I've lurked around for a while now and I've seen some posts about some distaste towards the f40 Transmission, what's the deal? I was seriously thinking about using this tranny as it usually runs around 300-500 on ebay for a new one and Its a freaking 6speed, with the motor option that I'm currently exploring (well 3 actually) I thought it would be a smart match. So what am I missing about this transmission? thanks

Syn

Syn...by the time its actually in...its very expensive. And first gear is absolutely useless. Six isn't always better

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87 GT...SBC...Fast as hell

quote Originally posted by jaymelk2: Syn...by the time its actually in...its very expensive. And first gear is absolutely useless. Six isn't always better

I prefer 5 myself. and in bumber to bumper Traffic an auto is the way to go.

From what I have also heard first gear on some some versions is very short. I drove a 3.9, 6 speed, G6 coupe. I did feel first could have been skipped with the torque of the 3.9. I also have heard later versions had revised gearing, but I don't know when those were produced. I don't think the transmission is still in production at this time.

well with what I'm going to be throwing at it putting an auto would be silly and a 5 speed would be even sillier. when you say short first gear what do you mean? I know the 5 speed in my Camaro will get barely to 10 mph before it just craps all the way out, in other words I've reached the end and need to shift. 1.37:1, 1.05:1, 0.85:1, 0.71:1 3-6 north American 2007 model, I think the gear ratios could be a little steeper if you have a higher horsepower application. I've not really seen any viable 5 speed options out there that i would be satisfied with, I really want and need that extra gear. are there any other solutions? I don't think gm has made any other 6 speed transaxles. (which is very sad)

quote Originally posted by Syn: I've lurked around for a while now and I've seen some posts about some distaste towards the f40 Transmission, what's the deal? I was seriously thinking about using this tranny as it usually runs around 300-500 on ebay for a new one and Its a freaking 6speed, with the motor option that I'm currently exploring (well 3 actually) I thought it would be a smart match. So what am I missing about this transmission? thanks Syn

The upside & the reason I built a kit for the 6 speed years ago, is that the 6 speed takes the Fiero in to the 21st Century. Adding a modern NEW transmission to new engine choices. IMBHO, the 6 speed conversion is what the Fiero needed to be popular for another 20 years. The old Fiero transmissions were getting kind of old.

You're going to hear a lot of talk about 1st gear being to low... but it's about the same as a stock Fiero transmisssion.

People need to realize that no one in the Fiero community can afford to have a custom transmission built & that you could wait for another 20 years for GM (or anyone) to build a factory transmission that has all of the good stuff & none of the drawbacks.

It is a lot of fun to drive & it's nice to have a new transmission to install when you're installing a new engine.

Some advocate an automatic instead, I'd rather have a Sports car with a stick shift, they're more fun to drive.

The downside is that it can be expensive to install the 6 speed. The <$500 initial price for the transmission is very attractive. However, you do need a lot of extra parts to make it actually operational in a Fiero.

You need a lot of G6 6 speed specific parts to make it all happen. Plus you need a modified Fiero shifter, new shift cables, a different clutch etc.

One guy on this Forum has claimed that it can be done for $600.00, but when asked he has never been able to supply a clue as to how he came up with that. BTW, he has never completed a 6 speed swap to prove his contention.

A few others' have worked on 6 speed swaps & have fabricated axle tripots & made other modifications in the axle & intermediate shaft area. They've been working on those projects for quite some time & I would guess that a couple of them might be completed. I'm sure that if they have been completed & tested, those people will speak up. AS of right now we & our customers have completed more than 40 6 speed swaps & they are all on the road.


We have a 6 speed conversion kit & this is how I describe it on my web site.......

Our New 6-Speed Fiero Transmission Conversion Kit allows you to mount the new Pontiac G6 6 speed transmission into any stick shift Pontiac Fiero.

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.

