This is an L98 tuned port. Injector pulse is batched odd-even...something that surprised me. Way back when, I thought TPI would be sequential...but that's OBD2...and reminds me of how this mess started.
See...lol...grab a seat and I'll explain from the start.../TLDR incoming.
I wanted to build my projection of what an SS350 should have been. Sport truck trim, wheels, and decals, 454SS gauge cluster (115 speedo and 6k tach), buckets/console, sport mirrors, driving lights, fast ratio steering, rear sway bar, all factory stuff...and to top it off, the same L98 that came in the Z28, T/A, and Vette (less the aluminum vette heads).
I always assumed I'd have to change to a SD or MAF ECM from an F-body, with a 700R4 to do this. But in my research, I found a guy that would modify a junkyard harness for me, so I could keep driving the truck. Also he suggested Ed Wright of Fastchip to tune it. He said Ed could do it using my factory PCM. Ed confirmed that and I talked some with him about the engine. It wasn't wild. 081 heads, with 2.02/1.50's, headers, 4 bolt roller block, flat tops, windage tray, etc. But I'd bought an SLP cam grind that Ed didn't like. He suggested instead that I use the ZZ3. So I bought that too. I assembled the engine while the harness was worked. Once I got it all together it ran but surged horribly at an idle, and bucked fiercely if you let out too abruptly at highway speed, but it ran well enough to get it to Tulsa. So I arranged with Ed to drive it up to be tuned. In my mind, I was expecting a dyno tune.
Well no dyno was involved. I think he had kind of a cookie-cutter, shake and bake approach to tuning ZZ3 equipped TPI's, and that's why he wanted the ZZ3 in it instead of the SLP. Also, he was kind of torqued at me that I didn't spend the $800 on factory Bosch injectors. I'd opt'd $300 for Accel units instead. He got it WAY closer than it had been, but not right. He told me the injectors were complicating the tuning, and he didn't have time to continue right then and wanted me to leave it. Well, I'm in Wichita Falls, so Tulsa isn't what I call close...that just wasn't an option. So we agreed on mailing chips back and forth, which was painful to say the least. It ran decent enough to drive daily, and the pull in first gear was OUTSTANDING. The launch was seriously impressive for that engine. But it had bugs. At times it felt like it pulled in tiers, had some detonation, and it never would leave as hard if snapping to WOT as it did snapping it halfway and then walking it on down. After about the 3rd or 4th chip, I abandoned trying to deal with Ed. It wasn't getting any better and both our patience were being tried. Can't really criticize him though...I had no way to log and he's not a magician. He did hang in there, and without complaining about the price, either. It just wasn't getting solved that way. I wanted someone once and for all, to tune the damn thing on a dyno, get it right, and be done.
I did more research, and came up with Fuel Injection Specialties in San Antonio. They had great communication and were confidence-inspiring (and they didn't needle me about my injectors). They told me the only way to ever really get that right was to switch to the 7730, and either go 700R4 or siamese the harness and stack my original PCM to run my 4L60E. I already decided I was just going to get a 700R4. They suggested that I leave the control circuits for the 4L60E anyway to leave that option open. I opted in. I sent them the harness, and while the truck was down, I installed a TCI street fighter 700R4 and a cheap vette/S-10 converter. When I got the harness back, I threw a stock memcal in it. It didn't have the balls that it had with the old PCM, but it was smooth, and ran good enough to cruise it to San Antonio without issue. The stall was perfect. It didn't move when you put it in gear, didn't creep at a light, but at a 2500 cruise, it didn't lay back on the converter, either. I drove it up there and left the truck with FIS for a couple of days while I checked out the Alamo and the caves. They replaced the injectors with Accel 24lb's by the time they finished. Their final tune put it at 275 RWH. Honestly, I was somewhat disappointed. Not in the numbers, but it just didn't run as strong as it had with Ed's setup. It wasn't a subtle difference, either...especially from a stop...30-40 ft/lbs short, by the feels. But it ran decent, it ran smooth, everything worked...speedo, cruise, it shifted and drove REAL nice. I had traded power for 'nice' behavior and I was really just sick of messing with it. So I resigned and just drove it for a few years.
Eventually, I got tired of the 700's gap between 1st and 2nd...started looking around at options. I Landed on a 200-4R. The 2.74 1st sounded like a soluton, and 200's are forgiving concerning parasitic loss. So, I contacted Art Carr, and another tranny shop that shall remain un-named. The latter talked me into a 4L80E instead. This, in part, because I had a boner for the possibility of adapting TPI to OBD2, getting the ability to tune via email (still trying to get back that power I felt with the old PCM). They assured me swap to the 4L80E would be seamless, and I could use a standalone controller until I found someone to convert the TPI over to OBD2, at which point the controller could be sold, and the PCM would control both engine and tranny as well as expand my options like sequential injection, adding MAF, etc. I had stars in my eyes.
