Exhaust popping on overun

[bullstarz]

I have a PLX sensor (https://www.plxdevices.com/PLX-Wideb...uges-s/125.htm ) just so I can see what’s going on with the gauge, then an AEM (https://www.aemelectronics.com/produ...afr-controller) for the ECU. You can get any system, it doesn’t have to be one of the top one, as they are not being used as a reference to fuelling real-time. They will still set you back a min of £150. Well worth it some do Bluetooth as well.

[trunt]

I have been looking at these, thought it just need to put a boss on each of my cars and I can then move the kit form car to car to "set them up" then remove and screw in a blanking plug.

Roger

Yes that would work, just needs a clean 12v and a ground, I put a relay on mine so that it was not fed by the “dirty” ignition line. I thought about putting a plug in both down pipes but in the end felt it was pointless.

Being carbs the numbers wonder a little, but you can see what’s going on. Mine sits at about 15 on cruise, 16 would be nicer, and 12.5 -13 on accelerating, 11.5- 12 would be the ideal but even putting 40 wt oil in the dash pots didn’t change that much . strange. But it’s not leaning out so all is well.

[marshman]

Yes that would work, just needs a clean 12v and a ground, I put a relay on mine so that it was not fed by the “dirty” ignition line. I thought about putting a plug in both down pipes but in the end felt it was pointless.

Being carbs the numbers wonder a little, but you can see what’s going on. Mine sits at about 15 on cruise, 16 would be nicer, and 12.5 -13 on accelerating, 11.5- 12 would be the ideal but even putting 40 wt oil in the dash pots didn’t change that much . strange. But it’s not leaning out so all is well.

Thanks. Running lean whilst on long runs "cruising" down the motorway is my main concern. All the home tuning you can do tends to be at idle / no load. Rolling roads are costly - this could be a good compromise - especially as I said I can use it on several cars. Just need to work out how you determine which bit of the metering needle is "being" used at various times - might drill a couple of holes in the bonnet and put a couple of graduated sticks on top of the pistons Life was so much easier with leaded fuel when you could see the change in colour of the spark pugs and exhaust tail pipe.

Probably wasting my time, I have lived without knowing the AFR for the last 40 years, but it is something else to play with and put on the shelf in the man cave

[trunt]

Thanks. Running lean whilst on long runs "cruising" down the motorway is my main concern. All the home tuning you can do tends to be at idle / no load. Rolling roads are costly - this could be a good compromise - especially as I said I can use it on several cars. Just need to work out how you determine which bit of the metering needle is "being" used at various times - might drill a couple of holes in the bonnet and put a couple of graduated sticks on top of the pistons Life was so much easier with leaded fuel when you could see the change in colour of the spark pugs and exhaust tail pipe.

Been there- done that..

https://www.terryhunt.co.uk/tech/picsc/pics.htm

https://www.terryhunt.co.uk/tech/picsb/pics.htm

My MIni turbo project needed to have the right mixture or the pistons snapped lands.. only did that once or twice! Of course a Mini is much easier with the single carb, plus I had the bonnet on quick release hinges so it came off easily..

You will definitely see the cruise mixture, I was quite surprised how good it was, not worth messing with IMHO

[KOY 23]

Anyone who sells or changes carbs should have an AFR meter as it’s the most reliable way of seeing what’s happening in the engine. I bought replacement carb and was initially happy with it. A fellow soc member suggested that I fit an AFR meter to see if mine was running as weak as his. I did and found it was running way too weak. In hindsight I should have returned the kit and replaced the Strombergs rather then spend more money on rejetting it and rolling road sessions.