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. However, the G6 just started using the 6 speed in 2006. This may make them a hard to find in the salvage yards. Optionally, you can find the transmissions on Ebay for $400 or $500 each. They can also be purchased at your local GM dealer parts department(at about $1850.00 each).

In addition to the transmission this swap requires several other G6 driveline parts. We have 2 versions of the 6 speed conversion kit. The Economy 6 Speed Conversion Kit includes all of the custom parts that it takes to complete the conversion & allows you to buy the needed G6 parts on your own.The Master 6 Speed Conversion Kit includes all parts in the Economy kit plus all of the new G6 parts that are needed.
The Economy 6 Speed Conversion Kit Includes:
At one point or another, you will need all of the following parts to complete the swap.

Custom Length Left side axle
Custom Length Right side axle
Mounting for Intermediate Shaft Bearing (specify engine being used)
V-8 Archie Stage III F-2 Clutch
Flywheel Friction Plate (specify engine being used)
Forward Transmission Mount (specify engine being used)
Rear Transmission Mount
6 Speed Shift Cable Mounting Brackets
Clutch Line Adapter

The price for the Economy 6 Speed Conversion Kit is $1724.00


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When doing the 6 speed swap to a LSx engine, you will also need these parts:
LSx Forward Right Engine Mount
LSx Right Rear Engine Mount
The price for these LSx specific parts is $235.00.

If you are obtaining the Intermediate Shaft for the 6 Speed G6 Transmission, it will be necessary for you to send it to us so we can do a LSx specific modification & ship it back to you. Cost for this modification is $110.00. This modification is only needed on LSx engines.

If you are obtaining the Left and Right Side G6 Axle Assembly, it will be necessary for you to send it to us so we can Pre-assemble it for you & ship it back to you.


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You will need to use a modified 4 speed Fiero shifter to complete this swap. If you send your shifter to us, we will make the modifications & send it back to you for $ 150.00.
You will need to use 2 Fiero Getrag Select Cables on this swap. (we recommend using new cables from Rodney Dickman) 1 of them remains unmodified. The other Select Cable needs to be modified. You can send that cable to us & we’ll do the modification for $80.00 or we can provide a new modified cable for $240.00. (Note that since this was written, we now have the one cable custom made & you can use a stock Getrag Select Cable for the other cable)

If you are also getting a quote for a V-8 engine swap kit, some of these parts are redundant with parts supplied in that kit, so the prices will be reduced accordingly.
The Master 6 Speed Conversion Kit includes:
Custom Length Left side axle
Custom Length Right side axle
Mounting for Intermediate Shaft Bearing (specify engine being used)
V-8 Archie Stage III F-2 Clutch
Flywheel Friction Plate (specify engine being used)
LSx Forward Right Engine Mount
LSx Right Rear Engine Mount
Forward Transmission Mount (specify engine being used)
Rear Transmission Mount
6 Speed Shift Cable Mounting Brackets
Clutch Line Adapter
Intermediate Shaft for 6 Speed G6 Transmission
Left Side G6 Axle Assembly
Right Side G6 Axle Assembly
G6 Hyd. Clutch Line Fitting Check Valve
Dakota Digital SGI-5
The Price for the Master 6 Speed Conversion Kit Without the Transmission is $ 3271.00.
The above parts list doesn’t include the actual transmission. The transmission itself is currently available on EBay at $300 to $400 each. This is a much lower price than buying the transmission new from your GM dealer. I’d suggest getting them on EBay while they last.


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You will need to use a modified 4 speed Fiero shifter to complete this swap. If you send your shifter to us, we will make the modifications & send it back to you for $ 150.00.

If you are also getting a quote for a V-8 engine swap kit, some of these parts are redundant with parts supplied in that kit, so the prices will be reduced accordingly.

Additiionally, I'm sure this thread will turn into an arguement. But the facts remain.

