I figured I would ask some of the guru's here on the forum. I have found very little info in the archives about this. Most of the info is for getrags.

I have been working with a buddy of mine on making some custom gear ratios for an 85-86 muncie 4 speed. Basically he can machine up anything that we need and has many years of experiance in tranny shops. He's made many a gear before.

We want to make the most ideal setup for a 4.9 V8. Decent splits and use the torque. Gas mileage is a deffinate factor also. Performance is not the most important thing for this setup though a little off the line would be good. Can anyone suggest a good setup?

Tell me what you know and help me to understand all that is involved. Trannies have always been my weak point when it comes to the mechanics. Lets discuss.


EDIT: To add some more info on the car itself... before you guys ask.

Rebuilt caddy 4.9 with Delta cam and port work. Fuel cutoff set to 5600rpm. Will pull there no problem but power drops after 5000rpm. 225/55-16 tires and possibly switching to 245/45-17. Basically same diameter.

[This message has been edited by Fieroseverywhere (edited 06-27-2008).]

First off, youll need to figure out straight cut gears, and get over the noise to make it worth while IMO. The 4speed is hands down the best trans for a 4.9/3800.

I would love to see someone make up some custom gears for the 4 and 5 speed muncies. It would be nice to see 3000 rpm at 80.

Steve

The 3.65 gear tranny is well documented as the best performance tranny for the Fiero. The shortcomings of the tranny are these

1. No reverse gear synchroes
2. Final drive gear is a little buzzy.

If I was modifying a 3.65, and had the ability, I would add the missing synchroes (if it can be done in the space) and change the gear ratio for 4th.

Apart from that it is pretty optimum.

Arn

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I love my 4.10 gearing. but - a longer 1st would REALLY be nice. I dont do much freeway at all, so I dont care about a longer 4th - but - turning 3500rpm to do 70mph is quite a chore. really wrecks the milage. but, boy does it ever put the power to the pavement. so - yes - for me, and where & how I drive - the 4.10 with the 3.65 1st gear would be the choice. but, as mentioned - it REALLY sucks on the freeway - unless you like driving on the freeway in your passing gear. but, my intent when I did the 4.10 gears was eventually getting tallers wheels/tires, which will shift back my final ratio to something more "friendly".

I have thought the same thing. I love the way my 4 speed drives with the 2.8. However with the 4.9 it is far from ideal. It just really needs better ratios in 1st and 4th. These are the two major problems I want to address. I had never heard of the synchros in reverse. Didn't even know that was an issue. I'm not to worried about that since I will be spending very little time there. The way I want to do this is probably not what most fiero owners are going for. The car has more power then stock but wont ever see any kind of track use. Its more of a cruiser with a little get up and go. The 4.9 really is great for this purpose. Its a great cruiser with excellant drivebility and very smooth power. I just want the tranny to match the motor for this purpose... without blowing itself to pieces.

Has anyone ever tried to see how tall the gears can actually go? How much room is in the case to work with? I'm not looking to just mix and match parts. I want to make a new setup for the 3.65 to make it ideal as possible to utilize the low end torque without having to shift half way through the innersection and to maximize gas mileage. Transmissions are just not where my strengths are.

Would it be possible to do 0-60 in first? Is there space to use a gear that big? How about using 4th as an overdrive only?

Work will begin sometime after next weekend. I will be bringing an extra 4 speed over for us to split and play with. I was just hoping someone has done something like this before and might be able to give up some pointers.

[This message has been edited by Fieroseverywhere (edited 06-28-2008).]

I cant find the thread but there are several people on here that had some ideas of what would be good gear ratios for the 4 and 5 speed transmissions with different engines. Maybe some of them will chime in as I do have both 4 and 5 speed Muncies and would like a chance at better gearing if it were possible with the 3800.

Steve

I am not recalling specifics off the top of my head, but as I recall the 3.65 2nd gear pulls to 60 mph. I can check it today on the cruise

Arn

Ok. I'm going to bring what info I have found here for quick reference.

First, the gear ratios that were available in the fiero.

Year - Style, Code - Axle - 1st - 2nd - 3rd - 4th - rev
1984 - econo 4 speed, MY8 - 3.32 - 3.69 - 1.95 - 1.24 - 0.73 - 3.42
1984 - perf 4 speed, M19 - 4.10 - 3.53 - 1.95 - 1.24 - 0.81 - 3.42
85-86 - V6/4-speed, M17 - 3.65 - 3.31 - 1.95 - 1.24 - 0.81 - 3.42

I have heard that there were some differences between the 84 and 85-86 years besides the ratios and the cases but at this point I am not sure what they are. Maybe someone can explain this to me?

