F14CRAZY

Supercharging (this time, it's real)

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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.

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. 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>

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Perfect Power units measure absolute manifold pressure, tps and rpm to come up with the values to translate to the ECU. Now if it can do that and retard timing whats not being thought of?

(At first I thought it was just a MAF to MAF translator)

I've heard of piggybacks not being able to compensate for real weather situations, (runs perfect on dyno, lousy out on the street)

Large injectors, low horsepower computer = make small adjustments large, but the more powerful engine requires the fuel anyways.

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Comparing the Reatta LN3 (right) throttle body to the L67's (left).

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This is me holding up a new LN3 intake manifold gasket on the L67 manifold. Notice the extra intake port I mentioned on the bottom left.

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Happened to take this pic on Maui's spoiler grin.gif. On the bottom is the L67 gasket, and the LN3 is on top.

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Throttle body off of my LN3

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Another shot of the engine without the throttle body

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Fuel rail and injectors removed

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Intake manifold off

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What a mess!

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L67 gasket sitting on the LN3 (not ready yet). You can see where the extra port is going to sit...not a big deal

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Had to stand on the table for this shot...kind of pointless, but it's the L67 (left) and LN3 (right) manifolds.

Put over 4 hours into the project tonight and got a lot done. Got my LN3 torn down. Tomorrow, I should be able to install the L67 manifold. The last thing I got done before calling it a night was I removed the big aluminum assembly that the power steering pump and belt tensioner mount to. Though the L67's assembly is a bit more complex, I checked the bolt pattern and yes, it should bolt up.

That's about it. Catch you all later

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The extra hole will be on opposite corners of the manifold. From the driver's position it will be at the right rear and the left front. They are the PCV passages you won't have on the LN3 heads. They are not oiling holes, although they will likely look oily. They do connect internally to the black box you mentioned. On the TPI manifold from an L27, it is on the far right side. My best guess is if you use the L67 gaskets, the s/c manifold will seal up fine on the blank spot of the LN3 head, rendering the PCV inoperative. This is a gray area and I do not know for certain if the flat area on the LN3 and L27/L67 is the same size. I know the bolt pattern is the same. You could plumb PCV from one or both valve covers, or possibly some open area on the S/C lower manifold open to the valley like stock. In any case, an oil baffle or seperator will be needed below the hole. There is very little room inside the valve covers so you will have to investigate thoroughly before you poke holes in them. I have been considering using the lower part of an L27 TPI manifold with a custom welded upper plenum for the turbo project. The PCV is also a problem, just like you have, but I had given serious thought to cutting off the stock EGR hookup from the LN3 and welding it on the new plenum. By the way, the early model TPI 3800 did not use any EGR at all.

As for the ECM not sensing boost, that is absolutely true. It never has been true, even for the GN's, but the programming was designed to assume it was there based on the amount of air flow. Air flow is really the key and how to capture all of it without going out of the range of the ECM or the ability to adjust to the air flow is lost. Working on that problem on the flow bench now. The 3" MAF from a 3400 engine appears to flow just over 1.5 times the air at the same frequency output as the stock MAF.

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As I understand it...

PCV, positive crankcase ventilation, is to let blowby gasses out of the inside of the motor...there's a line that connects from the front valve cover and runs to the throttle body (connects about where the TPS is, I know cuz it gets in the way). Isn't this a PCV line? Is it good enough?

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The MAF in your photo looks just like the integrated MAF/throttle body from the L27 TPI manifold. It is also made by Hitachi. I checked the L27 throttle size and it is exactly the same size as the LN3. The one for the s/c may be larger, but I bet the stock LN3 intake hose will slip right on the s/c MAF.

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The line from the valve cover to the throttle body is part of the system. That line allows filtered air to enter the engine and the PCV valve on the right rear of the intake is subject to manifold vacuum and flows a metered amount of air, drawn from the valley area, into the intake plenum. The pan on the bottom of the LN3 manifold acts as the oil baffle to keep oil splash from being sucked in. If you remove the pan you will see the PCV valve grommet in the lower manifold is inside this pan. You need both intake of air to the inside of the engine and the metering valve to pull the air through and into the intake. Old style PCV systems allowed air in one valve cover (like ours) and the PCV valve was connected to the opposite one. Maybe two front valve covers would work??

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2seater: thanks for all your help...in yellow above, this cover has "PCV" stamped on it. Does it my cause at all?

I really like the idea of two front valve covers. I probably wouldn't have ever thought of such an idea. I have easy access to an '88 Rivi (which I've parted out a lot already) and will see if the front and rear covers are compatible. I imagine they are.

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<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.

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Will be posting photos of today's work later...

Picked up gaskets from Advance Auto Parts, and I think I have all the ones I need this time. We dropped by the parts Riviera and got the front valve cover. I'll be pimp, with not one, but two oil fill caps!

Since I had all the junk out of the way, I decided to go ahead and mess with the harmonic balancer. I'll post the pix comparing the two, but they're pretty much compatible with each other. The crankshaft position sensor and the toothed ring thing are different. I had the idea of swapping the toothed ring from my '89 balancer to the L67 balancer, but the LN3 balancer has like propriety bolts or something, so we gave up. I took a look at both crankshaft position sensors, and the L67's will bolt up to the LN3 (I've got photos of those too). The L67 sensor had some cracks in it, so I held off on putting it on (gonna pick one up later, my 3rd visit to advance auto parts today. The manager is giving me discounts now).

Had to use a 15/16'' socket (yeah I know it's metric) with a breaker bar, with like a 5 foot extension, and my little brother (14) standing on my dad's 48'' aluminum pipe wrench around the balancer to get the L67's balancer off.