Archie

Syn....I'm not a six cyl guy but nosrac has a rockin' 3800 that runs a auto behind his motor....very very fast. Not an auto guy? I can understand that...however it depends on what you're doing with your car if you think a five is silly. I have a getrag behing almost 400 hp and haven't had an ounce of trouble other than ripping two axles in half. No it's not a drag car but it IS a very fast street car.
All you get with the f40 is a higher overdrive for better highway rpms

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87 GT...SBC...Fast as hell

Archie thank you for all the valuable information, I appreciate it a lot and that now gives me direction so I can actually sit down and figure out a couple of things. I don't want this to turn into an argument, that wasn't my intention I wanted to gain more information from people who have done it to figure out what I need to do on my transmission. I am still sold on the idea of a 6 speed and I know there is going to have to be a lot of custom fab work on it as I've seen around here. I was prepared for that when I went in and decided on this transmission. I have a few reasons for choosing this engine and the main one is that I need the extra overdrive gear and automatics and me have never gotten along as long as I have lived. Archie my Fiero is an auto ATM so I already knew all that was going to have to be changed so that cost was already on my mind. With the driving that I'm going to be doing on this car an automatic doesn't make any sense for me at all, I'll never understand why an automatic is better for bumper to bumper traffic and I've heard all the arguments for and against. Again it was not my intention for this to start any arguments, I just wanted more information. thanks again Archie, I will probably message you in the future about it.

The current Cruze Eco and Cruze LS offer a 6 speed manual, as will the upcoming Chevy Sonic, but they are attached to Ecotec blocks. Archie is right. If you want a six speed, this is the only viable swap at the moment, and is not inexpensive to do properly. Has anyone done a 3.9, six speed pull out swap from a G6?

Noones arguing Syn...you asked what the deal was with it. As I said...its VERY expensive.Archie just confirmed that for you. I built my whole car including the sbc for close to half of what Archies master kit costs.
Build what you think is cool and you're comfortable with. I just don't see an advantage with the f40 other than highway rpm. The more noticable guys on here don't really argue...heated discussion yes...but not argue. Nosrac...Dobey...Mustangsbeware...These are guys I seem to disagree with on alot of things but in the end I respect their opinions because they do know their cars...and in the end it doesn't matter if you like the car or not, you have to respect the time and skill of the guy who built it. This is why occasionally I look at some of the ricers even though I despise the car...it was the guy who spent hundreds of hours building it that I respect.
Most car guys are highly ingenious and handle problems with voracity.

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87 GT...SBC...Fast as hell

If you're planning a swap that brings into question the stock transmission durability then it's something to consider. Otherwise except for an exceptional custom effort on the car itself I wouldn't bother doing it again. My goal for the swap was high power capacity and fuel economy, I accomplished both.

There is a one piece aluminum flywheel available for it now through clutchmasters but since it's a custom order you'd be looking at ~$750 for it. I feel my investment in it was worth it because of the hwy mpg return, but that will vary depending on the engine swapped as you need good low end torque at the lower hwy rpm. I gained 8 mpg hwy over my previous engine and trans combo partly because of it and there's still more to go. That's a savings of more than 3 gal per tank of hwy driving. I should recover my investment cost in fuel savings in less than 2yrs at my current driving rate and possibly near 1 yr especially if prices keep climbing at the pump and I am able to squeeze an additional expected 2 mpg out of it. I actually use 6th gear in town.

quote Originally posted by Rick 88: The current Cruze Eco and Cruze LS offer a 6 speed manual, as will the upcoming Chevy Sonic, but they are attached to Ecotec blocks. Archie is right. If you want a six speed, this is the only viable swap at the moment, and is not inexpensive to do properly. Has anyone done a 3.9, six speed pull out swap from a G6?

The Cruze Eco 6 speed is different than the one in the LS. Great for MPG on the highway, but if you want to think about putting it behind a V8, or even a V6, I wouldn't even think about it. The gearing is even less fit for it. However, I do think the casing is based on the same design as the F40, and it may be possible to change the bell housing if you really wanted to.

