rodriequez- this swap will not be any cheaper than any other sbc swap out there. it will take a lot fabricating, requiring cutting and welding. its too early to tell if it would take about the same man hours as other popular swap kits, if this proceedure was in a kit form.

smoooth- he didnt want any then.... he sure as $hit dont want any now!!!

80's boy- it all depends on the size of your "tool". the bigger the tool.... the easier it is.

gtfiero1- i dont think you have to move the gas tank, i did it to provide a little better weight distribution and gain a couple of gallons of gas.

Well nothing is better than "helping"with a V8 if I don't have one!!

I will still race him someday but he knows that I have no money so ...all in fun just to see how VERY LITTLE he would beat me by hee hee

quote Originally posted by California Kid: [This message has been edited by California Kid (edited 06-21-2003).]

Looks like a V8 Lotus Esprit Turbo chassis... Been through them a few times!!!

Cool though, I've often thought that would work well under a Fiero.

THEN we could say a Fiero has "Lotus Suspension" LOL!!!

DKOV -

So Perk, what did you do with your back glass if the roll cage is coming through it ? Are you going tube chassis with Lexan glass or what ? I really liked your idea about the tubes replacing the factory junk, but one should be very careful with the measurements. I don't wanna end up with my car walking like a dog down the track !! LOL... Keep us updated Tony and don't forget to take notes while I go out and get a bigger "tool". LOL.....

p.s.- Perk if you have some pics that would be awesome too.

Yeah 80's BOY I will be using a Lexan rear window, or maybe Percy's Speedglass. If you're not running a full cage the bars don't have to go through the window, they can weld up to the firewall below it. If your factory upper rails are in good shape between the strut towers and rear firewall you could also just weld tubular bars from the back of the strut towers down to the main frame rails. Put a bend in 'em so they look trick though.

Sorry no pics yet. I have some pics of the DEconstruction that haven't been developed yet, and I am still waiting almost patiently for parts to begin building. Gonna call today to check on progress with the cage kit.

Found out yesterday why everyone here is so afraid of the lighter TH325 that I have coming too. Turns out the TH325 is actually a super weak TH200 (3spd) inside. I thought it had TH350 guts. The TH325-4L is actually based on the stronger TH2004R but the front-drive case is weak - according to someone on this site in another thread.

I have to figure out what I am going to do now. I understand that the TH425 is much stronger but I can't justify a 253lb tranny to get that strength. Kinda defeats my purpose - though it may work fine for others.

perk

Perk,

Picking up my Lexan rear window today. As for the tube chassis, how about this:

Sorry, just can't help butting into the conversation.

Paul

WHOLE - EEE - CRAP !!!!

What a showoff.

Hey that's not a TH425 you just get outta here !!

j/k

I'm putting tubes in my chassis but it's technically just an "enhanced" Fiero space frame for this project - we won't talk about the other one right now cuz it doesn't fit here, and I'm not a show off like Paul!

Just kidding Paul , have you driven that thing yet?

perk

quote Originally posted by 80's BOY: WHOLE - EEE - CRAP !!!! What a showoff. Hey that's not a TH425 you just get outta here !! j/k

That's putting it 'Mildy'...

More Pic's..??

Sorry guys,

I have been reading this thread for a while. With all of the longitude engine talk, I guess I just couldn't hold back. I think that the setup you guys are talking about will make for one heck of a straight line car!

It was somewhat uncalled for. Please continue with the discussion. (I gotta show off sometimes! )

I'll post more pictures soon under a "Fiero SS" (cheesey name, I know) Update.

Paul

quote Originally posted by R Runner:...I think that the setup you guys are talking about will make for one heck of a straight line car!...

(The following is from a diehard 1/4-miler)

Straight lines are fun but I gotta "twist-and-shout" a little too! That has been my challenge - to produce a moderately streetable combination that does all things reasonably well, handles lots of power, and is affordable to build. Much easier said than done.

The hard part is not upsetting the balance of the car too much.

perk

[This message has been edited by perkidelic (edited 07-02-2003).]

