OldsTrofeo

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I got a reply from Ryan... <span style="font-weight: bold">Philip, if your fuel pressure is dropping off with higher RPM's or more boost present, the fuel system is not adequate for the job. Can I assume you are using the stock L67 fuel rail and pressure regulator along with the injectors?</span></div></div> He programmed your chip without knowing what injectors you're using? That could be a problem! <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"><span style="font-weight: bold"> Don't set the plug gap at 0.025". That is far too small. A plug gap setting of 0.050" is what I would use.</span></div></div> I hear this *all* the time! It's amazing what people assume without testing. If you're getting a misfire, this will often clear it up on a DIS system. I never set supercharged engines larger than .045", usually .025-.035".

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Yes, the L67 throttle linkages use the two cables. One's for the pedal and the other's the cruise control. However, the LN3 uses a 3rd cable that runs to the top of the transmission. It's a pretty short cable. I checked on our regular LN3 cars again and the black plate that's used do use this cable. I just need to figure out how to attached it to the linkages using the old plate. The L67 linkages don't have a provision for this cable. </div></div> You definately want the TV cable. This controls transmission shifting and pressure. Avoid driving it much until it's connected and properly adjusted.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Today I bought my own fuel pressure gauge and a new Bosch oxygen sensor. Now, I can get my own readings whenever I please. During the 1st two seconds with key on, engine off, I read 40 psi. Then, it drops to 38. Within 5 minutes, it drops to 30 psi. Is this normal, or a sign of an injector stuck open? I'm still going to get a new pump (Ryan suggests one for a '89 Turbo Trans Am) and mess with that, but wanted to give you these readings and let you guys know that I have my own gauge and can check it whenever you think it should be. After installing the new oxygen sensor, should I go ahead and start the car and report back new ECM readings? Thank you guys so much for all the help and advice on this project. A big, complex, expensive puzzle. And sometimes, you need to make your own peices. Or make some pieces fit. But we'll figure it out </div></div> I wouldn't go jumping in and replacing a fuel pump yet, check your readings first. Not that a higher output pump would be bad, but you may not need it. Don't worry about the O2 sensor at this time, in fact you could unplug it for the testing phase. Clear the codes by unhooking the battery (or BLM reset function on a scan tool). This will prevent the ECM from performing fuel correction until you get everything else right. With the O2 unplugged, the ECM should show a reading ~450mV. This will set an SES, but won't be a problem for testing. Try gapping your spark plugs to .025" and see if that helps. DIS is a somewhat weak ignition system and with the boost you've added can easily flame out, especially if you're running a bit lean.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I wonder if you can find the correct combination of larger injectors and slot covering so as to avoid the necessity of have to tweak the ecm. I used the larger later throttle body and injectors. I am hoping this works. I just connected the original egr via copper 1/2" tubing street els. I used silver solder to join them and then wrapped it with metal tape. The issue that I am now stuck on is how to connect the fuel lines to the new fuel manifold. </div></div> This is a very poor way to do it from a driveability standpoint. When adding this much air under pressure, not only will fueling be a concern but ignition timing as well. You might get it to run, but it would never be right.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Trofeo, I think I understand the point you are trying to get across. The only way I can see the bypass theory would be true is if the main straight through passage is larger, and it may be. The Hitachi MAF passage for the actual sensor is tied into the main passage and all air must pass through the throttle body. From the flow bench testing I am doing, the throttle body itself make essentially zero difference in the air flow through the MAF. I have tested it by itself, attached to the throttle body and with and without the screen. The screen does decrease total flow by 3%-5% in the upper flow range. It would make a difference if the T/B was smaller. I am curious as to the internal passage sizes for the L67 MAF. If they are the same as the LN3, the air flow vs frequency has to be the same, unless the sensor itself is different. I will see if I can find the frequency response is supposed to be for the L67 MAF. </div></div> It's not the internal passage where the MAF sensor wires are that I'm referring to. It's the overall internal diameter of the throttle body itself. It's quite a bit larger. I don't have any handy to measure, but if you could get them side by side, you'll see the difference. The MAF sensor can only calculate the air that passes over the wires, it doesn't know the amount that is capable of flowing through the throttle body. That's where the MAF tables in the ECM's code comes in. When the engineers wrote the code, they knew how much air was flowing into the throttle body for a specific frequency response from the MAF. If you look at the code for the LN3, the MAF tables top out at 170gm/sec, while the L67 ends at 255gm/sec. I'm not sure what you mean by 'bypass theory'. The MAF doesn't bypass air, it just sits in the air stream and calculates the air crossing the wires. Unlike the old 'air door' systems, it can't actually see the total volume of air, just what is crossing the wires.