The tranny discussion is a long one, but I'll spare you most of it. When the tranny shop did their swap, they did two things that bit me with regard to current day. They tapped the original 4L60E VSS into the 80 controller's VSS wiring as I've recently found out. And for whatever reason cut the 700R's VSS circuit at the ECM as discussed earlier in the thread. They didn't tell me they did it, so no discussion of why they did it ever took place. I can only assume that at some point, where the 7730 sees MPH exceed a ridiculous speed (256 mph?) that something shuts down. My guess, based on what I saw last night, is that they hit that limit at about 12.5 mph during a test drive. The other thing was the converter. I gave them a window of 1800-2200. They said they didn't think they could keep it under 2200, but they could positively guarantee no more than 2500 with the 9" they were having custom made. I'm 53. I've had my share of hot rod triumphs and goofs. I was seriously doubtful that a 9" converter could be limited to 2500. But they were adamant about it, so I said 'OK'.
It took multiple visits/attempts before they had it shifting anywhere near right, in spite of my ranting about not wanting a breakneck shift. I do not for the life of me understand why some of these tranny shops insist on first hitting so ridiculously hard. They opt for crude brutality instead of finesse and precision. Anyway, after swapping in the 80, I noticed my fuel economy really tanked (no pun intended). I thought it was the parasitic loss in the tranny + the hellish stall. It had gone from 'no more than 2500' (which actually turned out to be 2800) to flash-stalling to 3800+ in about 4 months. Kind of excessive for a TPI motor. I really couldn't tell how it was running because it flashed right past the grunt area of the rpm range. If the tires got loose, they'd FRY all the way into the top of 2nd gear, and stay frying until you either let out of it or popped a tire. If they bit, it was loud and poochy. Just generally not fun to drive anymore.
The stall got worse, and started making a noise that sounded like whisking an eggbeater inside of a coffee can anytime you stalled it with the brake. For $4000, it was going back to them to get made right. I told him I didn't have confidence that the 9" could be kept under 2500, and that I thought an 11" would be better even if I had to pay an upcharge. He told me there was no in between...Said no one MADE an 11" for an 80. They had me over a barrel because I hadn't looked into it myself, and was ignorant. I was getting pissed, because he was getting attitude. It was a 9", the stock 13.75", or get bent and take my garbage home, as far as he was concerned. I said hell with it, put a stocker in it. I was hot, but there was nothing I could do but drop it off and wait for them to call for pickup. It's a 2 hr drive, btw. I was still kinda erk'd when I picked it up. I just handed him cash for the stocker and got in the truck and left. I got hot again when I felt how hard it lurched when I put it in gear, but it was time to GTFO. When I got home, and looked in the back of the truck for the 9", I figured out not only had I paid another $300 for the stock converter, but they'd also KEPT the $500 9". I went Full...Blown...Daffy Duck, but no way was I going back to end up in jail 2 hrs away from home. It was all-around a terrible experience, that is apparently still haunting me today. That really was and still is, a horrible converter that eats carrier bearings. And I just keep uncovering shoddy things they did...Even as recent as last July...it goes on and on, but I'll stop.
Wasn't long, I ended up buying a new turbo Bimmer and just let the truck sit. Aspirations of OBD2 went out the door. I only drove the truck when I needed to haul stuff, which wasn't often. About 10 years passed, and it got where it just ran worse and worse, so it sat more and more.
Now, the nature of my job has changed enough that I need the truck back in shape. Really I should replace it, but I'm too OCD, and I don't need another payment...so I've dug back in and straightened up almost all of it's issues. Entirely new A/C system, including big, dual electric fans, 75 amp relays, 34" 2 row radiator, a 250 amp alternator, new dash, stereo, speakers, new Bilsteins, carrier bearing, tires, all new sensors, etc. But the mileage is still crappy, so I started talking with a tuner...got Tuner Pro...started logging. At some point, he asked if the logs I'd been sending were with me just sitting in the driveway revving, because the TunerPro logs showed 0 mph. I explained that I was actually driving, but the VSS wasn't connected because of the inclusion of the 4L80E and its controller (or so I thought). That's when I learned that VSS is actually kind of important for the 7730 to see. Without it, I'm abandoning things like lean cruise and deceleration leanout, and no telling what else. I'm guessing that's why my mileage went to hell after the 80's install, and it had damn little to to with parasitic loss OR the converter. The tuner told me I needed to figure out a way to get that signal back to the ECM. And when I started thinking about it...I really couldn't understand why the gauges were working with no input from the tranny
...which is exactly where this thread began.
Heh...I'm sure it's way more than anyone wants to read, but it's therapeutic for me, so...
