dapiper

During development of my L28 custom turbo with DynoJet and complete data acq, found 3" Flowmaster imposed 7.5 psi at 18 psi, 370 RWHP which dropped to 2.5 psi after cut off, which matched same with DynoMax straight thru oval can. HP jumped to 410 with no other changes, had 38 psig at turbine b4.

Lots of great turbo's but my favorite was Chris from AZ with rusty orange Z and old Toy Turbo. This retrofit has plenty of room and cross flow head and 4 valve VE. Just priced them at around $800. He pulled 550 RWHP with a piggyback PFCON (ugh). Anyone ever done this retro? Have plenty of pix, but not sure how to post? TurboDave

Had head crack at #4 cyl intake welded and replaced seat on my custom turbo. Checked fine when fresh before run in but now after 20 mi, compression is down to 130 psi and leakdown at 22-13%. Others 145 psi and 3%. Leakdown and compression were fine even when leaking coolant into chamber before repair. Did not touch lower end. No change in valve clearance. Noticable air noise in crankcase during leakdown test. Squirted oil into cyl, which brought compr up and reduced leakdown to 13% consistant. Air noise now modulated with gushing sound like oil film being sheared intermittantly. Minor air noise now perceptable in intake. Whatya think? Other tests?

The DeltaGate is high maintenence. I just had to replace the diaphrgm again after only 2 years. Now that Bob Keller sold out, you have to buy from dealer and the parts price is higher. Also I've found that they care little for the little guy. Or maybe they just are a bunch of salesmen devoid of tech knowledge.

Yeah, I got a sheet of something similar I will try in meantime, probably would become frayed and sloppy after a while. The stuff I'm looking for keeps it shape and is formed around the object like the turbine exh shields.

Hey anyone know source for that SS foil, ceramic wool sandwich composite material similar to whats available for turbine heat shields. Considering fab for my cast iron exh manifold to reduce under hood heat. Could make as two piece clamshell with wire grommets. One piece fits under and on over top of manifold for easy assy. Look on page 102 of Dec issue of Turbo Magazine at Rado's NORAD motor exhaust heat shield. I've seen these used on jet engines. I will check at GE on Monday, since Google search turned up nothing. OBTW, Turbonetics was mum on their source for turbine heat shields. Since Bob Keller sold out three years ago, they don't seem to remember the little guy.

Was considering P90 until found MSA does not carry exh valves. Other sources anyone? Otherwise I may just stay with my N42.

I guess we are all masochists who love a challenge. Persistence hell, its obsession. Sure got a lot of laughs from that link. Good to know I'm not alone. Kind of sick sense of humor, but I really roared. You really know how to wield Maxwells Hammer. I just kind of sneeked up on it.

Yeah, lots of chamber work unshrouding valves and polish with Cratex. Removed 3.5 cc ea chamber. Cam is old Racer Brown turbo grind 246°I/236°E at 0.050" with 0.485 lift on N42 head and block. MSD TurboTimingMaster retards 18° init to 28° final at 20 psi. Aria's forged pistons with reverse deflector dish vol of 11cc and 11:1 A/F on boost. I/C is 160 sq in unit first import of HKS back in '87. Turbo is Turbonetics H3. I probably should't admit it, but been at this since '75 and blew a lot of motors along the learning curve.

Yes, the proj nose will mechanically adv the timing, hence will require less ign advance. Over 14 psi, I add 5 gal TurboBlue race gas to tank for track. Dyno pulls at 20 psi had 110 octane Shell race gas.

I've run 18 psi with head bolts, just make sure everything is flat and clean and degreased. Torque on at least three steps to 60 ft-lb. Recommend stock gasket only.

I have run the NGK BP8ES at 20 psi for years with no problems. The projected nose is worth about 4 deg adv compared to non-proj. Total adv is 28 deg with 8:1 CR in L28.

The L engine heads like to walk around unless clamped with studs. What I see is weeping at gasket. Head may have been hot once and warped slightly and lost seal. Clean it up and see if it reseals. I have run these weepers b4 for quite a while. May want to turn down the boost some....yeah,right. Assume compression chks OK, but keep an eye on it and your coolant level. Pop rad cap and see if it huffs at you, under press...cud be blown to coolant jkt.

Thought it was the gasket blown to jacket, but heart sunk when gasket intact, had to be head or cyl wall. There is a fine crack running radially out from intake valve boss across quench ledge of chamber about half way to edge. Have a lot of chamber work on this head and hate to loose it. Anyone tried welding head?

Found designengineering.com has variety of heat shroud material. Will try that b4 cooling fan. OBTW, what's with Summit's "handling charges"?

