Pyro

should be 3.54 gear. But a lot can happen to a car in 35 years didn't think a 78 would come with a 4 speed. 75 or 76 did come with 4 speeds, I thought the 77 and 78 came with 5 spds.????? what year 5 speed did you put in? It is easy to throw a turbo on a z engine. I have done 5 turbo installs on Z's. My first was on a ragged out 78 with 200K+ miles. Just lock out the ignition advance and set timing to 26 degree at idle, use a 8:1 fmu for fuel enrichment, add the stock turbo exhaust manifold, turbo, wastegates, oil lines, and j-pipe. Then my old car ran a 14.6 at 96 mph and beat my buddies V8 1990 mustang. Can do a turbo setup like this for under$ 300.00 in used parts. Later did the same thing in a 76, but used a better turbo, 12 to 14 psi of boost, 7.4:1 cr, intercooler, better fuel pump, better clutch. ran 13.7 at 108 mph in the 1/4 mile (bad traction). Locked out timing and FMU's will work ok at low boost, but not very well over 10 psi. So, much better to just do a megasquirt efi system first.

Autozone. Felpro is 1mm. get a head gasket that matches the block year. in your case, a 81 to 83 280zx. A p79 and p90 is the same gasket

it is more like 135Hp at the tires for a 78. Mild cam and free flowing exhaust will make a fairly big difference. But compression is low (8.3:1 cr), so not much cam can be used. Maybe you can pick 20hp with a mild regind cam (260 degree) with a header and 2-1/2" exhaust. increasing the compression to 10:1 with some flat tops and using a 280 degree cam could get you another 20hp, thus reaching your +40hp goal. The stock intake and stock efi system becomes a hp bottle neck very soon (say, at 160hp) . installing a 81 to 83 5 spd and a 3.90 gear (stock 81 to 83 setup) makes a nice improvement for 3rd and 4th gear acceleration. It would be better to first install a megasquirt 2 efi system then bolting on a stock turbo system. You can easily make 225hp with the stock engine with 10 psi of boost and a intercooler. But then the stock clutch will burn up in short order.(a 2+2 clutch will fix that)

yes, I saw that. But I bet it isn't smooth with that cable snaking around like that, especially with that pita TV cable. the idea is to keep the throttle cable as straight as possible, so the extension of the pedal rod towards the center of the car will straighten out the cable. just a fyi.

for the throttle, i recommend you take off the gas pedal and weld a short piece of angle iron on the end of the pedal rod (under the dash). then put the carb cable of the end of that. This way the cable will have a straighter shot to the carb linkage. I have done this on 2 different v8 conversions and it works much better than snaking the cable to the carb. However, you will need to drill another hole in the firewall to pass the cable.

check out this 400. http://www.chevyhiperformance.com/techarticles/148_0401_chevrolet_406_ci_engine_build/index.html 490hp/525ftlbs on 87 octane.

Off your meds again it seems. never said it would work for sure. Just said it would be worth a try. your statement "more often than not", also states it may work. I say, install the pump, return the fuel with the stock line and see what the return pressure is before swapping tanks and running new lines (as recommend above) Looping the fuel back on a 5/16 line generates less than 1 psi of back pressure (i do know that from experience), maybe a 3/16 could be as low as 5 or 10. But as I said, I don't know because I haven't tried it, but still worth a try (even if I haven't personally tried it). The method you described also is worth a try. However, the return line pressure should always be measured when doing things like this. lines get clogged over the years.

never done it, but read the stock 240 return line will work as a return line for a stock efi pump. It would be worth a try.

Stock NA cams work better than the stock turbo cam in my experience. good for another 500 rpms. You can run NA cams as long as the cam is internally oiled (1977 on up). no spray bars on P90 heads. In other words, you need to use NA cam from a N47 or P79 head.

if you want a quieter exhaust then don't turn the pipes down before the diff. Instead of dumping, go into a Y pipe with a 3 to 3.5" inch output, use some mandrel bent pipe to get around the diff then into another muffler (in the stock location).

seems like Z car guys also like 67 to 72 chevy trucks. I see a lot of those trucks in the background in pictures of Z's. I have a 70 c10, LWB , lowed 4/6, BBC, th400, 3.08 lsd, ps, disk pb, AC, power locks, green avocado faded paint. Mopar makes a good engine. seems like a lot of work to swap one bb for another. I think a bigger mopar would have been about the same with less work. But i prefer chevy also. You will learn to hate TV cables. That is the problem with 700 and 200r's. Plus they never seem to shift when you want them to. good luck.

