Cannonball89

I am looking for an STI differential with a 3.54 ratio. The 2006 and 2007 have this ratio, the difference being that 2006 is a CLSD and the 2007 is a Torsen. I would be interested in either one. I also need the side axles that John Coffey makes, if you have either or both of these parts that you want to get rid of, shoot me a PM. I am in Westminster MD, but shipping could be an option.

I was just on Wilwood's website and saw that master cylinder and thought "hmmmm... that looks a LOT like an S30 master cylinder!" I was going to check the dimensions with a vernier tomorrow and see if it matched up but then I decided to search on Hybridz to see if anybody else had noticed it and here it is! My pedal has felt rather spongy after converting the rear drums to discs from an 83 280zx, I think this 1" master cylinder would bring back the rock solid feel that my car had with the drums. I might have to put this bad boy on the top of my Christmas list...

I have a Hurst Shifter with a Mustang shift lever and I had to cut out the center console. I plan on using fiberglass to make my own contours at some point so it looks a little better. My car is a 3/71 with a 260z or 280z console.

Yea I don't think phantom grip is the way I want to go... there might not be any clutch disks to wear out... but instead your wearing the spider gears and the case... not an improvment in my eyes. I will look into powerbrute, cusco, and kaaz, but I think a factory suburu LSD is going to be better for a street car. I don't want a 3.90 diff, with my turbo it will be faster with the 3.54 diff, and I want a clutch over a helical, so as far as I know I am limited to the 2006 STI diff. I haven't seen what the newer 2009-2011 cars have yet, but I think 2006 is the only year that will work.

I am going to put some sort of LSD in my 240z over this winter. My first choice is the Subaru STI R180, with John Coffey's side axles. I figure that swap will cost between $800 and $1000 ($500 for the side axles, and anywhere from $300-$500 for the differential itself). While browsing Z Specialties site today I saw that they now sell and LSD conversion kit for the open R180, for $350. This would probably be a cheaper solution, even though I would probably pay someone to install it into my differential (the instructions look somewhat intimidating). What I don't know is if this would be nearly as good as an STI LSD. I haven't found any reviews of it, and the Z Specialties site doesn't really tell you what kind of LSD it is, other than a statement saying there are "no clutch discs to wear out" so it is obviously not a clutch LSD. The picture looks like one of the Phantom Grip unit's I have seen. I'm sure some of you can I.D. it from the picture below. So what are your thoughts on this? Is it worth $350, or should I just look around for an STI Diff and get on the side axle group buy list. Here is the link: http://www.datsunstore.com/product_info.php/products_id/1569

It might be too late, but some air horns inside the plenum at the mouth of each runner would really help the engine breathe. Great fab work though.

I have been running a surge tank with the return from the FPR going into the top of the surge tank with no problems. Johns point about fuel heating may be somewhat true, but with a large low pressure pump feeding the surge tank, I believe that fuel is moving so quickly through the surge tank that it doesn't make a huge difference (after a long drive on the highway or even after a 1/4 mile run the surge tank is still cool to the touch, and it is mounted under the hood too). A surge tank is not like a gas tank, where fuel is sitting and waiting to be sucked in by the fuel pump, it has a very high volume of fuel being pumped through it at a high velocity, making heat soak not much of a factor. In my case I have a 140GPH low pressure pump feeding the surge tank, which feeds a 70GPH high pressure pump that feeds the injectors. That 140GPH pump is moving a lot of fuel through that surge tank every minute. I have never had any issue with pressure on the return side of the FPR creating any spike in fuel pressure, which would show up as a rich spike in the datalogs. It's really just a matter of preference, but I think it is just simpler plumbing to run the return from the injectors into the surge tank (especially if it is mounted under the hood) than to have two separate return lines (one from the FPR and one from the surge tank) running into the gas tank.

No, It doesn't matter, the low pressure pump feeding the surge tank will push the fuel out of the return line and into the gas tank when the surge tank gets full. The surge tank may become slightly pressurized, but that's really a good thing, having a slight pressure against the inlet of the high pressure pump.

Id buy one

LOL Just thinking too hard without knowing enough.

Could something like a thrust augmentor be used to help a turbo spool faster? I envision an air pump drawing in outside air, and injecting it into a thrust augmentor positioned before the turbine housing on the exhaust manifold/header making the cold air expand and provide that extra "umphhh" to get the compressor spinning faster. Of course any benefit might be outweighed by the extra drag on the crank by the air pump. And it would make it impossible to use a WBo2 sensor. Or there could be a system that utilizes the EGR pump. Under cruise the EGR is injected into the manifold like usual, but there could be a valve that could divert the EGR through an air-to-air cooler, then injected into a thrust augmentor mounted before the turbine housing when you go to WOT. From what I understand it is pressure differential between the entrance of the turbine housing and the exit of the turbine housing that make the turbo spool, so anything that would increase that pressure differential (like expanding cold air) should spool the turbo faster, allowing large turbo's to be used without much "lag". What I don't know, because I have never studied physics or worked on propulsion engines, is if "thrust" is essentially the same concept as "pressure". But that's just my 2 cents.

Carroll county MD is nice. It is a rural, country area but it is only about an hour from baltimore and DC. With that being said, as soon as I get a degree I plan on moving south where housing is cheap and you don't get six feet of snow in a week...

