TimZ

Hi All... I've been struggling with fuel starvation issues for the majority of the summer this year and after inspecting/upgrading/replacing everything else, I bit the bullet and revisited my stock modified fuel tank. When I converted to E85 I eventually changed over to a very high capacity pump and the stock fuel pickup would no longer suffice. My original plan was to tap into the existing swirl pot inside the tank and use a larger ID pipe (0.75"id as I recall) to connect it to a weld-on rear sump pickup (sorry, I don't have any pics of the old setup). To deal with the E85, I had a local internally coat the tank with an alcohol resistant coating. This worked fine for a year or so, but started to have issues this year. The new plan has been to remove the stock swirl pot and plumbing and replace it with a much larger one that could keep my pump fed. I settled on a 7'x7"x10" stainless steel box that I would slide into the bottom of the tank: ...this should give me a ~2 gallon head of fuel to keep the pump fed - MUCH larger than the stock piece. I added two 1/2" NPT female fittings to the bottom of the box to feed the two -10 hoses to the pump. In order to keep the box filled with fuel I took a two-pronged approach. First, the stock swirlpot uses a jet pump fed by the return line to transfer fuel from the tank and keep the pot full (here's the Wiki on Jet pumps). I wanted to also use this approach, so I fabbed a much larger injector pump from a series of fittings: ...the black fittings on the left are tapered inlet -10 male to -12 ORB tapered fuel fittings, the tee is a -12 ORB tee, and the stainless bits are to adapt a 3/8"id Swagelok fitting for the new 3/8" stainless internal return line. I drilled out the Swagelok fitting to allow the 3/8" stainless line to protrude into the tee: As a backup I fabbed a trap door inlet from a modified stainless piano hinge: Here's how it all fits together inside the tank: After removing the old soldered-on rear sump, I had to cut a square hole in the bottom of the tank to accomodate the box, in the location of the stock swirlpot. I removed the swirlpot and associated plumbing, and cut and drilled out the stock outlet and return lines. I replaced the outlet line with a stainless 3/8"NPT female coupling to accomodate the new return line: I cut two 4" access holes in the top of the tank to allow me to get to everything inside and see what was going on. I found a pair of bolt rings for fuel cell inlets that I could use to cap these holes off when I was done. I then spent HOURS AND HOURS removing the old internal coating everywhere and cleaning up the inside of the tank. I used Permatex liquid rust converter (tested it first by submerging a test piece in E85 for 24 hours with no ill effects) to do a first coating of the inside of the tank. After this cured, I used Caswell two-part epoxy to completely coat the inside of the tank with an alcohol-proof coating, leaving an inch or two from the edge of the big square hole for the stainless "box", in order to allow welding it in later. this allowed much better access to all the nooks and crannies inside the tank while coating it. After welding the box in, I finished the epoxy coating around its edges through the two access holes, and plumbed in the jet pump and return line fittings: I'm happy to report that I've got this all back into my car and it appears to be working flawlessly! Here's a couple of final pics of it installed:

I agree with Bob, but just to be fair, this also depends on what the tuner was told was expected of him. With only 30 miles on the new turbo, I don't see how this could have been a very mature calibration, but did the tuner know that? When I show up for a set of dyno pulls, I'm there to benchmark a new configuration and I've already done a ton of very thorough instrumented street tuning. I'm only there to tweak for best performance and understand the effects of any configuration changes. In this circumstance I'd expect to do a trial run to make sure everything is ready to go, but then I pretty much go straight to WOT pulls. Communication is key - If you showed up at a shop with a raw tune and told the operator this and made it clear that you wanted him to do a full tune then this should have warranted extreme caution and Bob is dead on. However if you just showed up and gave the operator the impression that you just wanted some "power pulls", then I don't think I'd blame him for this.

What do you mean by "not productive"? What makes you think that? The restrictor plate idea almost certainly won't work like you are thinking. If that's what you want to do, then just get a smaller AR turbine housing and be done with it - that's essentially what you are trying to do with the fixed restrictor plate.

