rossman

That sounds low. Mine is ~15 psi and I know I have at least two small vacuum leaks.

This is what I thought. Then the often referenced text from the Atlantic Z-Car Club, Fuel Pump Circuit Information (http://www.atlanticz.ca/zclub/techtips/fuelpump/index.html )must be incorrect: The fuel pump control for the 78 - 81 N/A. When the engine is not running the oil pressure switch is closed and the transistor at the 'L' terminal of the alternator is "closed" and BOTH idiot lights for ALT and OIL are ON. When the key is turned to ON the idiot lights are on and the fuel pump is OFF. The fuel pump only "starts" when the key is turned to Start. These years used three relays to control the fuel pump. If the engine stops / stalls the loss of BOTH ALT and OIL signals simultaneously shuts off the fuel pump. So is the 78 fuel pump circuit like this one or the earlier 75-77? Thanks for you help. Ross

This may be a stupid question but anyway here it goes... I am trying to diagnose a hard starting problem with my stock 78 280 fuel system. Per the Atlantic Zcar EFI tech tips, the 78 should have a oil pressure light. Mine does not, at least I cannot find it. Where is it located? My car was manufactured in 9/77, the title and owners manual say 78.

Thanks ktm. That post is confusing unless you read the whole thing thru. I scanned it before and got confused. I reread it just now and the answer is there. Match the throw out bearing to the pressure plate. Now I am trying to figure out why the "extra" 3 bolts bolt holes on the pressure plate don't line up with the holes on the flywheel. I didn't realize the 240mm pressure plates had 3 extra bolts until I removed it again.

I guess need a shorter throw out bearing collar. The picture shows the slave cylinder piston pushed all the way in. Will a 280z 2+2 collar work?? I did a search but didn't find a definitive answer. Cheers, Ross

Thanks for your replies. I have decided to go ahead and upgrade. As pjo suggested it would be more economical than spending money on a custom exhaust for this turbo when I plan to upgrade anyway. So, I took that advice and purchased a turbo exhaust manifold off ebay earlier this week. Now I need to decide between a Holset HY35 or a T3/T4 turbo.

I added a picture of the exhaust manifold adapter and oil return.

Thanks pjo. Yeah I don't know if I want to invest too much in this system.

Here ya go! http://picasaweb.google.com/rossharold/OldSchoolTurbo280z

Good idea, thanks.

I guess my expectations may be little low. I may install a wide band and just start tuning it to see what I can get.

To me that is a custom set up. I guess you mean I don't have to do any custom engine work. This is good news, I really wanted to avoid it.

Sorry I guess I rambled a bit. Do you think I could make this system produce ~200 - 225 HP without significant risk of detonation? I plan to eventually design a custom 300 - 350 HP turbo setup so I don't want to destroy the engine.

I recently purchased a '78 280z with a custom bolt-on turbo set-up. The system was designed by Bell Engineering in the early 80's. It has a Rajay R70 turbo with custom piping, variable rate fuel pressure regulator, modified NA exhaust manifold with a diverter to the turbo and welded on fitting for the external wastegate. As far as I know, everything else including the FI is stock NA hardware. The previous owner purchased the car with a broken connecting rod. He rebuilt the engine with Nissan .020 over turbo pistons and used the stock NA head (N47). The stock NA injectors are clogged (it sat for a while) and the down pipe is rusted thru. I checked the turbo shaft by hand and it does not have any perceptible play. I did check that the car will run by installing some old leaky injectors that the PO gave me with the car. Just looking at the turbo it seems really small which makes sense since the system was designed for an NA engine. The turbo setup was designed for a high compression NA engine but now it has turbo pistons. It seems like that the turbo will have to flow quite a bit more to get significant boost and this may put the turbo out of its efficiency range and lead to detonation. This is especially bad since the setup does not have an IC or water injection. I was hoping to get 200+ HP out of this car. I am trying to decide if it is worth my time and money to get a new custom exhaust installed and attempt to tune up the car with the turbo setup "as-is." Thanks, Ross