TimZ

No, he's right - there is a version of the TWM DCOE replacement that has a mounting boss for the TPS sensor, and it mounts on the throttle shaft.

Probably good advice. Also, according to the data that I have seen, the combustion chamber volume for the N42 and N47 are the same, meaning that they should give identical CRs. The main difference is the exhaust ports.

Well, I haven't seen your cage, but you might be surprised at what becomes accessible to your head in an accident. Also, I'm not doubting the structural integrity of your cage, but I'll bet those circle track guys wear helmets. And they are probably using proper racing harnesses, which do a very effective job of limiting where your head can and can't go in an accident.

Not sure what you mean by 'unsupported opinion' - I thought I had supported this with pretty logical arguments. In fact, I would contend that while possibly not popular, this particular opinion was as well supported as anything in this thread. Most full cages that I have seen have a forward hoop that follows the windshield and anchors up by the front of the doors. This is usually connected to the rest of the cage by a pair of bars that run along the top of the side window. Guess what - if you aren't properly strapped in (i.e., 5-point harness) and wearing a helmet, it won't take that much of an impact to whip your head into that bar. Also, are you saying that helmets don't add much of a safety factor? Did I read that right? I'm sorry, but that's just silly. Find me just one cage manufacturer that will say in writing that their cage is as safe (doesn't even have to say 'safer' - 'as safe' is just fine) as no cage for unhelmeted passengers wearing 3-point retractable belts, and I will retract my statmentment. Just one. Seriously. Just one. I guess my main point was to get people to think about what they are doing. Just because the racers do it on their track cars does not automatically make it suitable or even desirable for street cars. Safety systems designed for track cars make many assumptions about the environment that the vehicle operates in and the equipment that the driver is wearing/using. These assumptions are not always valid on the street. Also, this is not to say that you couldn't design a cage that improves the stock vehicle's safety for 'normal' passengers - it's just that I have yet to see one for our cars designed that way.

Being from Marietta, I would have guessed military. I've noticed a couple of references to the tube frame/cage adding safety, so I thought I'd offer up a somewhat heretical opinion... I'll buy into the idea of a full cage with a properly anchored multi point harness being safer, but only in a car that is a 100% track car. In a car that sees time primarily on the street, I'm not convinced that this is the case. First off, a tube based cage (even if it's padded) makes the assumption that you will be wearing a helmet so that your skull won't get crushed against it. It also makes the assumption that your motion will be well-constrained by a properly anchored multi-point harness, so your neck won't get broken by it if you hit it at a weird angle. Neither of these are true on the street. I don't know anybody that wears a helmet in their car on the street (huge red flag to the cops ), and a racing harness is totally impractical on the street (if you've ever used one, you know what I mean). Second, adding a bunch of stiffness to the chassis with tube reinforcement can be good for handling, if done properly. However, you run a VERY good chance of screwing up the crush zones that are designed into the body (AFAIK, they were in fact doing this even in the 70s). The end result here could very easily be the exact opposite of what you thought you were getting, safety-wise. I've been thinking about this for a while, and I'm not convinced that you are really any better off at all with a full cage on the street.

Wasn't trying to make you feel bad... I often shake my head when I see what people pay for stuff on the newer cars, too - and often for relatively mediocre performance for the price. I was just pointing out that when you farm _everything_ out, the price goes up pretty steeply. Personally, I've never seen the attraction to just buying a turnkey fast car. How much skill does that take? For me, making it is at least half the fun.

The TPS can be used for load sensing in some situations, although I don't think it would work by itself on a turbocharged application. It is generally less accurate, though. One big advantage of the TPS signal is that it is not nearly as noisy as the MAP signal for high vacuum/low flow situations. This is why it is sometimes preferred for radically cammed engines and/or low volume IR manifolds. The TPS Blend function on the TECII and III basically performs a crossover function between the TPS at idle and the MAP for WOT, where it is more accurate. As far as plenum volume goes, for an IR manifold like we are talking about here, plenum volume won't matter at idle as it is on the wrong side of the throttle plates to help. If you want to use a MAP sensor, summing all of the runners together is essential - it maximizes the volume that the sensor is drawing from, and smoothes out the individual pulses from each cylinder. At higher rpm/load, this becomes less and less of a problem. Using the TPS here can work, assuming it's a NA application. Personally, I would prefer to use the MAP signal, possibly blended with TPS if you have that functionality. I would only go TPS-only as a last resort.

The key phrase here is "installed". The lion's share of that $16k was mostly in performing the swap and ironing out the problems for you. If you did all the work yourself, the IS300 swap would probably be cheaper, too (although performance parts, while available are most likely pretty pricey). How much do you think TopEnd would charge for a turnkey "400hp" 240Z?

Sorry - didn't mean to sound like a snide comment.

Maybe this could help... I usually do a sort on either RPM or MAP values (pick one). For this example, let's say I sorted on MAP. Then, I grab all of the data from one MAP breakpoint range (let's say 0-5psi of boost - don't know how the DFI displays it) and use it to create a 2d scatter plot of whatever it is that I want to analyze (injector pulse width in this example - I usually do this with AFR error) vs. RPM. You do need to repeat this several times for each MAP breakpoint range, but it's a bit easier to read and understand than a 3d scatter plot. Hopefully that makes sense - if it doesn't, send me some example data, and I'll make an example for you (the email address in my profile is up to date).

