I understand it pretty well Will and considered similarity in ability between the balancer and the flywheel. The real motivator in re-examining the subject is that you said "End of discussion". You know better than that.
Seriously my thinking and consideration is more from a physics base than occupational so I question for more understanding. Whatever the case, much of the documentation on dualmass flywheels ascribes reduction in tranny gear wear as well as dampening protection from high torque applications (what likely destroyed my F40) as a benefit so you have a lot of correcting to do among the companies stating such.
Whatever you do Fierobsessed make sure you have a good sprung hub on Kevlar disc material as it is noisy on engagement with the tiny spring G6 hub I'm using. I believe I've already mentioned it but the easiest fix for tranny noise without the dualmass flywheel is idle rpm held around 1000.
I understand it pretty well Will and considered similarity in ability between the balancer and the flywheel. The real motivator in re-examining the subject is that you said "End of discussion". You know better than that.
I knew I'd get pushback on it, but I also know that such devices are employed for noise reduction.
The BMW community doesn't see high failure rates from the S5D-310Z when used with an unsprung disk and a lightweight single mass flywheel.
Your argument seems to be that the dual mass flywheel acts like a harmonic damper in such a way that it reduces peak torque through the drivetrain. This is not the case. A harmonic damper does not reduce peak torque at all. The only way the flywheel can reduce peak torque through the drivetrain is by slipping. If it only deflects, then a firing impulse will fully deflect it, and peak torque will go through the flywheel to the transmission without being reduced.
The only way available to you to sensibly make a counter argument is to measure the torsional stiffness of the flywheel. Have you done that?
Today, I worked on the exhaust. Mainly the downpipe, and the curvy pipe that goes under the engine, the one I call the question mark pipe. The downpipe to the flex joint, and the flex joint to the 90 degree both had a bit of gap that needed to be filled in. So I changed my steel wire out for stainless wire in the MIG, so these two weld joints got migged, I did the pulse method of welding. The problem with that was that it left little pinholes that I later needed to run the TIG over. Stainless mig is crap. but it'll fill in gaps, where it's not practical to with the TIG. Either way, it's done, and I am satisfied
Then I assembled it.
More parts are on the way. I got a couple more V-bands, one to seperate the question mark pipe from the muffler system, just for convienience. And another to build a Catalytic delete pipe. I don't need it, but if I race, or dyno, It might find its way onto the car...
I bought a 3" muffler, a Borla 40085
I also picked up some more pipe to complete the exhaust, and a couple of exhaust tips. I really wanted to retain the stock tips, but being just 2" pipe inlet, they might have been a bit of a bottle neck. For the new tips, I chose these:
Next week I should be able to assemble the rest of the exhaust.
I honestly don't have a lot of time for side work. You'd be shocked if you knew how few man-hours I've actually put into this project. It's probably about 5-6 hours a week. I just work like crazy when I am on it, get a whole buttload of work done, snap a few pics... ect. And to be honest, it is some of the cleanest work I've ever done!
Once this exhaust stuff is all done, there really isn't a whole heck of a lot of work left. I still have to put together an engine, but that will go very quickly. I still need to make a flywheel, do a bunch of wiring, a bunch of minor things need to be buttoned up. Almost all the money dedicated to this project has been spent, I just need to buy a clutch, and a bunch of small ancillary stuff. It still surprises me how far along this project is, and how little time I have put into it, and for that matter, how much money I HAVE put into it :-)
The oil enter's the GT35R turbo through a .035" restriction hole, the the drain line has a 1/2" ID. So I'm not worried about the drain hose being small at all, probably a bit small for a journal bearing turbo though. I know some gasses must be released through the drain line to the oil pan as well, but it shouldn't be a problem... I hope.
It's time for another update.
Over the last week, while waiting for exhaust parts to show up, I dove deep into the task of building a wire harness. I finally finished the wiring this morning. I can honestly say, I put about a good 30 hours into the harness, perhaps a little more.
If I recall correctly, it started out as a 3.1L Chevy Celebrity harness. I stripped the whole thing down to just what I needed I also had a donor V6 Fiero harness that I got the C500, C203, the bulkhead part, and some of the wiring and connectors from.
