fuel ratios

[Alan L]

Any suggestions as to how to modify the fuel ratios. I am getting 15.5-16 on low throttle, and it hestitates/bogs until boost. Then on boost, down to around 10.5. If I lean it up to 12 for boost, it will be so lean off boost it will barely run.
Wondering about fiddling WUR pressure, or disconnecting the vacuum/boost assit on the WUR.
Seems to me varying the range is quite difficult without affecting the other end?
I know about the electronic WUR - but wonder if there are other options first.
Thx
Alan

[stup]

Yep you will have to adjust the warm control pressure in the wur internally if you have not got a b.leask one,raising the control pressure will lean it out a bit for you and should help stop your rich dive in afr mid-range although you will have to check your still no leaner than 12-12.2 at max revs,the boost enrichment can be adjusted inside there also which will help you get your target afr at max revs..
For idle and light throttle you can adjust afr on top of the metering head..
If you have all adjusted as good as you can and are still getting this rich midrange afr a rpm delay switch for your boost enrichment signal can help.
Around 14 afr at idle and light throttle is a good figure to aim for imho

[DonE]

There is tons of info on this site about adjusting AFR's using the stock WUR and a couple of aftermarket units. Take a couple hours and do a search.

[Alan L]

Thanks - leaving for track right now.
Will have a tweek if I get a chance. I did drop the WUR pressures just after I got the beast - they seemed out of whack with specs - dropped them by about 20 psi to get back into spec range.
This may be the problem.
Alan

[Craig 930 RS]

Track day at 10.5 AFR? Yikes

Yes, search using 'Leask' and 'adjsutable WUR' - lot of BTDT experiences from myself and others -

[Alan L]

Thanks Craig - I have a lot of misses on searches - keep getting notes about not enough words or similar. Will spend some time now - but was a bit of scramble to get the beast running well enough to make track day.
I managed to adjust WUR before first track run. Too far - was running 13-13.5 under boost. Pulled in after two laps.
Hit it near spot on for next run - sitting between 12 -12.5 for rest of day.
The low throttle bit is the problem now - kept richening the idle screw - but still leaning out big time under low throttle - 15.5 - max out at 16.
Makes it very hard to drive off the corners - loosing lots of time. I richened idle to the point where it is idling lumpy too rich - but at race temps it still leans off too much, off boost.
Flames out the back on over- run they say (and some backfiring). Just sad I can't see them too.
What an awesome beast on track - but definitely a challenge to drive - particularly with the bogging down and turbo lag in the corners. Eventually learned to keep the boost up (0-0.1 bar) way early with throttle to drive off corner.
But I'm sure it should be a bit better than this.
Will do some searching. But what a buzz - just doubled my miles in the beast - and most of it under WOT!
Yahoo!.
Alan

[NathanUK]

Maybe you should try the UTCIS WUR.

[Alan L]

Nathan - I have never heard of the UTCIS WUR - what is it?
Alan

[NathanUK]

The released digital wur.

http://forums.pelicanparts.com/showthread.php?t=379783

http://forums.rennlist.com/rennforums/showthread.php?t=422450