof Rails
Body Side Strips - Xenons - Bright Pack - Cold Pack - Premium Stereo
Alpine Roof - Towpack - Alpine Touchscreen Satnav - Veba Rear DVD changer
Alpine Roof Monitor - Webasto FBH Timer - Awesome Brembo Frt & S/C Rr Brakes
|
| Wed Mar 19 2008 11:32pm |
|
|
10forcash
Site Sponsor
Joined: 09 Jun 2005
Location: In the naughty corner.... eligible for parole 2025
Posts: 13960
|
There is a seperate brake vaccum pump on the TDV6 for Freelander 2 Diesel, Discovery 3 / RR Sport TDV6 & RR Sport TDV8, Defender (TD5 & Puma) - available Now!
Vehicle modifications, preparation, training and equipment also available
|
| Wed Mar 19 2008 11:33pm |
|
|
simonsi
Joined: 14 Oct 2007
Location: Leicester
Posts: 668
|
Gareth wrote:How is vacuum generated for the brake servo?
Diesels use a dedicated vacuum pump, not induction vacuum as there isnīt any (or not enough as there is with a petrol engine). Cheers
Simon
TDV6 S Auto - Zambezi Silver - JE Tune - RRS 19" - Sidesteps - Roof Rails
Body Side Strips - Xenons - Bright Pack - Cold Pack - Premium Stereo
Alpine Roof - Towpack - Alpine Touchscreen Satnav - Veba Rear DVD changer
Alpine Roof Monitor - Webasto FBH Timer - Awesome Brembo Frt & S/C Rr Brakes
|
| Wed Mar 19 2008 11:34pm |
|
|
10forcash
Site Sponsor
Joined: 09 Jun 2005
Location: In the naughty corner.... eligible for parole 2025
Posts: 13960
|
The butterfly mapping isn't as simplistic as 'EGR open butterfly closed' - it's a closed loop system with input from various sensors including engine speed for Freelander 2 Diesel, Discovery 3 / RR Sport TDV6 & RR Sport TDV8, Defender (TD5 & Puma) - available Now!
Vehicle modifications, preparation, training and equipment also available
|
| Wed Mar 19 2008 11:36pm |
|
|
Gareth
Site Moderator
Joined: 07 Dec 2004
Location: Bob the Builders 'ere
Posts: 9577
|
In a way, I'm glad of that. Wouldn't want to think that LR had made the D3 too 'retro' 
FFS they'll be fitting mechanical hand brakes next  Silver TDV6 HSE
Pepper White Cooper S Convertible
Old English White MGB GT
Ex Military 109 Series 2a Soft Top
|
| Wed Mar 19 2008 11:37pm |
|
|
j,moore
Joined: 26 Nov 2007
Location: n.lincs
Posts: 106
|
hi, the butterfly vale has nothing to do whith engine braking and the brakes are completly seprate to the air induction,
|
| Wed Mar 19 2008 11:38pm |
|
|
|
|
j,moore
Joined: 26 Nov 2007
Location: n.lincs
Posts: 106
|
if you were to go into engine mapping on a common rail diesel engine you would be up all night, yes there are sensors that monitor and adjust many things such as air flow, oxygen levels, other gas levels, air temps, fuel temps and so on and so on but it all boils down to basics. even the tuning people will tell you (or mabye not) there is alot of trial and error to get a good happy medium of power out of an engine. the modifications i have done were in my own intrests and if anyone else cares to try the same method then it is up to them. i must say that my disco3 has done 37,000miles in les than two years of witch 17000 of them have been done cince the mods and so far there have been no problems whith performance or failure of egr components (touch wood), and the oil stays cleaner, so that makes me happy.
so thanks again, jim.
|
| Wed Mar 19 2008 11:59pm |
|
|
pbhawkin
Joined: 14 Dec 2006
Location: Mudgee
Posts: 263
|
Quote:as j moore states the butterfly is there to create vacuum where none would normally exist in order for the EGR system to work
I guess the Venturi effect that occurs with fast moving air past an opening would not be enough to create sufficient vacuum to make the EGR efficient and that the Butterfly valve creates a greater vacuum?
HAS anyone asked their friendly LR mechanic what the implications are if this was done on a car that was IN warrenty? regards
Peter
__________________________________________
2007 TDV6 SE E-diff, adaptive lights, home made front mudflaps, WaxGuarded, Lightskins light AND paint protection, Reversing camera. Mitchell Bros tow hitch.
2001 Volvo XC70 Cross Country
|
| Thu Mar 20 2008 12:31am |
|
|