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> In the middle of this pic, it looks like a vacuum line is missing and I can't figure out what to connect it to...suggestions?</div></div> That fitting should have a little foam filter over it. <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Is the wastegate solenoid thing the black plastic device that has a vacuum line running to it, that sits behind the supercharger housing? As this is not really used, do I leave it there or remove it?</div></div> That is your boost control valve, not a wastegate. The ECM you're using is not programmed for boost control, though with a supercharger I wouldn't consider this a big concern. Many of the SC3800 conversions run withh the bypass valve blocked closed without problems. I would suggest leaving it just like you have it now. This way you still have the vacuum bypass for light load conditions. Especially with your cone air filter, this will keep the cruising noise level down quite a bit. You'll have a big howl from the blower at WOT!

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Hmmm, it uses the same model MAF? In theory the MAF should max out somewhere around 220-225 hp., maybe a little less. I do know the MAF will generate higher frequencies than the stock ECM can read (I have tested it on the flow bench), so the ECM for that engine may have a larger range than ours? I have also found that the one sensor I have from a 3300 engine will read lower frequency at the same air flow by 15%-17%. In other words it can read higher air flows and still stay within the read range of the ECM. I have two 3800 sensors and they show a maximum variation of 5%. I will be very interested to see what sort of signal you get from the MAF when you get it running. Have you figured out how to operate the boost control? </div></div> It's not the frequency that changes, in fact it would come as no great surprise that the L67 and LN3 MAF would interchange. The difference is in the volume of air that flows past it. Look at the size difference of the throttle bodies. The MAF is only measuring the amount of air flowing past it, so the calculation in the ECM needs to be adjusted to compensate for the larger volume of air <span style="font-style: italic">around</span> the MAF wires. This is the LN3's 170gm/sec vs. 255gm/sec of the L67. Let me know if this doesn't make sense and I'll try to explain it better.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">1) you cannot put an "L" balancer on a "C" crank and have it work properly. The shape of the snout is different.</div></div> I sort of expected this, but wasn't sure. Will be interesting to see his results. F14CRAZY: Be careful installing that balancer. If it doesn't go on all the way, you might be removing it with a torch... <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">2) There are MAP adherants and those who sware by MAF. It really does not matter though IMNSHO MAP lags MAF slightly. Probably not enough to bother at the relatively slow speed of a 68HC11.</div></div> I don't have a huge preference either way on the P4's, but really like the LS series engines with both. The MAP seems to pick up transitions a little faster (air flow sensed vs. actual manifold filling). Can really make them run nice that way. Like you said, with the speed of the processor, it doesn't really matter. Even worse with an old C3... <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">You can derive either from the other when you use LV8 (load value 8 which compensates for a number of fudge factors including temperature) and rpm. Nice thing about MAF is there is no zero crossing but the "C" MAF tables top out at 170 gm/sec and a boosted engine can easily exceed that. I have not gotten real deep into that aspect but there are those who have. </div></div> I have heard of people changing the MAF tables in this ECM for higher flow rates with good results. The GMECM list would be a good place to inquire about this, as I think that's where I heard about it. <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"><span style="font-weight: bold">F14CRAZY said:</span> I'm assuming that the signals are the same. </div></div> Yes, all dual sensor 3800 crank signals are the same.