Posi-traction is what GM calls their limited-slip differential.

Like Kleenex is a type of tissue.

quote Originally posted by CTFieroGT87: There are different kinds of limited slip, but the overall definition is trying to be posi, but not quite posi. In both cars I have, which have LSDs, they spin both tires in a straight line and are one-leggers when turning. So locked when straight and open when turning. A lot of cars can light up both tires with open differentials, but that doesn't necessarily mean much, they just happened to lose grip at the same time.

a std diff will do that just fine if the friction under both tires is equal. in a turn the weight goes to the outside tire and the inside tire spins because it has less friction compared to the outside tire. If you really have a LSD it will let the tires turn at different speeds up to a point then it will lock the rear and both tires will spin, it does not matter if you are in a turn or not...

go on any lsd mfr website (torsen ,quaiffe etc) and you can learn all about the types of lsd's.an lsd for a front driver is a different type of lsd in that it doesnt use internal clutches,instead using a worm and pinion arrangement.clutch type lsd's are not safe for front drive transmissions(which is what most fiero owners are using)

quote Originally posted by wftb: an lsd for a front driver is a different type of lsd in that it doesnt use internal clutches,instead using a worm and pinion arrangement.clutch type lsd's are not safe for front drive transmissions(which is what most fiero owners are using)

I didn't know that. So let's see if it's clear as mud yet...

1. Spools lock the axles together permanently
2. Open diff's never lock the axles together
3. LSDs (in general) let the axles turn independently until torque bias engages the clutches (or whatever) to lock the axles together

I think I got it now. Thanks guys! Now I know my LSD!!

[This message has been edited by Hulk (edited 08-17-2006).]

quote Originally posted by wftb: clutch type lsd's are not safe for front drive transmissions(which is what most fiero owners are using)

Care to elaborate?

quote Originally posted by FieroMonkey: This may not be good for those expecting a good deal more durability from this tranny torque wise. If the report on the torque loads this tranny can handle were including the load reducing factors of the Dual-Mass Flywheel, then this is bad. Because unless you are incorperating the DM Flywheel with your V8 swap, or built-up 3800 swap, you can expect less durability on this tranny when using bigger torque throwing motors. I guess a good question might be, weather or not the projected torque loads of the tranny included the reduction of load from the Flywheel, and if it did, just how much reduction there is in the torque the tranny can withstand, should you swap a motor on without a Dual-Mass Flywheel.

Actually I believe the main purpose of the dual mass flywheel is to reduce engine vibration being transmissed to the transmission. GM and Ford started doing this with their diesels some time ago because customers complained of noise and 'gear rattle', specifically at idle with the transmission in neutral. Most aftermarket clutch manufacturers offer a kit to switch these to the much lower cost and FAR MORE RELIABLE standard flywheel. The GM and Ford DMF's were never a great design and tended to be problematic. Heavy trucks stuck with standard flywheels and for the most part, told customers to live with the chatter at idle. Much of this was reduced when they went to fine mesh gearing in the main box. I honestly don't see the advantage to having a dual-mass flywheel on a naturally balanced motor like the 60 degree V6. In fact I don't see it as an advantage with a properly balanced V8 either. As well all know diesels tend to shake like a bastard though even that has been reduced in the newer engines.


My $0.02

Reguardless, the 6 speed and the 5 speeds both have load ratings that absolutly kill the getrag, witch is a pretty darn robust transmission. It's weak point was the differential, witch was revised, after the Fiero years, yet the load rating did not change.

clutch type (posi trac) diferrentials tend to lock up when they kick in. they break loose on a rear wheel drive car when they hit the next corner .on a front driver they dont break loose as quickly and that can send you in the ditch.the torque sensing differentials never allow both wheels to drive at exactly the same speed(lockup condition)so they are much safer.go to the torsen website ,they explain it better than i can.i had a torsen in my 96 f 150 and it was amazing.

so this is a no on the G6 tranny?

I heard the solstice has a shorter 1st I know some would love the tranny, but others are looking for a longer throw. I'm just looking for options...