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Here, we have the backsides of both harmonic balancers. L67 on the left, LN3 on the right. The bores, keyway, and diameter are all the same.

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Top (I guess you could say) view of the balancers, on my dumb trailer, with my dad and his van in the background. With the balancers placed on their front sides on a flat surface, a level put on top of them proves that they're the same thickness.

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And this view, if you're interested. Not much to see

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And, the crankshaft position sensors of the L67 (left) and LN3 (right). I'll be back soon, like in half an hour and post more about what happened today. Made some progress, but wanted to get these pix up for you guys

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Well, I made some decent progress. Haven't got any L67 parts bolted up, yet. But they will bolt up fine.

Today, since I had the aluminum idler/tensioner assembly off, I decided that it would be a good time to mess with the harmonic balancer. The L67 uses two belts, so, we have different crankshaft pulleys to deal with. It took a lot of physical violence to get the one off the L67, but the LN3 balancer was easy (had it off less than a year ago). The aluminum interrupter/interruptor ring of the L67 balancer is of a larger diameter compared with the LN3s, so it wouldn't mesh with the crankshaft position sensor of the LN3. My first idea was to swap the interrupter rings...an examination concluded that they could be swapped. But the LN3 had bolts with propriety heads. I thought I needed Torx sockets for it so I picked up a set, but those didn't get it either. I tried a ton of 1/4'' drive sockets and none of those worked. The L67 had 2 regular hex headed bolts which came quietly. After spending too much time on it, I decided that it would be easier to swap the sensors themselves. As you can see, they're slightly different, but will bolt into place. I'm assuming that the signals are the same. The L67's sensor had a crack, so I picked up a new one from Advance ($28).

I didn't have the new sensor, but I tried putting the L67 balancer on my crankshaft and it started ok...didn't want to tighten it down cuz it was a PITA to get off the L67 crank. However, I tried the LN3 balancer on the L67 shaft, and it fits perfectly fine.

As I posted earlier, I got the front valve cover from the parts Rivi, so I'll have the exit vent for the PCV.

Soon to have two oil fill caps grin.gif . I'll be back on it tomorrow.

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The Reatta is what it is: a semi-luxury, two-passenger sports-oriented, limited-production automobile. It's now past its prime, with out-of-date electronics. You wanna stuff a 707 jet engine in a Piper Club? You're gonna create more problems than you started with. Beware what you create; it's gonna be a monster, capable of killing you with a smile.

<span style="font-weight: bold"> -- ALF</span>

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It gets worse...

On my Explorer message board with a dude with a Bronco II, with a few thousand posts. He had a 2.9L with a 5 speed. Then went to a 4.0L OHV and an A4LD auto. Then recently, he went to a 5.0L/4R70W auto from a Mounty, and got rid of the AWD that came with and went with a 2 speed transfer case.

And it's his everyday driver grin.gif

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1) you cannot put an "L" balancer on a "C" crank and have it work properly. The shape of the snout is different.

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.

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.

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I don't wish to disagree with the honerable Padgett, but I beg to differ...I fitted the L67 balancer to my crankshaft this morning. Pix will follow. I stopped inside to eat lunch.

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<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.

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Today, Day 4...got the harmonic balancer mess over with, swapped the rear valve cover, and messed with the tensioner assembly

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New L67 crankshaft position sensor

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Sometimes, some physical violence is needed for those harmonic balancers...

You may have noticed, but in a few of my pix there's been a can of ether. We always have a lot for my dad's diesel and I found out that it's a fantastic, cheap cleaner. Good for getting crud of bolts before you put them on.

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Check it out! Harmonic balancer ready to go. My dad and I both messed with it, but it went on fine. Balancer and its bolt are tight and it spins true. The L67's bolt had more threads on it (hard to explain, but it's more normal compared with the goofy LN3 bolt).

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Notice my dual front valve cover arrangment. It's aluminum. I cleaned it up with some stripper. I didn't feel like waiting and matching paint, etc, so I'm mounting it as is. I'll get to painting it eventually. I do have the cap.

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Idler/tensioner assembly mounted. It's massive compared with the old one, but the bolt holes are the same. The alternator goes where the power steering pump usually is on a Reatta, and the power steering pump sits down and back. I had to remove the resevoir for it to bolt up, so I'm going to go to the parts Lesabre we have and rob the resevoir...the TPI motor and this L67 use a resevoir that sits kind of where the EGR valve is on our Reattas. I'll run some hose to it, shouldn't be a problem. I misplaced one of the bolts for the pump, so I'll run to Mid-States tomorrow and get a replacement.

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No pix today, but not much to see...

It's day 5 of the project. Stopped by Mid States bolt and screw and got another bolt to mount the power steering pump to the tensioner assembly (I lost one bolt). Resevoir is gonna have to be relocated, with lines run to the pump and to the power steering cooler line. Not a big deal though.

I got the intake manifold mounted, new gaskets and all. The Reatta FSM says to torque it to 88 ft/in=7.3 ft/lbs, which I did. Is this ok? Was wondering if supercharging would make a difference, but the gaskets for the L67 and the LN3 were the same, only different in the L67 having that extra port. No problems at all bolting it up though.

Tomorrow I'll pick up some hose to run from the water pump to the heater core and for the p/s pump and stuff.

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ha it looks like it is, but actually it isn't. Pipe wrench is almost touching the hood. It was almost in the way

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Day 6!

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Got those coolant tubes stuck in the motor

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And here's a shot of my rigged up power steering line

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