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I thought I should continue the Reatta story a little bit further. I have been looking for photos of the first long distance trip, and I can see them in my minds eye, but they may not be digital being from about 1996 ? Anyone that has seen my posts with mostly performance "adjustments" knows these aren't professional in nature but more of a trial and error process, plus it is a learning experience. I will try to synopsize what and where I have looked for improvements with varying levels of success. Initially in the '90's it was the usual homemade air intake with a cone filter. Then it was a colder 160 degree thermostat sourced from a vendor of Grand National parts and tuning. This was coupled with a new PROM from ED Wright at Superchips. This had the net effect of a slight increase in performance at the higher end at this expense of low speed crispness and requirement for premium fuel. Also had the coolant fan operations changed to match the thermostat. Along the way, discovered and corrected the rear exhaust manifold restriction plus had all of the engine exhaust parts ceramic coated inside and out in titanium gray with heat shielding eliminated. That worked just fine and looks good, but costly. They hang on the wall now. Around this same time, about the turn of the century (which I never thought I would say), I spoke with a guy in Iowa that worked with the GN guys enlarging stock throttle bodies. I sent him one and he machined it larger internally and made a new throttle plate to match. The bigger throttle does have a tiny effect but I had to close it almost to the point of sticking in the bore to get the idle down. This same guy made an adapter cone for my first turbo to throttle body connection when that experiment began. Somewhere in there I removed the cat and replaced with a straight pipe. This was about the same time I came upon a flowbench forum that promoted homebuilt plans and techniques. I believed it evolved to be called Flowbench Tech now. I did build a very simple but reasonably powerful bench of my own which I used at first to test things like the stock cat. vs the straight pipe and later a replacement cat. Not satisfied, I purchased a junkyard engine, an '89, to "build". Bored .020" over, L27 replacement pistons with more compression height to approx. zero deck, hand ported stock heads and first use of flowbench for conventional testing. All very Rube Goldberg but educational. The stock engine with 92k miles on it went on a stand and parked in the corner. The new engine worked well. Definitely gained some performance in conjunction with my previous items. Of course I couldn't leave that alone so decided to try turbocharging since I had a welder and various collected used turbochargers. I also collected used exhaust manifolds and I think this is when I brought a used camshaft home from a donor engine that I was stripping of parts to cut up and modify. More on that later. This where the throttle body adapter comes in to blow directly into the MAF from the compressor of the turbocharger. A friend donated some used GN injectors and the whole works was built and installed with the replacement engine still in the car. The first drive was a revelation. The faster I went, the faster the car wanted to go. It boosted very quickly and it wanted to go. I had no tuning at this point, just the stock chip. Two things come together here, caused by my lack of knowledge. It boosted very quickly and had knock issues. This is when I got involved with Ryan at GM Tuners and he burned several chips for me over time. I had put together an engine that worked well naturally aspirated but when turbocharged, the quench or squish distance was in a bad place for suppressing knock, plus there was no intercooler to cool the inlet air. Over time we got it better, adding alcohol injection, changing the fueling and timing, adding a tps improver to get full fueling earlier, but the factory ECM can only read up to 170gm/sec and we blew right through that threshold within seconds of launch. That meant everything beyond the ECM charts was a guess. It did work well but had to be relatively gentle and aware. I put about 38k miles on that engine in both N/A and turbocharged form. More to follow Photos: First gen Flowbench from 2005, raw first gen turbo piping B4 black ceramic coating from 2003, first ceramic coated stock exhaust manifolds and first turbo installed from 2005

Agree in general if running tires and wheels with matching specifications to the OEM fitment. Many of us have changed wheel diameter, width and offset, plus tire diameter, aspect ratio and width, as well as type of tire, so I do believe a bit of custom tuning may be necessary. One item I have noticed over the years has been some lack of concern for the speed and load rating of the OEM tires. I don't remember the load rating offhand but the factory H speed rating is 130mph, which does effect the tire construction. I have seen occasional references to tires that are a good deal and maybe a long tread life but a lower "S" or "T" speed rating. Probably fine for a cruiser but would fall short of the factory design parameters.

It is the operating condition when several sensor inputs become active and are used to adjust the operating parameters of the drivetrain. Prior to that time, the engine and associated transaxle operate in what is called open loop, which is pre-programmed settings and charts within the ECM. One of the thresholds to get to closed loop is the coolant temperature to indicate the engine can tolerate leaner mixtures and greater loads where the O2 sensor can adjust fueling to achieve stoichiometric or theoretically perfect balance of fuel and air. I think there is a timer function in the ECM too to engage closed loop in a warm engine after a short start up routine. I don't remember other requirements offhand. There is a loop indicator in the climate control screen when in diagnostic mode on a '90. I think it enables EGR, cruise control, TCC and other items.

As someone who works for a tire company, I would recommend sticking with the pressures on the door. It's more complicated than this, but generally, tires are designed assuming you are following those recommendations. Mostly it is about having the proper footprint for even wear over the life of the tire. Running the pressure higher will generally cause the tire to wear faster in the center, and lower pressure will tend to cause shoulder wear. Of course this also depends on having proper front end alignment as well as rotating your tires regularly. This is kind of over simplified, but you shouldn't go wrong by running what's on the door.

" tire technology has come a long way since 1988, and that the recommendation is now somewhat obsolete." Not true, is still valid for stock tires, that said I have been running 225x60x16s on factory 16x7 wheels (like crosslaces) for several decades. Fiero had bigger wheels and tires & never thought 215s looked right. ps biggest change has been the addition of a nylon cap/ply under the tread, keeps the tread from coming apart.

Late 88s (after 3000) could have a factory sunroof. Even later ones changed the Teves return line from rubber to steel. Finally the ALDL jumper for the Teves diagnostic flash changed from A-G (88) to A-H (89-on).