Talk to V8 Archies he has a kit for the G6 and the info you may need.

We’ve now designed a kit to enable this new 6 speed to be installed into all stick shift Fieros. If you have a stock Fiero engine or a SBC engine swap or anything in between, we have a kit that will allow you to install the 6 speed. As you might know we do a lot of Chevy V-8 conversions here & have a lot of customers out there with SBC’s in their cars. The SBC version of our 6 speed conversion allows the SBC guys to use all of the major parts of their original V-8 conversion when retro-fitting the 6 speed.

The G6 6 speed is just ¼” longer that the Fiero Getrag transmission. The end of the trans that is the closest to the left side frame rail is larger in profile because that transmission has 3 gear shafts instead of the Fiero’s 2 shafts.

The G6 just started using the 6 speed in 2006, so you don’t see a lot of them in the salvage yards yet. They are available now at your local GM dealer parts department. As you will see, a large part of the total cost of the swap is the G6 specific parts. The swap can be very affordable if you can obtain these parts at a salvage yard.

So far there are 7 Fieros around N. America sporting this transmission.

I can email you more info.

Archie

------------------

quote Originally posted by Archie: I can email you more info. Archie

PM sent.. I'm just wondering if the solstice by any luck will get gears, shorter/taller. It'd be nice to have some options

quote Originally posted by LoW_KeY: PM sent.. I'm just wondering if the solstice by any luck will get gears, shorter/taller. It'd be nice to have some options

Since the Solstice is Front Engine / Rear Drive, nothing about it's transmissions will work on a Fiero or G6 transmission.

To those with questions about how non-LSD and LSD work;
http://auto.howstuffworks.com/differential.htm

bumpy.

We already know it works

------------------
Palm Beach Fieros
http://pbfieros.tripod.com

Red: TPI V8 + 6-Speed Yellow: Nitrous 3.4 + 4 speed Auto

I just drove my new '88 Formula with a 377 SBC & the 6 speed today. Just finished it earlier today & drove it after lunch.

What a kick in the seat of the pants. I love it.

I never thought I'd say this but now I'm thinking about selling my LS1 Solstice so I can have more Fieros with 6 speeds & V-8's.

There's a lot to be said for a good old plain Jane Bubble Top with lots of engine in it.







Archie

It's the carb sitting on there. When those back to barrels kick in, it's like having another gear!
Now that's just my opinion, because I'm old school.
Sure would be nice to have one of those 6 speeds though.
Have a Great Day
Gary

quote Originally posted by Archie: I never thought I'd say this but now I'm thinking about selling my LS1 Solstice so I can have more Fieros with 6 speeds & V-8's. Archie

Wow. That's saying a lot.

Most likely this is the car I'll be bringing to Daytona this year. I've never taken the same car to Daytona 2 years in a row before.

Because Daytona is the 1st show of the year for me, I usually just finish the car I'm taking a day or 2 before we leave.

Last year the PFF Roadster only had about 20 miles on it when we loaded it up to take to Daytona. I had just finished the GT40 & had only driven it a few miles before taking it to Daytona in 2004. The 1st "test drive" for that car was driving from the show to the hotel Saturday after the show. The year that I brought the Stinger to Daytona it had been done about 4 weeks but it but it had been to 2 shows (Vette-Fest & WOW) before we took it to FL. The weather here was lousy so it wasn't driven on the streets between those 3 shows. I'll bet it had less than 10 miles on it when it got to FL. I did start driving it on a daily basis after we got back from Daytona.

With this car, It will be nice to have a car that has actually been broken in before I leave for Daytona.

This Formula is a real nice car & I plan to put an LS2 in it sometime this next year. That's why I'm using the '84 decklid on it 'cus I'm saving the original '88 decklid for when we swap to the LS engine.

For now I plan to have some fun & see if I can break the 6 speed for the next couple of months.

BTW, I can bring you a 6 speed when I come down if you'd like.

Archie

At a week in CA was a trail. It was for a Jeep. A big locked up Jeep? Ummm, never mind its the moon.