[This message has been edited by perkidelic (edited 07-02-2003).]

Screw that....just point the car in the direction you want to go extremely fast and hold on !!!

That's my history 80's BOY. In cars and most recently on wheelie bar-LESS motorcycles. I have been a diehard point-n-shoot guy most of my life. Always will be. Just wanna do the twist in my "old age"

cardealer - you know we're just flappin our gums, keeping this near the top, and waiting for more right?

perk

quote Originally posted by perkidelic: That's my history 80's BOY. In cars and most recently on wheelie bar-LESS motorcycles. I have been a diehard point-n-shoot guy most of my life. Always will be. Just wanna do the twist in my "old age" cardealer - you know we're just flappin our gums, keeping this near the top, and waiting for more right? perk

flap away!!!!!! nothing new today, to big of list of "honey do's". my "warden" (wife) has other plans for me today, but if the big brown truck (ups) shows up today maybe i can get paroled.

quote Originally posted by perkidelic: Found out yesterday why everyone here is so afraid of the lighter TH325 that I have coming too. Turns out the TH325 is actually a super weak TH200 (3spd) inside. I thought it had TH350 guts. The TH325-4L is actually based on the stronger TH2004R but the front-drive case is weak - according to someone on this site in another thread. perk

Hey Perk,
While we're all waiting around for these reversal developments, maybe you could enlighten us further about the thm325. I don't mean to challange you, I'm just asking about specifically what you have learned.

I had spoken directly with two builders who used the 325, and spoken directly with three different trans rebuilders. They all ranked the 325-4 (the overdrive 4spd) as the most troublesome and weakest....the 325 as the lightest and as being stronger than the -4....and the 425 as the strongest but heaviest.

I have not been able to compare internal part numbers amoung the many various transmissions (like the 200 you mention). However everything I ever heard and read suggested the thm325 had the 350 trans in it's ancestory. I do know that the 325 has a wider chaindrive than the 325-4....and all rebuild shops said the 325-4 was just not as robustly built as the two previous models, that they saw the -4 in the shop frequently as compared to the other two.

No problem opm I don't see it as a challenge. The only way we'll ever get to the bottom of this is to constantly question pick and pry until we find the good, the bad, and the ugly.

The transmission shop I talked to is Rossler's. He is the guy who builds Lingenfelter's C5 auto transaxles, and runs a 6.73 sec @ 213mph '55 Chevy racecar, jsut to give you an idea of his qualifications.

I thought the same thing that the TH325 was based on TH350 internals, but they told me it was actually TH200 guts. Not saying they couldn't be wrong - just relaying what I learned.

It is believable because that the TH325 was produced from 79-81. 79 is also when GM came out with the downsized G-body cars (Monte, Cutlass, Regal, Grand Prix). The first G-bodies with weak 305 smog motors were notorious for destroying transmissions. That transmission was the weakling TH200. I know if this first hand because my mom bought a 79 Monte Carlo new and within a couple years had to have a TH350 retrofitted. There was even a kit that was sold to make the conversion easy. The guy at the tranny shop thought it was my car, which it eventually did become, and put a shift kit in it - which my mom wasn't real crazy about.

All that to say I think it is definitely possible and highly likely that GM would use their new wonder tranny in the new Eldos and Toronados too.

perk

I too have heard that the TH325 is based on the TH200. If I remember correctly, didn't the oil pans on the TH200 have the word "METRIC" stamped into the pan? Perhaps the TH325 would have the same stamping. I don't know as the only TH325's I have seen have been in the car. Someone in a previous post said the TH425 weighed 250 lbs....is this the weight with the diff attached?

quote Originally posted by TONY_C: I too have heard that the TH325 is based on the TH200. If I remember correctly, didn't the oil pans on the TH200 have the word "METRIC" stamped into the pan? Perhaps the TH325 would have the same stamping. I don't know as the only TH325's I have seen have been in the car. Someone in a previous post said the TH425 weighed 250 lbs....is this the weight with the diff attached?

