Six_Shooter

I am installing a 280Z tach in my 1973 240Z, and have run into a slight issue, my tach is not reacting like it should, slow and twitchy. In looking at diagrams I have noticed there is a resistor inline between the negative coil terminal and the tach itself. I have no indication of value though. What is the value of this resistor? This is a picture that I found in a search for reference of what I'm talking about: Thanks

I guess people here don't understand the other benefits of running a lrge sub, such as a 15". A larger subwoofer will play lower frequencies, easier and at lower volumes, for a fuller richer sound. I had two 15" subs in my 1985 Buick Skyhawk, that had probably a little less passenger compartment volumn than an S30, and it sounded sweet. I used an aperiodic "enclosure", in which there is a resistive membrane that tunes the resistance to the air mass to be exactly what the sub needs to play that frequency. Tight, accurate, and will play extremely low. The trade off is effciancy, it takes a LOT of power to make an aperiod enclosure play loudly. Mine was very effciant for some reason in that I would be able to break 130 db, IIRC I hit amaximum of about 132db, which is extremely efficiant for two 15s in an aperiodic design. I would use this style enclosure again, but in a hatchback design such as the S30, the rear wave would need to be vented to the outside of the car, and I like to keep my bass, and sound within my car. Also venting to the outside would introduce a path for moisture to work it's way through the membrane and into the enclosure, possibly effecting the subwoofers. I'll probably end up installing a pair of 10s or 12s in my 240, because I have 3 12s and 8 10s sitting in my basement right now, and if I don't sell them I'll use what I have. Is this overkill? Nope not in the least, especially when set-up for sound quality, in the right enclosure.

Sounds like you're talking about trying to vent the BOV into the exhaust pre-turbine, there's oine HUGE problem with that idea. The exhaust pressure pre turbine is commonly twice that of the intake, sometimes higher. I.E. 10 PSIG boost pressure will have around 20 PSIG exhaust pressure pre turbine. So the BOV would never open, due to the exhaust pressure holding it closed, and if it did some how manage to open, then exhaust gasses would then be introduced into the intake system. Good to think outside the box though.

In this pic: I see a black "hole" in the compressor housing, is that a blind hole (drilled but not all the way through) or is it all the way into the compressor housing, and causing a vacuum/boost leak? If it is open all the way through like I suspect, then I would say plug that and go for another drive, since it is after the MAF, that will cause havok, with metering the air and susequntaly the fuel needed.

Yes a clogged cat could also do what you describe, but I would think the temps of the exhaust after the cat would be lower if that were the case. What kind of exhaust pressure do you have at the tail pipe? I know this is kind of subjective without using some sort of pressure gauge, but you should be able to tell if there's decent flow (pressure) at the tip vs a lack of, that could indicate a clogged cat or muffler.

Have you tried replacing the O2 sensor? You say it runs fine in open loop (warm up) but once warm and goes into closed loop, that's when it runs poorly. Compression test? Vacuum leaks? Fuel pressure at WOT/under load? Check your ground between your engine block and chassis/battery, I've seen this be the culprit of far too many "incurable running issues".

71 lbs/hr injectors not too much for his combo? Looking at RCs calculator that kind of flow at .80% DC, .60 BSFC, and 43 PSIG delta fuel pressure, would support: 570 crank HP. Big-Phil is putting down just over 300 at the wheels (330 was it?), and there's no way there's in excess of 250HP being lost through the drivetrain. There's other factors as well that point to too much injector, his reported AFRs, which yes will go up with the alky injection, but I don't see any information on comparison to before any alky injection, and even if the alky is raising the AFRs by one point that's still more than 11:1, since Phill never said what the actual numbers were, just "more than 10:1", which in any engine is way too high, the DC being only 60%, the recent turbo failure that could be and very likely is related to the AFRs being so high. I can't say for sure what Phil is making for crank HP, but it would likely be around the 400 HP mark, maybe 425 at the crank, which would still be quite a bit of parisitic HP loss through the drivetrain, and for that power level would only require 50 to 54 lbs/hr injectors (525 to 567 cc/min). Working the formula backwards, at 60% DC, it shows to be supoorting 425 HP, for 71 lbs/hr/459cc injectors. I'm all for "too large of an injector", but Phil's just seem excessive.

This one is going to get eaten alive.

Forgive my ignorance of th RB series engines, but does the RB30 have a taller deck hight than teh RB26 and that's where the extra 38mm hight comes from?

As much as I don't care for the MS, I would agree and say the MS is a great option in this scenario. The option I'm going with is a little more involved in the retrofit of the ECM and harness, but I know the ECM I will be using well, and like to stick with what I know, and already have at my disposal.