I've been meaning to ask this for a bit, but for some reaon it kept slipping my mind until now. Anywho...


Thinking about what a dual-mass flywheel is and does... the thing is somewhere between a vibration damper and a shock absorber from what I've been able to gather. Some would argue that it's employed not so much as to reduce overall vibes as it is to soften the "blows" the tranny might receive from a torquey engine and hard shifting.

This line of thinking led me to wonder whether the published torque rating and purported abuse-friendliness of the F40 makes the assumption that it will only ever be coupled through a DM flywheel, or if the ratings are for the tranny alone (regardless of the clutch/flywheel used).

I haven't yet tried to get an answer out of GM or any other "authority" yet; just idle musings so far.

So my question is... has anyone who has coupled the F40 to an engine with some grunt, using a conventional flywheel, and driven it hard, managed to break any of the tranny's internals yet?

[This message has been edited by dguy (edited 01-19-2007).]

Dual mass flywheels are almost always heavier than single mass flywheels. This makes things HARDER on the transmission, while the cushion theoretically makes things easier. Which effect is stronger?

Compliant (NOT soft and gooey) powertrain mounts do a lot to soften the shocks, too. That's why I don't like solid mounts.

Hey guy's, this may be a stupid question but does anyone here know if the G6 six speed is a direct bolt up to the Cadillac 3.6L VVT engine. I know GM uses a turbo charged 2.8L VVT engine which from what I understand is the same block as the 3.6L with the G6 transmission in the SAAB 9-3 sport-combi so that being said, I assume the transmission should bolt directly to the 3.6L right?

quote Originally posted by Eau_Rouge: Hey guy's, this may be a stupid question but does anyone here know if the G6 six speed is a direct bolt up to the Cadillac 3.6L VVT engine. I know GM uses a turbo charged 2.8L VVT engine which from what I understand is the same block as the 3.6L with the G6 transmission in the SAAB 9-3 sport-combi so that being said, I assume the transmission should bolt directly to the 3.6L right?

No, the Caddy will not bolt up to the G6 tranny. The new 3.6 DOHC is made in many versions or will soon be. The new 60* DOHC VVT and variable intake runner V6 will be offered in sizes from 2.8 all the way up to 4.0. BUT the Caddy is the ONLY domestic version that wont bolt to the G6 tranny or more accurately known as the 60* GM V6 bell housing bolt pattern. The Caddy version of the new 60* DOHC V6 is a rear wheel drive and uses an Aisan tranny. Every year GM is inserting the new V6 in a new car, this year it is the Saturn.

I guess I'll have to look into it a little more. The 3.6VVT is by far my engine of choice and I'm hoping to find an application that will bolt up directly to the g6 six speed. I understand that for 2007 it will also be used in two Saturn models, the Pontiac G6 and also the GMC Acadia. If there is no direct bolt up, I'll have to get an adapter plate fabricated...I've already purchased the 6 speed and can't wait to use it.

It seems, from what I am reading, any of the FWD 60* engines will bolt to the G6 6-speed...

I am in Germany and they love manual transmissions still here in Europe. There are 3 different models of the Opel that have one of these V-6s and a 6 speed manual. I will be looking to do a swap from one of those cars come the end of summer...

Has anyone looked to see if any of the cars have a spindle that will adapt to the Fiero? Then you just have to have the drive shafts made to the right length.

------------------
2005 Smart ForTwo
1986 Austin Mini
1986 Fiero GT 5-speed (waiting on a brake upgrade)

So archie, does this mean you have a kit ready where I can install a SC3800 onto the trans?

quote Originally posted by RandomTask: So archie, does this mean you have a kit ready where I can install a SC3800 onto the trans?

(A) If you're doing a LS1, LS2, LT1, or any normal SBC engine in your Fiero, I have 100% of what you'll need to complete the job. Those that already have a Chevy engine in your car can be assured that you can retro-fit the 6 speed into the car & still use all the V-8 kits parts you already have except the clutch. The parts I've designed, to do the 6 speed conversion, will work with all the V-8 Archie kit parts you already have.

