TimZ

Okay, I'm at my wit's end, here... I KNOW this must have been posted before, but I couldn't find an answer for this specific problem. I need to pull my diff, and I'm down to the point where I need to get the halfshafts out. With the u-jointed shafts, I knew how to do this, but the only place that I can see to pry on the cv shafts is made of SHEET METAL . I already bent the crap out of one of them, thinking that Nissan couldn't have been that dumb, and must have made that surface so that it could be pryed on. NOT. How do you guys go about removing these things? I'm down to pulling the a-arms, and dropping the whole assembly. But even then, I don't see how to get these things out without messing them up.

quote: Originally posted by 240Z Turbo: Hey TimZ, did you not get over 375hp@wheels by street tuning alone? Yes, this is true... Nice thing was that I didn't have to pay anybody anything to tune my engine, and I knew what I had when I was done. Granted, I had to spend some time learning how to tune, but I didn't see this as a negative. ...Still don't.

That sounds alot better. Do you have some method of checking the air to fuel ratio through the gears?

quote: Originally posted by Cerberus: If you want your tech II set up right you need a DYNO .Personally I don't like too piss into the wind you get all wet .You can screw with the adjustments all day ,but if you use a dyno 3 too 4 pulls you are DONE.SET IT AND FORGET IT!!!! I'm afraid I have to disagree with this. IF you use the datalogging features intelligently, you can do a very respectable job, without the aid of a dyno. As far as 3 to 4 dyno pulls to get a good calibration, I don't think so. IF you started with a calibration that was pretty close, then yes, you can do some very impressive things with a few dyno pulls. But, to say that you can start from scratch, do 4 dyno pulls, and be all done is dreaming. The trouble is that dyno testing (at least with inertial dynos) is really only helpful for full power calibration, which is a very small part of the big picture. It doesn't do very much at all for part throttle driveability, transient response, cold start, etc. - the stuff that you actually need 98% of the time. Granted, if you were talking about a more sophisticated dyno that could load the vehicle at constant speeds, then you could do alot more good with dyno runs. But in this case, you'd still need ALOT more than 4 runs. Don't get me wrong - dyno testing is a powerful tool, but it's not the only thing you need. Oh - hopefully this was obvious, but this applies to tuning any fuel/ignition system, not just the TEC. As far as the TECIII goes, the only things I've heard about it were along the lines of "Don't hold your breath".

Whatever you use for a fuel filter, it needs to be rated for use with fuel injection systems. The pressures are much higher, so you want something that can handle this.

I agree that you should just use a stock regulator. I'm still a little worried about the pump, though. As I recall, you were having a problem where the fuel pressure would rise to something like 55psi, and then drop to something like 40psi when the boost came on. Did you ever find out why that was happening? Did you check the fuel filter as James suggested? If you are going to be running 15psi of boost, your pump will still have to deliver 36.5 (base) + 15psi = 51.5 psi of fuel pressure under boost. If the pump couldn't maintain 50psi under boost before, chances are that it still won't. The big injectors should help, but if the pump can't flow enough, the pump can't flow enough. Just to give you some more doomsday warnings, here is a link to a recent thread on the Vishnu forum: http://www.vishnuperformance.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=1&t=000886 Not exactly the same situation, but similar enough.

I understand that it's a pain in the ass, and would understand completely, IF he had been selling the stuff as a hobby, which he apparently was not. That's just part of the cost of doing business, IMHO. I've always felt that if he thought it was 'too much trouble' to actually deliver the stuff he's selling, he should get the hell out of the business.

...It's "Maximum"

Scotty... I'm only gonna say it one more time... YOU NEED FUEL BEFORE YOU NEED BOOST! Have you addressed your fuel delivery problems yet? If you don't address that, I can guarantee that you'll be replacing pistons soon. Not trying to be a prick, but you really need to make sure you can supply enough fuel, BEFORE you start cranking up the boost.

Yeah - I thought I'd mentioned that they were really wide a couple of times before. I heard a story from an engineer on the program that they were considering the 5.4 DOHC for the Mercury Marauder, but it wouldn't fit in the Grand Marquis' engine bay! Think about that one for a minute. Apparently, the 5.4 is done with a stroke increase, and they actually increased the block deck height to do it. So, the 5.4 is EVEN BIGGER.

Okay, I'll take a crack at it... Could the problem be that the halfshafts will be impossibly too far back, unless the motor is located quite a ways forward? ...or is it just the sump being in the front? [ August 11, 2001: Message edited by: TimZ ]

My intake manifold has been modified to accept o-ring style injectors (see the recent post in the Fuel Delivery section), so my injectors will not help you. Unfortunately (for you, anyway ), I never used the stock injectors with my setup. I believe that James (240ZTurbo) had found some big injectors that at least had the same mounting arrangement at the manifold end of the injectors. I think they were from an RX7 or something. You might find something on that if you do a search.