Okay - He's redeemed himself. Too bad he couldn't have photoshopped that out...

I've seen two or three setups like that on Camaros and Firebirds. lately.

One additional point to this is that many (if not most) of the bolts in the suspension are stressed in shear, not tension. So you need to know the shear strength of the bolt you are replacing in many cases, and this is harder to find. As I recall, the shear strength of a fastener does not necessarily increase with tensile strength, either.

Can't make a guess on the loss (depends on the slip ratio), but yes it would result in a lower reading.

Maybe, but I'm not convinced that there is a correlation there. On a batch fired system, at least one of the cylinders is phased properly (possibly two if it fires every 360 degrees instead of every 720). So if this were true you would expect that batch fired engines would have valve deposit problems on all but one (possibly two) cylinders. While I have not researched it, I have never heard of this being true. I mean come on - it's not like anybody is truly expecting their 600hp L series motor to go without maintenance for the number of miles required to get this kind of deposit buildup anyway. Still contending that sequential won't do didly for max power - it's not logical to expect it to.

The time limit isn't really the issue, at least not in the way you appear to be thinking. Assuming batch mode is still synced to the engine events, 80% duty cycle is still 80% duty cycle, regardless of how the individual injectors are phased to each other. The issue is that the intake valve runs at a fixed duty cycle of somewhere around 35% (assume ~250 degrees open out of 720 degrees of rotation). So, once you get appreciably above a 35% injector duty cycle (i.e. more than part throttle, low rpm), the injector is going to be firing on a closed valve for a good part of the time no matter what you do. The higher your injector duty cycle gets, the less difference sequential makes. In fact, once you get above ~70% duty cycle, you are more likely to be firing on a closed valve than not, regardless of how you phase the injector. David - not trying to rain on your parade, but you original post made it sound like you were assuming sequential was going unlock some sort of power secret (you wouldn't be the first person who thought that). It is helpful for part throttle low rpm response and it can make a noticeable difference there, but I really think it's greatest value is when you are an oem that has to pass emmisions tests. Like I said, just trying to keep expectations realistic.

...you meant open loop, right? I would not recommend tuning on boost with untuned closed loop feedback. EGT is a good tool to use, but it's response is much slower than either type of O2 sensor, and you can't datalog it (at least not on the TEC - I'm assuming the DFI is the same way). So even if you see a funky reading, it will be very difficult to correlate that back to which cells need adjustment, especially for fuel delivery (timing does generally need to be smoothed, so you can make broader changes there) . Just like everything else, you need to apply some common sense while trying to tune on boost. Find a safe place to tune (hopefully this is obvious), and you will need to be able to limit the rate of change for engine RPM and MAP. This pretty much means use higher gears (downside = illegal speeds), or in many cases you can drag your brakes against the throttle to go through cells that you are interested. If you are dragging the brakes, be sure to let them cool between runs. Also, try to always start the run at the same intake air temp, assuming you can see this. If you can't, then it is also a good idea to let the underhood temps stabilize between runs (part throttle cruise to keep air moving). Like Pete said, start rich and sneak up on it, and always listen for anything unusual (misfires, knock, etc).

These are very good questions. It was mentioned that "all the top guys" want sequential - I'm not sure that this is true. What is the expected gain? In general, sequential is helpful for smoothing out idle and improving emmisions at moderate (i.e. part throttle) output levels. I don't think that you'll see any power gains from such a setup at all. This is not to say that smooth idle and emmisions are not important, just trying to keep expectations realistic.

Your base fuel map is pretty much the same thing at the TECII's VE table. I wouldn't worry so much about discontinuities in the table as I would in the actual mixture. Contrary to popular belief, there is no law that states that your map has to look smooth. It's not uncommon to have weird resonances in the intake/fuel system that make a properly tuned map look pretty funky. Log some data that shows a trouble spot. At a minimum, collect MAP (I'm assuming speed/density), RPM, measured AFR (don't worry too much about whether you have wideband or not), and EGO feedback corrections (if you have it). You are probably going to find that right before the feedback goes insane, you have a rich or lean spot. First step is to figure out why - could be bad base map, could be bad acceleration enrichments, could be something else. One thing that I have found helpful is to pull your data into Excel, and sort by let's say RPM. You can then make a scatter plot of AFR vs MAP for each RPM range in your base fuel map (you could swap RPM and MAP in this example if you like). From this it's pretty easy to see where the fuel map needs to be adjusted. Again, I wouldn't worry too much about not having a wideband - you can still do quite a bit with a narrowband sensor. If it says you are rich, you most likely really are rich - it's just not very accurate about exactly how rich you are. Well, you do need to have a good connection to battery ground, but I would recommend taking everything to the engine block for ground. Preferably to the same point on the engine block.

He did - and it didn't work as well. Nice numbers, Dan. I've been of the opinion that the N42's supposed detonation problem was bs for quite some time, too. Glad to see someone else out there disproving the myths.

I would recommend plumbing the wstegate back into the exhast considerably farther downstream than 2". The wastegate dumps to a lower pressure area that way. I would think that you would have less problems with cracking that way, too. I would at least try to blend back into the downpipe at the last 90 degree turn at the botom. If you are worried about flex, install a flex pipe inline on the wastegate outlet. Do a web search on "exhaust flex pipe" - you should find plenty of suppliers.