6ixB58 wrote

Hey OP, Now that PTF released the Flex Fuel Kit for engine bay where it fits closer, would you have considered their kit or still have gone with dorch?

AshtonPJT wrote

I would do the ptf kit, better build quality.

abbike18 wrote

Got my Dorch kit today and installed it. Took me exactly an hour and 15 min to install. First try with BMW multi map and everything worked great. Pulled one log as well at E30 to compare to the non-multimap E30.

Kit was well done and instructions were great. The instructions make it look like there are more steps than there really are. They are just very detailed and don't leave anything out. The only barrier to this kit is comfort with repining connectors. If you've ever done this before the kit was a breeze. Couple of pictures attached.

I understand that the PTF kit is easier to install, but I had a very specific reason for going with the Dorch kit. The whole point of the kit is that you don't have to change your behavior or worry about what you put in your tank. My issue with the PTF kit is that when the sensor is on the gas tank, you are forgetting about all the fuel in the low pressure line that still has to be burned before the fuel that the sensor just read actually gets to the cylinders.

This means if you have a high ethanol empty tank and fill with pump gas, your engine will be running a pump gas tune with high ethanol gas (you'll run lean) until you get through the gas in the line. If you go from an empty pump gas tank to high ethanol, you'll be running way too aggressively while you burn up the pump gas in the line.

I did a few calculations, and assuming the gas line is 12 ft long (from PTF sensor to injector) and has a diameter of 8mm..theres actually 0.05gal of gas in the lines. At 20mpg that's a mile of driving or at a reasonable idling rate that's 11.6 min of idling. I don't know about you, but I wouldn't want to drive a mile with a E30 tune while I'm on pump 91...And even if you are ok with doing that what happens if someone else fills up your car? Do you want to explain to them to baby the car for approximately a mile after a fill up?

If you take the Dorch approach and move the sensor as close as possible to the HPFP, theres maybe 1.5 feet of total line between the sensor and the injectors. that's 0.12 miles or 1.5min of idling to burn that up. That's basically pulling out of the gas station and that's it. That feels a lot more reasonable to me.

But wait! The PTF kit has a parallel flow adaptor so that the flex fuel sensor doesn't impede any fuel flow. My calculations show this is not an issue. The TU pump pumps 1.178 cc/rev. At 7k rpm that's 495 liters per hour. That causes a 0.6 psi drop across the sensor in an 80psi system - less than 1%. Not a big deal.

Pressure drop source:
http://foreinnovations.blogspot.com/2014/04/restrictive-flex-fuel-sensor.html

Finally some logs before and after. I might do some more...we'll see. I would like to do a 91 comparison.

Log from a regular Stage 2 E30 map:
https://www.bootmod3.net/log?id=6296a646ae729b4203862612

Log from a multi map Stage 2 91 map with flex fuel at E30:
https://www.bootmod3.net/log?id=62d22b30c090c60574d11c6d

Biggest issue now is that theres no way to run a multi map that gives you stage 2+ power when you have ethanol in your tank, but scales it back to stage 2 when you have 91 (for those of us that live in areas with only 91). Need to bug PTF about that.

_ink wrote

Thanks abbike18! I emailed Dorch and they sent me specific the specific X3 instructions with the correct wiring colours... This would have helped alot from the start ..... All sorted now!

SelmirX3 wrote

Hi

Do you have install instruction for X3 I have also problem with the wirring color/pin

abbike18 wrote

Check that out

SelmirX3 wrote

Thanks I will try today

blackops23 wrote

I’m in the process of adding a few things to my wife’s G01. Ordered PTF ECA and dorch 2.5 HPFP. Problem is the PTF ECA does not mate with dorch out of the box. I emailed Dorch and they were very helpful. Told me to take a part the ECA which leaves you with just a continental GM branded ethanol content analyzer. It does have larger ports than the 5/16ths BM3 module so I guess that’s a plus along with it taking up less space. They told me to send in the hose that came with the hpfp and they’ll exchange it for a hose kit for ECA. Essentially 2 smaller hoses in lieu of one long one. This should do the trick. I hope all the BM3 flex fuel multi-map stuff has all the kinks worked out as this thread is pretty old. I’m also adding a pure 850 turbo and upgraded charge pipe. Next on the list will be diff bolts/bushings and driveshaft as that seems to be the weak point when adding some more power.