This is what the completed harness looks like
This set of connectors is over by the battery, From top to bottom: Ignition Power feed to ICM ECM to ICM connection Crank sensor to ICM C500 Connector Constant power connetion
This set of connectors is located near the starter, From top to bottom: Wideband O2 Sensor controller Ground lug Oil Pressure Sensor Heated O2 sensor A/C compressor clutch control Starter solenoid control Alternator power feed
This set of connectors is located on the rear of the engine block, From top to bottom Knock sensor Alternator charge indicator (somewhat hidden in the picture) Reverse switch Crank Sensor Alternator Power VSS
These 3 connectors are located near where the power steering pump was Wastegate Control MAP sensor Injector harness connection The 6 injector connections are also shown.
This set of connectors is located under and around the throttle body, From top to bottom: Ambient intake air IAT Pre-intercooler IAT Coolant temperature sensor Post-intercooler IAT Throttle Position Sensor Canister purge Solenoid Idle Air Control Valve Exhaust Gas Recirculator
These connectors are located under the drivers side deck grill, from top to bottom:
Electric Cruise control Fuel pump relay Cruise control switch interconnection A/C relay I may wind up needing to add a third relay to invert the brake signal to operate the cruise correctly
This is the ECM, and the related goods. You can see near the bulkhead passthrough, the Dakota Digital SGI-5 Speed signal converter. This takes the 78 tooth 60,000 PPM VSS signal, and converts it to a 30 tooth 24,000 PPM signal, then feeds it to the ECM. The ECM then converts the 24,000 PPM signal to a 4000 PPM signal. One thing I love about the 1227730 ECM, is that an 87-88 2.5L computer holder works perfectly with it!
You can also see a pigtail sticking out of the harness near the ECM, That contains this simple circuit that buffers the 4000 PPM signal from the ECM for the speedometer. Normally the speedometer is directly connected to a VSS, so this little circuit makes the signal compatible
Some of the stuff I needed for the exhaust started showing up. I got my muffler and my tips! But, I got the wrong radius mandrel bent 3" stainless to feed it. The correct stuff is now on order, but it won't be here till the end of the week.
Stock tips VS new tips
Since I haven't done a fit check in a while It's time to do one. With the new muffler being 5" in diameter and round, I must make sure everything I've done is working out. And that the muffler will fit where I need it to
Overall Fitment, stll looking great! Wastegate is tightly packed in where I wanted it
This one was a nail biter as I was installing the engine, it was really close!
I tried sticking the muffler in, and found the happy spot for it, Sorry no pictures of that yet, but I got the info I need, the muffler does indeed fit, but not exactly where I expected it to.
I forgot to put up a pic of the Front Mount Heat Exchanger, so here it is:
While I was doing the wire harness, I realized I needed some more connectors to do the job. I found a couple of Fiero's in the pic-a-part and scored a few things, Like the computer holder for the 7730, another 87 4 cyl throttle cable (for my other project...) some A/C hoses, (again for my other project) and I got this! Recall weatherstrip! in great shape too!
But, on the other end of the spectrum, I saw this horable thing at the pic-a-part:
[This message has been edited by Fierobsessed (edited 03-18-2013).]
Originally posted by Fierobsessed: This is the ECM, and the related goods. You can see near the bulkhead passthrough, the Dakota Digital SGI-5 Speed signal converter. This takes the 78 tooth 60,000 PPM VSS signal, and converts it to a 30 tooth 24,000 PPM signal, then feeds it to the ECM. The ECM then converts the 24,000 PPM signal to a 4000 PPM signal. One thing I love about the 1227730 ECM, is that an 87-88 2.5L computer holder works perfectly with it!
You can also see a pigtail sticking out of the harness near the ECM, That contains this simple circuit that buffers the 4000 PPM signal from the ECM for the speedometer. Normally the speedometer is directly connected to a VSS, so this little circuit makes the signal compatible
You should need two of those pull-up circuits, one going into the ECM from the SGI and one from the ECM to the odometer. I was told by Dakota after telling them about the combination that I would need a pull-up which is what you displayed, for the signal coming from the the SGI module and when tested without it I did not get a signal to the odometer with the circuit between the ECM and odometer installed alone.