(B) If you have a 2.8, 3.1 or 3.4 or 4.9, 4.5, 4.1 Caddies, I have 95% of what you'll need to complete the job. You will have to cut one part to fit & drill a few holes. I do not supply the engine mounts for these engines, so I'm assuming that you either already have the engines in the car or you have provisions to mount them into your car.

(C) If you have any 3800 or 3800SC, All of the items in "(B)" above apply. I have 90% of what you need If, while putting the transmission in, you can take a couple of measurements for me, then I can supply 95% of what you'll need. You will still need to cut one part to fit & drill a few holes.

While people are working to find the cheap way to do the swap, I'm already doing them. We've completed 11 cars in house & have sold kits for 6 customer built cars. I've already found the least expensive way to do the swap while keeping the quality level as high as possible.

Hope that helps.

Archie

BTW: Here's the latest 6 speed swap with a new Crate LS2 engine. ........

[This message has been edited by Archie (edited 04-17-2007).]

Archie did my 2.8 6-speed and it's well documented in the archives.
I got to drive it only a couple of days before handing the car off to a mechanic for a roller-cam 3.4 engine swap. At which point the mechanic tried screwing me. So I am suing the mechanic and the car is unfinished for almost a year now...being held on a mechanic's lein...but that's another story for another time.

Anyway, I was doing 65mph @ 2000 rpm in 6th gear. The clutch felt heavy due to Archie's solution for eliminating the DMF and using a standard Fiero flywheel and clutch. I have installed an aluminum flywheel which should fix that issue. However, due to the circumstances mentioned above, I haven't driven it with the aluminum flywheel, though I expect better results.

The shifter itself felt a little tough to find the gears, but I think that is normal for this transmission. I felt it was just a matter of getting used to it vs. driving a getrag for 11 years...

I wish Archie was willing to do my performance V6 rebuild+swap at the time. I wouldn't be in the mess I am in if I had a place that emphasizes quality and customer satisfaction like Archie does. Remember, you get what you pay for. Oh Archie, will you ever change your wicked "V8 only" ways?

lou, not to distract you from installing it, but generally the benefit of an aluminum flywheel is less rotating mass. A 'heavy' clutch is an effect of clamping force (IE the pressure plate.) A different size slave cylinder as well as master cylinder effect how much fluid is moved and can also effect the clamping force. I could be wrong, but just some food for thought.

Thanks archie, I leave for AZ next week for about a month- 2 months, but when I get back, we'll be doing business

quote Originally posted by lou_dias: Oh Archie, will you ever change your wicked "V8 only" ways?

Sorry, not very likely. I've already forgot more about SBC's than most people know about other swaps. I don't know enough about 6 banger swaps to ask people to pay me money so I can learn on their cars.

Over the last 18 years, I've seen several people get into the engine swap business. They'd do just about any swap you wanted. They knew a few things about every swap but were an expert on none of them. Eventually that would catch up to them as they would cut corners or not be aware of the best way to do something on a swap they didn't know enough about. It finally got to where customers who were picking up cars couldn't even get out of the county before they would break down.

You can't be everything to everybody.

Archie

[This message has been edited by Archie (edited 04-18-2007).]

quote Originally posted by RandomTask: lou, not to distract you from installing it, but generally the benefit of an aluminum flywheel is less rotating mass. A 'heavy' clutch is an effect of clamping force (IE the pressure plate.) A different size slave cylinder as well as master cylinder effect how much fluid is moved and can also effect the clamping force. I could be wrong, but just some food for thought. Thanks archie, I leave for AZ next week for about a month- 2 months, but when I get back, we'll be doing business

Archie did use a performance clutch and I've always used stock clutched in my Fieros so that could be the issue. I don't want to go into further detail about why I feel the aluminum flywheel is a better choice for 6-speed conversions as that would involve giving up details on Archie's kit, and that's not my place.

Does anyone have the 3900 spec for how much the crankshaft-flywheel flange is from the engine's trnamission mounting surface?

good thread guys... looks like this trans works pretty good, would love to try this trans in the future

Hi guys, I hope you don't mind me hijacking this thread, as I didn't think it was appropriate to start a new one for my questions.

