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  1. obe

    Fuel Cooling

    Hi JohnD I'm going to very politely and respectfully disagree with you about ducting air to other areas. Putting aside the specifics of cooling groupC prototype racers doing 200mph down the mulsanne straight for a second I don't know that any road speed we are going to reach in a Triumph is going to stall air in any reasonably sized hose , convoluted or not. We can prove this relatively simply because most of the cars we are driving have convoluted hoses in the heating/ventilation system and I've never knowingly experienced the air stall (ie no output from the vents) in any car I've driven at any normal, or abnormal, speed. To all practical extents as long as you have the air 1) taken from a high pressure area and 2) exiting into a low pressure area you will get a flow of air. Indeed the flow of air from the vents of my Stag at normal road speeds without the fan switched on is quite significant and certainly well worth venting through a fuel cooler, and that's air from in front of the windscreen into the cabin which I would imagine is less of a pressure differential than air taken from a front vertical face (radiator grille or similar) and vented to a low pressure area (top flat surface or better still behind a little gurney flap). Using the air con to cool fuel is something I've seen for at least 25 years .. certainly TVR have been doing that at least that long (the cars I have most experience of) and I can't imagine they were the first .. though they have a habit of placing fuel tanks in the boot and covering them in insulating carpet which does rather increase the fuel temperature somewhat. I take your point about the effect of cool fuel on intake temps, and that it is a *relatively* poor way to reduce charge temps, good point well made. Though of course once you've exhausted all ways to keep the air cool you might turn your attention to the fuel, especially as fuel vapour takes up 800 times the space of fuel droplets .. keeping the fuel cool enough to remain in droplet form will aid power. http://practicalphysics.org/change-volume-petrol-petrol-vapour.html best wishes
  2. It's well known in the world of fitting aftermarket ecus that you need to run some resistance in the HT side, usually resistive plugs is enough. The magnecors are very low resistance I think which is maybe causing ringing in the HT system (multiple high voltage spikes collapsing into the primary winding and then the first two collapses are enough to generate two back emf signals high enough to trick the tacho into thinking there's been two firing events and so the rev counter showing double the rpm?)
  3. obe

    Fuel Cooling

    I like the idea of having a fuel cooler .. fuel boils at low temps (I actually have fuel boiling in petrol tanks on the rolling road it gets so hot in some tanks) and anything you can do to keep it cooler is a good thing I think ? The good news is you can put the cooler anywhere you want to (within reason) and just duct cold air from a high pressure area at the front of the car with large bore convoluted pipes. As long as the other side of the cooler vents to a low pressure area you will still get good airflow across the matrix and keep the cooler in a safer place :) An even safer option would be a chargecooler style system but that's maybe getting a bit OTT haha) Nice topic :)
  4. Sorry no it's not for a triumph engine it's for TVR's own straight six engine, I was just saying that as this company have done a small run of heads for a parts supplier then maybe they'd be cost effective if anyone / a group was to approach them for a triumph head?
  5. Interesting thread resurrected In the TVR world which is where I come from, this company linked below do a head for the straight six tvr engine sold through Racing Green / TVR Parts Ltd .. it's very small volumes, probably less than 20 units sold so far ? but they must have thought it worthwhile pursuing, which for a business means they thought they'd make money from it which means good value for money for very low volume production. http://www.ultimatep.com/index.asp Reading the associated website blurb suggests the owner Simon Armstrong is a pretty clever cookie! Might be worth a look for someone with determination and deeper pockets than me.
  6. obe

    EFI issue. K3.

    46mm if that's what they are is good for about 50hp/cylinder so pretty big! The good news about rescaling your initial throttle percentages is that the ecu makes a calculation based on interpolation so when you rescale the throttle sites you won't completely mess up the mapping you've already done, it will work out the new numbers to put in the cells for you.. it won't be a perfect correlation against the new percentage sites because the interpolation is linear and the change of airflow is essentially a log (or inverse log?) function, but it will be somewhere close and means you're not starting from scratch again the fact the interpolation is linear is also a very good reason to stack your off-idle cells close together for best relationship of fuel v airflow.
  7. obe

    EFI issue. K3.