I wrote a thread on it with the specified changes/calibration to run the odometer and the digital cruise if you think it will be helpful. Don't forget to twist the signal wires from the vss sensor.
Hmm... Interesting, I'll check that out. I'm surprised that you needed one between the SGI-5 and the ECM. The SGI-5 has both open collector outputs and A/C outputs, open collector would need a pull-up, A/C should replicate the VSS signal. I'll go check out that thread. Thanks for the feedback!
I see that you basically set yours up to create a 4K PPM input system. If I read it correctly, you used OUT4 (Open Collector) which natively divides the 60,000 PPM of the F40 by 32, then your multiplier factor of 2.024 sets you up with a 3795 PPM output, or about 4K.
I plan on using it in a different manor, as a straight divider. You will always need to use the pullup if you are coming out of OUT2, OUT4, or OUT5 as they are "Open Collector" meaning it just grounds the wire to trigger a signal.
OUT1 and OUT3 are AC output, they shouldn't need any pullup resistor, or circuit, they should simulate a VSS.
Screw what the manual tells you to do. Read past that nonsence. It seems like SW3, doesn't effect OUT1 (AC) and OUT2 (OC) they are always going to put out the factored ratio of the input directly, between 4X to 1/4X.
With SW3 off, It natively divides the input by 2 for both OUT3 (AC) and OUT4 (OC), and divides by 4 for OUT5 (OC) All changeable by a factor of 4X to 1/4X, Good for cutting down pulse counts reasonably. With SW3 on, it divides by 16 for OUT3 (AC) 32 for OUT4 (OC) and 64 for OUT5 (OC) All changeable by a factor of 4X to 1/4X So you'd use this setting if you REALLY need to cut down the pulse count by a substantial factor.
So I plan on using OUT1, all switches OFF and running a multiplier of .386 (10 Corse, 6 Fine) to straight divide the number of teeth from 78 to 30.1, Ideally I would need 30. OR I can use OUT3, all switches OFF and a multiplier of .771 (14 Corse, 10 Fine) to first divide the pulses in half, then factor that by .771 to arrive at 30.1 ish again.
With this, no mods should be needed to the Road Speed Constant or I/P Divisor. It will be recieving the same 24k PPM that TGP ($8F) is used to seeing, at least I hope. But, It's all talk till I can prove it, right?
Good call on the twisting of the pairs for the VSS. I should have done that, not too late though. I've used a SGI-5 before (SGI-5B, Metal case) in the past, and it did exhibit some extreme twitchiness on the speedometer that seemed somehow related to the engine RPM, while I was not moving. Plus this time my VSS and crank sensor leads are in the same bundle, so twisting the pairs would probably be a wise thing to do.
[This message has been edited by Fierobsessed (edited 03-19-2013).]
Looking at Fuel pumps, I felt it was obvious that a 255 LPH pump should flow in the range needed for my engine. They generally can support around 500 hp or so. In the 255 LPH flow category we have a lot of options, at really good prices. Everyone runs the Walbro's. Many complain of noise, and some of reliability issues.
I was doing a bunch of research on each of the available 255 LPH pumps, and the truth is that its not easy to do. No one does an honest side by side comparison of this category of pumps. I was going nuts trying to find the "best" pump. So much so that my girlfriend started researching too. She actually found one that has a lifetime replacement warranty, promises to be quiet and had an independent test, which also sited the Walbro f2000169.
HFP Brands, HFP-343
Walbro f2000169
And for $79, seems like a winner. This looks like this is the same pump that is supplied by TRE Performance.
Although you can set the road speed constant to display speed correctly inside the ECM, the I/P pulse divisor in obd1 ecms only has a few valid settings, none of which are compatible with 60k ppm. They can only do 8 potential divisor rates. So, without it, I would have no speedometer or odo.
Originally posted by Fierobsessed: Although you can set the road speed constant to display speed correctly inside the ECM, the I/P pulse divisor in obd1 ecms only has a few valid settings, none of which are compatible with 60k ppm. They can only do 8 potential divisor rates. So, without it, I would have no speedometer or odo.
