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post #107 of (permalink) Old 01-26-2015, 12:41 PM
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I was happy with 150MJ/170AC until I measured the high EGT’s at high cruising speeds. 155MJ/200 AC fixed that but now my WOT mixtures are fat below 5000. They were fat below 4000 before. That costs torque – I know that from the dyno. The torque drops off when the AFR drops below 11. So I want to lean out that area and I decided to block the lowest row of holes in the F34 emulsion tubes. When I went to block these holes I “discovered” that I had already blocked two of them before I got the EGT sensor. Now with all 4 blocked there is no noticeable improvement on the WOT mixture but my cruising temperatures have gone up – the exact opposite of what I was looking for. So I unblocked all 4 holes and now my cruising temperatures are much lower and my high power AFR is a little bit fatter. So the next step is to return to 150MJ/170AC and see if my cruising EGT’s are acceptable. If they are not then I will drill some more low holes in the emulsion tubes. This confirms what John Passini wrote - that emulsion tubes have a small effect at full throttle and a large effect at part throttle.

I had done a 7 to 100 mph rolling start pull up the hill in 21.3 last week. I do not do standing start pulls because I don't want to abuse the clutch. Today I did 17.1 going down the hill. The two way average is 19.2. I figure a good driver could go from zero to 7 mph in 1 second so my 0 to 100 is about 20.2 seconds – 1 second faster than a stock Montreal in the 1973 R&T European test.

Ed Prytherch
79 Spider
76 Suzuki GT500
2011 Jaguar XKR

A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke

Last edited by alfaparticle; 01-26-2015 at 12:50 PM.
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