Six_Shooter

I don't think we are agreeing, completly. I prefer higher SCR engines, due to better off boost drivability, better combsution in off boost conditions, which can make for a more efficiant engine, and reduce emmisions, and in theory a higher SCR enging could spool a turbo sooner. I've read theories about a lower SCR engine being able to "injest more" air and fuel mixture than a higher SCR engine, but I don't completly buy into it. The difference in volume between TDC and BDC is what is more important, and that difference is larger with a higher SCR engine, hence the increased SCR. Again, I've seen reports where increasing the SCR reduced detonation probability, due to the better quench and control of the mixture in the combustion chamber. I do believe that even old engines can benefit from newer control technology, hense why I have a semi-late model GM ECM running my L28. Those kits that you speak of, do they tune for each installation, or just a general tune? Is there any tuning at all? Using single digit boost levels (that produce a certain amount of desired power) on stock engines is a safety net. If you look hard enough people that own those same cars/engines wil have pushed the limits on thier own, and tuned the controls appropriatly. There could be other variables like piston esign (though I know some BMW forced induction kits come with new pistons, with a better design), or crank limits, etc, I wouldn't look at the SCR as being the sole factor. I think you're still getting caught up in bigger peak numbers = better, and to some people it is, but teh reality is, if we advertised power increasing products with an "average increase" or showing something a little more meaningful like an increase in area under the curve, or even extending it, like forced induction does well, then less people would be interested in the overal peak number and more interested in the gains that matter. A larger peak number does not always mean that there is a large gain elsewhere as well, doesn't mean it doesn't, just isn't an indication that it does. I think you're also getting caught up in the "boost numbers" too much. Again, the numbers that show up on the gauge are really just for reference, we should be measuring CFM, or some measurement of airflow to really be able to compare numbers in a manner that will tell you something. The single digit boost numbers on those late model engines could very likely exceed in power what double digit boost numbers on other engines of similar design and displacement could. Again, there are many variables that need to be looked at when building a forced induction engine, or putting forced induction on an existing engine, SCR is rarely of any real concern, I look at more of the design and better yet how the engine reacts to the increased air flow, and tune accordingly. Yes you are correct, I am passionate about my point of view, I've seen way too many people follow advice that was well meaning, but then be disapointed with the results, rebuild and follow possibly "less conventional" methods and be blown away by the results. Sometimes a nudge in a certain direction is all that is needed to find a new means to an end. I'm not saying disregard what has been done previously, just look at why it was done that way and look at what could be improved on, and why something worked or failed in the past.

