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Hi guys. as some of you guys might have seen from another topic I started (http://forums.hybridz.org/topic/122459-air-intake-temperature-soar-when-i-step-off-the-gas/), I've been giving some thoughts to the air intake temperature. Afer poking around the engine while it was still warm, I realized that all the metal air pipes (duh, yeah i know, but it's important for heat conduction) were exposed to the warm engine bay air, and to the engine's radiating heat, and that the radiator's fan blew hot air pretty much directly on them. Touching all these nice pipes, I realized that the pipe from the turbo to the intercooler pretty much too hot to touch (duh again, I'd read about the heat coming from compressing the air but you don't realize how hot till you experience it). I also realized that the pipe from the intercooler to the throttle body started off cool and ended up very warm (can touch for a few seconds) close to the TB. The transition was quite sharp where I've placed a heat shield (sheet metal cut to fit around the pipes to try to limit the filter breathing in air from the engine bay - it didn't make much of a difference for the air temp there). I don't know if the heat shield is helping or it's just because the hot air blown by the fan hits the pipe from there on... I started looking around on the net, and some people had also thought of insulating this particular pipe. There is some debate as to the usefulness of doing this, and none of the sites were particularly methodical with the data taking, so i figured I'd try it, and gather before and after data too. Here is a series of pictures as to what I did to insulate the pipe (after gathering data; more on this later) this is the piping system, as I got the car (plus the heat shield I made) This is the insulation I've used. It's a foam tube to insulate house piping bought at a hardware store for 5$ for 6 feet, 2inch diameter. as you can see, I cut triangles out so I'd be able to bend it to follow the pipe. I eyeballed the cuts, and had to make the triangles wider only once to be able to follow the curve of the pipe this is the other side, since the pipe is s-shaped. with the foam almost all on the pipe to illustrate the use of the cuts With it all in place. tie wrapped on, ghetto style with ugly, white, break-if-you-look-at-them-too-long tie-wraps I had around The final product, with the heat shield seen from a different angle. I know there are gaps in the insulation, but i figure this can be a prototype and i can make it better if it turns out to be useful.... I'll try to post tomorrow on the data I've gathered about the intake temperature before the insulation mod; the file is on my work computer. I've gathered a bunch of info on how fast the temperature goes up once I'm parked iddling after the drive to work. I've got graphs and all, easy to read. post insulation data will be another week or so, I'm guessing, since I don't drive it to work every day (t-tops were leaky, and I've recently cut out part of the floor to fix rust, so no driving when it's wet) I'm also planning on changing the air filter location and making a cold air scoop under the radiator mount, so that and other data will be useful on that too. Stay tuned for other topics I'll start when I gather the supplies I need, the main supply I lack being time)... Comments and suggestions welcomed, follow this post if you're curious to see how it turned out. ******************************see posts 2 and 5 for info, and post 15 for a pre-emptive conclusion********************************

Hi guys. I have a 1983 280zx, modified by the guy who sold it to me. Rebuilt engine, T3/T4 turbo, front mount intercooler, blow-off valve, megasquirt… The air filter was located behind the driver side headlight, which is good for protecting it from dust and rocks (and it gets fresh air through holes in the radiator mount for intercooler piping) but it breathes gross hot air when stopped or doing city driving (upwards from 120 degrees Farenheght)). See photo for details. It was supposed to need nothing but megasquirt tuning, but the more I play with it, the more I think there are other issues (I think not all the injectors work well amongst other things). I’m also new to the turbo thing, only having had stock NA engines before. The issue that brings me here today is that I am embarking on a cold air intake build (I plan on building a scoop that goes under the rad and maybe back up in front of it (no more room to go through the rad supports as the weird intercooler has both in and out on the same side, that side), with the filter in an isolated box between the rad and the engine. See upcoming post with air pressure and temperature tests...) and also am looking into isolating my intake piping (see other posts on that, with data too). I don’t want to build things that are useless, so I started taking data before so I can compare before and after. I’ve been measuring and comparing temperatures under various situations and came to the realisation that I might have a problem (not sure, thus the post). If I cruise on the highway at steady speed (say 75mph), I get steady temperature: today at ambient 82 degrees, I got 90 degrees at the air filter, and 120-130 degrees at the air intake temperature (AIT) sensor (I don’t actually know where the guy put that sensor. Any clues?). I’m not certain how good this is, but it does not seems too too bad (still not happy that I’m gaining 65-85 degrees WITH an intercooler under very little load and high air flow. Opinions?). The potential problem occurs as soon as I lift of the gas. If I lift off a little, say to slow down to 60mph(without de-clutching), the temperature climb real quick to 155-175 degrees AIT, while everything else stays the same (air filter temp, RPMs, air flow…). If I completely let go of the gas (without declutching), the AIT skyrockets to 190-215 degrees. In both cases, the temps stay high for a while and only then decrease slowly (unless I give it gas, at which point they go back down quick enough I guess). If I let go of the gas but immediately de-clutch and stay in neutral, the temperature goes up to 150-165, but then comes back down on its own quick enough. I thinking the really high temperature I see when I don’t de-clutch might be a combination of A) slower moving air that gets to take the time to absorb more heat and B ) the fact that, because the engine is working still, there is a significant amount of exhaust that might make the turbo work and thus heat up the air. But how come the intercooler wouldn’t be making up for that? So, is that temp spike normal(ish)? Should I be worried? Any explanations?