Two things come to mind: Read this post and see if it applies to you: http://forums.hybridz.org/index.php/topic/69706-reaction-disk-pictures-and-walkthrough/page__p__658366__hl__%2Breaction+%2Bdisc__fromsearch__1#entry658366 Did you bleed the system at the master cylinder first, or did you just bleed at the four corners? There should be two bleeder screws right on the master cylinder - bleed it there first, then do the calipers, in order starting at the farthest from the MC (left rear, due to the line routing).

As long as the regulator can bypass enough of the new pump's increased flow you should be fine. You should be able to get the fuel pressure down to around your base pressure minus ~7psi. As long

These are a little shorter than you spec'ed, but they appear to be the "short valves"... http://www.ferrea.com/sportcomp-valves-competition-plus-valves.php Ferrea can pretty much make you whatever you want, depending on how much you want to spend. They made me a set of "Super Alloy" valves for my N42 head. Would've liked to have had sodium filled, but as I recall they didn't have blanks in (or close to) my size.

Restrictions at the inlet definitely do not help, but in the link I provided they mention that fuel temperature alone can cause this. They are saying that the fuel only needs to exceed ~120degF, which isn't much of a stretch if the ambient temps are 105. In my case I suspect that the really high flow pump that I am using is not helping - the regulator ends up returning much more fuel from the engine to the tank than a lower flow pump would, so in addition to the pump trying to pull more fuel from the tank, it's also causing more hot fuel to come back from the engine bay. I'm looking into some heat management strategies, including insulating the fuel rails and post filter in the engine bay (trying to come up with something that doesn't look like sh1t ), and adding a heat exchanger on the fuel return line back near the tank. Also thinking about adding the competition hood vent/scoop thingy if I can find one. I'll post something up about it when I find out if it's actually helping.

I just ran into a similar issue with some record high temps here in the midwest - it appears that the fuel in the tank is getting heated up to the point that it causes cavitation issues at the pump inlet. Next time this happens, try putting your hand on the tank and see how hot it is. http://fuelab.com/customer-support/28-avoiding-cavitation/79-avoiding-cavitation

I've been using an LM-1 for years now with no real issues. The warmup only takes ~30 seconds and it's up and running, plus you can preset it to whatever output you want during this time. EGO feedback is generally open loop during warmup anyway, so how exactly is this a problem?

I didn't do that did I? I have to admit, I was pretty sure you'd chime in when i posted this. Ahem... I would never do that - that would be wrong! I did have a check valve and filter on the vent line intended to prevent a vacuum and encourage positive pressure in the tank and it appeared to be working - at least when I opened the gas cap it would release pressure from the tank. I thought about running a boost line to the vent for about two seconds, but I suspect that would be a bit much... I saw a post you made a while back that mentioned using a small cooler on the return line to keep the fuel temperatures down which looked like an interesting idea. Just have to find something compatible with e85...

That's my suspicion too. The -10 lines will go directly from the tank to the Y at the pre filter - no quick disconects this time .

Update - I talked with Fuelab yesteday, and they found the problem - cavitation damage to the pump impeller that reduced its flow/pressure capability. They did in fact fix and re-flow test it free of charge, even though they could have claimed improper install if they had wanted to be jerks about it. I didn't even have to make a stink about it. Their ratings appear to be conservative, btw - the pump is now flowing over 200gph at 45psi. So I do give them my endorsement. This does point out an important point though - this is a really high flow pump! I was using a pair of -8 lines y'ed into their 828 Series -10 75-micron screen pre-filter. This was fed from a modified stock tank with a pair of 1/2"NPT rear sump pickups. I was using 3000 series JiffyTite quick release fittings on each of the two -8 lines for serviceability. I did check and both -8 tank ports appear to flow just fine. And this was still too restrictive for this pump. I'm going to be changing to a pair of -10s directly to the pre-filter and hopefully this will be okay. I'm coming to the conclusion that I probably went a bit too far on the overkill side with this pump. If you are not going to run over ~1000hp, you might want to go down a size (or two) from this pump and not have to worry as much about this stuff. Probably a 41401 (or a 41402 if you plan to run E85) would be plenty. And less money too!