In all the years I've seen dyno charts and racing times, I have never once seen a lower SCR engine with more boost create any more power than a higher SCR engine with the same or even a little less amount of boost, as much else being equal as possible. I'm not syaing it hasn't happened, I just haven't seen it. I'd also want to look at other aspects too. What people seem to forget is that "boost pressure" is really just a measurement of restriction in the intake tract, and the largest restriction is (just about) always at the valve itself. Where all that air that people jam through 4" IC pipes, huge intercoolers and larger intake manifolds, ends up hitting the bottle neck of turning and going into the cylinder itself. This restriction at the valve or head port is hat causes the pressure in the itake when the forced induction device (turbo or supercharger) is pushing more air than the engine can actually injest on it's own, this part should be known by anyone using forced induction, and bring it up just to make sure we are all on the same page. Now our goal is not really to make lots of "boost pressure", Boost pressure as read on a boost gauge, referenced from the intake manifold really is irrelevant and can only really be applied to that particular engine or set of engines all prepped the same. What we really care about is cylinder pressure, higher cylinder pressure, with the correct amount of fuel mixed in and proper spark, delivered at the right time to create max cylinder pressure just before the piston passes TDC, is what creates the horse power we long for. If you were to open up the restriction, in this case the valve/head port, you would see a drop in "boost pressure", for the same power being made, or more specifically same CFM. So now we have less "boost pressure", more CFM, and higher cylinder pressure, that means more horse power. Yes, I am simplifying this analogy. Now what else can be done to increase this cylinder pressure?, that's right, squeeze that air and fuel mixture a bit tighter, by raising the SCR. What most people do wrong when they raise the SCR, or just leave it alone as in the case of adding forced induction to a non-factory forced induction engine is leave or install improper controls. The main controller that we never seem to look at is the nut behind the wheel, this is the biggest contributer to engines blowing, forced induction or not. It is these controls that have the biggest effect on the longevity of an engine, not the SCR, not the cam, not pistons, not the block but the controls. You can have the best parts ever made in an engine, but with poor control of those parts it's never going to perform well. On the flip side, and I've seen this, you can assemble an engine with seemingly junk parts, but with good controls on these junk parts the engine can last for a very long time, and quite probably out perform that "better" engine. My experiance is not unique, it's from planning out what I parts I use and not allowing my right foot to get a head of my tune. For all intents and puproses, my engine is assembled with junk parts, many are stock parts from various applications I just applied many years of my own experiance and a lot more of what I've read and information that has been shared with me by others that tend to break away from "conventional wisdom", and find out what really needs to be done to make something work well. Most "max effort" forced induction engines I see are now well into double digit static compression ratios. I've seen quite a few street driven engines, that have double digit SCRs and live with being daily abused for quite a while. This is not a new idea either, people have been pushing this way for quite a few years, just the majority scoffed at the idea because it's not how it was done before, without realizing what was actually different, being the controls. We also have better control of manufacturing processes, that allow previously considered "weak links" to be made with better precision, and allowing them to be abused more before failing. Now if all you had to control your L28ET, was the stock L28ET electronics box (I have a hard time calling it an ECU, due to the very limited control it actually gives), then yeah, raising compression is not recommended, nor is adding more boost, that's just a problem waiting to explode. Same goes for a newer car, even one that has better controls, lets use a WRX for example, add a boost controller to a stock WRX and crank the boost, it's going to likely live a short life, same goes if you decide to change just the SCR, or just the injectors or what ever part you want to, without tuning for these changes then the controls are not matched to equipment and I'll go back to my previous statement that the controls are what will determine the reliability and longevity of a given engine. A few decades ago, all we really had were carbs and by todays standards poorly designed spark distributing devices that would allow the engines to run and would actually run pretty decently, but maximizing the combination was very difficult and would usually lead to either a good running engine for drivability but poor WOT/top end performance or a good WOT/top end machine with poor drivability and then there were the select few who would have a decent compromise in between, and it is these people that realized that the compromise was a much better way to go. You speak of area under the curve, well I'll take a wider "area under the curve" with less peak power to a large power peak anyday. The reason being, that during acceleration, most engines go through fairly wide ranges of RPM operation, at shifts, changing as much as a few thousand RPM, having a wider flatter curve, means that you will be in accellerating more than waiting to hit the power peak than the guy that has a very peaky power band (provided he doesn't have more gears to keep the RPM tight). If I was driving at one or a very small change in RPM, than the peaky engine would be more desirable. But I know that I use my car, as most do, to regularly to head down to the store to grab some snacks, to work, out cruising, etc, I don't want to have the need to rev it to a few thousand RPM, just to get it near a power peak, I like my broader curves, thanks. I do agree that "ideal" paramaters of an engine are determined by many specific factors to how that engine will be used. I haven't seen anyone ask what the use of the vehicle is, commuter, road racing, drag, auto-x, etc, not that knowning the type of use would help lock down what SCR anyone should have, but it would help determine other factors in how the engine needs to be set up and ultimatly controlled. Just arbitrarily saying to someone that XX.X:1 SCR is what you need is like saying this is the food you want to eat without asking what thier prefences are. You may tell them they want chinese cuisine, when they really want a steak. Get what I'm saying?

Tach, comes out the front.

Again, it doesn't matter if it's carb or EFI, the back feed happens on the same circuit that powers up the EFI, so regardless of induction/engine control with the diode the car will stay running. Not ALL alternators are like that, just some, and the 280Z/X alternator may be like that, personally I used a GM alternator in mine, I didn't need to add a diode. I can't explain why the wire would get that hot, I didn't make the adaptor harness nor see it first hand. Yes, both sides of a two tower coil should have the same spark intensity, or at least so close that we wouldn't be able to tell without using some test equipmet to measure spark energy.

Just bypass the resistor. If the output from the EDIS didn't work, the output from the MS likely won't either.

The diode is so that the alternator does not back feed the ignition wire, and keep the ignition circuit powered up. Has nothing to do with what engine control you are using.