Instead though, the Cruze Eco trans behind an LNF would be very nice. A perfect match even, I think.

well I'm not really ready to say, partly because I have a disorder that doesn't allow me to do things like everyone else (ocd) but once I figure it out I'm going to lay it out on the table with pictures but I know that I'm going to be putting anywhere between 300-500 hp, so I know the gears are going to need to be modified to handle that kind of HP it just depends on which motor I go with because they all have their pros and cons and I'm trying to weigh them out, finding them and get some up close and personal time with them like trans mounting surfaces and things of that nature. I enjoy building things and I love fabricating things so don't be surprised if I actually make my own parts, big geek here and CAD is my friend.

Mine isn't finished yet, so this doesn't count, but If you fab your own mounts I think the f40 could be done for about 1600.
Here's where I stand with mine at this point.

Trans 400
axles 220
clutch 400
flywheel 100
Hydraulic connection 10
speedo interface (est.) 200?
shift cables (est.) 200?

The build is still in progress, but it will get finished. I'm in too deep to stop now ...build thread: https://www.fiero.nl/forum/Forum2/HTML/113506.html

[This message has been edited by 1fatcat (edited 07-30-2011).]

quote Originally posted by Syn: I would love to see some documentation on this because as it stands right now GMPARTSDIRECT.com has manual transmissions for a Chevy cruze for both the 1.4 and 1.8 ecotecs for 1500 bucks, and the 1.4s I believe only came with a 6 speed so I'm assuming they are both the same transmission. not suited for a v6 or v8 application but I'm not ruling out the ecotec just yet.

The 1.4 Turbo comes with six speed automatic only, unless it is in the ECO model where the 6 speed manual is available as well.

The F40 is cheap to purchase but expensive/complicated to install.

Pros:
$500 shipped for a new zero mile transmission
Highest rated GM FWD manual transmission
6th gear drops the cruise RPM at 70 mph by 381 rpm (or 15.6%) when compared to the Getrag - with 24.6" tires.

Cons:
Installation requires replacing everything transmission related with new or modified parts: flywheel, clutch, hydraulic connector, shifter cable brackets, shifter cables, shifter, transmission mounts and axles. Spend the $$ and buy a kit or spend your time for a DIY solution.
Overall first gear*final drive is 13.38 vs. 12.60 of the fiero getrag. This is 6% shorter. If you shift at 6000 rpm, the F40 will peak at 32.79 mph whereas the getrag will get you to 34.74 mph (again 24.6" tire).

I am a fan of the F40 and going through the effort to install a couple of them in my personal cars. I want the stronger rating, the lower cruise RPM for better fuel efficiency, and the inexpensive replacement costs in the future. Since GM has switched over to using the same tripod spline with the 5 speed FWD auto, applications with F40 compatible tripods are quite popular these days with various lengths... but an axle solution is only one item on the long list of needed parts.

The F23 is starting to gain some favor since it was used on a turbo 3800 and didn't break while it was used. It also allows the use of a stock fiero axles and does not need a custom flywheel.
However, this transmission was GM rated weaker, the 1st* FD ratio is even steeper than the F40 (14.14 and 13.75) unless you buy 2 transmissions and piece them together to get 13.00 which is still steeper than the Getrag. The cruise RPM on the F23 is higher than the getrag as well (2680, 2536 with the best case 2 transmission combo being 2397... and only that last one is lower than the Getrag's 2486).

People's opinion of the various transmission options will be based on their personal value system and what goals they are trying to accomplish. There is no right answer.

quote Originally posted by Syn: well I'm not really ready to say, partly because I have a disorder that doesn't allow me to do things like everyone else (ocd) but once I figure it out I'm going to lay it out on the table with pictures but I know that I'm going to be putting anywhere between 300-500 hp, so I know the gears are going to need to be modified to handle that kind of HP it just depends on which motor I go with because they all have their pros and cons and I'm trying to weigh them out, finding them and get some up close and personal time with them like trans mounting surfaces and things of that nature. I enjoy building things and I love fabricating things so don't be surprised if I actually make my own parts, big geek here and CAD is my friend.