    I notice you've got your throttle percentages quite large per load site, presumably you have small butterflies? If you find you're driving around alot on cruise between throttle 0 and 1 you can usefully reduce the initial percentages to say 2 percent between load sites for the first 3 or 4 throttle sites and gain a lot of extra resolution (if your throttle butterflies need it). You have the rpm sites at 200rpm initially, that's good for refining the map over small rpm changes, but your speed integer of 32 means that the adaption only occurs whilst the crosshair cursor is in the middle of a cell. This means you probably only have something like a 50rpm spread over which adaption is being learned, and the rpm scatter is likely to take the rpm outside those learning limits so set the speed_int to 127 and that will allow learning over the full width of each cell. You can turning on adaption for idle too rather than leaving it closed loop / not learning. Set the load_int to say 80 which allows learning though most of the throttle travel in any given cell, but not at the edges of the cell (I suggest this because f your 5 percent load site increments, that's quite a wide spread, but I'm used to large butterflies with a high rate of change of airflow per degree). Set the target afr to 0.5 to begin with, that means that if the afr reached during fuel trimming is 0.5afr rich OR weak of the target then an adaption number will be stored. This will give a coarse learned fuel map .. you can reduce that later as you refine your map based on the adaptions learned. I send cars out with the AFR target at 0.1 afr once the fuel map is nicely refined. I also set the after start delay to 60 seconds on the basis I dont want any adaptions occuring until I know the engine has stabilised after a startup. Hot fuel being purged from the engine bay and other heat soak and after-start fuelling stuff can influence the learned values so you want adaption to only take place when you know the engine bay and fuel system has had cool fuel and air through it after a hot restart. Similarly if your normal engine run temp is something like 80deg you can stop adaption until say 75deg, that way you don't have the influence of any warmup trimming taking place. You still have 7 percent of injection correction in your coolant table at 60 degrees, so best plan is to wait until youre close to thermostat temp before allowing adaption. Any fuelling changes that need to be made to the warm up tables then only occur in open loop operation and can't influence the adaptive table. There's a lot to look at, including the lambda signal smoothing and position of the lambda which influence what gain you might choose to use. If you're ever on your way south near sheffield let me know and I can talk you through some thing face to face which is always easier than trying to explain stuff on the net! Happy tuning though .. the emerald is quite intuitive really once you get to grips with it.
  8. obe

    EFI issue. K3.

    As regards your wish to run MAP sensing for load .. that's fine, but TPS is a far faster way to map the ecu esepcially if you want to visit a dyno and pay for mapping hours. As mentioned previously, every time you revisit a particular throttle position and rpm site the airflow is the same as the last time you visited it. Smilarly every time you revisit a particular manifold vacuum and rpm site the airflow is the same as last time you visited it. If it wasn't you'd never be able to map the fuel or ignition tables at all, the values required in each cell would be different if the "load" varied every time you revisited a particular cell. In actual fact the "load" is exactly the same each time you revisit any particular cell in the map. Are you UK based?
  9. obe

    EFI issue. K3.

    Reducing your rpm slots to 200rpm is a good move especially at say sub 3000rpm, but that will slow down your adaptive table learning unless you increase the allowed load site threshold. I suggest you set the load and rpm allowable threshold to 127 which will allow learning whilst you're anywhere inside a given load cell and give you a fair but coarsely adapted map, but at least will get you lots of cells populated in the adaptive table Also allow a wide afr tolerance, say 0.5afr. The way the emerald learns it's values is the ecu has to trim the mixture and then only when the mixture is within the allowed afr range will a value be learned. This means that you need to spend lots of time at any one rpm/throttle site for it to learn anything useful even with the allowable limits set very wide. Once you've got a fuel map that's trimmed up over as many sites as possible you can then reduce the afr allowed range to say 0.1afr, and the loadcell threshold to say 32 and then the ecu will refine your coarse map even further.
  10. obe

    EFI issue. K3.

    Point taken about time spent at any one load site .. especially important if you hold a load site for a length of time and the resulting chamber temperature increase brings about pinking which you'd previously missed if you were travelling through the load sites quickly. Fair point well made. On the dyno of course it's very easy to hold a load site and dial in the fuel and ignition required .. one point I often see with regards to timing (especially distributors) is to hold the car uphill and swing the dizzy until it pinks, then retard slightly. This is likely to put you too far advanced even if you retard it slightly from the point of pinking. By the time the engine is pinking you're already well past the minimum best timing to make the power. In the absence of any test equipment though it's likely the best method for many people and has been used for decades for setting up timing of course
  11. obe

    EFI issue. K3.

    Hi all first post so bear with me on forum etiquette etc please You don't need MAP sensor to get the engine running properly, TPS is an excellent way to map the car and far quicker and easier to get a very good base map on TPS than using a MAP sensor. You do need a good throttle spindle to TPS sensor mechanism though, any play in the system will result in airflow changes that aren't picked up as a throttle signal change at the ECU. This is a particular issue at small throttle positions where rate of change of airflow is at its greatest. I have a dislike for innovate widebands, too unreliable. My preference is for AEM .. 180 pounds off ebay and so reliable actually map using one on my dyno. On the subject of load, whenever you visit any combination of throttle angle v revs the airflow is the same as the last time you visited it (atmospheric conditions excepted) , whether you're going uphill or downhill is irrelevant . Hello to all
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