I'm thinking perhaps that was just a brain fart, mixing up two weird tire names with double "Z"'s in them?

Blizzaks? Why? You realize that they are horrible on warm dry pavement, right?

What kind of track? Straight or curvy? For street/road race/autocross duty you might want to look at the Dunlop Direzza Sport Z1 Star Spec for about the same price. If you are primarily street and 1/4 mile, then take a good hard look at something like the MT ET Street drag radials - straight line traction is really good and the handling isn't anywhere near as bad as you might think. I ran R-spec road race tires for years, and finally admitted to myself that I wasn't really doing much (if any) road course work with my car. I switched to the MT ET Street drag radials and have been MUCH happier.

What are you plans for the car? Street driving? Road Course/autocross? Drag race? Do you really plan to be driving it in the rain, enough to justify going with the "dry/wet" designation? 400rwhp is getting to be a traction challenge - you'll need all the sticky you can get...

You are describing classic heat soak/vapor lock symptoms. This is a common problem on FI Z's that many don't seem to know about, to the point that Nissan added a blower fan on the ZX's to address the problem, as rossman pointed out.

Hi Joel - That appears to be the list price - I bought mine here for less than that. Hold off a few days on ordering the 42401 - I've been experiencing what appears to be a flow problem with my pump since I took the car out of storage this spring. The pump is at Fuelab being diagnosed now, so I'd prefer to hold off on a full recommendation until I see how well they take care of me...

The sensor is my MAP sensor - I'm using an exhaust backpressure (EBP) sensor from a duramax diesel - the pressure range is ~18in of vacuum to ~38psi boost, so it gives a much better fit to my engine and acts like a 4 bar, but with resolution more like a 3 bar. The feed lines are small enough that they don't appreciably effect the readings when I balance the ITBs. This was another reason to run things like the brake booster from a different source. BTW, don't expect much vacuum at idle if you are running ITBs with any kind of aggressive cam- I see ~5in of vacuum at idle . I ended up running an electric vacuum pump from a VW diesel for the brake booster and accessories.

This is exactly what did - basically drill and tap the rail at points that line up with the ports on your manifold and fit vacuum line sized hose barb fittings to each. Here's a pic - it's the silver rail that's attached to the valve cover (note that I picked up the brake booster signal from a separate rail that is integrated into the plenum, but you could take it from the end if this rail if you like):

Maybe I missed something, but my recollection is that this only applies if the taper is opening up the cross sectional area, as opposed to this case where the taper is causing the cross-sectional area to get smaller.

No issues with the rest of this, but I'm thinking that these two might be a bit overstated. I've been using NPG-R coolant for some time now (essentially just after this thread was started), and I have not observed higher temperatures at all. As you are alluding to, the heat transfer is less efficient, but for me the combination of the diesel water pump and stock mechanical fan appear to be more than enough to keep the coolant temps at 195 (my t-stat's setpoint). I saw it creep up to maybe 215 stuck in traffic in the Woodward Dream Cruise, but that went away as soon as I got out of traffic. Also, NPG-R boils at 400degF at 7psi system pressure so I would think this would change when nucleate boiling occurs by a LOT. Finally, I'm one of the others that got struck through . I've never been as impressed as I thought I should be by Water Wetter. When I was having cooling problems, adding Water Wetter made no discernible difference in the performance of my cooling system. Not saying it doesn't do anything, but it's not a panacea.

I would think that you should be able to do better than that, lead foot or not. That's about what I get with 600+ hp and E85...

If he wants to let them go cheap since they're the wrong part I wouldn't mind having a spare... edit - oops I think I read that backwards. Never mind...

I agree on using the higher BFSC for both the injector calcs and the pump requirements. Also, on the flow for the Walbro pump, that appears to be the flow rating at 43.5psi, which is lower than what you'll be needing at max boost. Here's a link to some Walbro flow charts - you should use the flow rating for the base pressure plus the max boost pressure you'll be running... http://www.gnttype.org/techarea/fuelsystem/walbroflow.html