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Max_torque

Getting Comfortable
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  1. Remember, on a Diesel: Fuel = Torque (as no throttle for the air side) SO if it were overfuelling, the engine would be producing more torque. As you only press the accel pedal till the car accelerates or reaches the required cruising speed, more torque means you just back off earlier to the lower required torque value Diesels run lean all the time (>100:1 AFR at idle, approx 16:1AFR at WOT) you new improved efficiency exhaust and turbo will pump more air through the system, causing it to run leaner, but as the same quanity of fuel will be injected, the torque will be the same. (Fuel quanity is basically looked up from driver demanded torque, ie accel pedal position, the air quanity is just targeted to deliver a sensible AFR (within limits of EGT, NOx, cyl pressures EGR rates etc) The system already over delivers on the air side. If for some reason the fuel injection TIMING was wrong, then more fuel wouldnt necessarily mean more torque, but typically this would cause a lot of grey / black smoke from the exhaust due to the incomplete combustion. Only transiently (i.e. WOT stamp in at 1500rpm) will your engine deliver more torque than std (without remapping) as only here will demanded fuel quanity be limited (the "smoke limited fuelling") as it takes a while for the turbo to make the required boost pressure to get enough air flowing through the engine to allow "all" the WOT fuel quanity to be added. Your VNT turbo should spool up faster, meaning more response and torque transiently, but steady state fuelling will be unaffected.
  2. Assuming you have the MAP sensor line connected downstream (plenum side) of the throttle plate, then if you have a genuine 80 kPA in the plenum (due to open throttle or air leaks etc) then your engine IS at high load and would rev to the limiter in neutral!! so, assuming this isnt happening you either have 1) dodgy MAP sensor 2) dodgy ground to MAP sensor 3) air leak in PIPE to map sensor If you check the MAP with the ignition on, but the engine NOT running MAP should be at atmospheric pressure, roundabout 100 kPa When the engine starts, this will fall rapidly to around 20 to 40 kpa at idle depending on the cam setup/idle speed / ignition angle etc
  3. I don't know how much you guys know about how a narrow band lambda sensor works, but unfortunately they are really next to useless for accurately determing the current AFR of your engine. They are designed to have a large voltage swing as the AFR traverses the stoichiometric zone, and this enables std engine management to know when the exhaust afr has crossed lambda 1. It does this because to maximise catalyst conversion efficiency the exhaust AFR must be oscillated either side (in a very small window, typically 0.97 to 1.04 lambda) of lambda 1 continuously (the rich-lean conditions allow the different active components in the 3 way catalyst to convert the pollutants, i.e. lean to oxidise the THC's and rich to minimise the NOx etc) Because of the sensors characteristic, it is highly innaccurate at telling you anything other than you are lean, or rich, HOW lean or rich (which is what you probably want to know) is so far up or down the voltage curve as to be virtually worthless (also sensor ageing massively effects the actual output voltage values either side of lambda 1) It could be useful if all you want to know is that your engine stays rich when you accelerate hard, but that rich could be as lean as 0.99 lambda, rather than the 0.85 (or less) required to stop your engine going bang. The real answer is of course to use a wide band sensor, but these take much more electronics to drive as they compare current flow across a reference cell as a comparitor to estimate exhaust gas oxygen content. Typical narrow band curve attached, see how small the voltage swings are between say 0.8 and 1.0 lambda etc Please don't take this as a negative comment on your diy systems, i'm all for people doing stuff like this themselves, but i wouldn't want you to take the output values as gospel and cream cracker your engines!! (edited to add: EMS systems that have narrow band sensors do NOT use these sensors as feedback devices at high loads, when target fuelling is not lambda 1, they go "open loop" at this point. This is why most newer EMS's use wide band sensors for continuous closed loop control (well almost continuous, disabled during deccels and large load transients etc)
  4. Hi all, I'm looking for some Auto transmission options for my little project, and i was wondering if anyone has transplanted the 5 speed ZF autobox into the place of the 4 speeder??? It looks like the 5HP24 has a seperate bellhousing, so a 5hp24 core from say a BMW 540i might fit into the gap where a 4HP24 was in a RR ?? Any ideas anyone......
  5. Oh yeah, and on the previous posts subjects of being hit by unregistered cars etc, what we need is the gov to stop spending money on stupid speed cameras (that only measure velocity and rely totally on a valid car ID to work) and get some more police officers onto our roads and steets!!!
  6. Can i ask a question that is sort of connected to stolen LR's ?? I am looking at building up a LR from parts, and a quick perusal of Ebay and the like quickly turns up hords of Defender and Disco bits. Does anyone have any idea how much of this stuff might be stolen, and is there any way of telling if it is ???? I'd hate to fuel the thefts of someone's LR to fuel my build, even unknowingly!!
  7. a chop to 104" looks to produce some reasonable proportions on a 110 SW, although mod'ing the rear doors will be a PITA!! Now the hunt is on to find 110 Td5 and D3 donors, each with very careless previous owners, maybe a D3 thats been shiney side down and a 110 thats had a light knock on a front corner etc
  8. Hi all, I have been looking at a ZFHP22/4 auto transmission option using the Computshift programmable ECU, does anyone have any experience of using this system in their defender (or any other LR for that matter)?? I am really interested in how "high load" gear shifts work, because i have read the installation / calibration manuals for the system and i can't see any "engine torque down" routine. For example, you are at wide open throttle and change down (or up), how does the engine torque get reduced to protect the box (& engine) from over reving / over load etc?? Maybe people just calibrate a "ferociously fast" shift to protect the box / engine, but thats pretty horrible at low speed etc ???
