z-ya

What year is the tach in your 240Z from? 70-72 are current sensing. 73' and later models are voltage sensing. If on the back of the tach there is a loop of wire going through a plastic fixture held on by one screw, then it is a current sensing tach.

This is not entirely true. The PWM current limit % is actually the inverse of the current limit. It really should be called "PWM Current", with the limit being removed. At 100%, the current is not limited, and this is the correct setting for low Z injectors with series resistors installed. At 30%, the current is being limited 70% by the PWM circuit (or 30% of the current is being allowed, depending on how you like to look at it). None of the PWM settings have anything to do with injector duty cycle. This is entirely controlled by the required fuel variable, your VE table, and engine load/RPM. datman, your settings are fine. The PWM circuit only allows 30% of the current to flow through your injectors. The PWM circuit protects both the drivers and the injectors.

You really need a current probe to measure opening time. A voltage probe can measure the pulse width, and also confirm your PWM settings (if you use them). But to measure actual opening time, you need a current probe.

Stock injectors are around 2.4 Ohm So 3 in parallel = 0.8 Ohms. Your three 6 ohm resistors in parallel = 2 ohms 0.8 + 2.0 = 2.8 Ohms If you wire them like this attachment, you will have around 8.4 Ohms for each injector/resistor combination, which should be good. wiring.txt

Is this how you plan on wiring each bank? Bank1 +12V ---- INJECTOR -----RESISTOR--------------- DRIVER1 +12V ---- INJECTOR -----RESISTOR--------------- DRIVER1 +12V ---- INJECTOR -----RESISTOR--------------- DRIVER1 Bank2 +12V ---- INJECTOR -----RESISTOR--------------- DRIVER2 +12V ---- INJECTOR -----RESISTOR--------------- DRIVER2 +12V ---- INJECTOR -----RESISTOR--------------- DRIVER2

I always put a single resistor in series with each +12v inejector lead. Five Ohms, 5-10W is usually OK. Run one 6.2 Ohm on each driver output. Two ohms is too low.

Shine a flashlight into one of the spark plug holes with the piston at TDC. If it is a flat top piston, then there is nothing you need to do besides maybe a performance cam, header, intake, exhaust. You don't need forged pistons for an NA L6. The N47 head flows almost as good at the N42, and at your HP levels, you are not using all that the N47 can produce. I'm running one on my race motor and it's making 180WHP with a medium cam, header, exhaust, intake, Just intake port matching was done to the head. Drive it, and enjoy it.

What resistance/power rating did you order?

I've had this problem on other ECUs that use the Ford VR sensor. Each time the fan turns on, the engine would stumble because the VR signal was interfered with. When the fan motor starts, a spike of EMI (electromagnetic interference) is generated. If the sensor is close to the fan motor, this will induce an unwanted signal into the VR sensor. Best thing to do is to move you fan away from the sensor. I found that within an inch, you will have interference. Move the fan so the fan motor is 3-4" away from sensor.

Great info, thanks for posting it.

If it has the stock dish pistons, a P90 head will lower the compression ratio to around 7.5:1. Not good for NA power. Check the casting number on the block. If it is an F54 block, it might have flat tops in there. This will get you close to 10:1 with the N47 head.

The chances of having a bad piece of shielded cable is rare. Consider yourself lucky (or not)

The majority of the time the opening times are slower though. I think I had one injector that had a slightly faster opening time with a 4 Ohm series resistor. In general though, adding the series resistors makes a low Z injector into a high Z one, slowing the opening time.

Rick is right on with the PWM description. The PWM is simple way to limit the current when in the hold state. Look at one of the current plots from my measurements, you can see the PWM current ripple. I have made some measurements with current limiting resistors and the PWM off, and the opening time is less that if the PWM settings were optimized without resistors. I've run injectors in PWM mode on the stimulator for hours at 85% duty cycle, and the output drivers barely get warm (my Wife asks what the hell is that clicking sound is coming from my office!). I think that your injectors are just getting hot on the track. They are fine on the street, right? As the injectors get hot the opening characteristics can change, especially if you are on the hairy edge with your PWM settings. What injectors are you using? Tony, I totally believe in the KISS principal, and I'm not talking about the rock band either

Rick, Are you using a stock Ford trigger wheel on the car and the drill press? Does the VR sensor output look the same on the scope when running on the drill press as when on the engine? The VR signal is supposed to look something like this: There is a 0.5V hysteresis so that the EDIS module ignores the VR sensor output until it crosses 0.5V. Is the VR output 10Vpp? I would trigger the scope on the voltage droop on the EDIS module and look at the PIP output with the other channel. If it looks like the PIP output goes off consistantly after the voltage droop, then it is most likely the EDIS module resetting. Try running the EDIS module off a different +12V source, or put a stout battery charger on the main battery. Let me know how you make out.

Hey Rick, You should try calling Technotoytuning directly: (530) 626-7334 Great to meet you at the convention.

I did a similar thing putting a head back on. I didn't get the cam timing right. The engine ran, but was like a slug. Then I checked the can timing and it was off at least a few links. When I pulled the head I got the same smilies you've got. All but 3 valves were lightly bent, but the guides were OK. Yea, it sucked, but I got it back together just in time to blow some ring lands detonating under boost. So that motor is totally toast. It's only money.....

The stock dle fuel pressure should be in the 35-40psi range.

You can set it to 1.0ms if you like, and you will most likely be OK. I optimized the settings for the injectors in the spread sheet. The MS manual was probably written just using Megatune and a running engine, without a current probe and scope.

I think the manual is talking about injector opening time, not PWM threshold. You should keep the injector opening time set to 1.0ms.

I have to agree with Ron. Finding a reputable dealer that can help you work out all the kinks in your install, and help you tune it is extremely important. Begin shameless plug for Ron: I've used Wolf EMS systems in a number of installs with great success. The RB26DETT swap that I'll be involved with this winter will use a Wolf system from Ron. End shameless plug for Ron

Have you ever looked at a tire wheel combo and said that either the rim is too wide, or too narrow? To me, if the tire sidewall is on the same vertical plane as the wheel mounting surface (parallel), it is a good fit. If the sidewall pitches inward or outward from that plane, then I would define it as negative or positive "bulge" respectively. Does that clear up my not so technical use of terms? I'll take some photos and post.

There are probably 50 different systems you could use, each one with with it's own advantages and disadvantages. We could exchange posts for the next year and not talk about all of them. I think you need to see what other SCCA racers are using, and also do some reading in the "Engine Components" section of this site. There are a number of head to head competitions out there too.

Lot's of people run 225s on 7" rims. The actual tire determines how much they bulge. The 225-45ZR15 Hoosiers fit great on 7" rims with very little bulging. The 225-15ZR15 RA-1s are a different story on 7" rims. The 245-45ZR16 RA-1s fit nice on 8" rims. I know a lot of racers that run 225s on 7" rims (like every SCCA ITS racer).

What did you have your shocks set to? I run 3 in front, and 5 in the rear on my silver car at the track. I set them to 1 on the street. I have 250lb springs on the silver car. The old Bad Dog (junkyard dog) leaned almost as much as your car with 250lb springs. It would lift the inside front tire in tight turns. It now has 350lb front and 375lb rear on it. The lean you do see is mostly the 225-50ZR15 RA-1 tires. They have a fair amount of sidewall. I changed to 225-45ZR15 Hoosiers later in the day, but I don't think any of the photos are with those tires on the car. The RA-1s are great in the rain, but not so great in the dry as compared to the Hoosiers. I'm also not running a rear sway bar as the car turns much better without it.