I also have the diagrams and parts lists out of the 22p. I will scan in and get them posted in the next day or two so we can have them as a reference also.

to add to the confusion: there is also the 4-speed which was used in the chevy citation. it also used the same Muncie 4-speed. and, it had other 4th gear options. so, for more existing gears - might wanna look them up as well.

quote Originally posted by Pyrthian: to add to the confusion: there is also the 4-speed which was used in the chevy citation. it also used the same Muncie 4-speed. and, it had other 4th gear options. so, for more existing gears - might wanna look them up as well.

Interesting. I found some references to the citation having its own gear ratios but can't seem to find any info as to what they were. Seems they had a longer first and were capable of 60mph in second. Forth was also setup for better gas mileage.

I'm keenly interested in this topic. Poor ratio match to high torque (V8) engines is one reason I gave up any 4.9 fantasies. I've been using the gear ratio spreadsheet Capt. Fiero posted a while back. I forget who he got it from, but it's ideal for these "what-if' calculations.
My first pass with stock components yeilded the "hybrid econo/V6 4 speed"
1st gear = 3.31 (Stock V6)
2nd gear = 1.95 (Stock V6)
3rd gear = 1.24 (Stock Econo 4 spd)
4th gear = 0.73 (Stock econo 4 spd)
Final Drive = 3.32 (Stock Econo 4 spd)

With 205/60-15 tirees, this gives 1944 RPM @ 60 mph, pretty good for cruising. I'm led to believe these pieces will all fit into a later V6 4-speed ribbed case. The gear splits (rpm drop on shifts) are uniform, giving about the best 4-speed that the factory never made. At 5500 RPM you'll be going 37 in first, and about 64 in second.

A 4.9 can use cruise RPM of about 1500 at 60 MPH. So your friend will have to create a much longer final drive at least. The individual ratios may be left alone, or changed to whatever you deem best. I'm sure if they can be produced affordably, your buddy can recoup his investment by selling several sets to forum members. This has always been a sticking point for high-torque V8 & V6 guys, most of them want longer gears.

I don't know how to post my hacked-up version of Capt. Fiero's spreadsheet, but I'm happy E-Mail it to someone smarter than I.

You can also take a 80 citation or Phoenix 4 spd (which has the 3.32 and the .81 4th) and put the gears in the v6 case. That's what I did on my 4.9 turbo swap. 4th gear was about the same as 5th on the getrag.

quote Originally posted by Rhino88gt: You can also take a 80 citation or Phoenix 4 spd (which has the 3.32 and the .81 4th) and put the gears in the v6 case. That's what I did on my 4.9 turbo swap. 4th gear was about the same as 5th on the getrag.

very intrested in this can you explain more i have a 4spd with the 3.65 finial drive but i really would like to be able to cuise at 80 with out turing 4500 or so idk exactly right now its down (spun rod bearing)

you shouldn't be turning 4500 @ 80mph with the 3.65, should be more like 3000. The 80 citation gears made it turn about ~2600-2700 @ 80mph, IIRC. You will want to put the gears in the v6 case though, the 80 cit. case is the same as the 84 4cyl fiero 4 speeds. VERY simple swap.

IF you're gonna make custom gears, I would buy a set IF the ratios were more like those in transmissions intended for a V8. What I'd really prefer is a custom final drive around 3.0000:1 But for the econo 3.32:1 final, IF you could make your ratios (1) 2.74:1, (2) 1.57:1, (3) 1.00:1, (4) 0.67:1. The V6 case is stronger. And IF we could have these ratios AND the 3.000:1 final, we'd be in V8 heaven. The V6 second had a different tooth count than the earlier 4-cyl, so 1.954545454:1 became 1.95000:1 for the V6. I researched this trans, and there were only ever 2 different 4th gear ratios. 0.73:1 and 0.81:1 also, there were only ever 2 first gear ratios. 3.31:1 and 3.53:1. third was only ever 1.24:1

quote Originally posted by Isolde: IF you're gonna make custom gears, I would buy a set IF the ratios were more like those in transmissions intended for a V8. What I'd really prefer is a custom final drive around 3.0000:1 But for the econo 3.32:1 final, IF you could make your ratios (1) 2.74:1, (2) 1.57:1, (3) 1.00:1, (4) 0.67:1. The V6 case is stronger. And IF we could have these ratios AND the 3.000:1 final, we'd be in V8 heaven. The V6 second had a different tooth count than the earlier 4-cyl, so 1.954545454:1 became 1.95000:1 for the V6. I researched this trans, and there were only ever 2 different 4th gear ratios. 0.73:1 and 0.81:1 also, there were only ever 2 first gear ratios. 3.31:1 and 3.53:1. third was only ever 1.24:1

Here is what I have been playing with. Pretty close to what you have there. I found a decent gear ratio calculator here...
http://www.f-body.org/gears/
Its a very basic program but does give you a good idea of RPM's at different speeds and in different gears.