  9. I think the other important thing about old cars is the material they are made from, and how much energy that took and how easy it is to recover that material when recycled. From memory there were only 3 plastic parts on my old SIIa, everything else was either steel or alluminium. modern cars are very very plastic, tricky and expensive / polluting to recycle. If the Gov was actually serious about Co2 reduction, they would implement tax benefits to employers / employees for "work at home days" at a stroke you could probably have over 50% of the uk working population work from home one day a week, giving an immediate 10% Co2 reduction (not to mention helping traffic flow etc etc) If the goverment spent money on proper wide area access to highspeed optical broadband internet then many many people wouldnt have to drive at all. I am also following the goverments advice to drive 5miles less a week, on monday, i got to within 2.5 miles of work, then pulled over in a layby for the day to save the planet...... ;-)
  10. I think the "excess" length will be the easy bit to deal with, i would really like a "just over 100 inch" wheel base, maybe 102" to 104", looking at a pic of an L319 chassis, the centre of the rails looks reasonably parallel, so would lend itself to being cut n' shut i think. The chassis is also "flatter" in side profile than a 110 chassis, as it doesn't have to hop up and over a beam axle between the wheels, so although the spring top platforms look high, i suspect they might just fit under the floor of a std defender rear tub. Probably the biggest issues might be rear crossmember and front inner wings? Also i suspect, looking at pics, that the torsional stiffness of a D3 bare chassis is nowhere near that of a 110 bare chassis, strengh being given by the D3 monocoque body bolted on top. I plan to use a modified full external cage on the defender body to restore this strength. If i can get some dimensions, then i could get some of this into CAD for an inital look see........
  11. What on earth happens when two or more D3 are parked close together then?? does it form a black hole ??? lol! Persumably by now chassis dims should have found there way into the various trade publications for crash repairs / body shell jigging etc, that might be my best bet ?? So far, i know that a D3 track (tyre centreline to tyre centre line) is about 1610mm (vs 1486 for defender), but i'm really looking to see how a Defender bulkhead would sit across the wider bowed D3 chassis rails etc
  12. Hi all, My 2010 project, the Discofender (or possibly the Defovery) has started to take some sort of direction, and i could really do with a D3 chassis diagram that shows the major dimensions, for example, those across the rails, or between wishbone hard points etc. Does anyone know where i can find this info (prefferably for free (obviously ;-) but as a last resort after exchanging some ££ ??)
  13. Kinda looking a bit like this maybe..... (wow, it's easy to build land rovers in photoshop, probably a bit harder in reality lol)
  14. I'm currently spec'ing / costing / designing a 100" hybrid Defender, but to move the plot on a bit, based on a D3 IRS suspended chassis, with 110 SW body (5 doors) and powering the whole thing with a BMW 535d motor and autobox....... I think it will all fit together somehow!!
  15. Thanks for the ideas guys, i have kinda rulled out beam axles as i would like the vehicle to have decent road handling (please don't take this as a slur on beams, i love them, but i have been there and done that on beams, so i fancied a challenge of going IRS) I had kind of mentally split the problems down into a few sections: chassis body: 1) shortening D3 chassis - more difficult than earlier LR chassis as it is curved in both planes (up/down, left/right) 2) getting the rear SW door to fit with the rear wheel - photoshop suggests this is do-able by either shortening doors or cutting arch into door lower pannel, or both 3) D3 + LR body structure torsional stiffness - LR body = jelly !!, plan to use full external cage to add high level stifness to structure - normal D3 body is on rubber isolators, do basic chassis stiffness can't be too bad (but it certainly aint as stiff as a std 110 chassis with it's deep box sides etc 4) basic width issue - need to do more research onto D3 and 110 front and rear track (hub to hub width) to work out when the wheels might end up Powertrain: 1) assume use complete 2.7 V6 diesel + trans / diffs / hubs etc unchanged from D3 - as they are designed for a GWV way above what i'll be running they should stand up to the battering from 35" tyres (needs more thought this one!!) 2) immo - retain std D3 immobiliser system and keys / steering column Interior: 1) as much std late model 110 stuff as possible - transplant D3 DIS (driver info system, or the dash to you or i) into 110 b/head space 2) HVAC - no idea yet, will need to retain D3 HVAC ECU to avoid can bus errors 3) security - no idea yet - poss issues with Central locking, alarm systems, (especially interior sensing) Powertrain and body electronics: 1) P/train ecus - std engine + trans ecu - no changes 2) BCM - probably the worst part - some body functions will just no exist, like 2 zone heating / interior lighting etc - needs thought !! lol 3) ABS / TCS / EAS / TRS - shouldn't be any serious probs as whole system will be installed so, easy really................ i have so say i'm not really a big fan of the TDV8 engine, it's performance these days is only adequate for it's bulk / size, if i had the ultimate choice i'd stick in a BMW 3 litre twin turbo diesel (305bhp, 650Nm std) Anyone care to comment on things i've missed - which i'm sure will be a lot of things!
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