All this talk of extremly low SCRs makes me cringe. I have never ran anthing lower than 8.8:1 on a boosted engine, a couple as high as 9.6:1, one of my next builds I plan to push it to around 10:1 (next one will be around 9.5/6:1). SCR is just a guide line. There is one post so far that I've seen in this thread has some good insight, cam events, and a few other variables can really change what the actual cylinder pressure is. Another thing to consider is that on some engines, raising the SCR, with no other changes has reduced the tendacy to "knock" or pre-detonate. Some say this is due to the higher quench that is acheived with a higher SCR engine. People are absolutly astonished that I am running a turbo on my 8.8:1 L28, and wonder how it doesn't detonate. Especially running no IC (plan to soon enough) and pump gas (91 octane). All this talk of lowering the SCR IMO should be left in the '60s where engine management was literally decades behind where we are now. Back then there were only carbs, or in some cases mechanical injection, with points ignition maybe a few "transistorized" ignitions coming along later, all of this gave very poor control over mixture and spark timing, so the only option at the time was lower the SCR, in an attampt to reduce pre-ignition. It usually worked. With the controls we have now, EFI, Distributeless Ignition Systems, meth/propane injection, and many other controls that are very finite, allow for very close control of the intake charge and exactly what is happening in the cylinder, which now allows us to run previously unheard of combinations, being daily abused and living very well in those conditions. EFI also allows much more flexible options in control, such as pulling timing at a certain RPM, but then adding back in a few RPM later, if it's necessary to do so. There's just so much that EFI can do for any engine, especially when it comes to forced induction set-ups that I don't think the real potential has been realized yet. Just one example is a Honda Engine, that was over 10:1 SCR (10.8:1 IIRC), ran 18 PSIG of boost and was the shops daily beater/delivery pick-up vehicle. Yes I know that's a honda, and the mechanicals are different than an L-series, but some of what worked on that engine can be applied to other engines. IIRC it was built by a guy known as "The Old One" who has been working with Hondas and Turbos for a very long time. It's been a while since I read the article so I might have the name wrong. My own Datsun has an N/A L28 that has from specs I've read 8.8:1 SCR, like I said, I run no IC currently, and run 91 octane pump gas. I am currently running 10 PSIG of boost, which ramps to 14 PSIG above 70 MPH. I haven't had much time above 70 MPH to get that mapped out completly yet. I might see around 2* of KR (Knock Retard), if the ambiant temp is warm or I had just been on a hard blast, since my air filter is currently living beside the exhaust manifold, also something I plan to change. My MAT sensor is reporting temps of around 130* F on a hard blast, where even cruising I see around 100* (Which is why I will be moving the filter, just haven't had the time yet). I don't see the valve seats dropping due too low of SCR, I see that as more of an installation problem. The heat of running the engine, be it in boost conditions or not, likely caused the two dis-similar metals to expand at different rates and what caused the seats to fall out. They also likely fell out at high RPM, where the valves will be opening and closing rather often, and could also cause the seats to start to resonate, and with the heat there can dislodge something like a valve seat.

I don't think I understand what is being attempted here, but maybe getting a foggy picture...... Are you wanting to take an average ordinary conventional turbocharger, and instead of connecting the Turbine inlet to the exhaust manifold of an engine, you want to attach an electrically driven "fan" to the turbine inlet to drive the turbo? If that really is the case, you need to do a bit more research on how turbochargers really work. The average input pressure to a turbine will be approximatly twice what the boost pressure is. There is some veriation to this, but it is a commonly accepted principal of what drives a turbocharger. On top of that, why would you want to take mechanical power (crank) that drives an alternator that then creates electrical power, that charges batteries and runs this electric fan that changes the electrical power back to mechanical, that then is being converted to pressuring a gas (the air we breath), to then again be converted to mechanical power (through the turbine wheel and compressor wheels) to pressure the same gas that was being pressurized by the fan, to feed the engine? I'm sure there are more conversions of energy in there too, especially if you want to the BTUs of the gas being used, to turn the crank, that could also be used to drive the turbine more directly, through the use of the now "burned" gas and the by products of which do run turbines conventionally. The most effciant way to get to where you want to be is a straight line. I don't understand why so many people want to connect electrical power to things that don't need it. The best advice is: Don't try to re-invent the wheel.

I realize that people have triggered thier coils directly from MS, without issue, but in this case it sounds like the "igniter" or more specifically the transistor used to trigger the coil is either weak and not allowing a strong enough ground to charge the coil, or there is a weak ground reference to the transistor/MS. Another thing that comes to mind is if the dwell is too short, I'm not sure how dwell is controlled/effected on MS, since I don't use one, and would really need to be so short to describe what you're seeing that I would be surprised to see any spark at all. The HEI module sounds like a better option. I'm used to GM ignitions anyway, where the dizzy/crank position sensor triggers the ICM, and the EMS, just reads RPM from the ICM and sends a signal to the ICM to control timing.

Stock fuel rails are not aluminum, they are a type of steel, I just don't remember whether it was galvanized or stainless.