I know people are going to scoff at this.... But Phil, do some looking around for info on the interweebnet, many, MANY people have proven the old "cast pistons are weak" theory VERY wrong, in that they will usually take LOTS of abuse before breaking down, or causing problems. What has been found is that any piston failures are usually due to a manufacturing defect, not the process in which they were made. Personal experiance, I used Hypereutectic CAST pistons in a V6 I built a few years ago, from Federal Mogul. They were stock replacements for the N/A version of the engine I built (3.1 GM 660 3.2L with the bore), I abused those pistons, with not enough fuel, too much timing, over 30,000 KMs of HARD abuse, and they looked almost brand new when I pulled them out of the block (after cleaning) and are now being used by someone else in another engine, that is also seeing plenty of abuse. Now I did have a good head on that engine, aluminkum with splayed valves and "fast burn" heart shaped combustion chambers that probably helped with some of the resistance to detonation, though at the big end of the track, when I had no where near enough fuel, the knock became so bad that the ECM pulled the timing and the truck literally fell on it's face, but would pull the front end up quite a bit when the timing would come back in. I just wish I knew then what I know now about tuning and had the equipment I might have been able to tune it better. Anyway, just saying that I'm sure you'll find that you can lean it out some and still be plenty safe with the tune. 10:1 AFR is too much for ANY engine, and surprised that you're not finding your oil level go UP after driving the car with fuel being added to the mix.

The restrictors go in the feed side. Restricting the return would only make any blow-by/seal leak problems worse. Have you tried running more timing than 20*? I've found that on other applications you can "lean out" a mix by adding some timing, at least to that point just before knock starts. I am really thinking that you just need smaller injectors, or at least reduce the PW up top.

Thank you, that gives me hope for the injectors I have, and plan to use. I figured that the alky injection was adding to the AFRs as well. It almost sounds like you're simply running it too fat, and causing some of the problems.

This is how you blow up a turbo:

Big-Phil, I gotta ask: "Handjob"? Umm did I miss something in the video, and glad I did? In all seriousness, what was your injector PW and duty cycle when in boost? You said your AFR was going "off the scale, beyond 10:1". This would lead me to believe that I could get away with injectors half the size (or there abouts) that according to calculations should support the HP your producing.

Man, I definatly couldn't wait that long. I've had my car in my possesion for 3 months and I've already changed it. Next up is turbo and EFI, and I'm working on getting the parts together and ready to install. I hope to have it on in less than a month.

Odd. That one was a bit tricky, since I have a vent that dumps right there, luckily it was soft plastic and was able to force it out of the way to put that bolt in.

Thanks.

Yep, we'll need to do that ay some point. Maybe cruise to an OZC meet together. Zed fest is coming up too, that I might go to. I'll give you guys a call tonight, and hopefully cruise out to check out your progress.

That was the frame rail.

I agree on leaving it as is. I work with a guy that has been screwing with one of his cars to "limit power" to allow his son to drive the car. He's been playing with timing control, throttle limiting, etc. He finds that it's difficult to drive (timing control had the car surging), accel from throttle limiting was dangerous to get on a highway, he still thinks there's a way to do it. Teach him about responsibility, and then go out on the car with him, showing him the proper way to drive. If he's anything like I was as a kid, he'll probably have no problem finding the "power limiting" device and temporarily disabling it whil you're not around. Ever car guy I know of that had thier fathers do this to them as a kid would joke about how they would disable the limiter and then re-enable it when they went home. If you want to give him a slow car, give him a slow car, not a slightly faster car, that has been detuned or modified to limit power. From what I've seen these cars are really no faster than a late '80s or early '90s Cavalier/Sunbird, which I had many of, first car was a 1981 Honda Prelude, wasn't slow, but wasn't a rocket ship either. Probably just about on par with the performance of a 280Z. I really don't feel it is safe to detune or modify a car for this purpose. There have been more than a few occasions, where the best way out of the situation was by powering away from it, and if the car was limited on power I don't know that I owuld have made it out of those situations unscathed. I can appreciate what you want to do though. I've read about this poor wiper performance, but last week I drove an hour each way to a Z car meet, and it rained for a good 60% of the drive, and my wipers were just fine, had no windsheild fogging problems (no A/C either), just turned the DEF on, and let it go. The rain wasn't exactly light at times either.

I thought the SRT-4 boost gauge was run from the ECU or at least connected in parralel with the MAP sensor, like the old turbo Sunbirds were. If it's mechanical, then have at it.

Well I put the synchromesh in tonight, but haven't had a chance to take it for a spin yet, the GF's car was parked behind mine, and didn't feel like moving it. There should be an improvement in the whine/howl I was getting, since I got next to no oil out of the tranny.

That would be great, check your PMs

No, the NSS/reverse light switch is on the passenger side of the tranny. Both wires are black. I'd like to find out where they go, becauxse I could then use them for other functions, without running new wires. I run wires in vehicles for a living the less time I spend doing that on my own rides the better. It looks like some sort of solenoid. I'll have to look in the fiche to see if anything is mentioned there, but I lost ALL of that when my last laptop died, even the links to get them.