I talked to V8 Archie many months ago about using the GM F40 6speed for my own V8 swap. I am attempting a V8 swap into a 2nd gen MR2. To date, no one has successfully completed one of these swaps (2 known attempts were made, but not completed). In summary, I am using a '97 Audi 4.2 V8, coupled to the F40. The short answer about why such a weird motor is that its the only one that:
1) will fit the chassis without cutting the shock towers and frame
2) makes decent power and torque out of the box (300 ft lbs and 300 hp)
3) is reliable.
If you want to read all about it, you can on either the MR2 forum (requires membership), or on the Audi forums here: http://www.motorgeek.com/ph...iewtopic.php?t=19049

Now, on to my questions. I hope that V8 Archie can give me some advice here.

I have to use a custom clutch combination. As you guys know, the F40 uses a 1.00" diameter 23 tooth spline, and I assume its metric. I found that a used Porsche G50 clutch disk slipped right on. So, my plan is to order the Audi clutch with a Porshe spline.
I am trying to figure out how thick my custom adaptor plate needs to be, and how far into the bellhousing my flywheel needs to go.

Up to now, my experience with clutches has simply been "buy the right one for the engine/trans in my car, put it in, and go drive".
As a Mech Engr, I know that there are certain clearances that need to be maintained between the parts, while at the different stages of clutch engagement and release.

I have to figure out how much throw or travel my Throwout bearing should have (its a hydraulic TO bearing), which is determined by how much the PP should move. I did some searching on the internet, and what I found is from this site: http://www.novak-adapt.com/...dge/clutches_etc.htm

(words in brackets are mine)

quote The pressure plate must move about .100 to .120 of an inch to RELEASE THE DISC and provide .030 to .050 air gap between the disc and the flywheel. The release bearing must move away from the fingers or diaphragm sping at least 1/16" (.0625 rounded off to .06) for freeplay. [when disengaged]

I put the disk on the flywheel, and bolted down the PP, and measured the location of the diaphragm fingers.

To figure out the required TO bearing travel, I found some washers that measured .050in. (1.3mm) in thickness, and placed many of them around the friction area of my flywheel, placed the disk on there, and bolted down the PP again.



This simulates full release, however the info on the website above is a bit contradictory. On one hand they say the PP should move .100 to .120 inches (2.5 to 3.0mm) to give the disk .030 to .050 inches (0.8 to 1.3mm) of air between it and the flywheel surface, but they don't mention any air on the other side of the disk, between it and the PP surface.




I don't know if that is an oversight on the author's part or what. Also, the disk I have has spring steel holding the friction surface (sandwiched between the friction surfaces), and the spring steel is a tiny bit wavey, and I am pretty sure this is on purpose. This helps give a more gradual grab when the clutch is released (I read about this on the web somewhere).

I then measured the location of the diaphram fingers, and compared this to their location when the washers are not in there (fully clamped PP).


Since I want to get this right the first time, I decided to create an air gap on the other side of the disk with more washers as spacers. My reasoning behind this is that I want to be SURE that the clutch disengages. Also, because my simulation does not allow the disk to relax (and the wavey spring steel to cause the disk thickness to increase), I needed to allow a little room for that.
All I had left were .038 inch (.94mm) thick washers, so I used those.
Again, installed the PP cover.



An interesting thing happened this time: As I got the PP cover bolted down, and it was nearly touching the Flyweel, it started getting EASIER to tighten the bolts! I think this is a good sign. I think the reason behind this is that the lever angle of the diaphragm fingers were chosen so that when you get near the bottom of the clutch pedal travel, it gets easier for you to hold the clutch in.

I found that in this scenario (air space on BOTH sides of the clutch disk), the total required diaphram finger travel is 9.1mm.

The F40 hydraulic TO bearing has 0.53 inches (13.4mm) of total available travel. This sounds almost perfect because at full retraction, the TO bearing is supposed to have an air gap between itself and the diaphram fingers. The air gap (according to the site above) should be around .063inches (1.6mm)




What I don't understand is that the TO bearing has a spring in it that keeps it fully extended.

