Hi,

trying to plan out my bike carb build for my 6n to crack on with once I’ve replaced the sills. 
I am wondering whether I’ll be able to run carbs with my standard ecu (AEX) Leaving all the sensors in place, and moving the map sensor (I think these use a map sensor?) to the new manifold on its own balanced takeoff.
I’d fuel using a t piece and probably have it remapped If necessary  and the carbs tuned.

Reason for wanting to do this being that I REALLY hate wiring, and really love spending less money on things 🙂

 

thanks 

Why would you want to keep the MAP/IAT sensor ? as it's only there to modify the injector pulses and would serve zero purpose with bike carbs

It was my understanding that the MAP would give me ignition advance, Is this not the case then?

If my experience with twin40 carbs conversion and Bosch Dignition is anything to go by, the advance driven off the MAP sensor to standard ECU won't give enough ignition advance

at most points on the load curve.

 

So you'll need to factor in remapping ignition timing anyway. You might well be able to reuse a MAP sensor with Speeduino or Megajolt or similar.  I strongly recommend 

a snubber in the line to reduce the pulse effect at the balance tube. 

https://www.dellorto.co.uk/shop/vw-carburettor-kits-parts/vw-aircooled-manifolds-linkages-parts/other-parts-vw-aircooled-manifolds-linkages-parts/anti-pulse-valve-vacuum/

 

 

 

 

 

 

 

 

36 minutes ago, dvderlm said:

If my experience with twin40 carbs conversion and Bosch Dignition is anything to go by, the advance driven off the MAP sensor to standard ECU won't give enough ignition advance

at most points on the load curve.

 

So you'll need to factor in remapping ignition timing anyway. You might well be able to reuse a MAP sensor with Speeduino or Megajolt or similar.  I strongly recommend 

a snubber in the line to reduce the pulse effect at the balance tube. 

https://www.dellorto.co.uk/shop/vw-carburettor-kits-parts/vw-aircooled-manifolds-linkages-parts/other-parts-vw-aircooled-manifolds-linkages-parts/anti-pulse-valve-vacuum/

 

 

 

 

 

 

 

 

Cheers that’s food for Thought. Hadn’t  heard of Speeduino before, sure I’ve got an mega board lying around somewhere. An ITB setup might not be as far fetched as I thought 😎 

do people normally use stock injectors etc for that or would they be going with the injection off the bike?

Bike injectors should have the capacity, smaller engine spinning twice as fast.

Only the duty-cycle would be different.

If used bike ITB have injectors fitted and working (from crashed bike say) I'd use them. 

 

(that said, I am a carbs guy, so take anything I write about injection as speculation). 

On 20/08/2020 at 08:36, dvderlm said:

Bike injectors should have the capacity, smaller engine spinning twice as fast.

Only the duty-cycle would be different.

If used bike ITB have injectors fitted and working (from crashed bike say) I'd use them. 

 

(that said, I am a carbs guy, so take anything I write about injection as speculation). 

Just had a thought; my engine uses a hall sensor anyway, so should it be possible to run carbs and have the right (or at least some) spark advance etc Leaving everything in place? 
 

Seems to be really hard to find any info on ignition for the 8v 6ns. Loads about the valvers But I get that’s due to their not using a distributor (I think lol).

Ive seen people saying 8vs are “the easiest” to convert to carbs  but they never say why 🙄

mk2 1986-90 ignition amp, loom and connect to your Hall sender. see the FAQ on bike carbs

On 07/09/2020 at 06:04, dvderlm said:

mk2 1986-90 ignition amp, loom and connect to your Hall sender. see the FAQ on bike carbs

Bostin, would that be the tci amp then rather than the vacuum setup? 
what happens to the ecu when all that side of it is disconnected, will it still run the fuel pump & clocks etc? I take it the immobiliser will just do nothing as it’s no longer running the ignition? Cheers

yes tci amp. Does start, dwell and rev dependent advance.

 

Clocks are monitoring not controlling, so ignition output from ECU is just disconnected, but sensors remain for all the dials like temp and oil pressure. 

 

Rev counter is probably a black/red lead on coil(guess), but I think the FAQ covers that.

https://www.clubpolo.co.uk/forum/55-faq/