261 pounds fully loaded, final drive, full pan and converter, output shafts.

o.k. the th325 issue - its just weak, the clutch bands are small,the clutch drum and the chain cant take much torque. final drive is not much different than the one in a 125.
if you cant put it in a reverse rotation its not worth doing. the balance will still be a huge factor even though its lighter than the th425. i will check on doing a th325 in reverse rotation to see if its possible to do it properly.

Hey Tony, would a Cadillac shop manual help with information about the TH425 ? I found one for a 1976 but my tranny is a 1975. Were they in production multiple years ? The 500cid's were from 70-76 so are the tranny's like that too ? Thanks.

Good info, all around.

...I think I recall that the true weak point of the 200 trans was not in the launch or first gear, but in the shift to second. I do think I recall that the 325 and 200 and several other trans as well shared common parts related to reverse and low gear. Bear in mind that this is all foggy recollection after scouring parts lists.

...I will certianly agree that the 425 is the torque monster, hands down. :> A lot of builders don't grasp the concept of "mission" when building. In Cardealer and Perk's case (and maybe Tony's) the mission is obviously to handle as much motor hp & torque as can be lavished out. My situation (or mission of the build) is to develop a performance daily driver...heck, a business woman is the actual paying customer. Thats why I chose the LT1 and thm325.

...can the 325 be reversed using Cardealer's or Tony's methods? Gee, I sure hope so. I wonder what Cardealer has up his sleeve? Past discussions with Tony have led me to "dry fit" an LT1 with the 325 in search of a "reversed" installation. I figure it can be done, but not by using the methods Tony has described, ie working on the axels, etc. This "reversal" would employ a "tunnel" extension/adaptor plates/trans output shaft extension, which would both flip the differential and move it back along the LT1 to where there would be no oilpan or other interference reguarding the axles. Axles swap easily because they employ the snap ring retainer as in stock Fiero (ie easy to swap sides with the output axels). Bear in mind that the LT1 may have a different oilpan profile than the common sbc or bigblock.

...the good thing I like so far about my situation is I only have $250 tied up in the trans/diff/axles and I fabricated the chassis so I could drop in a stock Fiero cradle/drivetrain, a 325/425 "un reversed cradle/drivetrain, or a Porche/Audi cradle/drivetrain. This leaves me loads of room for a reversed 325/425, considering I am using a 10.5" frame stretch.

I really do wonder what Cardealer has up his sleeve?

[This message has been edited by opm2000 (edited 07-02-2003).]

As for me, I am DETERMINED to maintain a good weight distribution, and as much of the mid-engine handling dynamic as possible. That being said, I realize that some compromises must be made because I am trying to stuff a much larger, much more powerful, engine in a place designed for economy transportation.

I have some new tricks up my sleeve, that are basically an extension of this whole TH425/325 concept. Have to do some more measuring, thinking, and researching, and then I'll share some details. I am up to my neck in building my new garage right now, but if I can find some time to clean a space out in the old one and do some experimenting I'll back the details with pics. I already have the car stripped to the chassis, just need some time to play with it.

perk

Post # 101.5 THE "X" LOL......

Figured you Austin boys would appreciate that !!

Brian

p.s. - BUMP !!!

how can yo tell the difference between the th325 and th425.

quote Originally posted by rodrieguz: how can yo tell the difference between the th325 and th425.

My guess is the easiest way would be the pan. You guys have any good shots of the pans - good reference material for the future. I canceled my "order" for my TH325 so I can't help.

Hey cardealer & TONY_C

Question of the day:

How far is your bellhousing from the firewall with the reversed install? I think I remember you guys saying something about doing some minor work on the firewall. Was that for the chain drive transfer unit or the bellhousing. Also, was it the actual firewall, or was it the horizontal brace, that you had to trim?

perk - todd's hot rods

According to my VERRRRYYYY preliminary measurements, you've got a tight 24 inches to play with from the axle points to the rear firewall. The way I figure it, your rear tranny mount (or equivalent of) should sit at somewhat the same position as your front cradle mounts. Look at the design of the firewall, and there's your challenge. I don't know about cardealer, but I am designing a low-profile rear tranny mount that "frames out" that area to help support the tranny on the backside. I plan on keeping my factory tank if it's possible. I hope to not cut out too much if any of the rear firewall but the way it looks there's gonna be some trimming involved to say the least.

