TimZ

As far as I can tell, this is correct. Just realize that you are not increasing the resolution of the sensor or the A/D converter. The minimum pressure increment you can resolve with the Sensor - 8bit A/D combo doesn't change and will be 1.6kPa if you are using the sensor mentioned above. What you are doing is getting the most out of the available MAP breakpoints for your application. Pete's suggestion of testing the system by applying known pressures at the sensor is a very good idea. Never hurts to be sure of what you've got.

Good Advice - that was pretty much the main point I was trying to get across, too.

If you read the graph, flow was measured at varying valve lifts from 0.20" to 0.55" in 0.05" increments. And yes that's how it's generally done. Nice improvement over stock, btw. Interesting that as much as that head flows stock, it was pretty much done at ~0.35" valve lift.

AND they just keep cranking it like maybe it'll be okay...

I just love the chunks of catalyst falling out the tailpipe.

This is pretty funny - what an idiot... BTW, you can find this on YouTube by searching on "CTS-V idiot"

Sorry - not trying to be difficult, it's just generally easier to reason with something if you understand how it's supposed to work.

It sounds like you are talking about adding (or modifying existing) signal conditioning before the A/D - is that what you mean here?

I think the reason is most likely that the A/D converter section of the micro uses a single voltage reference for all 8 A/Ds. This dictates that all of the A/Ds have the same 0-5V input voltage span. You can't have it customize the input range of just the MAP sensor channel without screwing up the other seven channels, too. As far as the scaling goes, it makes sense that the MS itself would not do any scaling - it really doesn't need to know what the scale factor is, so long as it's consistent between the input and all of the tables that use it. The scaling should all take place in the calibration and datalogging software so that the users can better understand what they are looking at. Hopefully I'm not coming off sounding like a jerk on this subject - while this might seem like minutia, it's really easy to be fooled into thinking that the processor is doing more for you than it really is, and it's really easy to get "lost" if you are making the wrong assumptions as to what is going on.

yup -exactly

Ummm... this should be obvious, but if you are checking for spark with the plug out of the engine, disconnect the injector for that cylinder. Good way to start a fire. Can't you just pull the plug wire off the plug and check for spark to a ground point?

Yes it's scaled, but as you go to higher range sensors, you still only have 255 steps of resolution, as I mentioned above. This is important to understand. For instance, for a "normal" engine that typically sees 20 to 100kPa when off boost, if you are using an MPXH6400 4 bar sensor (as cygnusx1 is above) with a 4.6 volt span and 20 - 400kPa range (1.6kPa per LSB), only 50 steps of the total 255 will be available for "drivability" tuning. That's pretty coarse. If Phil decides to put the big cam back in, he's more likely to only see 50-100kPa when off boost, so with that same sensor he'll only have 31 of the total 255 steps available for drivability. Also, note that this does not take into account the error band of the sensor, which is spec'ed at +/- 5.5 kPa.

I was referring to the A/D converter resolution, not the processor itself. Actually, the 1.6kPa per LSB resolution assumes a full 5V span for the sensor. I have seen 4 bar sensors that don't use the full 5V. So, if your sensor has a 4 volt span, the min resolution is 2kPa per LSB

Looks like 8-bit

That's true, but it's a good idea to understand what the controller will do if you go outside the map - does it flatline (probably), or does it use the last known slope and extrapolate? I guess I don't understand the logic of not using all of the resolution that you have available - if you have 0-100kPa range and 12 cells, why not use 8kPa steps and all of the cells? Or better yet, since you probably aren't going to actually be doing anything besides closed throttle decel in the 0 - 20 kPa range (possibly higher depending on your cam: 20kPa equates to ~24in of vacuum), why not go from 20-100kPa in 7 kPa steps? Also, if you are using big injectors (like Phil is), it's a good idea to take a look at the point where the commanded injector pulsewidth will be less than the min injector on-time. For instance, if 40kPa MAP is going to result in you being under the min on-time, then having cells at 20 and 30 doesn't make much sense.

