ktm

I never had luck with my plugs gapped at 0.03, I was getting misses. I know that others have had to gap them down to 0.025 or even lower in an attempt to cure the misfire issue (not with LS1 coils but just in general here on Hybridz). I would venture a guess that the LS1 coils are not quite hot enough to produce the spark at 15 psi of boost with plugs gapped at 0.03 (don't know your AFR either); I know I was missing and you were too. It may not be an issue of a failure but rather strength.

I was going to respond to your other thread, but I will chime in here. Your current setup is fine, you just need to tune for it. You stated your AFRs were 13 to 13.5; while that is fine for an N/A application, it is death for a boosted engine. Just rebuild your current setup and retune. Target 11.5 to 12.0. Additionally, what is your timing like? I've found that you can only safely run around 20 to 22 degrees at 15 psi on California 91 octane; this is with a 7.4:1 compression engine (stock bottom and head). Your cam may allow you to run more timing with your 1mm HG and flattop setup, however, you need to do dyno tuning with the ability to detect knock. A thicker HG will give you more buffer with respect to timing, but you will still need to tune with a means of detecting knock.

My plugs are gapped at 0.025". My coil dwell is set at 6 ms and I am running Magnecor wires. My target AFR at the higher boost levels is 12:1. Any richer than around 11.5 to 11.8 and I start to get a slight misfire.

They are going to be reliable in the long term. We do not need anyone running around screaming the sky is falling, especially if they have not truly diagnosed the problem. I am running 22 to 25 psi of boost with my target AFR at 12:1 from 13 psi on. I do not and have not had misfire issues.

I would like to thank everyone for their insight. In the end I will just stick with the car after what Austin, Jon and others have said. I was just buttoning up the engine tonight after replacing a methanol injector controller (car has been down 2 weeks) and a damn t-bolt clamp that connects the IC hose to the TB broke. I had hoped to drive it tomorrow. Ah well, time to find one locally if I can so that I can drive it on the weekend.

I personally aim for an AFR of 12.5 up to 13 psi, 12 from 13 psi on. Below an AFR of 12.5 timing plays a much greater role in reducing detonation than increasing fuel. This based on my own tuning experience on my engine. You do not need to spend more money on upgrades to your engine. Your tune is what caused you problem. As a matter of fact, your attention to quality parts is what caused such a catastrophic failue. The 1 mm metal? Gasket did not fail but rather a ring/ringland. I've detonated 3 headgaskets to death myself while tuning. They were OEM though. I am successfully putting down around 400 wheel ft-lbs on a stock block, stock head and stock intake.

You detonated with AFRs at 13. Anything above 12.5 is dangerous especially on 91. What tuner told you to aim for 13 to 13.5? I would find another tuner.

Who assembled the engine? As Careless asked, what about a tune? How much boost are you running? You asked me about methanol injection and said you run race gas. Is this still the case? You cannot really 'safely' run more than 15 to 18 psi on cali gas. What are you compression numbers for all cylinders?

Phil, oh how I wish I could have another car. The wife's agreed, but only after we move to a bigger house. Z8Red, I hear you about modding for modding sakes. I've tried to adhere to my plan the best I could. I realize that I would have modified the stroker as well to a degree. I just need to drive the damn thing more. I've been cursed with a spate of new parts breaking which sidelines me, and then I get the "while I'm at it" bug.

It looks like it has canards on the valve covers.

Doh! My mistake , I looked for it before posting but apparently missed it.

I can't really explain it, maybe its's just a moment of weakness brought on by my constant tinkering. I have myself convinced that a stroker, while less powerful, would yield more enjoyment because I would stop tinkering with the damn thing and just drive it! This is probably just one of those self-pity pleas that you need to air out every once in a while and have a buddy that will usually slap some sense into you.

Picked this up at zcar.com It's a small world after all Just read #1 and #4.....

The past few weeks a little thought that was in the back of my head has been nudging itself forward. The more I work on my car, the more modifications I do, the more persistent the thought. Basically, I've deviated away from my original plans for the car.....deviated quite significantly I might add. I originally wanted to do a stroker setup but convinced myself that price per horsepower was important, so I opted to go turbo. I love my setup, but I really am feeling that I should have gone the stroker route. I've been toying with the idea of trying to arrange a trade.....my car for a well-sorted, 1972 or earlier 240z stroker with triple mikuni's or ITBs. Am I nuts?

How is the "factory service manual" too general? How is the wiring diagram contained in both documents "too general"?

Rear rotors are quite easy to find. The front rotors, however, are damn near impossible. deja, thanks for the link, but they do not make a distinction between turbo and non-turbo products. For instance, Powerstop does not make a non-turbo front rotor: Powerstop

The problem does not lie in our ability to read but the way in which you made your statement. Thread title "LS Coils Fail" Quote "just a word that LS coils are not bullet proof" Without going into any other discussion, you come out with said thread title and statement. There were more than 1 of us that came to the same conclusion after reading your thread.

It is irresponsible to blame the coils when you have no idea why you have a misfire. Plugs gapped correctly? Condition of plugs? Plug wires? Tuning? Low AFRs? Coil dwell settings? Timing? Professional installation means nothing. I installed my own and I am pushing 22+ psi without misses. I did have misses earlier, but it was due to plug gap and AFRs too low at that psi.

The small box you are referring to is most likely the ballast resistor. In the picture below, it is the rectangular shaped item under the blue coil. The tach is not working because the wires to the ballast resistor are not connected correctly.

The original mount relies on a a single bolt for the structural support. The upper bolt is not used for structural support only lateral adjustment of the alternator. If you opt to use the turnbuckle, that will provide the additional structural support you are seeking. Don't take this the wrong way, but I think that you are overly concerned about the mounting on the alternator.

I've been looking for a few days now trying to track down aftermarket vented rotors for the 300zx swap. All I can find are OE replacement rotors. It looks like I am going to have to go with the OE replacements unless someone knows of a place to pick up some nice aftermarket units.

http://forums.hybridz.org/showthread.php?t=137235 The alternator is mounted using a Class 10.9 (SAE Grade 8 - can't get much better than that) 10 mm bolt. Flimsy is not the word I would use. Edit: I should also clarify that if you go with the turnbuckle as shown in the picture, you do NOT need to modify the upper part of the alternator, since the turnbuckle eyelet attaches to the outside of the alternator tab.

My sister lives in Raleigh-Durham and emailed me the pictures as well. Pretty incredible. I would love to have a snow day or two again.

Was that a Jag at 2:28 in the other lane? Incredible performances.