Pyro

easier to switch to a 200r-4 or 700r. I helped a friend install a dana44 from a 80 corvette into a Z. A lsd diff with 2.87 gears. with a thm350 trans it still ran 3000 rpm at 75 or 80 mph and feels a little doggy in 1st and 2nd due to the high gears. plus it was a trick to get the vette diff in the stock location. cover mods, 1/2 shaft mods, front mount fab. he recently switched to a 200r4 trans. we just had to move the trans mount and adjust the shifter and set up the TV cable on the carb. drive shaft was the same. now he is in the process of getting new 3.55 gears in the vette diff so 1st and 2nd feel stronger. i would go 5 spd manual. automatics suck in a z. use a GM t5 with a 3.90 gear. works great!!!

could also be the ignition module going bad. it is a 4x4x1 black box under the passenger side dash.

I understand the need to save money, but you do realize that 1978 was 31 years ago, right? I don't think installing a 30 year old ac system is a good idea.

finding a good use V8 with trans is the easy part. install a V8 is not so easy. Lots of things to do which will nickel and dime you to death. go with a complete L28 turbo engine, much much easier install.

I have had good results with the msd 2225 pump. I'm thinking the walbro pumps need bigger fuel lines to run right.

I found that these pumps get loud when they don't get enough fuel into the pump. I ended up pulling my tank drain plug and re-tapped it to fit a 1/4 npt. then put on a 90 degree barb fitting and ran that to the pump. you have a weird problem. hope you get it figured out.

with an automatic I would use the forward mounted position (like you have it). Yes, the weight on the nose of the car will be more. But the engine cooling is much better with the engine more forward. The forward position creates a lot more room around the transmission and the transmission tunnel which is the path hot air takes to leave the engine compartment. An automatic transmission almost touches the body in the set back position which restricts the air flow greatly. if nose weight becomes an issue, then move the battery to the back and get some aluminum heads, intake, and water pump.

I checked the maps on the t04b-v trims and it looks like the compressor will work as long as the engine doesn't build max boost under 3600 rpm. Which is about what the T3 stage 5 turbine does on a L28. The v trim compressors will surge on a L28 with a stock T3 turbine (low rpm boost). Furthermore, will need to run about 14 psi with a cam that makes max power at 6500 rpms (around a stage 2 or 3 msa turbo cam) to hit the 400hp goal. good luck with your build.

"i wanna know if i still have to custom order oem dimension forged tubo pistons OR if i can use flattop forged pistons and use a thicker head gasket and have the same reliability tunes and turbine sizes are just speculation becuase anything can happen i want to know mechanically are they the same in reliability" Well, if you are going to get a custom set of forged pistons made, then don't make them to oem dimensions Instead of making a round dish, you should make a D-shaped dish that matches the combustion chamber shape. This helps quenching, which reduces ping. FYI, stock dish is about 12cc. installing a 2mm gasket on a 8.8:1 cr L28 (flat top with p90 or p79) will make 8.3:1 cr. You didn't spec your cam but it sounds like you are after high rpms, so a bigger cam must be used. Furthermore, a stage 5 turbine flows well, so more overlap (bigger cam) can be tolerated. Therefore, you are needing a cam like a MSA turbo stage 2 or 3 to match the turbine and the high rpm requirement. These cams will work well with higher compression than the stock turbo 7.4:1 cr . So, it would be better to used 8:1 cr or maybe 8.3:1 cr (stock 75 to 80 compression ratio). You could rebuild a 75 280 Z long block to stock specs and install a msa stage 3 turbo cam and get good results (no thick head gasket required) Thicker gaskets aren't a good idea. It messes with the timing chain. you would require an adjustable timing gear to set the cam timing correctly (unless the chain is stretched a lot). of course a forged piston is stronger, however, a stock piston can handle 400hp. detonation will kill the stock piston sooner than the forged but both will break if the engine detonates. Forged pistons required a bigger clearance in the cylinder bore to allow for thermal expansion. so, when cold they tend to be noisy when slapping around in the bore and produce blowby until warm. This can reduce engine life in a street car. not sure a to4b-v compressor will make 400 hp, have you checked the compressor maps?

A forged piston will also break if the tune is bad (detonation). stock piston can hold 400hp. (crank hp). compression tolerance will depend on the engine setup. longer duration cam, bigger turbo, free flowing turbine, efi tune, ect. What are your plans for a cam and turbo? The most important thing to get is a proper efi system with ignition timing control and a good tune.

