Jump to content


  • Content count

  • Joined

  • Last visited

About MarcD

  • Rank
    Advanced Member

Profile Information

  • Gender
  • Location
    New Zealand

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. running 4 rib belt. ratio 2.2 : 1 info I have is 16000rpm max continuous, 18500 max short time. 500cc discharge per rev. am now thinking its the inherent design of the old style roots blowers, and no matter what i do its going to be the same. looking at a MP62 / 90 charger or similar to replace it.....
  2. so frequency increases with revs, from 187hz upto 680hz at around 6k rpms Sc-1.m4a
  3. thanks for the offer Davidv, am in Hamilton. I'll give your methodology above a shot, and see how we get on. last night I replaced the pod intake with the stock air filter box, but no luck. I do have a smaller bypass valve, which I might try in case the issue is the openness of the Tial 50mm component. its more a howl than a whine. I'll take a sound file and attach it.
  4. thank you! I have tried the dual throttle body setup (one pre SC and one stock location) and that didnt make a difference. I'm about to take the SC off its so noisy. I'll give this a try. appreciate help
  5. so that didnt work! lol got an airbox from a Ford 2L, ecotech, which has quietened then intake noise considerably. now just the SC whine to go
  6. looking for some words of advice from the team! I have fabricated some brackets and fixed an AMR500 supercharger to cold side of Mazda MX5. Made the throttled volume small, and got it in a nice tight package. Have a bypass working for 100% boost dump at idle, progressively closing around half throttle. all up and running drives well on a really safe tune and I'm working through getting a decent tune into it. (have noted the intake temps rise rapidly under full throttle boost so might add secondary injector to plenum in future, but thats WIP) getting around 6psi boost at WOT which is within the range I was anticipating. However, it whines like crazy which I am told Roots type blowers will do, but they can be quietened down. At some revs its nicely quiet (2800 for example). At 100km/hr in 5th, approx 3200rpm (daily driver) its loud, not unbearable, but will quickly become tiresome! I know a bit about Hermholtz resonators, pressure waves and destructive frequencies, and fortunately the stock MX5 intake has one, so am going to try to incorporate that piece of the intake into the new intake. my questions... are Hermholtz the best solution? are there any other workable solutions (apart from taking off the SC!)? is it best to put the hermholtz before the SC or after? thanks in advance! Marc
  7. MarcD

    Windows tablet power from USB?

    looking good Greg. wish I bit the bullet and got one of those from NL when on sale last weekend! can you alter the VE tables? and also activate / deactivate quick tune using just the touchscreen? how do you input numbers? or is that keyboard requirement? thanks marc
  8. MarcD

    Windows tablet power from USB?

    no, but am watching with interest how you get on with it!!
  9. MarcD

    CLL fuel correction %

    HI Adam is there a way to get mixture map to "add back" the correction that CLL has applied and is registered in the log and then apply to the fuel table? am leaving CLL on as cheap insurance but want to ensure I am as close as possible with the map. thanks Marc
  10. MarcD

    Closed Loop fuel trims

    so I've implemented this. no other changes. initial observations on driving.. through the lambda gauge, not through Link software.. AF ratios settle much quicker, and remain constant. I have idle AF set a little richer to give better idle, I might change this leaner now as it appeared much more stable than previously below 3k rpm, low gears in traffic on neutral throttle there remains an oscillation although reduced in amplitude, but the wavelength has been increased dramatically. previously this would occur every 0.5 secs, now approx every 1.5 sec. I'll check the ecu log when I get the chance and compare. cheers Marc
  11. MarcD

    Closed Loop fuel trims

    I'm experiencing the oscillating adjustment with CLL with an aftermarket Wideband, not a CAN link. I've adjusted map to match your numbers. will upload before journey home from work and see if it improves. worst time for me is in stop go traffic, when lightly on throttle in first gear, crawling along. car starts to jump when CLL turned on with current setup (below). will report back later
  12. MarcD

    mixture map filter

    I use this as well, and have similar to Adam, but in addition I have ECT > 75 C (gotta be at operating temp, and if ECU log, I log anything over 400 rpm so I get cold start, warm up info as well.) Accel fuel < 1% (thinking here is that Accel fuel influences overall AF ratio) Adam - do you tune in Lambda or AF? any reason for one or the other or just preference?
  13. MarcD

    speed signal bounce

    its late here in Hamilton too! 1.61 km / mile so you need to multiply 4000 by 0.621 = 2484 pulses/km thats 248400 pulses @ 100 km/hr 4140 pulses/minute 69 pulses /sec which is a bit different to both my 5.8 and your 178 !!! aarrgh!! its an aluminium disc with 4 magnets imbedded in it. have found some pictures on the web - it might be that I have pushed it jsut a little too close to the spinning disc. I'll check again tomorrow.
  14. MarcD

    speed signal bounce

    https://www.jaycar.com.au/glass-reed-switch-n-o/p/SM1002 I am led to believe it gives 4000 pulses per mile, with equates to 160.9 pulses per 100m if 100 km/h this is 5.8 pulses per sec I think you might be right regarding the ability to handle the signal speed what I can do, tomorrow, is to log DI7 and then produce a time plot... would that help? Thanks Adam, appreciate your input.
  15. MarcD

    speed signal bounce

    mx5 na 1989 1.6 using Link g4+ mx5 has mechanical drive speedo. on the back of the later NA model MX5 speedo is a reed switch that gives an output 4x per rev. all the hardware is there on my 89, just no reed switch. so I got one from jaycar. soldered it in and connected it to DI7. verified it is working. pullup resistor on, active edge rising, calibration 125. however, there is a lot of variation in DI7 output at road speeds above 20 km/h is there anyway to smooth it in real time ? or any ideas on how to eliminate the variation Thanks Marc