The spring is not very strong (about 20 lbs of force compresses it--I can do it with my hands). But it seems to me that the TO bearing should be fully retracted when at rest (when its not pushing on the diaphragm fingers), so it should not have a spring at all, or it should have a spring that fully retracts it. The only thing I can think of is that the clutch pedal return spring pulls the fluid back out of the slave cylinder when the pedal is released, but this doens't make a whole lot of sense because of the way master cylinders are designed -- they have a resevoir that the hydraulic line opens up to, when the pedal is released. In my mind, when the pedal is released, it starts to pull fluid back from the slave cyl, then as soon as the master piston uncovers the resevoir hole, the spring in the slave will push it back out again, and suck the fluid back again.

Maybe someone can help me out understanding the F40 TO bearing.

Also, I was hoping someone who really knew clutches could help me out with the air gaps at disengagement. Did I get it right?

[This message has been edited by CBulen (edited 08-21-2008).]

You're probably making it a bit more complicated than it really is. There is almost always contact between the throwout bearing and the pressure plate flanges because the slave cylinders are spring loaded forcing the contact when not in use, including on the Getrag and Muncie. It's not a problem because the throwout bearing is also a roller bearing. You should probably focus on the installed free play or distance the throwout bearing can be retracted from the pressure plate release flanges and where the clutch hub splines ride on the input shaft since you are using a different disc than the original.

The dual mass flywheel is heavier than the stock Fiero flywheel but the added weight has its advantages, it can not however be redrilled for a different bolt pattern. Otherwise it works fine and a version of it is apparently used on the Cadillac CTS 2.8 and 3.6L as well as the Saab cars that use the F40. A local clutch builder if you have one would be a very big help to you.

quote Originally posted by Shadow_Wolf: Actually I believe the main purpose of the dual mass flywheel is to reduce engine vibration being transmissed to the transmission. GM and Ford started doing this with their diesels some time ago because customers complained of noise and 'gear rattle', specifically at idle with the transmission in neutral. Most aftermarket clutch manufacturers offer a kit to switch these to the much lower cost and FAR MORE RELIABLE standard flywheel. The GM and Ford DMF's were never a great design and tended to be problematic. Heavy trucks stuck with standard flywheels and for the most part, told customers to live with the chatter at idle... My $0.02

So that explains it!

I talked to the only trans parts supplier in my area to get recommendations on clutch specialists in my area, and I talked to the 2 best ones. Neither can build a clutch for me, so I am planning on using Clutchnet or Spec (spec has already told me they can do this clutch, but its waaaaaaaaay expensive).

Anyway, Joseph, I am trying to understand what you are saying.

Its my understanding that free play is the distance between the Diaphragm fingers and the contact face of the TO bearing, when the clutch pedals is disengaged. The info I found on the web says this shoud be about .06 to .13 inches. However, since the F40 TO bearing pushes out and contacts the fingers full time, even when the clutch pedal is disengaged, it seems to me that there would be no free play. Instead there would be some of the total travel of the TO bearing being used. In theory, if a clutch disk never wore down in thickness, I could install the flywheel far enough into the bellhousing that the TO bearing would be fully compressed while in the clutch fully disengaged condition. But because in the Real World, disks decrease in thickness over time (as well as the friction surfaces of the PP and flywheel), I should not fully compress the TO bearing when I put everything together, as the diaphram fingers will extend futhur out of the clutch cover over time, so I need to account for wear.

I am pretty sure my flywheel will need a spacer between it and the crank flange, so that the clutch disk hub splines will be engaged over thier full length, on the input shaft. Right now, I don't have a clutch disk that I can use for this (the Porshe disk has a HUGE rubber hub that will not fit under a regular push type clutch cover).

Is this what you mean ?

[This message has been edited by CBulen (edited 08-21-2008).]

quote Originally posted by jscott1: So that explains it!

So that's our rattling?