Yep - those look like the same injectors, and I am also using an N42 manifold. I took a look at mine tonight, but did not pull the injectors. Basically, the holes for the injectors were drilled out to accept the o-rings of the Siemens injectors. I had a machinist do mine. You might be able to just drill it out, but the surfaces need to be very smooth so that the o-rings can seal properly. You would have to be very careful, and use LOTS of aluminum cutting fluid, and preferably a good drill press and a new, high quality bit. Same goes for drilling the fuel rail, BTW. The thing that I couldn't tell for sure without pulling the injectors was whether the mounting ears for the old injectors interfered - if so, then you'd probably have to use an end mill to cut the holes. In that case I'd just take it to a machinist. Also, the bolt holes for the old injectors were welded up, and the protrusions that they made into the manifold runners were ground smooth.

quote: Originally posted by Ross C: OK, now if one 'jet coated' a caliper (ie. ceramic coated) it would now be insulated correct and that's not so good? or a non-issue for overbuilt rear brakes that might not get hot anyhow? I've been trying to find out what might work for coating calipers..... I'm guessing that the powdercoat would form a heat barrier as well. The JetHot probably wouldn't be much worse. We've been through this before, but I'm not convinced that the 'emissive' coatings will help, either. While they should help the radiative heat transfer, I have a feeling that they might adversely affect the convective heat transfer - due to the coating blocking direct air contact with the caliper. I would guess that the 'emissive' coating would help when the coated part is in an area with little or no airflow, though. [ August 10, 2001: Message edited by: TimZ ]

No. The FPR's job is to keep the difference in pressure between the fuel rail and the intake manifold constant. The base pressure is the pressure that the fuel rail has when there is zero vacuum at the FPR's reference port. You can easily check this pressure by disconnecting the reference hose to the FPR and checking the fuel pressure (just to be clear the reference hose is the vacuum line that goes from the manifold to the FPR). When your engine is idling, it has a vacuum in the intake manifold, meaning that the pressure in the intake is lower than atmospheric pressure. In this case, in order to keep the pressure difference across the injector constant, the FPR will drop the fuel rail pressure. For instance, let's say your base pressure was 52psi, and your idle vacuum was 15in. 15 inches of vacuum is roughly equivalent to -7psi, so your fuel rail pressure at idle would be 52 - 7 = 45psi. Conversely, when you have boost, your manifold pressure is higher than atmospheric, so the fuel rail pressure has to be increased to keep the pressure across the injector constant. If you have a base pressure of 52psi and 15psi of boost, the fuel rail pressure would have to be 52 + 15 = 67psi. If you hadn't noticed, I picked my numbers there for a reason . From what you are telling me, it sounds like your base pressure is somewhere around 52psi. It also sounds like your pump isn't keeping up. Many OEM pumps, including the stock pump for the Z, have an internal pressure relief that keeps them from running too high a pressure in the event of a failed FPR or clogged return line. If the pump is not designed for a turbo application, this pressure relief is usually set somewhere around 55psi.

This was kind of surprising... I have been running 50lb/hr injectors at a base pressure of about 58psi, and this has been working pretty well. At the last dyno session, we noticed that the fuel temperatures were running pretty high, and with the recent high ambient temperatures, the pump had started sounding rather strained. This worried me, and after some thought, I decided to try going to larger injectors, and running at a lower pressure. I picked up a set of 74lb/hr injectors today - they were exactly the same brand/line of injectors (Siemens/Deka) as my old ones, and it took me about 5 minutes to swap them out. I ran the fuel pressure all the way down to 38psi and fired it up. Amazingly, after retuning for the different injector charicteristics, the idle quality is much better now - it still has a stable idle at stoich and leaner - it wouldn't do that reliably before. And, it was still running much richer under boost than before - I had to lean it out considerably. I fully expected having to lean things out under boost - even derated to 38psi, these injectors flow about 11 lb/hr more than the old ones did (each) at 58psi. I was amazed at how well the car idled, though - apparently the lower pressure allows the injector to open and close more quickly - the dramatic increase in dynamic range is a very pleasant surprise. [ August 09, 2001: Message edited by: TimZ ]

quote: Originally posted by scottyMiz: Under boost it's 55psi when it's idling it's 45psi. Also (this is important) are you saying that your idle fuel pressure is 45psi with the reference hose hooked up to the FPR? Your fuel pressure at 15psi of boost should be 15 psi higher than the fuel pressure with the reference hose disconnected, not the fuel pressure at idle with the hose hooked up.

quote: Originally posted by Ross C: Powdercoated?? Either I'm misinformed or...but isn't powdercoating applied at ~400deg.F?? Anyone pushing their brakes HARD will see that easily! And more on a solid rotor. I went to 13's to avoid 1000+ F. Ross - that sounds in the ballpark for powdercoating - I though it was a bit higher than 400degF, but not much. Remember, the caliper hopefully won't get to 1000degF, just the rotor. Assuming the brakes are working, the caliper ought to be at ~500 degF or less, since most brake fluids will boil above that temp. Still, sounds like regular powercoating would be marginal. I'm pretty sure there are higher temp coatings available - JetHot, for instance, is applied at 650degF as I recall, and once cured, is good to 1400degF.

