Hi Woolfi, Des Hammill book on its way. To read each Carburettor via a Lambda am I right to assume 4 x Lambda's are required 1 x in each in each downpipe? I guess it would then be Multiple gauges or some sort of switching system.Woolfi wrote: ↑Sat Nov 14, 2020 9:41 pmHello Colin,
"I find your comments very enlightening as I was also considering injection, however straight pipes to the airbox and possibly SU's or a setup on a rolling road for the Strombergs looks like a better option all being considered."
If you mount two pipes with a bigger diamter to the airfilterboxes and you make a hole of 45 mm longline in the two front silencers, the mixture is becomming weaker. Unfortunately too weak.
Can can't cure this with "turning srews" at the carb. You need 4 carb needles, which are less thick in the upper area (thin end of needle), the the small round cleft between the carb-needle and the jet is a very little bit bigger. Through thius bigger cleft, more gas can flow.
You need to measure the mixture, that you can see, if it is okay. You have to know, how much is okay. There is a book from Des Hammill "Tuning the SU-Cabrs). Buy thuis book !!! In this book he has a very clear desciption, how to change to shape of the needle, if you prepare a motor with different air-filters and different exhaust system for racing.
To measure the mixture, you have to mount a wide-band lambda measuring system into the car. I bought one from 'innovate' for roundabout 170 pound. You can drive with the car and can see JUST in time, how the mixture is. Depending of the position of the lambda-"Sonde' in the exhaust system, you can check one carb or two carbs of one side of the motor.
Invest this money and effort. The result for my car was, that in the rev range between 2000 und 4000 rpm, the motors with carbs was much stronger than the same motor of a friends car with EFI. I have done this test two times with the same result. 5,3 Vs 5,3 and later 6,0 vs 6,0.
If you don't want to shape needles with 1000er sanding paper, you can mount 4 SU Carbs. For SU carbs you maybe can find some needles which will "fit" and produce in different rev ranges and different throttle positions the correct mixture. S U offers 700 different needles.
I have produces 4 needles by myself It was a lot of work. But at the end I had a good result.
If you do all this correct, you never will miss EFI on your V12. Together with the 2,88 plus the long Getrag my 6,0 L HE car has a gas consumption of roundabout 19 mpg when cruising. Again no need for EFI.
Regards Wolfgang Gatza
My E is purely a road car so I am just looking for better efficiency and cleaner running as I am aware in standard trim although a joy to drive the V12 is considerably compromised in the breathing department.
I would be happy to try re shaping the needles and I have all grades of abrasive paper down to 1600#, is it a case of needle in the Lathe or a small drill (Dremel) in the vice? and is the method via trial and error until the Lambda reading is good?