OK. Well, picking a trans doesn't depend on the HP. It depends on the torque curve. So you need to figure out which engine you really want to go with, and stick to, and pick a trans to match up with what it puts out, and what sort of MPG and performance you want. You also need to know what tires you're going to use. Big sticky tires are going to make the shock load much higher, and so you're much more likely to break axles or a trans with them.

Big sticky tires will absorb more vibration and shock from the trans than hard, spinning, bouncing, street tires.

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Turbo 3800 E85 5spd spec5
11.53@126.7

quote Originally posted by Justinbart: Big sticky tires will absorb more vibration and shock from the trans than hard, spinning, bouncing, street tires.

Good point! Wheel hop is extremely hard on a transmission. (grab, release, grab, release, grab, release). Shock load up the wazzu!

quote Originally posted by dobey: OK. Well, picking a trans doesn't depend on the HP. It depends on the torque curve. So you need to figure out which engine you really want to go with, and stick to, and pick a trans to match up with what it puts out, and what sort of MPG and performance you want.

In the Fiero, picking a (manual) transmission actually depends on how much you feel like spending for crappy ratios.

quote Originally posted by Will: In the Fiero, picking a (manual) transmission actually depends on how much you feel like spending for crappy ratios.

You can always spend a crapload and get whatever ratios you please. Or spend a little more and go longitudinal with a Porsche or Audi trans which have better ratios for torquier engines, Any GM FWD trans is not going to be perfect behind a V8 since there were never any manual FWD V8 cars offered from GM.

But knowing what the engine is putting out, what tires you're putting the power through, and how you're going to drive the car, will tell you what gear ratios would be best for performance or MPG, and you can pick something that exists and is close enough, just go auto, or spend a ridiculous amount of money and get custom cut gears to fit in whatever housing you want to use. If I cared enough and had the money, I'd pay Quaife to make me the right gears and diff, for the F40 case. But I don't, and I don't think anyone else on here does either. Otherwise they'd probably be doing it. Of course, for that much, you can just buy a Corvette which already has much better ratios for the engine in it.

quote Originally posted by dobey: You can always spend a crapload and get whatever ratios you please. Or spend a little more and go longitudinal with a Porsche or Audi trans which have better ratios for torquier engines, Any GM FWD trans is not going to be perfect behind a V8 since there were never any manual FWD V8 cars offered from GM. But knowing what the engine is putting out, what tires you're putting the power through, and how you're going to drive the car, will tell you what gear ratios would be best for performance or MPG, and you can pick something that exists and is close enough, just go auto, or spend a ridiculous amount of money and get custom cut gears to fit in whatever housing you want to use. If I cared enough and had the money, I'd pay Quaife to make me the right gears and diff, for the F40 case. But I don't, and I don't think anyone else on here does either. Otherwise they'd probably be doing it. Of course, for that much, you can just buy a Corvette which already has much better ratios for the engine in it.

Very well put.

I went with an f40 for my build and here is why.

The first item i haven't seen mentioned here yet:
1) Ease of acquiring a Quaife differential. Go ahead and say i dont need it, but i love my torsional differentials and have had Quaife diffs in several cars

2) its rated for more torque than the Getrag (agreed that this doesn't mean that it can definitely hold more, but it certainly is a good sign)
3) Exactly as Archie said, it's a NEW transmission, that I'm putting behind a 15 mile old engine, in an expensive kit car. And a 5-speed would seem out of place in a "new" sports car.
4) Associated with the above, I'd have wanted to do a full rebuild on my Getrag anyways, even though nothing was wrong, just to ensure it was in top shape, thus mitigating some of the cost
5) Equal-length axles. Yeah yeah, i dont need em on a Fiero, whatever. In my Turbo FWD past this, plus a Quaife is the key to not tearing the steering wheel out of you hands, sure it wont do that on RWD, but i doubt the physics change because its int eh back of the car, and i want nice, balanced application of power especially around corners.
6) While the cost is "high" to install it, when you consider that I'm installing an essentially new ls3, in a custom kit car, with all the crap you have to buy for these.... Not really that bad. Plus a bit of the cost of Archie's kit is reduced when your buying the LSx kit as some of the items are duplicated.