I ran my IC pipie under the oil pan too: Old picture, doesn't show DIS upgrade: I don't know why more people don't run thier piping this way. My filter is also mounted directly to my turbo, with no issues of melting, I do see my intake temps are higher than I would like, and will be moving my filter to try and reduce the air temps.

I simply turbocharged my bone stock (AFAIK) N/A L28 that came in my 240Z. (*gasp*) I also don't see the reason to swap to a lower compression engine just to add a turbo, seems counter productive to me. Turbo block was not the only block to have a KS location, mine, which as I said was an N/A block, also had a KS location (which I tapped for a different thread for my GM KS). From the information I've found on my engine it has 8.8:1 SCR, which is even low to me for a boosted application. I've never quite under stood why people would want to run a low SCR, then lots of boost pressure to achieve a HP number that could be had with higher SCR and lower boost pressure, which protentially quicker spool, and definatly better off boost drievability. I laugh when people gasp when I tell them what my SCR is, they seem to be living in the 1960s and listening to the turbo "wisdom" of technology long replaced with newer and better controls, and just better and more efficiant mechanical technology. The only fitting that the N/A engine doesn't have is the oil return, which goes into the pan anyway, and can be added very easily, if not just swap the oil pan. My "N/A" L28 is running just fine with a Nissan turbo exhaust manifold, 6.5L diesel turbo, modified N42 intake (smoothed and machined for 14mm O-ring injectors), non-intercooled (hope to change that soon, just need some time to build the IC), GM ECM and DIS ignition, running about 10 PSIG, above 60 MPH (my boost ramps in by speed). Also most people will end up "upgrading" or swapping parts anyway which will then mean that most of those stock parts that were swapped in will be swapped out, I like to skip that step and just go to the end result or closer to it.

Deutsch > weatherpack. I've used both on projects over the years and I am a Deutsch connector convert now. Weather pack are good, they do seal well, but to me they are a bit sloppy in fit. The only drawback is that the Deutsch connectors require a special crimping tool, that can be a few hundred dollars. I have recentloy found out that there are a different style Deutsch connector that can use a more conventional (and cheaper) crimping tool, but have not used them myself, so I can't comment on how well they work. For some projects I have used junkyard connectors, but usually only when needing to connect to an existing component and can't find a replacement connector. I usually use that as a last resort though, since you will now have spliced wires, which any connection even done properly will add just a small bit of resistance to the circuit, and can add a spot for moisture to work it's way into the wire (which is why I've started using "liquid electrical tape" to seal splice connections).

Open up your tach, and bypass the large resistor that is connected to the "coil input". You can follow from the connection to the circuit board and will be the first resistor in line with it. I did this on mine to get my 280Z tach to work with my GM DIS ignition. If you do a search there is a thread with pictures showing the resitor to bypass. Just as a note, my tach stops reading at high RPM, some information I've read suggests that above 6200 RPM, the dwell is too short for the tach to read correctly, and so it stops reading. I don't spend much time above 6200 RPM, since my rev limiter is set around 6400 RPM, but I do see my tach drop frequently. LOL

There is one huge flaw with this theory. Every BOV/bypass valve/whatever you want to refer to it as, they function the same way, in that what causes them to open is the same for any system, including re-circulating and open to atmosphere. There are two, and in most cases 3 points where "pressure" is applied to open or close the valve. Lets look at the part that does most of the controlling of when the actual vent opens. That would be that top part where you attach the vacuum hose to. In that round part there is a diaphram. This diaphram has two sides. The top (farthest away from the valve) and the bottom (closest to the valve). The vacuum source is attached to to top side of this diaphram so that when vacuum is applied, it will create low pressure or vacuum in the space above the diaphram, this will make a pressure differential between the top and bottom of the diaphram allowing the dirphram to move, in a way that open the valve. Now the bottom side of the diaphram can be plumbed in a couple of ways, one way is to atmosphere, which most aftermarket BOVs I've seen are plumbed. So now we have approximatly 14.7 PSIA of pressure on the bottom side of the diaphram. Apply a vacuum to the top side and now the diaphram will want to move towards the vacuum. This is simple physics. Yes there will also be a spring above the diaphram, and this adds some resistance to opening, to work against the vacuum, and to ensure that the valve does indeed close when it's supposed to. The other way to plumb the bottom side of the diaphram is to the intake tubing, where we are pressurizing with the turbo. What this does is force pressure under the diaphram for a quick lift of the valve, to vent quickly. So as long as there is equal pressure on both sides of the diaphram which there will be with the throttle wide open (pressure is applied through that "vaccum" tube to the top of the diaphram), and now pressure applied below, the valve in theory will stay closed, because the spring that is on the top of the diaphram applies a little more force than pressure alone will. Now there is a 3rd spot that pressure is applied, and that is under the valve itself. Pressure to the valve also has influence on when or how long a BOV will be open. It is because of this that some BOVs, such as the 1st gen DSM BOV will open at a certain pressure without applying vacuum to the top of the diaphram. The pressure on both the bottom of the valve it self and to the bottom of the diaphram will overcome the pressure above the diaphram. It is because of the pressure applied to the valve itself in the BOV that they need to be installed in the correct orientation. Install a BOV backwards and it will have a hard time opening. Basically as long as there is pressure "below" the BOV and vacuum above the diaphram, such as what would happen at idle or low RPM cruise conditions, the BOV will be open, and not cause the situation to describe.

