What sort of retract setting are people using for an e3d Bowden? I used 4mm on my RepRapPro and it worked well but the same settings seem to be giving me trouble printing PLA, specifically; each time I retract the extruder has trouble pushing the filament for a few seconds, often loses a step or a few and then things start to go smooth again until the next retract. Detailed parts with many retracts are unprintable because the hit end is contently starving for filament and it products large gaps.
I know that PLA can expand in the hot end and assume my problem may be related to this, about to try with 1.5mm retracts but, does anyone have experience and possibly tips on using an E3D v5 Bowden?
4mm retracts sounds about right for bowdens. I hear some use 4.5 or even 5mm, but that gets even harder. I’ve heard some say to use 3.5mm. E3D is known to be a pain for Bowden & PLA, especially the v5. I haven’t heard if v6 is a big improvement for that setup.
1.75
Cheers for the confirmation Jeff 
I use 4.5 for PLA and abs. Make sure you have seasoned the heat break for PLA
@Jarred_Baines your on the right track and have done your research.
My experience, breakdown make sure that heatbreak to nozzle surface is perfect, season, lower amount of retract for PLA by 1-.25 (least amount of retract possible) … Then switch to direct drive HAHA JJ.
Add hop, and then crank up the travel speed 
That lets me get away with 2mm retraction on my big bowden, with minimal stringing.
With hop (or z-lift) just make sure that your Z max speed is just as high as your X-Y max.
Also minimize retractions in general in the slicer settings.
With a v6 I have mine set to 1mm at 100mm/s, but my bowden tube is a fairly short 30cm. I have problems with jamming if I go much above 3mm, which I suspect is from the hot PLA sticking to the “cold” heat break. Also, I’ve recently started drying my PLA with very positive results. It’s less sticky and stringy when dry.