Jump to content

All Activity

This stream auto-updates     

  1. Yesterday
  2. Enlarging a hole

    Funny you should say that, I did that to a large drill about two years ago when I wanted to mill a channel in the surface of a metal plate and didn't have either the right tools or time to take it somewhere, it worked well, but never had the nerve to admit to such rough engineering before! Alan
  3. Enlarging a hole

    You got away with it with existing in hand tooling, resourcefulness in the right application for the moment . Sometimes you just have to make do with what you have. A drill can be ground flat bottom like an endmill and can be used carefully to "move" an existing hole going to a larger diameter, carefully being key. Cheers Tim
  4. Trigger Wheel Mounting Vitesse

    Row 1 (top) is full throttle. Row 12 is throttle shut. IIRC the step between 11 and 12 was to address popping and banging on the over-run. I think the reality with the "red zone", especially at the upper reaches of the rpm range is that it either never goes there at all or spends almost no time there. Certainly that map (or one very like it) worked well for many thousands of miles and was only changed because the engine changed. Something else that shows a bit (I think there was a later variant which shows it more strongly or it may be the current map as the new engine is much fussier at idle) is the anti-stall - which is additional advance in the top left corner intended to help pick the revs up if it tries to die. Nick
  5. Trigger Wheel Mounting Vitesse

    Hello John Just create 2 maps one high end of WSM and one racing curve but suspect you wil need a RR session to find the best one! Then you can just switch on the fly if you want (look out F1) Plus you can make lots of maps and just save them and once you have one you think is near just keep trying the others as second map It is different for me I just want a drive able car and good MPG at cruising Roger
  6. Last week
  7. Trigger Wheel Mounting Vitesse

    They are 4 and 3. As apprentices a bit too junior as yet, but No.1 does enjoy "Papa's car", and No.2 likes to hammer in nails! John
  8. Trigger Wheel Mounting Vitesse

    I've plotted Centrifugal (top) and vacuum advance curves, from the workshop manual and from GT's book, which doesn't give any vacuum numbers. But his curves, and he includes several standard as well as this "typical racing curve", which are all quite different from the WSM one, all much, much higher. And the WSM is a range, indicated by thre upright lines. The WSM vacuum curve is difficult to translate, into practice as as well as a chart when it says 3.8 - 6.2 in of mercury - "must start to advance". I have presumed from zero towards the 8 degrees for the next step. All degrees in crank angle.
  9. Trigger Wheel Mounting Vitesse

    Hello John Welcome to the electronic world were most things do not make sense(its all smoke and mirrors!) But when you get your head around it it seems to work! (back to smoke and mirrors) if someone asks how it works use some big words and waffle on a bit until they glaze over then you are off the hook! Roger ps how old are the grandchildren? they would understand if 10 or above!
  10. Trigger Wheel Mounting Vitesse

    Only relative to another pressure, usually atmospheric.
  11. Trigger Wheel Mounting Vitesse

    Hello All I use one of these on Microsquirt PRT 03/04 I found the 2.5 to coarse a calibration they are all 0 to 5v so it is more sensitive. MAP sensor.pdf Roger
  12. Trigger Wheel Mounting Vitesse

    Not positive for MJL but for MS the standard sensor used is an absolute one with a 0 - 250kPa range, measuring from absolute zero (or somewhere near it) so 0kPa is 0, atmospheric at sea level is around 100 kPa and if you have forced induction you can go up to 1.5 Bar of boost before you need to upgrade to the 400kPa sensor. You rarely see less than 25kPa in my experience and that's on the over-run at reasonably high rpm. Idle typically in the 40 - 70 range dependent on how wild your cam is. Nick
  13. Trigger Wheel Mounting Vitesse

    Keep in mind that vacuum is a negative pressure...
  14. Trigger Wheel Mounting Vitesse

    Maybe I'm being pedantic, and it's in the use of words. MAP, "Manifold Absolute Pressure", uses the word "Absolute" so should give the pressure relative to zero. That's what "Absolute Pressure means, just as "Absolute temperature" is relative to absolute zero, -273.15C. If a true vacuum is Zero pressure, then the more closed the throttle, the lower that will be I think what is being measured is "Vacuum"or Relative pressure, below atmospheric. With a wde open throttle this will be low, not much difference from atmospheric, and with a closed throttle it will be high, as the enghine sucks air against resistance. John
  15. Enlarging a hole

    Glad you've done it! Me, I'd have used a die-grinder, with a burr, not a stone. Or, saw cuts radially from existing to desired radius, as many as possible, then a round file. John
  16. Trigger Wheel Mounting Vitesse

    Hello John I think it is the other way around! Low vacuum with open throttle high vacuum low throttle This may explain it? http://www.fastfieros.com/tech/map_sensors_and_how_they_work.htm Roger ps and the scale is reversed on MJL
  17. Enlarging a hole