I tried all of the I/P divisors and recall only 0 and 1 work properly, or at all. When I entered the other divisors it shut the odometer down for a few minutes before it would start working again.
Originally posted by Joseph Upson: I tried all of the I/P divisors and recall only 0 and 1 work properly, or at all. When I entered the other divisors it shut the odometer down for a few minutes before it would start working again.
That should read several, including some of the values you posted. I stopped experimenting when the temporary disabling of the odometer that resulted suggested something that could possibly damage the odometer electrically was occurring as I had already had prior incidents where the odometer needle swung violently to the point of coming off the gauge.
The road speed constant helped fine tune the odometer once the appropriate pulse divisor was selected. The bits don't show up in the 8F code mask in TP5 the way you have them posted but they do in Code59.
[This message has been edited by Joseph Upson (edited 03-20-2013).]
You can run the VSS wired right to the ecm and enter 60K for the ppm. This will make the ECM see the right speed. Then you can splice into the Yellow VSS wire to drive the Dakota Digital box and use it to run only the Fiero speedo. The best thing about this method is that the common "noise" (where the speedo randomly jumps to 20mph) the Dakota Digital box produces at low vehicle speeds will not be sent to the ECM, which can change idle speeds and cause other drivability issues.
You can run the VSS wired right to the ecm and enter 60K for the ppm. This will make the ECM see the right speed. Then you can splice into the Yellow VSS wire to drive the Dakota Digital box and use it to run only the Fiero speedo. The best thing about this method is that the common "noise" (where the speedo randomly jumps to 20mph) the Dakota Digital box produces at low vehicle speeds will not be sent to the ECM, which can change idle speeds and cause other drivability issues.
I believe I tried this approach unsuccessfully and I don't have any jumpy needle problems with the SGI unit in place, perhaps the cause is somewhere else.
I believe I tried this approach unsuccessfully and I don't have any jumpy needle problems with the SGI unit in place, perhaps the cause is somewhere else.
I ran the 92-94 HTOB getrag with a 24K VSS through the 7730 8D for several years using this method. During this time I also verified that the 7730 8D would accept 60K for PPM and all it did was scale the ECM speed by about 1/3.
Originally posted by fieroguru: I ran the 92-94 HTOB getrag with a 24K VSS through the 7730 8D for several years using this method. During this time I also verified that the 7730 8D would accept 60K for PPM and all it did was scale the ECM speed by about 1/3.
I'm sure it was one of your threads that I was following when I tried it, whatever the case I wasn't able to get it to work with 8F. My odometer is pretty close with the current arrangement and trouble free although I would have preferred the method you've described.
Back to the exhaust, We start out with another pile of pricey 304 stainless parts to be welded. Borla muffler 2, 2.5" mandrel bent 180's 4, 3" mandrel bent 90's 1, long piece 2.5" 2, exhaust tips.
The muffler itself is 5" in diameter, the factory muffler is around 4". So I had to find a little bit of room where a 5" round muffler would fit, I found that spot a little higher up. And of course, this meant loading the cradle back into the car yet again for yet another fit check... Seems like I do this alot.
The reason I chose this borla muffler was because its 304 stainless like every other component of this exhaust system. It has what practically amounts to a lifetime warranty, it is of a straight through design, it is relatively compact for a 3" muffler and only 15" long.
I started adding some pieces to the question mark pipe to extend it towards the rear for the muffler, I decided to add a V-band flange at this point as well, so that the muffler can easily be removed, if needed.
Some more test fits, It's like a game. I used a long level and a pair of clamps to give me a location reference of the trunk firewall, it just so happened to be located where the level was almost even with the back edge of the cradle mount platforms. So it was easy to keep track of.
Prop a few things up, make a few cuts and some welds, and the muffler is in place.
This is what I envisioned for after the muffler, that way I can keep the dual exhaust look. Which if it is a GT, really needs to have. I got smarter about plumming, I ditched the sawsall for the stainless and broke out the abrasive chop saw. I should have done that a lot earlier. It made easy and cheap work of these pipes! The number of sawsall blades I was burning through was costing a bit of money.