So, your fuel pressure with the reference hose to the FPR removed is 55psi, right? What does it go to when you are under boost? (should be 70psi at 15psi of boost)

Scotty - Have you ever checked your air/fuel mixture under boost? Sounds like you could be running lean and misfiring. Actually, could also sound wierd if you were really rich, but I kind of doubt that is your problem. Were you still running a downpipe, and disconnected the rest of the exhaust from it?

Could you expand on that a bit? When you say zero brake pressure, what do you mean? Firm pedal, but no decel? Mushy Pedal, no decel?

In general, high impedance injectors have slower turn-on and turn-off times, which means that they will have less useable range. In other words, if you go with a high impedance injector that will flow enough for a high performance application, chances are that you won't be able to get them to work right at idle. For a performance application, stick with low impedance injectors. Why do the OEMs use them, you ask? The low impedance means that they can be driven by lower current drive circuitry, which is cheaper. Also, overall power consumption is lower, which is also important to an OEM. I've heard that the low impedance injectors have a longer service lifetime, too.

quote: Originally posted by Drax240z: Obviously the 15psi one would need to be stiffer not to leak, when compared with the same BOV in the 7psi environment. This is true, but it may not need to be as much stiffer as you might think. The opening of the BOV is controlled by the pressure difference across the diaphragm that controls it. Interestingly, if it is plumbed correctly, the two sides of the diaphragm will see the boost pressure at the point that the BOV is installed, and the pressure in the manifold on the other side of the throttle. The pressure difference between the boost pressure and atmospheric pressure should not come into play. Usually, they are set to open at only a few psi pressure difference, so that the BOV opens as soon as the throttle is closed, and the pressure surge is kept to a minimum. The reason that the BOV needs to be adjustable is that this pressure difference varies, depending on where the BOV is installed. If it is installed immediately before the throttle, the pressure drop at WOT between the two reference points will be pretty small, and the BOV should not be affected by changes in boost pressure. If, on the other hand, the BOV is installed before the intercooler, the pressure drop at WOT is now dependant on the amount of flow going through the intercooler. It is then very possible for the pressure drop across the intercooler to be big enough to crack the BOV open. Under these circmstances, it would be necessary to increase the spring pressure of the BOV, until the pressure drop across the intercooler was not big enough to open it. [ July 29, 2001: Message edited by: TimZ ]

quote: Originally posted by BLKMGK: Brian, running the juice straight from the battery, through the fan, and through the switch is NOT as safe as using a relay. You're requiring a small switch to handle large loads and being forced to run high current capable wire into the cabin. ...Oops. I agree with Blkmgk on this. I was only considering the safety of getting the current directly from the battery. You should definitely still use a relay.

quote: Originally posted by Brian_O: My question was "once the switch is upgraded and a fuse or link is installed in the circuit, is wiring it straight to the battery inherently dangerous?" I now believe from reading all above that the answer is "no". There seems to be an inclination for some to use fusible links over fuses, or vice versa. Does one have an advantage over the other(for any application, not just this one), or is it just a preference? Thanks! Your first statement is correct - it is not inheritently dangerous, so long as you place the fuse or link as close to the battery as possible. In other words, keep the length of unfused wire to a minimum. Fusible links are inexpensive and easy to install. Also, they can handle higher current circuits. However, they are not terribly reliable, and it is difficult at best to predict at what current level they will actually blow. There is a reason that you don't see fusible links anymore in modern cars. That said, they are still better than nothing. Fuses have much more predictable behaviour, but they are more complicated and expensive to implement. You need to use a fuse holder (obviously), and find a place to mount it, such that it is reasonably well protected from the environment. When our cars were designed, the current state of the art in fuses didn't have a reliable, cost effective way of handling high current (say, > 30A) circuits, but fusible links handled this pretty well. Today, you can get an automotive grade 'Mega' fuse, that is capable of handling up to 200A, but they are pretty expensive. All else equal, I would always opt for a fuse. In your case, you should only require a ~40A circuit (or less), so I would try to go with an inline automotive grade fuse. If you can't find a fuse holder with big enough leads, try looking at the fuse holders that are being used with some of the high end stereo equipment - they are kind of expensive, but they will accomodate 8 or 4 gauge wires with ease.