    Well digging through an old box that probably hasn't been opened in 20+years I found a 19mm drill (well given age of it almost certainly a 3/4") it had a morse taper, but I have various old taper holders, so I just machined a rough looking one round so it would go in the Pillar Drill Chuck, and with everything locked as tight as it would go, I gave it a go, and it worked perfectly as you can see from attached shot. I think it only worked because it was Alloy, if it had been steel I think the tug of the existing hole would have been too strong, but anyway Job Done, maybe not a master piece of engineering, but will do me. You can see why I needed to drill off centre. Alan
  18. Enlarging a hole

    Starrett hole-cutter, with plate clamped to another plate to take the guide drill ??
  19. Trigger Wheel Mounting Vitesse

    Yes but if you look at 70% at 5.5K the advance is still 40 deg, which if I was lifting would be fine, but going back under load that's a lot of advance
  20. Trigger Wheel Mounting Vitesse

    Hello Alan Vacuum drops so ignition is retarded Roger
  21. ZDDP ppm mis-labelling

    As Penrite furnished me with the answer above, quoted by PeterC, immediately without any fudging......I will stay with them. Trust is everything. Iain
  22. Trigger Wheel Mounting Vitesse

    Hello John I just measured length and width 74mm x 45mm(average) added them 119 divide x 2 = 60 approx Which with 0.020"(0.5mm) gives 1.4cc 74mm dia gives 2.15cc a bit crude but probably close enough? Biggest chamber is 42.4cc + gasket (74mm x 0.7mm = 3cc) 45.4 Cylinder is 378.36cc + 45.4 = 423.76 / 45.4 = 9.333 to 1 So skim 2cc off = 0.028(.7mm) = 421.76 / 43.4 = 9.717 to 1 I think? Roger ps I think I will have 0.030" skimmed off I can always open the chambers a touch if necessary? they are within 0.3cc at the moment so will do final balancing when valve seats have been cut to the 3 angle
  23. Trigger Wheel Mounting Vitesse

    there will be low manifold pressure (indicated by small KPa values) when the throttle is closed and high manifold pressure (indicated by large KPa values) when the throttle is open. this is confusing. Manifold pressure will be LOWEST withe the hrottle closed. "Vacuum" - difference between manifold and atmosphere - will be highest behind a closed throttle. Unless the throttle plate blocks the orifice to the line, which it won't. j
  24. Trigger Wheel Mounting Vitesse

    Hello Alan and John If you set it as the MJL instructions. Configuring Normally Aspirated or Forced Induction Check the 'Normally Aspirated' box if that matches your engine type. This setting will scale the load axis for the runtime and logging views to 103KPa maximum. Otherwise, leave the box clear if your engine is turbocharged or supercharged. This will set the maximum scale to 255 KPa (approximately 21 PSI of boost) I do not think you will ever get to the minimum of the map! They say 103KPA which is 30in mercury and the WSM chart shows 20in mercury = 68 KPA I think you edit it in RPM and load bins then you can alter it to reflect what you get?(I think?) ask Nick This one of the maps I used on Spitty This site will do KPA to ins http://www.kylesconverter.com/pressure/kilopascals-to-inches-of-mercury
  25. Enlarging a hole

    Ah about the same price as the milling bit, and with a 19mm shank would easily go in my press chuck, as I also have a couple more 19mm holes to drill in the alloy it might do everything I need. Alan
  26. Trigger Wheel Mounting Vitesse

    Not Sure if you have to calibrate it you have the MAP version? There is nothing in the manual about having to calibrate the internal MAP sensor 5.1 MAP For 3D MAP control, simply connect the MJLJ bulkhead connector to a suitable vacuum point on the engine. A suitable vacuum point is one that gives a good representative indication of average manifold air pressure – take-off from a plenum chamber is best, and from the barrel of single choke on a multiple carburettor set-up is worst. It is recommended that the vacuum installation minimises the chance of moisture entering the MJLJ unit and affecting the on-board MAP sensor. Techniques such as not mounting the MJLJ well below the vacuum take off point and having a “U-bend” between the takeoff point and the MJLJ can help. Once you have connected the vacuum hose to the ECU start the engine. It should now be running with the MJLJ controlling the ignition advance in a 3D MAP mode. Check the timing at idle with a strobe light. It should be the timing set in the map for the idle rpm and measured MAP. Blip the throttle, whilst checking the timing using the Advance gauge in the Configurator. It should be move according to the values set in the map – there will be low manifold pressure (indicated by small KPa values) when the throttle is closed and high manifold pressure (indicated by large KPa values) when the throttle is open.
  27. Enlarging a hole

    I reckon this would be good, may need to borrow a maggiebase though A bit expensive to hire for only a few holes. https://www.ebay.co.uk/itm/ALFRA-ROTABROACH-TYPE-ANNULAR-MAG-DRILL-CUTTER-SHORT-LONG-BROACH/171376827777?hash=item27e6dadd81:m:mttiQBdl3jrDbzQXNx7-L1w He who dies with the most tools wins...
  1. Load more activity