Should use low impedance injectors. A turbo engine has a wide range of fuel delivery needs. (very little at idle and a lot at boost) So, you need to use an injector that has good control over it's entire duty cycle. And low impedance injectors have much better control at low duty cycles as compared to high impedance. high impedance works fine for non-turbo application, but you will have idle issues on a L28 if you use 440cc high impedance injectors. yes, 440cc is enough to make a 300 rwhp L28.

looks like san antonio.

charge pipe? got a turbo? what is your setup (year, turbo, na, set?)

if the car still has problems after the tank job, I say the ignition module is going out. runs good for awhile, starts to run bad, shuts down, then starts up again after awhile. repeat. classic signs. the ignition module is a black box around 4x4x1 inches under the dash on the passenger side.

4 or 5 inches is a lot to tweak a shifter. especially one like a T5, one that comes out of the top of the transmission. I would guess 2 inches offset would be about max to make an S shaped shifter. the 4 speed muncie uses a side mounted shifter linkage, so moving that shifter back is much easier. Just lengthen the linkage arms and make a new mounting plate. I say, move the engine back for the T5. When it is done, you will be much happier with the T5 for daily driving as compared to the thm350.

found it. http://www.datsport.com/Chapter_Seventeen.html

The msa turbo stage 1 cam has 10 more degrees on the intake as compared to the exhaust. 260/250 degrees I believe. mild turbo cams typically have less exhaust than intake duration so the turbine gets hit will a more "pure exhaust stream" (fast and hot). Plus less duration on the exhaust limits the overlap between the intake and exhaust. do a web search on racer brown cams. There is a nice write up on turbo cams. You maybe turning 6500 rpm but peak hp is long gone by that point using the stock turbo cam.

check out this site. They have most of the T04B compressors listed. http://www.squirrelpf.com/turbocalc/ I would try the stock NA cam to see if that helps. Put in the cam that was in the N42 head. Has 8 more degrees of duration which would give another 500 rpms of usable power and make more hp. Easy to install a cam. You could have a stock na cam ground to a 256/248. Just leave the exhaust lobes stock and have the intakes ground to longer duration (good for a turbo engine). Then use 0.160" lash pads only on the intake side. Deltacams can do a regrind for 60.00 and Courtesy Nissan sells lash pads for 3.00 each. Should get 1,000 more rpms out of the engine, and therefore more hp. Use the stock springs and retainers.

I guess that is a T04B-h3 compressor. With a L28, that turbo is over the surge line under 3000 rpm at low boost and gets into a safe range after 3500 with 14 psi. with a stage 3 turbine and 8.3:1 cr you will get much better results with a MSA stage 1 turbo cam or even a stock NA cam would be an improvement. decent numbers. good job! thanks for sharing.

Late closing intake valve from a long duration cam lowers cylinder pressure. On the compression stroke, the intake valve is still open as the piston is rising in the bore, so no air is captured until the valve closes which lowers cranking pressure. (less air to compress). This is called dynamic compression ratio (DCR). A stage 3 MSA cam should use a L28 with flat tops and a N42 or N47 head.

you still need more timing. 8 isn't nearly enough. and you still need to use the vacuum advance if you plan on getting any MPG.

back fire out of carb is lean and/or retarded ignition timing. you don't have a stock cam anymore, so stock ignition timing will not work. try 15 degrees advance at idle, then plug in the vacuum advance to the manifold vacuum for another 15. should be idling around 30. Adjust the idle to 800 or 900 rpm and set the idle mixtures screws for best/highest idle (highest vacuum). You should have a 2400 to 2800 stall converter with that cam, right? If that doesn't fix it, then add more accelerator pump.

first fix the turbo spool issue. should get full boost under 3000 rpm with a stock turbine, which makes lots and lots of torque.

280zx use the rear sump oil pans. I would use a turbo pan because it has the oil return line already in it. But not a big deal to put a drain line into a regular pan. The pan you have on now is a center sump (75 to 78 280z pan). There is lots of room to run IC pipe between the front crossmember and the rear sump pan in a first gen z. I used 2 inch and a friend of mine uses 2-1/4.

install a rear sump oil pan and oil pick up tube. re-clock the turbo downwards. run the pipe under the oil pan and up behind the alternator.