langa

There is lots of good information here and I have spent a considerable amount of time reading various posts on E85 conversions and fuel system setups. Thank you to all you knowledgeable folk who are willing to write up your experiences.

I have a very tidy S5 turbo daily driver that I am looking to do some mild modifications to.
I don’t want to go crazy with after-market parts where I don’t need to and I don’t have a particular power goal in mind. Just after a nice street car that will be reliable.

It’s currently running a freshly rebuilt, street ported but otherwise stock, S5 engine with an upgraded (Bosch) fuel pump and a Haltech PS1000. Fuel pump wiring has been upgraded. I’m having issues with a stock injector leaking after the car is shutoff, flooding the front rotor when one goes to start it up after it’s been sitting for a couple of hours. Also the poor little stock HT18-2S quickly runs out of puff as the revs increase, so it’s time to upgrade.

Here is what I have in mind:

• Walbro F90000267 E85 fuel pump PWM controlled by ECU
• Gates E85 (submersible, 100psi) EFI hose to replace all rubber fuel hoses
• Stock send and return hard lines
• Bosch E85 compatible 5micron filter
• ID1300 primary and ID1700 secondary injectors
• Stock fuel rails and FPR
• Honeywell fuel pressure sender
• Flex fuel sensor
• BW EFR7670 IWG (eventually)

Pretty sure, after all the reading and numbers I have done, it should work.
I need max 6000cc/min of fuel pump to satisfy the injectors, not that they will ever see 100% duty.
6000cc/min == 360l/hr
If, for example, it’s possible to run 20psi of boost on E85 with this injector combo, then the fuel pressure will need to be base pressure + 20psi == 54-59psi with stock fpr. This still gives me ~15psi of head room for pressure loss through the stock 5/16 lines and fuel filter before the relief valve in the fuel pump opens. At 13.5v the Walbro still flows 355l/hr at 70psi, at least on paper. From what I can gather, the pressure drop through the 5/16 hard lines should be less than 10psi at this flow rate. I’m an electronics engineer, not a mechanical, so fluid dynamics is not my strong point.

By using PWM control of the fuel pump, the larger pump won’t overwhelm the stock FPR at idle or cruise, my concern is at the other end. Any idea what the max pressure the stock FPR can handle from the pump before the regulator can’t hold pressure any more? Is it even relevant? I’m not too sure on how a rising rate FPR works, I assume the boost pressure applied to the FPR assists the spring/diaphragm in holding the bypass closed, or vice-versa in vacuum.

I’m happy to be told I’m wasting my time with the stock lines/rails/fpr, I’m going for simplicity not cost savings.

Cheers.

pzr2

iTrader: (3)

Ok... I'm quite new to the E85 scene as well, so I'll just supplant the info I've dug up to what you have and wait for someone more experienced to chime in (it's been a while, no takers?)

Anyhow, for the first item, have you considered whether the fueling demands match the turbo? The EFR7670 will do 64 lbs/min (albeit with a lot more boost than most people ask for), so assuming you use Howard's fuel calcs corrected for E85 at 11:1 AFRs and 85% injector duty cycle, which should be a bit overkill:

64/11*1.352/6.35*3785.41*1.41 = 6,612 cc/min total injector flow. Running 43.5psi, the IDs flow 1340cc/min and 1725cc/min respectively, should equate to 6130cc/min total. Which is a little short, but easily remedied by additional fuel pressure.

Note that at that amount of flow, you'd be aiming for 64*14.471/1.92 = 482 WHP. You're probably looking at less from other practical limitations such as knock, IATs, etc. My terrible memory is offering a rough estimate that people running the 7670 usually see 400 WHP at 15-20psi, but again, this is entirely dependent on many other factors, chief among which is the boost you're running.

That fuel pump is going to be the same one I'm running, although I'm likely running 2 pumps. It should serve you well, although do note that the outlet is a 3/8" barb, not the 5/16" as is the stock FC pump, or basically any other 38mm body fuel pump. You'll have to get up to some adaptation trickery if you're sticking to the stock sender unit, or you can just use a bulkhead fitting. You may as well, since you'll likely be upgrading the fuel pump wiring as well. The pump is thirsty! It has a maximum draw of 22 Amps, and it'll get closer to it as you push the pump to its specified limitations.

If you think you're going to be running a pump at the ragged edge of its rating, you really should be investing in fuel lines. A boost-a-pump would be more of a band-aid that only supplants a bit of extra flow out of the pumps, and running dual pumps will still see that extra fuel heating both solutions provide. That being said, in the spirit of simplicity, making new hard lines under the car will be a real pain in the rear, especially if you're hand-straightening it.