I'm feeling pretty positive and mentally refreshed today, so I guess I'll subject myself to some good old fashion "worthless dreamer" abuse

This is basically what my latest bright idea is all about:

Basically what I am doing is mounting a conventional transmission to my motor, turning them backwards and sticking them in my Fiero. The transmission will run up the center of the car (in the tunnel). I will, of course, have to do some cutting on the rear firewall and tunnel to get it in there. Actually, I plan to remove a big chunk and make a new removable fiberglass cover to replace the original metal.

What I am doing is using a gear-driven transfer unit (the purple blob) to send power back to the rear wheels, via a torque tube (yellowish-green thing). There it will go into a conventional rear-drive differential (blue hickey). That diff will be mounted right beside the block and one side will be longer to pass, under the pan, to the other side.

WHY?!?

Advantages:

*I get to choose from a wide variety of bulletproof transmissions. The first, used to set it up, will be a TH350 - cuz it is a universal size and I have one.

*I get to use a bulletproof rear differential, with an almost unlimited selection of gears and "posi" units.

*I move a lot of weight forward in the chassis. I am planning to move the engine as far forward as possible so that hopefully only a small portion of the motor is nehind the axle center line.

Disadvantages:

*I do have to move the gas tank from its optimum location, but I think that's a small price to pay.

*It's gonna take up a little interior space. I planned to run race buckets anyway, and this car is strictly a toy, so I can deal with it.

*It is a radical approach. I had hoped to do something that more people could take advantage of but that would compromise my personal "mission" too much.

As I said previously, this is the trick I have up my sleeve, which is an extension of the reversed Eldo/Toronado idea. I am just reversing a little farther up the road, and with components instead of an integrated piece.

I'm gonna start this month.

perk

Ummm.... two words...

oil pan ???

The oil pan will be notched just like the TH425 conversion requires. Don't go by the pic it's just a rough cut and paste deal to get a "feel" for what I have to do.

Come on dish it out - I can take it

perk

[This message has been edited by perkidelic (edited 07-05-2003).]

No no, it's not like that Perk. I think it's great you have your own design. I hope it goes well. Just asking the obvious that's all. There are probably some custom Moroso oil pans that will be close enough for you to hack up for that application. Okay we all are jabbering awaiting cardealer's responses. Hey big "T" whaddaya think about the Caddy manual would it be helpful or not ?

I didn't take your question like that 80's BOY I was just being silly. I am happy to answer any questions. After a long week of serious grueling work you have to ignore my weekend goofiness

we're gonna run out of jibberish cardealer

perk

quote Originally posted by perkidelic:

Much like a Lamborghini drivetrain. Just use a syclone Xfer case, S10 front suspension and make it AWD.

AIN'T YOU GOT THAT DONE YET???:demon:

Hey perk, do you have a drawing like that for a GT?

I mean BUMPPPPPPPp

Will - I actually thought about AWD since there is already a tunnel and the front suspension is bolt-on with almost nothing in the way. The problem is the extra weight - I want this car as light as possible and all the extra front drive stuff would add a significant amount. Would be a trick project though.

revin - I can do one, but right now I am feeling kind of lazy. When I have some free time and feel like playing I'll do one.

perk

perk-
interesting concept, i can only see a few areas of concearn.
1. the cost and design of having a drive that will hook to the back of a th350 and connect the drive shaft back to a final drive could be expensive. i have seen them in some jet boats but are way to big to fit.

2. supporting the final drive is the biggest problem i can see. if you could imagine how much torque there will be (even in a mild engine) trying to twist the final drive. the metal that will be needed to keep it stable will add the weight right back where you were trying to keep it out of.