Maybe pump internals corroded from crud in tank and/or bushings bad. Pump should run off batt.

My RC550 inj will clog after shutdown overnight causing bad idle for 5-10 mi. Suspect fuel rail heat soak deposits on inj. Anyone devised cooler? Wasn't there a stock inj fan cooler? Also considering insul wrap. Source anyone?

Recommend mock install. Do not use EFI pump on SU's. Float valves will blow open and flood badly causing fire hazard. It will not run, anyway. Rewire pump direct to batt thru fuse and relay with AWG 12 wire. Don't use stock wiring. Use 3/8" hose or AN8 line for supply.

Should rewire fuel pump direct to batt thru relay and fuse. Use AWG 12 to keep resis low. Pump can draw 10 amp when working against backpress from boost.

Hey, watchout take care, beware to all those contemplating retrofit of 280ZX alt in earlier 280Z. There is the diode problem for the 240's but a different problem on the 280's. The dash brake light test relay needs to be unplugged, otherwise the 13 ohm coil will drain batt in few days idle. This relay is wired to old alt F (field) term which becomes the S (sense) terminal connected direct to 12 pos, hence draining batt. This relay is located under the pass seat. OBTW, anyone know what the fusible links' equivalent fuse amperage is?

Anything over about 13 psi must run 1/3 Turbo Blue for blend of 100 octane R+M/2. The ultimate runs at 20 psi were with 100 % Shell 110 octane leaded. Cannot recall blend number. My CR is 8:1 on N42 with total of 35 deg advance retarded to 27 at 20 psi. Removed 3.5 cc from chambers to unshroud valves OBTW, Mustang dyno said 310 hp with 3000lb inertial loading and 340 ft-lb. These pulls in 4th gear roll on to 18 psi. Basiclly 132% under mine and other DynoJets which were around 400 RWHP at same boost. These guys pretty green with their experience though. Did not include comments with each run and no printout, since printer broke all for $170 for 2 hrs, including widerange which was intermittant due to loose cable. Operator said he was reving to 6500 but trace cut off at 5700, below power peak. This probably explains why torque more than HP, which are usually equal on my motor. Hence, cannot compare HP but torque, which at 340 is still 15% low. Thought motor was tired, since 70 K mi, but still has 155 psi compression and 2-3% leakdown. Runs confirmed that load enrichment of 11:1 was timing out allowing ECU to revert to base map, which had to be set to 12.3:1 to sustain A/F at end of run. In addition, discovered that manif ref hose to FPR was leaking at 50 psi. That was worth 2 A/F or 13%. Maybe inertial load too high and should be set to 2500 lb to match weight of DynoJet drum? The 435 RWHP run was at 21 psi and 10 deg more duration cam on my DynoJet in '88. Had full instrumentation for moitoring boost, EGT, NB UEGO, Exh press, turbine press, fuel press, and induction charge temp and flow. Even had turbine meter for fuel flow, which went from 53 to 5 gph at max power. Meanwhile, how does 2750 pph and 40 GPH (measured, not calc) fuel equate to 310 HP? This is 0.8 BSFC which would not fire. Even assuming 340 HP, that's a pig rich 0.74 BSFC. We had no evidence of black smoke. The trace was smooth and continuous. The measured A/F was 12.3:1. This calcs to approx 406 HP at 0.55 BSFC.

OK gurus, what model do these fj20 rods come on? What about the front cover and oil pan. I have one of the comp baffled Design Products pans I wud like to use.

Sorry for delay in response. Yeah look me up anytime. I'm in West Chester. Yeah, just retired my Bosche blue tops. They flowed 45 pph static at 38 psi (470 cc/min) Actually ECU probably intermittant, calib is not holding, suspect hot wire HLM or coked up UEGO on Innovate. Considering Motec M48. Anyone tried one? TECIII has too few cells for high boost. Anyone tried one? My beast is 430 RWHP at 20 psi N42 L28. May ride mustang tomorrow. Expect 10% less than on my DynoJet. May wait 'til Fri when Walbro GSL392 received.

Regular hose clamps, although ugly, can be made to grip by welding four small tits on the edge of the intercooler tubing end. These will keep the hose from slipping on the tube. Place the clamp adjacent to the tits. Make the tits smooth, of course. Like a coordinated weld glob, no more than 1/8" high. Works for me at 21 psi. Tried toggles, but limited clamping range wud not work on my intercooler hose size.

When I had my DynoJet and was qualifying my fuel flow after inj upgrade, discovered aeration when tank below 5 gal static. Best to mount pump at tank; pump may have high NPSH reqmts (may not siphon well)