Here is what I was playing with...
5600 rpm redline
225/55-16 tires or 245/45-17 (basically same diameter)
3.0 final
2.5 first
1.5 second
1 third
.67 forth

Basically with this setup you can do 57 in first (at 5600rpm). At 2000rpm in 4th your doing 75mph. And a top speed of 213mph. I have no idea if there is even space in the case for this size gears. One problem I saw with the .67 forth is that you wouldn't be able to use forth til you hit about 55mph. I haven't worked out the splits as of yet so I'm not sure how the adjustments for that would need to be made. Its a very rough starting point and probably not very practical...

[This message has been edited by Fieroseverywhere (edited 07-01-2008).]

What do you mean you can't use 4th until 55? In a heavier '78 Camaro, with a stock, worn-out 350, I was able to easily pull 830 rpm @ 30 mph, using a 0.696:1 in the trans (700R-4 I swapped in) a 3.077:1 axle, and 26"-dia. tires. I got 25 mpg at 65 mph with my centrifugal advance not working. As for a 3.0:1 final, the beauty of 3.000 is that there are so many possible tooth counts that could get it. Really, for a manual trans, 3.0:1 diff, 25-26" tire car, a 2.5:1 first gear is a bit tall for anything less than a stroked V8. Still, I'll be following this thread with great interest.

quote Originally posted by Isolde: What do you mean you can't use 4th until 55?

The reason I said that is cause anything below 55 mph would be below 1500rpm. While the engine may be able to pull it, it can't be good for it. Maybe I'm wrong completely but like I said transmissions are not my strong suit. I know this engine pretty well since I built it. It just doesn't like to have a load on it below 1500. Probably cause of the cam change.

Either way I'm getting closer to where I wan't it to be. I will pick up the tranny this weekend and split the case sometime next week. We'll see just how close I can get to an ideal setup for this motor/tranny/car combination. I actually getting pretty excited about it now.

EDIT: Hmmm. Interesting....
https://www.fiero.nl/forum/Forum2/HTML/093104.html

[This message has been edited by Fieroseverywhere (edited 07-02-2008).]

back in the 80's when i worked at gm research we were playing with an electronically shifted 5 spd getrag. we got alot of the gear sets from a company called webster gear. the first one's we used were straight cut gears (noisy) later the were angled like a production set. pontiac used these gears also in their super duty race cars. webster used to have a variety of ratios but i don't know much about the company but when the x-11 guys were racing also they probably used the same company.

I think you should seek some tuning. My example was not a good one. The Vettes are making power to 6500 rpm, but can do 1400 rpm @ 65 mph, and I've had more than one 305 car pull 55 easily with gearing for 1600 @ 65. My '95 Z28's LT1 wasn't happy turning 1600 @ 65, but it didn't hurt either the bearings nor the gas mileage. Either you have a huge cam, or your tuning isn't right. Which engine are you running, and what are your cam specs?

quote Originally posted by Fieroseverywhere: Interesting. I found some references to the citation having its own gear ratios but can't seem to find any info as to what they were. Seems they had a longer first and were capable of 60mph in second. Forth was also setup for better gas mileage.

I'd check out the Citation yahoo group first. Somebody from there saw my post on here last fall when I was selling a set of tuned fwd citation headers for the 2.8:

http://autos.groups.yahoo.c...evycitationsforever/

quote Originally posted by Isolde: I think you should seek some tuning. My example was not a good one. The Vettes are making power to 6500 rpm, but can do 1400 rpm @ 65 mph, and I've had more than one 305 car pull 55 easily with gearing for 1600 @ 65. My '95 Z28's LT1 wasn't happy turning 1600 @ 65, but it didn't hurt either the bearings nor the gas mileage. Either you have a huge cam, or your tuning isn't right. Which engine are you running, and what are your cam specs?

Engine is a 93 caddy 4.9. Cam is a drop in fairly mild cam. 480 total lift I believe.

