z-ya

yes, you can use E12-80, but you still need to lock the advance mechanism. Yes, you can use a VB921 for the driver as long as you are running a V3 mainboard (or a modified V2.2). It is probably easier to use an HEI module than retrofit a VB921 to a V2.2 mainboard.

Can you give us more information about your setup? Initially, it sounds like you need to make adjustments to the acceleration enrichment and or your fuel map.

I'm OK with chromed fiberglass, plastic, lexan, or whatever. As long as they have the look. Good thinkin' Tony. To help the effort, I'd be interested in two sets.

I'm curious to see if a metal fabricator could just make the metal trim. Make it from stainless so you can chrome or polish them. Make the trim so it would work with the MSA style covers but have the metal trim cover the holes. Or, find out who makes the covers for MSA, and have them make a bunch without the holes. 2ManyZs: yea, I know Ken has been trying to pry a number of things from you. But you know, it is a shame to keep those hidden away in a box somewhere. They need to be proudly display on a nice Z (like mine, or Kens). Seriously, if we did find someone that could make them, can we borrow yours just to use as a template?

Has anyone seen headlight covers for standard headlight buckets (non-gnose) that have the metal trim? Hear is what the gnose versions look like:

I stick built my trigger bracket using 1/8" solid steel rod, some 1/8" plate, and a welder. http://www.zccne.org/gallery/albums/clubcar2006/DSC00006.jpg Absolutely rock solid to 7000RPM (rev limited) and easy to make.

I'm running 8psi, and like I said, even my 6 groove serpentine belt slips at high RPM when just slightly loose. Find a 6 groove pulley in the junkyard and save yourself some hassles later on.

You also need to drop the oil pump to change the distributor shaft for the ZXT disty.

I have a feeling that something is not right in how the VB921 is connected to the coil. Check your wiring again. Let the car sit, then have someone else start while you put your finger on the VB921. If something is shorted, it can heat up quickly, causing it to dies after a few seconds. That is where I would look.

The VB921 will only get warm if it is firing the coil. So when it dies, if you crank it, you get no spark? Or does it then start and run for a few seconds?

Take the cover off the MS, and put your finger on the VB921. Does it get hot?

No spark at all? How do you have the coil wired? What coil are you using? Sounds to me like your VB921 coil driver is shot. Did you run it at all with the spark output not inverted? It will overheat and burn up in a matter of minutes if you did. What is your dwell set to? It should be in the 2.5 to 3.0mS range for a stock ZX coil. Did you run it with a large dwell setting for a period of time. This could also damage the VB921.

Yes, you can. If you have a V3.0 MS, you can connect it like your diagram. You can also use a GM HEI module to trigger the MS. You can then either use another GM HEI module or a VB921 to drive the coil. From Moby's FAQ:

Do you have the spark inverted in the spark settings menu? Are you using the VB921 to fire the coil? If you the spark output must be inverted, or the VB921 will overheat. can you give us more information about your setup? Pete

If MT doesn't like your TPS settings, then you have to figure that out first. What typically happens is the VREF and GND are wired wrong (outside pins on TPS connector. Try swapping the VREF and GND signals on the TPS. If they are wired wrong, the TPS calibration will return a lower value for WOT vs. idle. MT wil report that something is funny.

Nice look!

Mike and I have been exchanging PMs in this, but basically this how to upgrade injectors when using MS. First thing to remeber is that not all injectors flow fuel at the same rate of change (flow vs. duty cycle). So two different 380cc/min inectors of different design will have a different flow vs. duty cycle plot. So when you upgrade to a higher flow rate injector, you cannot just change the "required fuel" setting in MT. You will need to make changes to the fuel map. Especially at the higher duty cycles (higher engine loads). This is how I have upgraded in the past. Let's say we are upgrading from 270cc/min injectors to 380cc/min ones: First, if you are using the calculated required fuel setting that MT does, do the same for the new injectors. If your required fuel constant is different than what MT calulates, then reduce the required fuel number by the percentage flow rate increase of the new injectors. This should get you close enough to get it started and idling. Let the motor come up to temperature, and then adjust the required fuel constant until you get the idle as smooth as possible. The math: Flow rate % increase = 1 - (270/380) = 0.29 x 100 = 29% I've done this upgrade, and the required fuel constants are as follows: 270cc/min = 11 380cc/min = 8 Required fuel constant increase = 1 - (8/11) = 0.27 x 100 = 27% So you see that the required fuel constant comes out almost correct. This is close enough to run it and drive it easy. The top end will be rich, but after tuning the top end, you will find that the injector opening time increase in the fuel map is not proportional to the required fuel constant increase across the fuel map. The bottom line: You will need to retune the fuel map for max power, but just scaling the required fuel constant will get you close enough for idle and cruising.

280ZEDX, I really like your setup, nice job on the fabrication. I almost want to mount my JCR SC on that side, just so I can run an air to air intercooler.

I still beleive that the closer the sensor is to the intake port on the head, the more accurate the measurement. Anywhere upstream of that will be less accurate IMO.

The N47 is what you want, mainly because of compression ratio and exhaust port shape. The N47 has round exhaust ports (with liners), and the N42 has square (no liners). Other than that they are the same. So if you have a round port header, stick with the N47. Better yet, find a Maxima N47 (MN47), it will give you slightly higher compression ratio. It also has a more modern combustion chamber shape (peanut). A P79 or P90 head will lower your compression ratio.

trwebb26, it's OK that your sensor is reading 130 deg, because that is most likely the actual intake manifold air temp. With the butterfly closed, and engine not running, there is no air flowing through the intake manifold so the IAT can increase greatly. I don't consider this heat soak. The IAT sensor is reporting the correct IAT to the MS. The MS uses it's IAT compensation algorithm to modify the mixture so that it is correct for all air temperatures. That is why I have a problem with locating anywhere but the intake manifold. If it is not mounted in the intake, it will give a false IAT reading to the MS.

Are you are using an open air type sensor? The sensor is already thermally isolated from the threaded collar. Not sure if any more isolation would help. I'm also not sure why people having problems with heat soak, but we've been there before. Every install I've done, I put it in the intake manifold, and none of them show any signs of heat soak. Even when using the CLT sensor as an IAT (no thermal isolation).

Why were you running it without an IAT? Do you have a stimulator?

Do you have +12v on one pin of the injector? Do you have resistors in series with the second injector pin and the MS? How do you have the injectors wired (3 in parallel on each injector driver)? Have you tested your MS on a stim?

Does MT show a steady RPM when cranking? Do you have fuel pressure when cranking?