stevefoster Posted May 18, 2001 Share Posted May 18, 2001 Thought I'd let you know how it went.... The Wed evening before the Thurs drive up to Scotland I went to Webcon in Sunbury to get the ECU remapped. They put a Formula Vauxhall map in it that eliminated the pinking problem entirely. Apparently I have a higher compression engine?! I am now running 38 mm Chokes on 45's on the VXC. Swapped down from 40 mm chokes and ?standard? Caterham jetting. The Caterham set was giving me average of 20-22 mpg. The usual F16 mains Can't remember the air correctors. I drove up to Scotland on the 55F8 idle jets that were giving a some hesitancy and lumpiness in lower rev ranges. On the motorway at a constant 70 (true speed) she returned at best 33 to the gallon. I could not believe it! Even the many blatty fast runs returned 28, 29 to the gallon. Half way throught the 5 day trip I swapped the Idle jets to 50F9 and retuned. This gave much better low throttle response but I never saw better than 27mpg. The worst mpg came on the twisties when I was really giving it stick and that was 26mpg. The whole trip of 10 fill ups, recorded an average of 27.1 mpg. A happy compromise. You can feel the amount of throttle needed to continue forward motion is much lighter than before. At 5000 miles a year I will save the cost of the mapping and rechoke / jetting in a couple of years in petrol alone! Of course the improvement in fun of driving is more difficult to put a price on. Link to comment Share on other sites More sharing options...
Tony Posted May 18, 2001 Share Posted May 18, 2001 Steve Apologies - I've obviously come in late on this topic, but... I've got Weber Alpha mapped ignition on my 1600 x-flow (with twin 40DCOE's) and I've never ever seen better than 26-7mpg, even when tootling. Getting serious drops it to less than 20mpg [:-(]. Which engine do you have? Link to comment Share on other sites More sharing options...
stevefoster Posted May 18, 2001 Author Share Posted May 18, 2001 2.0L 16V VXC on twin 45's /Steve Link to comment Share on other sites More sharing options...
olij Posted May 18, 2001 Share Posted May 18, 2001 Tony, out of interest what MPG were you getting before you had the engine mapped? Oli Link to comment Share on other sites More sharing options...
stevefoster Posted May 19, 2001 Author Share Posted May 19, 2001 Before the rejet 20mpg was about the best it would do. After rejet about 22 mpg. After mapping 27 on Haggis. 50 miles comes up with well over 1/4 tank. Thats as far as I have done on the work runs so far since Haggis. Link to comment Share on other sites More sharing options...
Tony Posted May 21, 2001 Share Posted May 21, 2001 Oli I used to get around 22-24mpg tootling, 18mpg or so when having fun, so fitting of 3D hasn't resulted in a substantial fuel benefit. Major improvement to smoothness, power and 'feel' though... Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now