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Thank you Trofeo. I brought up boost because Ryan told me this a while back... <span style="font-weight: bold">Philip, yes this should be able to be done physically, but the engine you have does not have as durable of internals as an engine that originally came with a supercharger. This means that your engine may not last very long if you put the supercharger on it. Yes, I can reprogram your computer to work with the larger injectors and dump more fuel, but your computer is still not going to be able to recognize the presence of the supercharger. While it will still work using your stock computer, it won't be perfect. </span></div></div> I agree that you will be shortening engine life with this project. Adding more power usually has that effect. Again, my biggest concern mechanically is that harmonic balancer. Aside from that, and a little work with the PCV, I don't see why it wouldn't work. It might not work for very long, but "C" motors are cheap and plentiful so you can pretty much blow them up and throw them away without concern. Don't worry about the computer not 'recognizing the presence of the supercharger'. The 92-95 supercharged computers don't have any way of knowing if the incoming air is pressurized in the manifold or under vacuum. The MAP sensor in these applications is only for the boost gauge. To run perfect, all it needs is a proper tune, which can be achieved with the 1228253 ECM, but it will take some specialized attention, and don't expect it to work right on the first chip. <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"><span style="font-weight: bold">Philip, the main problem we run into when trying to use a turbo or supercharger with you computer is that while I can reprogram it to dump enough fuel to compensate for boost, the computer will not be able to determine how much boost you are running nor exactly when you enter boost.</span></div></div> This is somewhat correct. With this computer, you're not trying to adjust for boost, you're adjusting for load and airflow. When tuning something like this, you need to forget about boost. <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"><span style="font-weight: bold">Basically what will happen is say at about 1psi of boost the computer will go into "power enrichment" mode which is when the computer will dump this extra fuel. However at 1psi of boost, obviously there will be too much fuel being dumped since we will have to reprogram the computer to dump enough fuel for say 10psi of boost which is what you will probably have at WOT. As you can see, fuel delivery isn't going to be perfect, but it does work.</span> </div></div> If this was true, none of the 92-95 supercharged cars would work correctly. In these computers, power enrichment is a multiplier. If your MAF tables are calibrated correctly, when you apply enough TPS to enter power enrichment mode the computer will add the PE calculation for that RPM to the formula for injector pulsewidth (it's a bit more complicated than that, but this should give you the general idea). As 'boost' goes up, airflow goes up. If your tables are correct it will provide the proper fueling. Ryan is going to have a big challenge getting this to run correctly without the car being physically present.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> I know that supercharging has been done before. However, nobody else has attempted a bolt on project to the existing LN3</div></div> I've heard of people doing it to an "L" engine, but not a "C". I'd recommend your first step to be attemtping to install the harmonic balancer. If it fits, start the engine and make sure you don't have a vibration. There are several part numbers for harmonic balancers for the 3800. Looking at a Dorman book, here's a few of them: 1988-1990 594-001 1995-2000 594-004 1991-1992 594-005 1993-1994 594-034 Dorman is an aftermarket company, they don't make any more part numbers than necessary. If this doesn't work, you'll want to take this project in a different direction. <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">It's not plug and play to install an entire, different engine either</div></div> Mechanically, it's very close. Electrically it's just as easy as what you're doing. <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I'm competent that from what Ryan has said, he's making me a good program for this</div></div> Not likely the first time. Get on thirdgen.org and find Grumpy. Ask him how many chips it takes to make something perfect. <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Again, electronics are the hard part with doing this work, which is why I'm not going with the series II/4T60e or anything else. By keeping the LN3 right where it is, the ECM won't care.</div></div> The ECM does not care what engine you have. It cares what it's sensor inputs are and that it has 6 saturated fuel injectors to drive. Now, by changing how it gets it's air and the size of the injectors you're using, you've just thrown off the code in that 32KB chip. By keeping the "C" engine, you will not make this part of the project any easier. <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">There's the boost issue and all, but at least gauges won't be a problem. I don't wish to offend or talk back or anything like that, just defend what I'm doing and why. </div></div> There is no boost issue! This ECM does not understand or see boost. You have no MAP sensor. I'm not offended, I'm just trying to explain how this ECM thinks. It has no comprehension of how the air gets in there, it just measures incoming air.