I'm in the process of tuning right now. The biggest problem I am now facing is a bad PROM. This is problably the reason the engine doesn't want to run below 1500. A new chip has been sent for programing but not sure when it will arrive back here. I'm actually amazed that the car runs at all with this problem. It probably shouldn't. So you are correct the tuning isn't right... yet.

Jerry455 : Thanks for the info. I'll see if they can tell me anything.

FieroFanatic13 : Thanks for the link.

[This message has been edited by Fieroseverywhere (edited 07-03-2008).]

Lift has nothing to do with how low of rpm the engine will drive at. What matters is duration and lobe separation angle. But a stock 4.9 cad would easily love a 3.00 x 0.67 =2.00 effective gear with 25-26" tire dia. I would expect 27 mpg at steady 65 mph.

quote Originally posted by Isolde: Lift has nothing to do with how low of rpm the engine will drive at. What matters is duration and lobe separation angle. But a stock 4.9 cad would easily love a 3.00 x 0.67 =2.00 effective gear with 25-26" tire dia. I would expect 27 mpg at steady 65 mph.

I can't remember the specs on the cam and I didn't write them down. Its just a mild bump up.

Gas mileage should be much better then that. I get about 24 now with the isuzu tranny, 205/45-16 tires, and the bad PROM. The PROM error is killing my mileage and performance very badly and making the car run in "limp mode". Once fixed I should see around 30 hwy as is. Better once I get the tranny changed out and proper tires on it. The purpose of the tranny change to is possibly increase mileage but more importantly give me something that won't break under a little fun.

Well, picking up the new tranny to start work will be delayed for another week. I have to drive down to the shop 125 miles away to get it (them). It was going to happen this weekend but a last minute change has delayed it a bit. It was unavoidable...

Dunno if this will help or not with deciding ratios....it is a different version of the calculator mentioned earlier, but allows you to compare multiple transmission ratios side by side.

http://www.cowspatoot.com/speedcalc

It has the standard transmissions from a Fiero figured already, and gives a couple user defined ones. I can add others in fairly easily if anyone feels there is a need.

I'm not buying 30 mpg with any stock Fiero stickshift ratios and any V8. I need proof. The BEST hope would be a 4.8 liter LS and an F40-MT2 6-speed.

Bump, I have to keep this on top! If any where near affordable, put me down for 2 sets!

It won't be affordable. The OP has no idea what he's getting into.

I believe he's brought this topic up before.

Just put together the best hybrid of production gears that you can.

[This message has been edited by Will (edited 07-07-2008).]

quote Originally posted by Will: It won't be affordable. The OP has no idea what he's getting into. I believe he's brought this topic up before. Just put together the best hybrid of production gears that you can.

exactly - getting custom gears cut aint cheap. tho, rounding up existing stock gearsets aint easy either. but, enough time trolling the boards.....

and - the 3.65 gearset is a mighty fine one.

quote Originally posted by Will: It won't be affordable. The OP has no idea what he's getting into. I believe he's brought this topic up before. Just put together the best hybrid of production gears that you can.

Actually I do have some sort of an idea of what I'm getting into, though as I have said, trannies are not my area of expertise. I know the cost of having a custom set made would be through the roof. The good news is I won't have to pay labor for this, only materials at a discounted price. This does not include what is lying around the shop that can be used for free. This will drop the cost significantly for me. Re-using gear sets out of other cars is an option also but ONLY if it fits into making the ideal setup. I have not said anything about offering these and at the moment don't have any plans to do so. I will offer details to anyone who asks as this project progresses. I was just hoping for some info from someone who has done this kind of thing with this transmission.

I was really hoping you would find this post Will. I believe your insight will be invaluable to this project. And no, I have not asked about this subject before. My problem with the best hybrid set I can put together is they still won't be just what I'm looking for.

While cost is a factor it is not the most important factor here. Building the most ideal transmission out of one of these is my main goal.

Thanks for all of your opinions but it seems that few people share my interest in building a proper transmission to suit the car.
I am still open to ideas if you have some. I will also post updates as they are available.

UPDATE: The Isuzu has had it. After only two months. One of the 3.65's will be going in next weekend as a replacement until such time as another one can be built up and tested enough to be installed.

quote Originally posted by Fieroseverywhere: ..... UPDATE: The Isuzu has had it. After only two months. One of the 3.65's will be going in next weekend as a replacement until such time as another one can be built up and tested enough to be installed.

well, this should give you a fine referance point to judge what you actually need/what out of your tranny.
the 3.65 is a fine tranny as-is. most would probably either want a 4th that cruises better on the freeway - or a 4th which is closer to third for racing.

quote Originally posted by Fieroseverywhere: it seems that few people share my interest in building a proper transmission to suit the car.