I'd ditch the stock fuel pressure regulator as well. The regulators are tiny and can't bypass enough fuel once you start upgrading pumps. I don't think you're looking at an issue with the regulator not holding pressure, but in that it can't release it. They tend to be overwhelmed by a Walbro 255, so there's no way in hell it's going to maintain a steady pressure with the 450 behind it. You may as well change your fuel rails too. It'll make the FPR switch a little easier. If your pressure sender is 1/8" NPT, the FPR will also make plumbing easier since they almost always have an extra 1/8" port on them.

The whole constant rate, rising rate fuel pressure issue is a matter of preference. Ask your tuner (by the way, what EMS do you plan on running?) what he/she prefers.

As for the submersible Gates hose, I'm assuming you're talking about the P/N 27093 hose? The idea behind a submersible hose is that it's resistant to degradation on the outside as well as the inner walls. I don't see the point in specifying submersible hose throughout the whole system, unless you can't find E85 hose that isn't submersible. I'd just use it in the tank. Also, Gates, for whatever reason, is horrible at actually sending you foot-long lengths of hose as advertised. The "foot-long" hose I was shipped ended up being 10 inches.

I've never heard of this Bosch filter, but so long as it's compatible with the E85, go ahead. Be mindful that you may have to replace this filter early on. E85 is notorious for stripping the gunk out of a fuel tank and sending it to your injectors, so clean the tank thoroughly and have spare filters on hand.

Hope that helps,
Luke

langa

Thanks Luke, a very comprehensive reply.

I've already decided to upgrade the whole fuel system. -6 hard lines, aftermarket fuel rails and regulator. It really wasn't worth the risk for simplicity's sake. I'm going to see if I can modify the stock fuel hanger plate with -6 bulkhead fittings. If they won't fit due to the proximity of the electrical connector, then I have access to a CNC milling machine and will make up a custom plate. Pump wiring has previously been upgraded, as I'm already running a Bosch pump.

The Gates (Barricade) submersible hose is the same price as their regular E85 hose, was only the convenience of ordering one length of the same hose to run the submersible everywhere.

I've spoken to the guys at Turblown about the EFR7670 and it's fueling requirements. I will only be running modest boost, not after huge power. It seems the limiting factor will be the single 460lph pump so we'll tune it to where it has a healthy safety margin for all fueling components. I don't want to be running so much power that I risk cracking irons, which from what I understand, can be an issue with un-doweled S5 engines due to the lack of meat around the factory dowel pins.

Will have EGT probes in the final setup. Also going to have to upgrade the intercooler. ECU is a Haltech PS1000.

Cheers,
Clint.

pzr2

iTrader: (3)

No problem! Glad to be of help. I just eyeballed my fuel hanger plate and it looks like it'll comfortably fit a bulkhead outlet, maybe 2 depending on how you do the return. Either way, it sounds like a fairly capable set up.

As for cracking irons, yes, a 7670 is encroaching on that territory, especially if you like surprising your engine with shock loads. Has Elliot already talked to you about reinforcing the engine? It's all really about flex at the dowel pins. The landings that the dowel pins insert into for the rear iron of most 13B-Ts are not very substantial, so they often crack when you throw double the original power at it. In terms of engine integrity, this isn't the end of the world, but it's still usually the end of that engine because your front main bearing is fed oil THROUGH that dowel pin. It cracks, oil spills out, and then the engine chews itself to bits from being starved of oil.

Turblown's 10mm studs are supposed to help reduce this flex by keeping a steady clamp load where the factory thru bolts might stretch. I've yet to see if this actually helps though, since my car's still in pieces. Another thing I'm trying is Pineapple Racing's solid dowel pins; again, no idea if they actually help. My ***-pull calculations based on moment of inertias say it should have about 25% more bending strength from being solid over hollow. While that doesn't directly do anything for the dowel pin landings, it should prevent "bowing" of the dowel pins that give the pins extra leverage on the landings. For this modification, you do need to run an external oil loop, but I planned on doing so anyways. You also mentioned doweling, and on top of that, there's studding (with studs 12.7mm or up). Both require precision machining of your block, so it's labor intensive, but widely regarded as the best thing you can do to reinforce a 13B. Conversely, the 10mm studs and the solid dowel pins require no machining, so you have options to reinforce your engine accordingly.

As always, hope that helps,
Luke