30psi of boost is about 308kPa (assuming ambient pressure at 14.7psi=1atm). It is a good idea to compress your scale a bit to give better control over the range that you will be using. Just keep in mind that no matter what you do you will be limited by the range of the sensor and the range of the A/D converter. For instance if your A/D is 8 bits, then the smallest kPa increment that you can work with is 1LSB = 408/255 = 1.6 kPa. You should keep your breakpoints far enough apart that there will be at least a few LSBs in each range. I tend to leave myself more breakpoints in the "driveability" part of the map, but only by a breakpoint or two. If you think about it, there are a wide range of conditions where you will be driving normally, but when you are in boost, you will almost always follow the same boost curve. For instance if your boost controller is set to 15 psi, then you will almost never be running at 13 psi except when you are passing through it on your way to 15psi. Also, does the MS allow you to set the rpm breakpoints? If it does, then you might consider setting up the rpm breakpoints so they are evenly spaced on a logarithmic scale instead of linearly. You don't see many people thinking of it that way, but RPM response is more akin to frequency response than anything else - RPM is a measure of frequency after all. This will end up looking like it's bunching up the breakpoints at low rpm and spreading them out at high rpm.

I tend to view the coatings as more of an enhancement to, rather than a substitute for the heat shield. It's going to be hard to beat the effectiveness of the heat shield with just coatings. That said, coatings with the heat shield would be even better. When I was using that style manifold, I went so far as to coat the heat shield itself - they actually look pretty sharp in the JetHot silver.

I guess most of the times that I had heard discussions on the non-webbed manifold, it was more in the guise of trying to keep the manifold temps lower. If that's important to you, then the heat shield is important. I agree that removing it would definitely make the install easier, but it kind of seems like a false economy when the result could be lowered resistance to detonation from increased intake air temps, especially on a turbo motor. Personally, I try to do as much as I can to keep the exhaust heat away from the intake and keep the intake air temps cool. And yes it is harder to install that way.

How so? My thinking would be that the factory heat shield reflects the heat away from the intake, and the lack of webbing then allows more airflow around the runners. Seems like they complement each other to me.

LOL - same here. If you have trouble coming up with the 27mm socket, a 1-1/16" socket should work, too.

Sounds familiar -I think it all started for me with a distributor recurve kit back in ~1980. First turbo setup was ~1987... I don't think it'll ever be "done". At least I hope not...

I agree - I just can't get away from the fact that if they are talking "cast is good enough" on the pistons, then you certainly don't need ~$5000 worth of head work. There is no reason a "normal" stroker buildup should have to cost that much. There are plenty of other options out there that shouldn't cost anywhere near that.

I guess I'm not seeing what the difference is for a stroker motor, especially if you are supplying the crank and rods and pistons that already fit. There is a small amount of clearancing that is needed for the rods to clear the block with the longer stroke, but that isn't exactly rocket science. Otherwise the cost should be the same as a standard rebuild.

Yes - if they don't have the piece you need in stock they can make one up for you - I sent them my turbine housing and they made that one for me. I even sent the v-band clamps along and they made sure that they would not interfere. Also, they are made from inconel, not just some high temperature fabric. I'm pretty sure that once they make one they keep the mold, so you might not have to go to that much trouble. As far as I know there are no distributors - you'll just have to call and see what they have (phone number is in the link above). In my experience, they are really easy to work with.

Either one should work - I would not recommend getting either in the black color, though. The blanket in the first ad looks to be shinier, which aside from looking nice might tend to reflect heat back to the turbine housing a bit better. I don't know what turbo you are using, but make sure that the blanket will fit your turbine housing. I have been really happy with the products from Advanced Thermal Products. They are a bit pricier (probably about double the prices above), but they do provide a really high quality product. Here are some pics of the cover they made for my GT42: