speeder

Yeah, Right!! For the wife. That's a good one, Scottie. Whatever the excuse, It's good to see you back to your Z "roots".

My server is down now, but when it's back up you can see pics of my setup in post #17.

You go, Gabe- Nice numbers.

Turns out the problem was a clogged fuel filter. Why people use those little 1-1/4" diameter tubes with the disc elements (like this: http://www.summitracing.com/parts/SUM-230101/ )inside for fuel injection is beyond me. The filter element had no visible debris captured (I visually checked it about 3 times during this embarassing episode) , but was restricting flow to the point where I could hardly blow through the assembly. Took the element out and the problem is gone! softop, PM me for the info you requested - It's not relevent to this thread. The fuel rail used on this engine is the stock LSx one, and yes, we had that one off to check.

Like Scottie said, "I am frustrated and angry at this whole situation." Bout sums up my mood too. I'm sure when we find the solution it will be a forehead slapper. We're back on it today with pump hanger rev 3.

I have done wastegates on a downward facing pipe (used 1.75" thick wall cast iron from a hardware store, 42mm T'netics Racegate) welded to the bottom of an L28 manifold, and see no difference in quality of boost control at the 400whp level compared to this adaptor. Above that hp level for an L28 I have no experience.

Yeah, that is puzzling - but I can see no reason for fuel pressure to decrease as a result. Also before this fuel pressure problem everything was good(smooth) on the datalogs. I think the major thing to look at is the wbafr trace - a classic signature of lean misfires, backed up with simultaneous decreasing fuel pressure. We're attacking the fuel pressure as a primary cause. Still don't understand the difficulty with making a pump and regulator work... But then I have had a horrible recent history with bad new parts.

I just installed this adaptor on a customer's L28. Welded it onto the manifold, and welded on a V-band for a Tial 38mm Wastegate. All V-bands on the stainless downpipe made a very compact installation. Turbo is a GT3076r, crazy fast spool. Even with less than optimal angles for the exhaust dump into the wastegate, that 38mm valve should outfow any internal gate I've seen. We got solid boost control from 12 -20psi with a Sard boost controller (after much guessing about how to make settings -Japanese Language Manual!), 12 pound spring in the wastegate. I would recommend this setup.

Well, We are building a dual Walbro pump setup to replace the single Bosch. Everything else checks out.

Datalog of the problem: Any insights are welcome!

Scottie/GNZ and I are working on a Megasquirted Turbo LS2 which is posessed. Tuning was progressing well until we started to see lean conditions starting under low boost conditions, and continueing to lean out under increasing boost until the car would backfire and stall. Rigging a fuel pressure gauge showed fuel pressure dropping from base pressure (~43psi) as boost increased. We were running twin Wabro 255s in the tank, and quickly found one of them bad, actually bleeding pressure from the good one when both were running. Long story short, getting the pump hanger with 2 Walbros back into the small tank opening (2nd Gen RX7) proved almost impossible, so we installed a single Bosch 044. Same fuel pressure problem. Troubleshooting to date: 1.Connecting compressed air to the the regulator (Aeromotive A1000) reference port while running the pump makes fuel pressure track properly ( fuel pressure increases from base setting at 1:1 ratio to reference). Reference air pressure was injected at the vacuum distribution block's feed point from the manifold to make sure a vacuum operated accessory on the block was not dropping manifold pressure. Same problem under boost load. 2.Just for grins, replaced the regulator. same problem. 3. Checked for no restrictions in the fuel lines or clogged filters. 4. Checked for full voltage at the pump relay (rear mounted battery, < 3 feet of 10 guage wire to the pump ) under load, looked good. (Can't get on the intank connections but pulled the pump and gave a good visual inspection - no way they are bad. 5. Installed a 255L Walbro inline downstream from the intank pump, with its own relay for power. Interesting result was the fuel pressure decrease under boost was WORSE! This has to be telling us something. Some sort of blockage? Bad (new) intank pump restricting flow? 6. I will once again verify no blockages in the fuel line - The pump hanger has been removed and tested to have no internal leaks or clogged filter sock. 7. Next is checking the injector drive signals for anything weird - I'll take a storage scope onboard and see what they look like. Grasping at straws, I did a quick calculation and found that 100% duty cycle with the 8 -65 lb injectors *could * have more flow than the Bosch could provide (depending on what the real specs of the pump are) , but certainly not with a booster pump inline. Also, at the problem area, 3600 rpm and 7 psi boost, datalogs report 75% duty cycle and 17MS pulse width. These numbers make no sense except for tuning adjustments made to compensate for low fuel pressure, not any kind of ECU-caused problem. I just want to verify these numbers with the scope. I'll post a datalog later. I would welcome any observatons/ suggestions here.

Tony, I'm working with the owner of this same car, and have another couple pages from the Sard manual needing translation. If ok, I'd like to get them to you. Thanks.

Use 3 of these: http://www.msdignition.com/Products/Coils/Accessories/8870_-_Coil_Interface_Block,GM_Dual_Tower_Coils.aspx

Go with ACT in your choice of torque capacity and be done with it. Thank you.

Check this out: http://forums.hybridz.org/showthread.php?t=109674&highlight=SPEC+Clutch Vette, Viper, and Supra guys love them, but they have a really bad rep on Datsuns.