All that said, the Getrag is an awesome trans, i remember it in my first Fiero very fondly, and people are running a TON of power to them (some more successfully than others).

If your going to do it, I'd recommend getting Archie's kit, I just finished bolting it up to my engine yesterday, and honestly, the thought that goes into that kit is impressive. Even the half-shaft is specially machined for a little bit of extra clearance near the ring gear for safety. Some people say that Archie's kits are expensive, I'll agree that the number might be higher than you initially expected, but considering all the R&D and headaches you do not have to do, not to mention the support you get from Archie, its worth it IMHO.

Ever had a Quaife in a RWD car?

A high torque bias ratio such as what works in a FWD car will induce understeer in a RWD car.

[This message has been edited by Will (edited 07-31-2011).]

quote Originally posted by whitey078: I went with an f40 for my build and here is why. The first item i haven't seen mentioned here yet: 1) Ease of acquiring a Quaife differential. Go ahead and say i dont need it, but i love my torsional differentials and have had Quaife diffs in several cars 2) its rated for more torque than the Getrag (agreed that this doesn't mean that it can definitely hold more, but it certainly is a good sign) 3) Exactly as Archie said, it's a NEW transmission, that I'm putting behind a 15 mile old engine, in an expensive kit car. And a 5-speed would seem out of place in a "new" sports car. 4) Associated with the above, I'd have wanted to do a full rebuild on my Getrag anyways, even though nothing was wrong, just to ensure it was in top shape, thus mitigating some of the cost 5) Equal-length axles. Yeah yeah, i dont need em on a Fiero, whatever. In my Turbo FWD past this, plus a Quaife is the key to not tearing the steering wheel out of you hands, sure it wont do that on RWD, but i doubt the physics change because its int eh back of the car, and i want nice, balanced application of power especially around corners. 6) While the cost is "high" to install it, when you consider that I'm installing an essentially new ls3, in a custom kit car, with all the crap you have to buy for these.... Not really that bad. Plus a bit of the cost of Archie's kit is reduced when your buying the LSx kit as some of the items are duplicated. All that said, the Getrag is an awesome trans, i remember it in my first Fiero very fondly, and people are running a TON of power to them (some more successfully than others). If your going to do it, I'd recommend getting Archie's kit, I just finished bolting it up to my engine yesterday, and honestly, the thought that goes into that kit is impressive. Even the half-shaft is specially machined for a little bit of extra clearance near the ring gear for safety. Some people say that Archie's kits are expensive, I'll agree that the number might be higher than you initially expected, but considering all the R&D and headaches you do not have to do, not to mention the support you get from Archie, its worth it IMHO.

Thank you for the reply, that was informative thought out and full of useful information that I can use. I am considering using archies kit as the ease of it all seams like a win over the reduced cost of doing it myself. I haven't made up my mind completely all I know is I need to pick my motor and to answer some other questions I'm planning on making this a widebody so I'm going to be using bigger tires *width and diameter* but I'm trying to keep the weight of the rim down if at all possible, I hate chrome, heavy and holds heat. If I do use an ecotec motor though its going to be turbo or supercharged because having a widebody car with a 4 banger that puts out 195 hp seems about as redundant as putting a 4 speed in a "new age sports car". But after all that I still have to strain, I'M NOT DOING AN AUTOMATIC, its not worth the headache, time, fluid, and are no where in the same country as fun to drive.