Got that in place
Starting to see it all come together, the finish line is close
And with the last couple of welds...
I can finally take a breather. There are a couple of little things to do, but the exhaust is done.
Onward! My fuel pump arrived yesterday. High Flow Fuel Systems, HFP-343
I suspected that this pump was probably the same one that TRE Performance sells, well... there is little question about that theory now!
I happen to have a Walbro kicking around that I have no intention of using, but to see them side by side is always a welcome comparison Clearly, they share the same top piece, possibly the same physical motor?
Looking into the inlet of the TRE Performance pump, it clearly has a (at least) two stage design, having a first stage "Fan Like" velocity pump that feeds fuel into the second stage positive displacement pump that pressurizes the fuel. Second stage pump's design I couldn't tell you. I can say that this style of design is very similar to all factory GM pumps, using a velocity pump that feeds a positive displacement pump. 4 cylinder Fieros actually use a two stage velocity pump only, that's why they produce so little pressure, but they actually flow very well.
The Walbro however, has a very obvious design, probably a single stage, Gerotor style positive displacement pump. This partially explains the Walbro's great dislike for low fuel levels, and to some extent the reason for its noise.
Another thing, both of these pumps draw around 13 amps. This is kind of a lot of power. All the fuel that gets pumped actually goes through the core of the motor carrying away the heat produced by this small high performance motor. So if you starve it for fuel, the motor will overheat quickly. So all high performance fuel pumps are subject to damage in the event of any fuel starvation. So having the first stage pump helps ensure a constant supply of fuel to the second stage pump. The walbro doesn't have this type of first stage, so that's why I say it's more sensitive to fuel levels. Not sure if all Walbro's are like this, the one I have is meant for a Grand Prix, so its not exactly apples to apples.
Lastly, I finally purchased a clutch. I went back to Clutchnet as I did previously since I was so pleased with the quality. I purchased a 6 puck sprung disc for a 2006 G6 GXP, which is 9-1/2" #6BS7G61
And, I got a pressure plate for a 1992 Firebird 3.1, which we all know is the 9-3/4" Pressure plate. I went with their "Yellow / Stage2" pressure plate. #YP3121
Clutchnet called me the next day to ask me about the difference in diameter from the disc to the pressure plate, and graciously offered since they had to make the clutch to order anyway, to fit the disc to the pressure plate. Which of course I agreed to. I have to say, that was a pleasant surprise.
I chose this disc and pressure plate based on Matt Hawkins reccomendations. He has a similar engine setup and he is using a 9-1/8" version of this disc with a stock replacement pressure plate, and has had no issues with it. So I have a larger diameter, and a somewhat stiffer pressure plate, so I'm less worried about slipping. I think I am a very conservative manual driver, and I am great about breaking in clutches anyway. I also have to tune this engine with boost disabled (WG spring removed), so the clutch and engine will have a chance to break in before I start adding boost to the equasion.
Oh, and if anyone is curious, I am sick of welding stainless. I circled a piece of stainless with my TIG a total of 38 times to create the exhaust, from manifold to tips, and it still isn't quite over, but I think my skill has improved quite a bit.
I'm sure you know this but the pump current is a function of load and voltage so when it fires up it will not likely draw that kind of amperage unless you're running high pressure and at the max voltage it is specd for, it would put a nice load on the motor at that output level also.
I believe you made a very good choice going with a pump other than Walbro for a daily driver. That was one noisy pump and every bit as sensitive even to normal low tank levels that stock pumps see without a problem. The 8100 V8 pump I just replaced it with almost requires that I put my head near the console in order to hear it.
So the working divisor bits should simply be increments of 32, up to 224.
Just a heads up since I ran into this problem today as the last hanging point before being able to drive the car after completing the new harness. Some two pin plugs are labeled in reverse with A and B terminals on the opposite sides so if you use a plug that didn't come directly from a Vss sensor make sure it has the proper arrangement, or you'll connect the plug up correctly color wise but backwards terminal wise, which may cause you to dig into your harness unnecessarily all of which I did before my Christopher Walken like psychic powers kicked in and prompted me to check after a new pull up circuit didn't resolve the problem.
