Arro

I'm new to the Z world but to turbocharging I'm an old hand. I don't see why I can't apply some of the same techniques I've successfully used before. Of course if there's a roadblock you know about that I don't, please by all means discuss it here

My 280ZX Turbo 5-speed 2-seater is bone stock. Here is what I plan to do.

10-Step plan:

1. Motorsport-style Cold Air Intake. I say "style" because the actual Motorsport piece is too much $$$ and I can make one and have it chromed for less. Otherwise it's gonna be a 90-degree bend with a dual-surface cone filter (those ones with the open ends and second reversed cone) right where the stock airbox is presently.

2. StarQuest intercooler. I'll be cutting a new hole for the IC pipes, probably an oval shaped one to accommodate the two pipes. I'll be buying the holesaw bit soon. I'll probably make it large enough to handle two 2.5" pipes, because I know one day I'll be running full 2.5" piping. I might even go ahead and upgrade the piping on the IC to 2.5", and do it all now.

3. IC piping. I plan to use mandrel sections from http://www.jcwhitney.com and silicone couplers. I'll even chrome the pieces for a nice show look. Pencil marks and a trip to the local exhaust shop should get them trimmed as needed for like 50 bux.

4. Larger T3 from a turbo Saab. The Saab turbos have larger compressor housings and should directly bolt onto the 280ZX manifold. I will only have to change out the O2 housing for the Nissan unit.

5. 3.5" Turbo-back exhaust. Why 3.5"? Because 3" mandrel-bent piping is what they recommend on all the other 4-cyllinder T3 turbocharged cars I own, and this is a much larger engine. Hell, I might even bite the bullet and go 4". I'll use press bends which are much much cheaper than welding up a bunch of mandrel sections, and the extra diameter will more than make up for it. My spool will be amazing. The cat section will be removable (i.e. flanged) so I can put in either a straight pipe or whoknows what. I have to find a 4" cat but I'm sure they exist. Otherwise I can run two 2.5" cats with Y-sections on either end, plenty of flow. For the muffler, hell, finding a 4" inlet/outlet muffler means sneaking into Supra TT territory, as some of those guys have them.

6. Gauges. What comes out: No more clock. No more stock boost gauge. No more oil pressure and water temp combo. What goes in, from left to right: Boost, O2, EGT. New Oil and Water gauges go on a pillar mount if I can find it, otherwise I'll make it myself.

7. Manual Boost Controller. I can and have built these things many times from home depot parts for like 20 bux. Bump it up on the stock fuel system until I see it leaning a bit. Then back it off another PSI for safety. Hopefully the stock fuel system can handle 2 more PSI. I can take a ziptie and put some restriction on the stock regulator's return line to bump up the fuel pressure a bit more.

8. DIY Extra injection. Cold start injectors from older Saabs are easy to find in local junkyards, and are cheap (or free depending on your scruples). You can plumb them in on the intake piping, after the MAF and before the throttle body. Wire it up with an adjustable pressure switch from Napa (adjustable to 30 or 40 psi I think), and set to click on where your fuel falls short as you turn up the boost. Using the 02 and EGT gauges you can see where that point is. Need more fuel? Add a second injector. OR, you can use a NOS fuel fogger instead, which is cleaner looking, and gives you the option to switch out jets. I'll go cold start, and play the KISS rule. They just plumb into your fuel rail with a brass "T" and some rubber fuel hose.

9. 18 PSI. I see lots of guys bump up to 12, sometimes even 15 psi. So why not 18? Of course I'll start at 10, then 12, then 15 beforehand. When I make the move to 18, I'll take off the head and rebuild it, add a copper head gasket, stud the block with ARP hardware, and put it all back on. That way the head is now sealed well. Next up comes the fuel support. A better flowing in-tank fuel pump. I don't know which, I'm not looking for a monster, just a reasonable increase. Between that and the extra injection I should be able to get to 18 PSI easilly. That should also be pushing it on the StarQuest IC, after 15 they're not all that efficient. But it should still be fine. Anything more and I'd have to opt for something larger like an NPR or a custom Spearco or Griffen core.

10. Suspension. I know I mentioned it last, but I said "go faster" so I went with the power mods first. Besides, my present suspension is in decent shape. Anyways, some kind of adjustable rears and fronts, probably coilovers so I can get the height where I want. Front and rear strut braces, and full swaybar package. Slap on a set of either Kuhmo Ecsta Supra 712's or some Falken Azenis tires, on the stocker 15's, and I'm done. Yes, I said 15's. Wider but otherwise I want to look stock. I don't need ricey 17" wheels and low profile tires, that's why I have all those other newer cars on my tagline below

There, the 10-step program I plan to put my Z through to make it go faster Comments?

Arro

Detonation is only the companion of the lean

That's what gauges and the old fashioned art of plug reading are for

And I know guys running 30PSI on stock T3 turbos (these are Dodge Daytona turbocars like the one in my tagline), and on stock longblocks no less. Go figure

lamneth9

I believe if you look the oil gauge is combined with an oil temp gauge; not water temp. Nissan traditionally puts the water temp gauge in the main cluster, with the notable exception of the 70-78 Z's. Oil temp is a very good thing to monitor on oil coled turbos, I have unfortunately known several people who have cooked their turbos blissfully unaware of this.


Lamneth
1983 280 ZXT, awaiting restoration
Former Z's;
1972 240 (2 of them)
1971 240
1977 280

lamneth9

My understanding of detonation is that it becomes a problem under high boost levels, the differential in compression (on vs. off boost) simply becomes too much; people used to use water injection to keep it under control.

Many years ago I was told the following saying: "Ya dump in lots of gas, lots of air, and when it starts to blow up ya dump in water..."

I believe this was prior to aftermarket engine management systems becoming as prevalent as they are today, so you couldn't have as great a difference in timing. As another person mentioned, larger turbos are an easier solution, the Garret T4's were used on Mustang SVO's and Merkur XR4Ti's and are fairly common.

Arro

That view of detonation couldn't be farther from the truth, it has to do with fuel stability and temperatures... fuel is not just a combustible, but is also an air charge temp reducer. So is an intercooler, be it air-to-air or water-to-air. Cold air and ram air induction help that too, as the air entering the turbo's compressor is much colder.

Turbos compress air. As the air does this the molecules squeeze together causing friction and generating heat. Fuel reduces this, so does water injection, by soaking up some of it. Too much water injection will be dangerous however. If there isnt enough heat to vaporize the water into steam, the remaining water will enter the combustion chamber and you will hydrolock the engine.

Depending on the octane of the fuel, gasoline is more or less stable at a certain temperature. 93 octane will have a higher stability range than 87, and thus you can run leaner with it. A nonintercooled car will run the risk of detination at less boost than an intercooled car. Either way, more fuel can be used to compensate for this, which is why one of the most common rules in turbo tuning is better RICH than sorry.

Timing can also cause detonation but then remember timing affects the air volume too which plays into air/fuel ratio all the same.

And finally yes a T3 can put down 30psi, 20 easilly. The reason why people opt for bigger turbos is that 20psi on small turbo "A" iis warmer air than 20 psi on larger turbo "B", meaning that you have to do less intercooling and worry less about air expansion by the time it reaches the combustion chamber. The reason why is because a larger compressor wheel can spin less revolutions to move the same air, thus heating the air up less.

But with good tuning, a T3 can push out plenty. Never sell your T3 short!