3. c/v axles and the connecting componates may need to be custom made.($$$$$)i would think that the cradle would have to be totally redone, a-arms ect.($$$$$)

there is only a few more little areas that i could see that could be resons for concearn but its too hard to type/explain.
i say go for it (!!!!), but a reversed th425 would be sooo much easier, and cheaper. i should have the proto type done in two more weeks, i am just waiting on the machine shop to finish to show you really how easy it will be to be able to do a reversed setup with a th425.
keep me updated on your design/progress !!!

Hey guys, that one's been done, several times over. http://www.vanheden.nu/ekitcar.htm

A couple of years ago, after some conversations with this fellow, I purchased a new transfer cse and did preliminary measurements & layouts to build this type drivetrain. The appeal to me was thinking that a modern engine was really optomised by a modern transmission, and this allowed it.

BTW, where this guy used a corvette rearend, a jag rearend or a custom hotrod irs rearend would work.

[This message has been edited by opm2000 (edited 07-07-2003).]

quote Originally posted by perkidelic: My guess is the easiest way would be the pan. You guys have any good shots of the pans - good reference material for the future. I canceled my "order" for my TH325 so I can't help. Hey cardealer & TONY_C Question of the day: How far is your bellhousing from the firewall with the reversed install? I think I remember you guys saying something about doing some minor work on the firewall. Was that for the chain drive transfer unit or the bellhousing. Also, was it the actual firewall, or was it the horizontal brace, that you had to trim? perk - todd's hot rods

TH325 and TH425 have some differences, the main one being that the TH425 has an electric kickdown and the TH325 uses a vacuum signal. Also, the short stub shaft that goes into the TH425 diff is held in place using a bolt while on the TH325 it has a snap ring similiar to how stcok Fiero axles attach to the tranny.

As for the firewall clearance, in my setup, I had to nocth the support channel that runs across the lower portion of the firewall to get the tranny far enough forward to have the diff remain in line with the Fiero hubs. A th325 might not need so much clearance, I think it may be slighty shorter from the back of the tranny to the centerline of the output shafts.
Btw, I should have some pics of the axles and tranny in place on the cradle by the end of the week. (hopefully)

cardealer

*Thanks for the feedback - good stuff. The more I think about it the more I am thinking about toying with the transfer unit myself. The easiest, cheapest, way would be to model the unit in wood and then sand or investment cast it in aluminum. For gears I am thinking about using a couple tranny gears. I can turn the shafts myself.

I have something in mind for supporting the final drive. I am thinking about using a narrowed Ford 9" rear end. That way I can have one tube and axle made longer to cross under the motor to drive the opposite wheel. There are perfect places on the cradle to mount it to. I would just design and fab a mount that would bolt directly to the cradle. If you look at your cradle there is a natural dip right along the axle center line and between the LCA pick up points.

Since CV joints and driveshafts are mostly round stock I can turn a lot of the pieces for that and have em checked, welded, and balanced. A friend just had a driveshaft shorted for his Pro Street Vega and it was only around $60, so with me doing all the fabricating that stuff shouldn't cost that much.

No need to reinvent the cradle cuz I am tieing short halfshafts from the 9" rear "differential" to the factory hubs and suspension.

Should be a fun project anyway cuz I LOVE fabricating!

opm2000

*Yeah that's pretty much what I am after - except I hope to run the torque tube from the transfer unit beside the tranny instead of under it - since my diff is gonna be off to the side of the motor (shorter wheelbase).

*Did you ever do anything with your idea?

*I think I remember a company advertising that setup for kit cars - it was around $1600 if memory serves me right.

Tony_C
Thanks for the specs. I am not using the TH325 anymore. I was trying to get an idea how far the back of your engine is from the firewall.

Ideally I wish I could push the engine far enough forward to run the far side axle behind the damper, instead of under the pan. That would allow me to really lower the engine.

Gotta do some more measuring. If either of you guys have a chance and remember see how far the bellhousing mounting surface of your block is from the upper firewall please.

perk

I agree with Kevin, that is some kind of 'Ailyen Teknolergy' you got going on in your garage.

Thanks for letting me borrow your cherry picker. Sorry about the scratched stickers on it, looking for some replacements for you. Know you miss that extra hp they provide.

Hope to be smowkn my tires soon!

smowknm