I did one just like that, but instead of just dumping the exhaust after the bullets, I went into a Y pipe (dual 2-1/2 inch to single 3 inch out) to 3 inch mandrel bent pipe to a dynomax turbo muffler (big case). I like to hear myself think when I drive.

best to get a complete kit. if you have a tall deck then use a 4.5 inch stroke. here is a kit http://www.summitracing.com/parts/ESP-11126030/ 515 cid, 4.280 bore, 4.5 stroke, 6.7" rods.

check out SPEC's page http://www.nipponpower.com/product.phtml?p=368&mmk=491 2 seater clutch "225mm" capacities stage : 267 ftlbs stage 2: 300 ftlbs (kevlar disk) stage 3: 350 ftlbs (6 puck semi-metallic, not good for street) stage 4: 350 ftlbs stage 5 499 ftlbs 2+2 clutch "240mm" stage 1: 395 ftlbs stage 2: 450 ftlbs (kevlar disk) stage 3: 515 ftlbs (6 puck semi-metallic, not god for street) stage 4: 515 ftlbs stage 5: 699 ftlbs I recommend a 240mm clutch for a turbo as I have personally burnt up "performance 225mm clutches" with mild turbo builds. 225mm clutches just don't hold the torque of 240mm.

A stock 225mm NA clutch has no chance on a turbo engine. A stock 240mm turbo/2+2 clutch works well on a mild turbo setup (say up to 225hp) If you are going to have 250 to 300hp then you will need to step up to a 240mm clutch setup. You will need a 2+2 flywheel, 2+2 throwout bearing hub (4mm shorter than the NA hub), and 3 more pressure plate mounting bolts (9 on the 240mm pressure plate versus 6 on the 225 mm pressure plate). I recommend a 240mm SPEC stage 1 or stage 2 (www.nipponpower.com). avoid the spec stage 3 for the street due to very quick engagements (on or off). you need a sprung clutch disk for the street. Speed cost money.

Yes, the stock 280 shifter will work fine with a gm 3 speed or 4 speed auto trans. Just takes some mild modifications to get the linkage arm length right and to drill a new hole in the gm linkage arm. Where you drill the hole is important as that controls the amount the trans linkage moves as compared the the stock shifter. Did it on a friend's conversion. He use a th350 then switched to a 200r. took awhile to get it adjusted so it would go from 1st to park correctly. I remember drilling a few different hole locations in the gm shifting arm to get the ratio correct. Has been a few years and can't remember all we did to it, but it wasn't much. I also remember grinding the stock shifter gate a little longer for 1st gear. if you have some skills and tools then you should be able to do it fairly easily. Make sure you put in a neutral safety switch.

Well, according to www.nipponpower.com the clutch part number for the 280z and 240zx is the same (spcsn541). Maybe that will help.

check out nipponpower.com SPEC clutches work well. Get a stage 1 or 2, Avoid the stage 3 or greater as they are hard to drive on the street (fast engagement, on or off and nothing in between)

Valve overlap doesn't effect cylinder pressure. The engine isn't even trying to make cylinder pressure during that part of the 4 stroke cycle. The intake closing point is what effects "dynamic compression ratio" what about a 270 degree cam do you want to know?

how much compression a L28 can take on pump gas depends greatly on the cam timing. I run 9:1cr with the stock cam, 9.5:1 with a 260 degree cam, 9.75:1 with a 270, 10:1 with a 280, 10.5:1 with a 290, 11:1 with a 300 degree cam. All on pump gas. The reason is..... the later the intake valve closes, the less air is trapped by the rising piston on the compression stroke, so less cylinder pressure. This is why more compression is required for bigger cams (later intake valve closing points). The intake valve is still open as the piston is rising in the bore, thus reducing the length of the compression stroke. So just saying you can't run more than 9:1 on pump gas is not the whole story. I have run P90's and P79 heads and can't tell any difference. However, it is hard to modify the P79 exhaust port due to the liners.

If you plan on using the stock turbine then you should not use a cam with any overlap. The stock turbine make lots of exhaust manifold back pressure and therefore doesn't tolerate overlap (intake and exhaust valve open at the same time). A good upgrade for a mild turbo build is to use a cam from a NA engine. The NA cam has 8 more degrees of duration and is good for another 500 rpms of usable power (5500 rpms) and doesn't have enough overlap to mess with the turbine.

Need to use stock springs up front (soft) and heavy springs in the rear. When the car takes off, you want the front to lift and the back to stay still. Looks very similar to the front staying still and the back squatting, which is bad. I would use a 100lb difference in spring rate between the front and the rear. This also cures front end plow which most z's suffer from anyways. So, 230 to 250 lb spring rate in the back and stock springs up front. Then lastly, fresh rubber on the rear is important. Width has less to do with it. as long as the tires are at least 215's you should be ok.

Need to cover the basics first. fuel and spark. you have some spark but you feel it is weak. try 12V's to the coil. need to check the ohms on the the coil. have your checked fuel pressure? have you checked to see if the injectors are getting a signal to fire? I'm guessing you have a 81 to 83 turbo ecu, right?

26 splines is the number of teeth on the input shaft for a V8 T5. The V6 T5 has 10 or 13 (I forget). I made the JTR mounting plate for the rear diff. easy to do if you have access to a lathe. The stock Z drive shaft u-joint looks wimpy compare to the stock chevy stuff, so did not want to use them.

I never considered using a 0.48 hot side T3, but maybe I'll try it one day. I bet it would be boosting just driving down the highway.