Try lack of budget

quote Originally posted by Pyrthian: well, this should give you a fine referance point to judge what you actually need/what out of your tranny. the 3.65 is a fine tranny as-is. most would probably either want a 4th that cruises better on the freeway - or a 4th which is closer to third for racing.

Exactly what I'm going to be doing. I've actually been daily driving an 85SE V6 for the last 3 years so I'm very farmiliar with this tranny. Just not with the 4.9 yet. I used the isuzu cause it came with the 88 cradle I swapped in. Should have kept the stock 3.65 the car had originally and saved myself some time. As they say... hindsight = 20/20.

Actually I spoke with my friend today and I think we are going to play with the final drive gear first and see what we get. Just making that taller could get me very close to my goal with relativly little work. Relativly.

As for the budget concerns my buddy really wants a fiero. I happen to have an extra 84SE auto that has sat around for a year and half that he has been dying to get his hands on. He fell in love when I let him drive it a while back.

quote Originally posted by Fieroseverywhere: I was really hoping you would find this post Will. I believe your insight will be invaluable to this project. And no, I have not asked about this subject before. My problem with the best hybrid set I can put together is they still won't be just what I'm looking for. While cost is a factor it is not the most important factor here. Building the most ideal transmission out of one of these is my main goal.

quote Originally posted by Fieroseverywhere: The car has more power then stock but wont ever see any kind of track use. Its more of a cruiser with a little get up and go.

These two statements seem incongruous.
I guess if you dont have to pay time when you have gears made, your viewpoint is different.
While your friend may be willing to do you a favor or trade you a Fiero for work, he's probably going to want money from everyone else.
I'd guesstimate a properly produced input shaft + 1st & 2nd output gears would cost ~$3000.
Properly produced means machined, hardened, cryo treated, ground, polished on the teeth and shot peened on the non-wear surfaces.
A gear is NOT ready for use if it's simply machined out of bar stock with no further operations.
I hope you've got an appropriate material in mind, too.

FYI, the 3.31 first with the 3.32 final gives you the tallest first gear you can have in a Fiero manual transmission.
The 0.72 fourth with 3.32 final gives you the tallest fourth you can have in a Fiero manua transmission.

Aren't those the two gears you were complaining about?

[This message has been edited by Will (edited 07-09-2008).]

Gearing Calculator

There's a link to a gearing calculator spreadsheet I made...Might help out. It's a little more full-featured than some of the online calculators.

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My Web page | The Turbo Super Duty Build.
You know that little voice that says it can't be done? I duct-taped its mouth shut and pushed it down a flight of stairs. (Leader of the Insurgency)

quote Originally posted by Will: FYI, the 3.31 first with the 3.32 final gives you the tallest first gear you can have in a Fiero manual transmission. The 0.72 fourth with 3.32 final gives you the tallest fourth you can have in a Fiero manua transmission. Aren't those the two gears you were complaining about?

Main Entry : incongruous
Part of Speech : adj
Definition : not congruous; disagreeing and inharmonious in character

I think my statements are congruous. I guess I should have said building the most ideal transmission for the cars intended purpose, cruising and all around daily driveability with a higher torque V8.

So are you saying that the gears simply cannot get any taller? As in, there just isn't enough room in the transmission itself? This is the big question that I have been trying to find an answer to. Nobody knows because nobody has ever tried to do this, from what I can tell.

If nothing else works that will be the combo I will go with. But work will start with a change of the final drive, if possible, and go from there. Changing out first and forth may not even be necissary if a change of the final can do what I'm looking to do. Thoughts?

Thank you for your insight. I appreciate it.

quote Originally posted by FastIndyFiero: Gearing Calculator There's a link to a gearing calculator spreadsheet I made...Might help out. It's a little more full-featured than some of the online calculators.

Thank you! I can't download at work but will give it a shot at home tonight.

[This message has been edited by Fieroseverywhere (edited 07-10-2008).]

What was incongruous was that you wanted a cruiser with optimized gearing.

A cruiser is a car with no specific purpose. Therefore, gearing can not be optimized.

If you're not going to take it to a road course and not going to autoX the car, then custom gearing just isn't worth the effort.

Extra tall low gears useable on a road course, for instance, are going to hurt the car's off the line performance.

Just build the hybrid 4 speed outlined above, try it, and then decide if you want custom gears. It is NOT trivial.

There's plenty of room in the case for taller 1st gear. Not sure about final, though.