Mopar Muscle Association UK

For those with wideband, what are your preferred numbers at WOT and idle?
I have 13.2ish at hot idle in gear. Couldn't get to WOT more than one very short blast and the car felt rich, I think I saw 10 come up on the guage.

For a street car, i would have it a little leaner at low rpm for better fuel consumption but high 12's low 13's for wot.

Thanks Mick, I haven't tuned the carb since the head change, but I now have something to aim for.

Could you point me in the direction to 'wideband'. Im assuming its some sort of tuning gizmo?

The carb on the Road Runner is set up pretty rich across the range. I've tried leaning it off and drivability suffered. It idles around 12.5, any leaner and I get a lean spot just off idle driving in traffic. Cruise is around 13/13.5, again any leaner and it feels underpowered and hesitates if I roll into the throttle. WOT it's set around 11/11.5, this is what it likes and it's slower on the strip if I lean it off. I could even feel the difference at WOT.
I spent many hours tuning the carb over a period of a few months and this is where I ended up. Once the car is warm it feels like fuel injection and is a pleasure to drive. Don't listen to people who tell you to aim for 14.7, just find out what the engine likes.

Thanks Mick, appreciate the detail. Not worried about 14.7 I'll leave that to fuel injected cars.

Bryan, a wideband allows for accurate fuel/air readings from you exhaust. The gauge feeds back live info telling whether you are lean/rich at different throttle settings. Very useful for tuning without guessing. You can also record readings and play back through lap top etc if you want.

http://www.aemelectronics.com/?q=produc ... -afr-gauge

Mick70RR wrote:The carb on the Road Runner is set up pretty rich across the range. I've tried leaning it off and drivability suffered. It idles around 12.5, any leaner and I get a lean spot just off idle driving in traffic. Cruise is around 13/13.5, again any leaner and it feels underpowered and hesitates if I roll into the throttle. WOT it's set around 11/11.5, this is what it likes and it's slower on the strip if I lean it off. I could even feel the difference at WOT.
I spent many hours tuning the carb over a period of a few months and this is where I ended up. Once the car is warm it feels like fuel injection and is a pleasure to drive. Don't listen to people who tell you to aim for 14.7, just find out what the engine likes.

Yeah, i think i would agree with that, every car is different and you've used it on the road a lot, whereas i just use it at the track, where i think a plug check can tell you more personally.
Mick

Bryan wrote:Could you point me in the direction to 'wideband'. Im assuming its some sort of tuning gizmo?

guage that shows fule air ratio based on a probe/ lambda senser in the exhaust.

19 mm metric bung (wheel nut off a rover) welded above the middle of the header pipe wall at the point of merge (needs to face the senser down a few degrees to stop water vapour collecting and running in)

bolt in a wide band lambda sensor (compression washer like a spark plug) ( heated 4 wire sensor)

run power and cables to guage

watch the red orange and green lights
and read off lamda or fuel air ratio readings

AEM UEGO on ebay produce a competent but plastic-y gauge sized like your oil pressure guage with decent bosch lambda sensor. there are many more expensive and better set ups but value for money and ease of use counts as well.

Dave

Thank you lads. I'll check out ebay for one.

Got mine running better now. Adjusted carb and now seeing high13's even 14 at idle.
However, WOT is seeing 11s which I reckon is a bit rich. Does feel a bit wooly when pressing to the floor.

Mine likes 13-13.5 cruise, 14 idle. Not sure WOT, I've not checked for a while. I know it's running great with no hesitiation anywhere, and it's returning 16 mpg

Thats what I aim for Paul. Don`t think I quite manage 16 mpg though, thats quite impressive

Ok , my initial road test figs. Rich at idle 11.5-12.5, once up and cruising and getting into part throttle it runs really smooth and picks up well showing mid 13s. However, on WOT it show 10-11 and I'm aware of MickRR view that his car likes that. Mine does feel a bit too fat and this shows if I jump on the throttle for WOT.
Think I'll down size the main jets and see how the car responds.
If I use progressive acceleration rather than mashing it the car reposed well with no surges, hiccups or hesitation so I'm in the right direction.
Used my 670 Holley VS for tests

Liking this wideband lark. My Holley 670 never idles properly , too rich and seemed to have lags and bogs etc. I was always guessing the tune.
An hour spent tuning with the wideband and I have 14s at idle and reduced WOT to around 12/11s.
Just baselines the carbs, re-set the floats and changed the jets down a size and it runs great and shows all the right numbers.
Well worth fitting that wideband set up

MilesnMiles wrote:Liking this wideband lark. My Holley 670 never idles properly , too rich and seemed to have lags and bogs etc. I was always guessing the tune.
An hour spent tuning with the wideband and I have 14s at idle and reduced WOT to around 12/11s.
Just baselines the carbs, re-set the floats and changed the jets down a size and it runs great and shows all the right numbers.
Well worth fitting that wideband set up

Excellent Miles