Jump to content

Accuspark Stealth Blacbox


Thrashed

Recommended Posts

Hi all

 

I am after a bit of advice. I have bought a accuspark stealth blackbox system. The system is just a 2d electronic ignition system. It came with a new dizzy which is locked out, but still has the vacuum advance.

 

The question I have is at the moment my dizzy does not have a vacuum advance. I have the zx6r bike carbs and can not find a vacuum take off from the carbs? I have googled and appears they do not have one?

 

The second bit is if I add a vacuum take off to the manifold, where is the best place to take this off? I have read different opinions on this, but some suggest you can just tap into one of the manifold runs with an M6 take off, some suggest a take off all 4 manifold runs into a plenum tube/ box to avoid pulsing.

 

Which is best and for what reason?

 

Also the system I currently have has the motocraft ignition amplifier. Do I need to remove this or do I just wire it up as per the accuspark instructions and leave the amplifier in place. I think I need to remove the amplifier?

 

Thanks guys

Link to comment
Share on other sites

Vac advance is an economy function on traditional ignition systems.

A 2D map with engine speed verses throttle opening does the same job in the electronics.

If the distributor is truely locked out then the vac will do nothing.

Link to comment
Share on other sites

My best guess as to why it is fitted is that the disy is a standard item from an old design engine that has been modified by locking everything out.

Leaving the vac advance mechanism in is simpler than making a special bit to keep the crud out.

Edited by IanS
Link to comment
Share on other sites

The black box is a 2d ignition map module. It will adjust ignition advance according to engine speed. It does the same job as the bob weights in a conventional dizzy, and it it is these weights which have been locked.

The addition of a vacuum advance module gives you a basic 3D ignition map to adjust advance according to engine load. It will increase advance at modest throttle openings and improve economy and drivability whatever type of carb you use. This feature is included in the Accuspark dizzy.

Vacuum take of would be best taken from each carb to a plenum to give constant and smooth vacuum but it's your choice whether want to go this far. If you only want a 2D map then don't connect up the vacuum module.

 

Cheers, Graham

  • Like 1
Link to comment
Share on other sites

Accuspark is not purely intended for performance cars. More for classics to replace less reliable points systems without messing up the OE look of the engine bay. Retaining the vacuum advance/retard also retains OE look and a little of the original cars character.

 

Nigel

Link to comment
Share on other sites

Guest old_timbo

If you are running high octane fuel on the road, a vac advance makes a lot of difference. The high octane fuel burns slowly / poorly especially at low engine speeds, at small throttle openings and lean mixtures. So you need a lot of extra advance to keep the emissions down (important at MOT time) and prevent combustion in the exhaust (banging and poping etc). It also smoothes pick-up from closed throttle.

I measured a standard Bosch dizzy for a Pinto and the vac advance can give another 20 degrees. So if your static advance at idle is 8 -12 degrees, with the vac connected you could have 20+ degrees at idle depending on how much vacuum the engine is pulling.

With my Megasquirt 3d map I found that 24 degrees of advance gave me the best idle using Shell V-Power, but with regular unleaded, which burns faster, it was much less fussy.

Link to comment
Share on other sites

Guest old_timbo

I don't think the plenum or pipe size is critical. However on the single pipe back from the plenum to the advance you can try different size restrictors to damp pressure pulses down. I think I ended up drilling a 1mm hole through the centre of a short length of small dia. studding which I fitted into the vac pipe.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...