Yep, I witness this frequently myself. A story from today, while I didn't hear the conversaition myself, this happened this morning before I got to work, my boss relayed this story. There is a vehicle that has come in, that I installed a remote starter in a while ago. The owners is having problems with unlocking. She was describing the problem to my boss, saying that she couldn't unlock the door, to get out because the remote wouldn't unlock the door. She asked "How do I get out?". I guess this is yet another variable, not that she couldn't find a way out, just that she couldn't find an alternate way out when the primary way didn't work. I don't think this is a young lady either. I mean even I can remember a time when power door locks were a novelty only for well to do people, a Keyless entry, WHAT is that? Now it seems that people forget how to acomplish tasks manually, and NEED the automatic or electronic means of accomplishing tasks. I don't understand it.

I haven't ever gone through what you are, at least not like this. The closest I've come is a couple times where if I was standing an inch to one side or the other, or possibly decided to take a route that I normally take instead of the one I did, I'd likely be dead or severly limited in my abilities to take care of myself, but these were all because of external body reasons, nothing to do with physical issues. What I have been through has made me look at my mortality in a whole different light as well, and it a VERY quick change of view. My Grandfather just went through a few procedures for Cancer this year, and I worried enough about him going through that, I can't imagine how it would effect me if the roles were reversed. I'm sure you'll be ok, but I know a few of us OZCer's will help out anyway we can.

I'm not usually into Japanese supercar videos, but that looks like fun. So what's in the trunk that needs a cooling duct passed through it?

Do you have a Mark's Work Warehouse around you? I don't know how big of a franchise it is, could be a semi-local thing. Anyway, my point is there should be a store near you that supplies clothes that are more for the tradesman/journyman industry. Also check out Salvation Army or Value Village. Winners may also have something that you could use.

Sounds like you have an injector or injector driver issue. There should be 12V on both side of the injector with the key on, engine not running. The 3-4V on one side shows that there is almost a ground signal on the signal side. Just not enough for the injector to be pulled open. Disconnect the injector clips and test for resistance to ground, with the engine not running this should be an extremly high resistance, better yet infinantly high, though there is sometimes high resistance to ground through the injector drivers. I suspect you may have a piched wire or possibly a bad relay board/injector driver.

http://www.zhome.com/ZCMnL/tech/280Alt.html

I agree, I've met too many people, sadly in my generation also, that can't figure out how to get themselves out of a wet paper bag, by simply stopping and thinking about the problem at hand. Too many have been spoon fed answers and have not been taught how to get from the problem to a solution. It almost seems to take an artist or someone that has a bit of obscurity to thier thinking to problem solve and these people are usually considered "smart" or "genius" by thier peers, simply because they think through problems, maybe it's just having some patience really is a virtue.

Ok, that's not how I read your first post. This one makes more sense. I still prefer a correct answer with just getting to the solution than an incorectly thought out answer. What I mean by that is some of us, can just look at a problem and figure out the solution in our heads, and have a hard time "showing" the work to get to that answer. For myself in many cases to "show the work" confuses me, and makes me second guess myself coming up with an incorrect solution, where as I had the correct solution from instinct.

The power to weight idea that was mentioned is exactly why I chose an S30 over some of the other cars I was looking at for a "toy". I usually set goals to meet and know that they will not be the end goal, but it's much easier to meet those smaller goals and be happy for a while, then to never meet or take years to meet that larger goal.

I agree that the car would likely get more as a turn key sale. On the flip side a friend of mine just sold his 2003 Mustang, that had a proffessionally built chassis, set-up for EZ street (power adder 10.5 class that usually runs in the high 7s), basically complete rolling, less engine, turbo and EFI system for $80,000. The car was basically new, completed earlier this year and had half a pass on it.