[This message has been edited by Joseph Upson (edited 03-28-2013).]
Thanks, I'll have to check out that connector thing. I wouldn't think that it's important, as far as I know the output signal is A/C, so it should have no polarity. But I did get that connector from some random harness...
The fuel pump has a "fixed" (sort of) displacement, and voltage is relatively stable, so it's load is only really dependent on pressure for the most part. And according to the chart it will draw between 12-13 amps all the time. The walbro would draw 9-11. So it is a bit of a hefty pump. It contributes to heating the fuel in the tank, which is a bit undesired. But for an engine that should be over 400 hp, I'm willing to make that small sacrifice.
I started machining the flywheel this morning, I have the 92 firebird flywheel, I'm cutting the outer ring off of it.
It shouldn't but believe me it makes a difference and my guess would be that it's because the square wave that is triggered would be negative (upside down) instead of positive. One thing is for sure, the odometer didn't budge and the data log showed no speed with it connected backwards.
In the AC socket on your wall, on side is neutral and one side is hot. The neutral is a return and the voltage on it doesn't change. The voltage on the hot wire fluctuates from -165 to +165. If you hook up a pin that's expecting fluctuating signal relative to a ground reference to the neutral wire, it won't see any signal.
Started machining the flywheel. For a factory flywheel the machining is pretty bad. My flywheel arbor and the face surface are bang on, but the rest of the machining is pretty bad, even the ring gear seat wobbled. There was a lot of holes drilled for balancing, I'm sure they just make sure the clutch surface is good, then balance it. I'm surprised that the external edge machining was that far off. I have a bit of work ahead of me.
In the AC socket on your wall, on side is neutral and one side is hot. The neutral is a return and the voltage on it doesn't change. The voltage on the hot wire fluctuates from -165 to +165. If you hook up a pin that's expecting fluctuating signal relative to a ground reference to the neutral wire, it won't see any signal.
I agree. But... on the VSS circuit, the ground is at the computer, not at the sensor. The sensor is plastic. So if you swap the wires, the old signal wire will be grounded, and the old ground will send back a signal. However, Joseph is correct, the signal would be upside down (mirror imaged) if traced on a scope. Perhaps the ECM cannot interperate the signal if it is upside down, I'd find it a little odd that he found that it can't interperate it, but it's totally possible. It's not exactly like an AC sine wave where everything is symmetrical, its more like a heart beat, with regularly timed pulses and silence between them.
I know the crank sensor can't handle an upside down signal, it relies on an initial "positive"* spike to show when the timing is, It doesn't like it when the initial spike is "negative"* going. *might be backwards, but the point stands.
Seems like this topic is a bit irrelevent to my build though. If Joseph is right and my ECM fails to see the VSS, I will have a fairly informed idea where to look. Either way, I won't know till I have everything together, and I can spin the wheels, or test it in place.
I did some machining on the flywheel today. I started with a stock 92 Firebird 3.1L flywheel. I knocked the ring gear off of it since it was absolutely useless with the F40.
So this is what I started with: Firebird 3.1L on the left, G6 GXP on the right
Underside
I could have machined the old ring gear seat down and pressed the Fiero ring gear on, but the seat would have been VERY thin. So I decided to cut off the entire outer ring. I cut a groove in the outer ring of the flywheel, Working this diameter pushes the absolute limit of what my 12X36 lathe can handle, It is a gap bed, but the flywheel just fits wihtin the supports of the saddle by less then 1/16", after a little unnessary diameter is taken down. I cut the groove deep enough to nearly seperate the ring from the flywheel.
Then, I took the flywheel out of the lathe and hit it on the concrete a number of times to crack the ring off. I didn't want to seperate the ring entirely using the lathe, It could have flung off and damaged the bed. With the ring seperated I put it back in the lathe to do some finishing cuts.
My lathe could barely reach around the back of the flywheel for the little bit of a back face cut that I needed to do, but I managed to get it.