I'm curious -- how many people who have posted in this thread have actually driven an F40 equiped Fiero?

quote Originally posted by Doc John: I'm curious -- how many people who have posted in this thread have actually driven an F40 equiped Fiero?

At least one lol.

I use the F40, I believe I was the second one to have one on the ground and running. Used it behind my 4.9 for 5 years
and it is now behind a LS3. Never had a problem and fun to drive. Everyone complains about first gear, yes it it short and
I use it if I have to start uphill, but most of the time on flat ground I use second. And that 6th gear makes pretty sweet
gas milage.

Jack

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WARNING: Surgeon General said it's okay to smoke 3800s

quote Originally posted by J Gunsett: Everyone complains about first gear, yes it it short and I use it if I have to start uphill, but most of the time on flat ground I use second. And that 6th gear makes pretty sweet gas milage. Jack

The first gear issue is a matter of power, the more you have, the quicker it runs out and although I've done it a time or two, starting in 2nd gear doesn't feel like it's good for my clutch. As for the overdrive, in about a week once the engine swap is completed and hopefully lean cruise in action, I believe I'll be posting receipts supporting 35+ mpg hwy. Definately worth the effort I went through installing it DIY.

quote Originally posted by Archie: A few others' have worked on 6 speed swaps & have fabricated axle tripots & made other modifications in the axle & intermediate shaft area.

Hey Archie,

out of cuiriosity... have you had any customers who wanted to use the intermediate shaft with another transmission, such as the 4 speed muncie? could it be modified to make it work? i have been looking for a solution to my Torque steer problem in my chevy citation ( FWD ): i have a 4.9L caddy engien with a 4 speed muncie installed. the LSDs that are available for that transmission really hurt the driveability of the car as far as steering control goes, and they tend to grenade the tranny after a while because of the poor wear characteristics. adding an intermediate shaft seems liek a great idea to help even out the axle length on both sides...

quote Originally posted by stickpony: Hey Archie, out of cuiriosity... have you had any customers who wanted to use the intermediate shaft with another transmission, such as the 4 speed muncie? could it be modified to make it work? i have been looking for a solution to my Torque steer problem in my chevy citation ( FWD ): i have a 4.9L caddy engien with a 4 speed muncie installed. the LSDs that are available for that transmission really hurt the driveability of the car as far as steering control goes, and they tend to grenade the tranny after a while because of the poor wear characteristics. adding an intermediate shaft seems liek a great idea to help even out the axle length on both sides...

The intermediate shaft assembly used on the Chevy Beretta 2.8 might be a better fit in your situation.

quote Originally posted by Will: Ever had a Quaife in a RWD car? A high torque bias ratio such as what works in a FWD car will induce understeer in a RWD car.

What is considered high? I have a 2.5:1 Torsen in my Miata and it's awesome.

quote Originally posted by Zac88GT: What is considered high? I have a 2.5:1 Torsen in my Miata and it's awesome.

It was discussed a while back (and the material I've seen on it was probably actually on the Fiero Racing List), but I think the Torsen built way back in the day for the 282 was 4:1.

[This message has been edited by Will (edited 07-31-2011).]

quote Originally posted by Zac88GT: What is considered high? I have a 2.5:1 Torsen in my Miata and it's awesome.

Correct me if I'm wrong, but isn't under-steer when the front tires dont have grip and the rear still does... I could see someone saying something like it causes over-steer, but then, maybe having the torsional diff allowed you to power out of a corner without losing rear tire grip, and thus you run into the limits of the fronts? Or maybe I'm just reading it wrong.

Maybe at higher speeds and heavy loads, it could cause the front wheels to be pushed straight ahead no matter what direction they are pointing? If both rear wheels have the same power being applied, it may act like a solid axle, or spool and push the front end straight even if your trying to turn?

That's basically it... it applies more power to the inside rear than an open diff would.