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> The Old Thread, "Supercharging, revisited" This is not a daydream, a crazy idea, speculation, etc. This time around, it's real.</div></div> Doesn't Greg Ross have a supercharger in his Reatta? I fail to see how it's been speculation before if it's been done. There's also an Oldsmobile Trofeo out there with a series II supercharged, saw it in a gas station in Indiana a couple years ago. BTW, a Trofeo and a Reatta alot alike. <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> We came to the conclusion that it isn't that easy. Ryan of Sinister Performance/GMtuners said it would be about $6k to swap an L67, the supercharged series II 3800 and 4T60-e transmission into a '90 Reatta. We chose the '90 to avoid any instrumentation complications (like with the ECC). He'd also need about 6 weeks to do it, not to mention that he's near Fort Wayne, IN and we're near Lansing, MI.</div></div> The instrumentation communications in the 90 is very similar to the eariler years, you still need the proper communications between the gauges and the body computer. Your body computer depends on the engine computer for much of it's data as well. In other words, you can't just go swapping computers. <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">There was no easy way, until now... I propose to obtain a complete engine from a '95 or so era Park Avenue (or Riviera), the "series 1" supercharged 3800, and directly swap the necessary parts onto my engine, for a planned increase of about 60 horsepower, to 225 hp, up from 165. Maybe2fast, also known as Don in Walled Lake, MI is my primary moral supporter.</div></div> You're buying the engine, then swapping parts to yours? Why not just install the entire engine? It's not exactly a P-N-P operation to install the supercharger on the early 3800. <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">From what I know, he knows, Ryan knows, and from other posts (like in Supercharging, Revisited [thanks guys]), this idea should work. We're not completely certain yet, but we think that the cylinder heads on my engine DO NOT need to be swapped out. </div></div> While the cylinder heads may be a concern, you may want to think about the rest of the engine. Camshaft profile, rotationg assembly balance (you'll need the twin belt balancer) and anything else that might be different. <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> The S/C engine, at least the series 1, is pretty much just an LN3. The crankshaft, pistons, and engine internals are pretty much the same. Nothing weird inside. The series II is a much different story, however, that's why we're skipping that one.</div></div> Yes, they're very similar. There was quite a few changes between the 88-90 engine and the 91-95 non-supercharged. <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Ryan of GMtuners previously said that he can reburn by EEPROM/memcal/ECM chip to accomodate the changes in fuel, air, and the boost. I will be sending this to him pretty soon (like this Tuesday, after president's day)</div></div> This is a mass airflow system, so it doesn't understand 'boost', just how much air is passing the sensor. There was some changes in the airflow sensor, so you might have some issues with it. <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I say this is real because I've already secured the funding. My dad handed me $600 cash, </div></div> <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I have school, my wonderful girlfriend (sorry guys, it isn't Jessica ) a life, etc so I can't work on this project 24/7, but with a weekend, I'd say that this swap could be easily done in a day. I tend to work at a kind of slow pace and don't always have critical stuff on hand like gaskets, uncommon sockets and wrenches, etc. But nevertheless, it won't take a month or anything. I could probably get it done in a week or two with my schedule. The good thing is that our Reattas are laid up for the winter anyway, so there's not much to do.</div></div> Be ready to spend alot more time than two weeks on it. If you've never tackled a major project like this, you're in for a surprise. There was a guy a year or so ago that was doing a Series II / 4T60E swap in another guy's Reatta. He got on the gmecm mailing list asking questions about how to get the gauges to work. Found out he'd swapped computers, made quite a mess of the car. Just be careful with the electronics, it's easy to get into a ringer on one of these cars.

Sent you a message, but haven't received a reply. Do you still have the manual? If so, PM me with your mailing address and I'll get the payment to you.

I'm interested. I don't have anything to trade, but $50 sounds fair. Where do I send it?

Do you still have parts? I really need some stuff. Please give me a phone number to contact you. Thanks!