TimZ

...trial fitment of the GT4294R It's huge, but it looks like I should be able to get it to fit. :mrgreen:

If the engine is allowed to run lean, or with too much retard I could see this, but I don't think a properly tuned turbo engine should see exhaust temps that are appreciably different from N/A. Granted, it's probably easier to get yourself into lean conditions or not have enough timing while tuning a turbo motor. I gererally run ~1450F at full boost. Isn't that about what N/A engines target?

I liked the original better...

I'm more inclined to think rust in the tank like everbody else, but did you ever try running with the gas cap loosened? Could be the vent lines are clogged, and the longer the engine runs, the bigger the vacuum pulled and the harder to draw fuel from the tank. This effect would probably be worse with a fuller tank (less air - the vacuum would grow more quickly).

If you make sure the cam and crank are aligned like this' date=' then you won't be able to get it wrong - the bright links will only align with the correct (marked) cam sprocket tooth. The three marked teeth are spaced too far apart to be able to reach the wrong ones if you use the above rough alignment. [b']However[/b], you DO need to worry about getting the bright links on the correct (marked with a dot) tooth - you don't want to be one tooth off. "About 2 o'clock and 4 o'clock" is definitely not good enough - that's just where you need to look for the correct timing marks. I guarantee it will run like sh!t if you are off a tooth.

Based on what? I guess I haven't researched it that thoroughly, but at a glance, the MegaSquirt appears to be on about the same level as my TEC-II, except with 12x12 maps (before anybody gets all mad, I'm not saying there is anything wrong with that). The AEM has an almost ridiculous amount of tuneable parameters, unless they have grossly simplified it lately.

btw, the plugs are salvageable, if you have a propane torch and a bit of patience. What has happend when you foul a plug is that the ceramic insulator around the center electrode has gotten a coating of conductive material (carbon), so your ignition coil's energy can just jump across that (much easier) instead of jumping the spark gap. You can take a propane torch and burn the carbon coating off of the center insulator (the one 'inside' the plug, not the insulator that the plug boot goes on), but it takes a while, and you have to keep the insulator red hot until it looks white all the way around the center electrode again.

That looks like you are going in the right general direction. Just to make you feel better, if the money that you had wrapped up in the N42 was from the cam (as opposed to really well done port work or something), you almost certainly would have wanted to change the cam out, anyway. N/A performance cams don't work well at all in turbo engines - the stock cam will probably work better. Also, the advice on getting something else for the turbo should not be discounted. This can make a really big difference, especially in the amount of heat added to acheive boost, as Scottie already mentioned - just because you have dropped your cr doesn't make this any less important. You could always sell your Z31 turbo on eBay and get something else...

Those are a second manifold vacuum summing network - the tubes feed a balance pipe that was integrated into the plenum. This secondary vacuum source is used to feed things like the brake booster and other vacuum accessories, and for the idle controller. I wanted these on an independent line, so that they wouldn't have undue infuence on the vacuum signals that determine the fuel delivery, like the MAP and the FPR reference. Thanks, Jeff. The clutch and trans (gForce T5) are holding up fine, so far. And yes, I did go to an r230. As far as how the car feels, it's noticeably lazier off boost, but it pulls really hard all the way to ~7000rpm. I did some playing around with driveability tuning, and it's really made a big difference. Also, as mentioned before, I'm really thinking that this cam just doesn't like backpressure at all, so the addition of the GT42R might actually help out quite a bit (crossing fingers). ...all too aware of this factor. At this point, everything out to the wheel ends has been upgraded, so hopefully things will hold together. We'll see...

Does this help?

It's mounted on the summing network that I made from fuel rail.

Cool - that's realy good to hear - at least now I don't have to feel like I ought to figure out how to make the Cannon piece work. ...me niether. Thanks, Tony

Ummm - yeah, I'm pretty sure Tony knows how the ECU works. I think that in the text you quoted, though, he was referring to using an N/A EFI setup on a turbo car. So, when the boost hits, the AFM gets pegged almost immediately. If the AFM is pegged, the ECU won't add any more fuel. Also, although Bastaad didn't care for it too much, the quote about the RRFPR being a bad carburetor is pretty much dead on, technically. If you look at the number of things you can tune, at least on a carb you have main and idle air and fuel jets that you can play with (sometimes more, depending on the carb). With the RRFPR, you just have one adjustment for fuel versus MAP, and that's it. In other words, if you were using a carburetor with that amount of adjustability, you'd most likely find yourself wishing you had bought a better carburetor.

I know what you mean - that's kind of my initial reaction too. However, it's really pretty much the same as using a 2mm head gasket to lower your CR.

Sorry - couldn't resist posting it again.

Yep...http://forums.hybridz.org/showthread.php?t=105832 This was on 94 octane Sunoco pump gas and 24psi. The head has been reworked, but most the the work was in the ports. The combustion chambers have mostly just been smoothed and ceramic coated. I have not had much in the way of detonation problems. Had some cooling issues that I have attributed to the electric fan and water pump, and the healthy intercooler that blocks the path to the radiator. I recently went back to the mechanical fan and water pump, and that issue appears to be gone.

You could opt for an N-series head. Smaller, open combustion chambers, so the quench wouldn't be an issue. What CR would 44.6cc net you?

I can't believe I'm adding to this post... I guess it's a good thing I don't build my car to please you. Personally, if anything ever happened to my L series, the turbo SR20 swap is probably what I'd do. I see lots of advantages (weight, package space, aftermarket support, for instance), and they can make some very serious power. Saying it's not an upgrade, even if it makes 1000hp is the dumbest thing I've ever heard. Have you looked at the SR20'ed Zs that exist on this forum, and their level of workmanship and performance? Or do you just care about how many cylinders it has? So let it go already!

Let the engine sit overnight, then back off ~1/8 turn, then retorque. I always back off each nut, then retorque it individually. I don't recommend backing them all off at once.