If you have a 50mm throttle body on it, it is larger than stock L28ET throttle body. And really I can say from experience that the 60mm 240sx throttle body isn't all it's chocked up to be. I found that my car will accelerate almost as hard at 3/4 throttle as it does at full throttle, and tip-in is really hard to get smooth. The car is just kind of hard to drive smoothly with that big 60mm throttle body. Unless you have done extensive cylinder head porting, just stick with a stock throttle body. I wish I had done that now looking back on it. And a 50mm throttle body is absolutely NOT the weak link, your intake runners are. Do some reading on here, you will learn a ton. There are several stickies under FAQ that tell you what the weak links are.

I would think that the thermal efficiency of compound compressors would be much higher than that of a single compressor at the same boost. That is just my speculation, I have no experience with them, but I would imagine that you could achieve very high manifold pressure without drastic increases in temperature, especially if you were to implement an intercooler both between the compressors and between the final compressor and the manifold.

I have a datalog from my Dyno session: The light blue line on the top chart is Boost/Vac. It seems pretty steady at around 12PSI, the wastegate spring is rated for 10PSI, so I suppose that indicates a little bit of creep, but not dangerous amounts. Unfortunately I was having a spark blowout issue that day due to incorrect dwell settings that didn't allow us to go beyond 5000RPM. It still made 250HP and 280lb/ft of torque though. I have since resolved the spark blowout issue and advanced the timing, and done a little more work on the fuel curves so I expect it is making closer to 300lb/ft of torque now. I have been trying to get to a dragstrip for the past several weeks but it seems to rain every damn saturday this time of year in Maryland Once I am finally able to get down a quarter mile I will post up a datalog of the full 1/4 mile pass to see if there is any creep in a real world situation, and of course post my timeslip. The online calculators say that my car should go mid 12's, but I don't think I will have the traction for that with my open R180 and 205/60-14 Sumitomo radials lol. I'm hoping for 13's at a MPH of around 100.

Glad to see my diagram getting cleaned up a little and put to good use! My only advice is to make sure that your switched power source in the diagram is getting power with both the key "on" and "start".

Yes you can do that, as long as you don't have open flame or sparks flying it should be safe to have a gas can sitting next to the car feeding a generic high pressure pump to feed the injectors, with a return line going back to the tank. I've done this to diagnose fuel delivery issues. This will allow to get the engine running, and ensure that all things are in good working order before you put the motor in your 77. Get the motor up to temp and do a compression and leak down test, that way you will know if you need to get it rebuilt before you have it sitting in the 77.

0.1ms is pretty short, I think you mean 1.0ms?

Also your pretty rich, Leaning it out some might make the mixture easier to ignite (maybe, although some say that a rich mixture is easier to ignite).

Sounds like the problem I recently had. Try reducing your spark duration settings. I have the msd blaster 2 coil triggered directly by megasquirt and my spark duration setting is currently at 1ms, dwell time is set at 3.5ms. If spark duration is too high, it will drastically reduce dwell time of the coil at high RPM which will cause the coil to not be charging long enough to produce a spark powerful enough to ignite the denser mixture. You could probably even reduce spark duration to below 1ms if needed. It doesn't really take a long time for the spark to initiate a flame front, but it does require a lot of voltage to jump the plug gap, which is why dwell duration needs to be about three times longer than spark duration at any given RPM. For single coil applications, Let's say X= number of spark events per second, and if X=(RPM/60)(# of cylinders/2), and if Y= milliseconds between spark events then Y=(1/X)(1000). Do the math and see how little time there is in between spark events with a single coil. Megasquirt will scale the sum of your max. dwell time settings and your max. spark duration settings until they fit within the window of time available for whatever RPM you are at. So as RPM increases, dwell and spark duration decrease. The trick is to have dwell significantly higher than spark duration so that dwell never drops below unacceptable levels, which will very upon how much boost you are running. It is important to understand that the max. dwell time setting dictates how long the coil will charge and the max. spark duration setting will dictate how long MS will wait before initiating the next charging cycle, and as RPM increases these numbers will be reduced by whatever percentage is needed to fit into the timeframe between ignition events. I am running 12PSI with a .030 plug gap on NGK BR8ES plugs using the same coil you are. So I don't think you need to run a wasted or sequential ignition system yet unless your power band is above 6500 or you plan on raising the boost signifigantly higher.

Well in that case any slippage of the belt on the alternator pulley could account for RPM discrepency. My main point is that regardless of what this shop told you, megasquirt is an accurate and reliable efi system. And your plan of using the stock sensors with megasquirt is a solid plan for now.

How can the battery possibly tell you anything about RPM? Correct me if im wrong, but I can't think of anyway you could possibly deduce anything about engine speed from the battery unless your some how measuring the clock rate of a certain draw such as coil(s) firing.

Most dyno shops will clamp their tach signal onto one of the spark plug wires just like a timing light, this is not an accurate way of measuring the RPM at all due to the noise coming off of the other plug wires. I can see where their would be a discrepancy in the RPM data at high RPM but it is almost certainly an issue with the shops RPM data, not megasquirt. If megasquirt is not reciecving accurate RPM data then the computer will lose sync and the engine will stumble and miss until it syncs again. I can't believe a shop would tell you that. Megasquirt has been proven to be rock solid and reliable on hundreds if not thousands of Z cars and is going to be the cheapest aftermarket efi system for your car with loads of support available to you. I would not use a shop that believes their RPM data to be more reliable than the ECU.

I see what you mean. I suppose that might be a slight improvement if you have ported the hole such as that it directs the exhaust gasses in that direction. On my turbine housing the hole is just drilled in at a 90* angle, so the exhaust gasses have to turn 90* anyway.

That is truly awesome tim. This is what I love about this site... rather than being full of dreamers it is full of doers...