The removed ring and the somewhat finished flywheel,
The bolts are flat head M10, I will need to countersink them.
These coupler nuts will hold the ring gear.
I will machine a groove in the coupler nuts, sit the ring gear in them, then weld the coupler nuts and the ring gear together.
The flywheel has 12 holes exactly 30 degrees apart around the edge, I drilled them out to fit the M10 bolts in a tight tolerance, and will countersink them. I'm debaiting on weather or not I will need to use all 12 holes, or just 6. I think 6 will be fine.
There is little to no centering hub left on the back of the crank with a flexplate mounted, I know I could peel the one ring off to expose a little more hub. The flywheel still has a chamfer on the inside of its ID, so it probably still wouldn't quite make it.
I don't know how the dimensions stack up, but if you need a spacer, you could make it locate on the ID of the pilot bore. Maybe you could turn a stepped bushing that would tap into the pilot bore and extend the OD of the locating shoulder.
You don't need the reinforcement washer when you're stacking a flywheel on top of the flex plate.
The circle you showed has 8 bolts... Is that a Northstar?
3800. It's the only flex plate I had laying around. I know I could have made some sort of adapter or something to get a flex plate sandwiched in there. I just didn't want to. Something about it just doesn't sit right with me. No real reason other then that.
The more I work on this flywheel, the more upset I become with its orignial manufacture. There isn't ANY concentricity amongst ANY of the critical dimensions. It was so bad I started questioning whether or not my 3 Jaw was centering correctly, so I broke out the 4 jaw and did a manual alignment using the pilot bore for center, and the face for straightness. Once I had it dialed in perfectly, I found that the machine work that I did already is still straight and true. My 3 jaw chucking was good.
Then, I began questioning whether the pilot bore was concentric with the pressure plate mounting bolts. Truth is... that it wasn't even close. I measured a total difference in distance from the closest to center, to the farthest from center at .034" So it's safe to say its .017" out of concentric. That's horrible. So for laughs, I tossed the pressure plate on to see how it fared.
Needless to say, It's not looking too good. Mind you, that this is a factory flywheel from GM, and a stock replacement pressureplate for a Getrag Fiero. Worse still, you should see how the internal pressure plate ring wobbles.
I believe that the wobbling, from either poor balance, or poor centering of the pressure plate was the reason that I was experiencing shift "lock out" at high RPM's. Basically what I mean is that the clutch was self engaging at high RPM, and made shifting difficult when ragging on it hard.
So, I'm going to have to finish the ring gear thing. Then, I need to drill and tap new pressure plate bolt holes. Once that's done, the flywheel will need surfacing, and balancing. This turned into a bigger project then I anticipated. Maybe I should have just used the dual mass... It is afterall, designed for the 60 degree engines.
[This message has been edited by Fierobsessed (edited 03-31-2013).]
Here's an update plus some recent experience and info that might be of use to you.
The computer does not care which terminal is connected to A or B on the Vss plug. After making a new pullup circuit and having the same problem and then correcting the wiring mismatch and having the same problem, it appears either the wiring arrangement for the 727 ecm I switched to is backwards, or I made a mistake that I have yet to see, as with the ECM recognized a signal in both wiring arrangements only with the input signal attached to the purple wire going into the ecm which is the understood ground for the Vss. Whatever the case once I got it working after all the tests I decided there is a pin assignment typo in the diagram.
Be sure to make a good oil catch can/separator, etc. Although many including myself at one point, are opposed to feeding vent pressure back into the engine, the system is actually beneficial to the motor when setup right. I picked up some good ideas from AutoSpeed that you may find helpful as I did. I had never considered what they did and what a fan of the site did to make the system very effective compared to the typical unbaffled container which I was always suspect of. I believe it was Will actually (not tooting his horn just giving him his due recognition (I still believe you're wrong about the flywheel)) that pointed out the need to have those combustion gases actively removed as they will certainly affect the cleanliness of the oil among other things.
You need better flow than the naturally aspirated ports, an easy approach would be a 1/2" fitting on the oil cap to avoid tampering with the valve covers if feasible.
Here are the links on AutoSpeed they have more than one on the subject:
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