FWD Trans to Midengine conversion

I've been researching the Fiero midengine V8 conversions, and I have a few questions, as I'm considering doing one, myself.

Some guys use a Longitudinal FWD transmission, such as a TH325-4L, from an '83-'85 Riviera, Toronado, El Dorado, or Seville.

What I haven't figured out, is how they use a "steering" axle on the rear, and how it becomes a "fixed" axle when they mount it in the rear of the vehicle.

Has anyone here done this type of conversion, or could someone at least explain how they make it so the rear wheels stay as a "fixed" straight axle?

The reason I ask, is that I'd like to experiment with a Buick 455, this transaxle that we're discussing, and build a midengine '70 Skylark or Chevelle.
If you really want to know why, it's just because I have all the parts to do it, and it will be something unique and different, and I think it would perform much differently, and better, with the engine behind the driver.

Thanks in advance, guys!

If the hub is incorperated into the rear suspension, and the rear suspension does not turn, it doesnt matter, same as an independent rear end.

Examine the 84-87 Fieros rear suspension linkage. What you would have to do is something similar, namely attach the tierods from the wheel hubs to a point on the frame (some Corvettes do this too).
Not related to the tierod gig is the fact that this isn't the happiest marriage of engine and chassis, at least from a handling standpoint. The engine sits WAY too high.
Have a look around the web, there are some websites, heres's one guys idea on how to do it--
http://www.fieroaddiction.com/SBCLa.html

TSC,
Please have patience with me, and forgive me for not understanding (yet), but if you take the steering linkage from the front, and move it to the rear, then how do you stop the tires from steering in the rear?

Examine the 84-87 Fieros rear suspension linkage. What you would have to do is something similar, namely attach the tierods from the wheel hubs to a point on the frame (some Corvettes do this too).
Not related to the tierod gig is the fact that this isn't the happiest marriage of engine and chassis, at least from a handling standpoint. The engine sits WAY too high.
Have a look around the web, there are some websites, heres's one guys idea on how to do it--
http://www.fieroaddiction.com/SBCLa.html

That's where I found the info that caused me to ask my question.:wink:

I'm not looking for criticism or analysis, yet, (I know that's not your intention, Lotus), but I just want to build something different for myself, just because I have the parts sitting around, and I don't want to just throw them away, I'd rather use them for something, and I thought this might be a cool thing!

Have you ever seen a Big Block powered Trike? With this same transmission design, it would also be possible for me to build that, too.

Check out Lightning V8 Trikes, and their Chevy 502 Trike!
It's cool, but it's WAY too long!
118" wheelbase is the same as my car.

By using the FWD transmission that we're discussing, I could shorten the wheelbase by almost 1/2, for better turning radius, among other advantages.

Now, back to my confusion...:icon16:

As the lotus driving porcine said, you simple anchor the steering arm to a point on the chassis. i.e. the part of the suspension the steering rack normaly attachs to, simply has a linkage run off it, that is mounted to the chassis in such away that it can move up and down with the suspension, but not allow the strut to turn.
If you use an adjustable linkage then you can also have some radicaly adjustable toe angles to go with it.

As the lotus driving porcine said, you simple anchor the steering arm to a point on the chassis. i.e. the part of the suspension the steering rack normaly attachs to, simply has a linkage run off it, that is mounted to the chassis in such away that it can move up and down with the suspension, but not allow the strut to turn.
If you use an adjustable linkage then you can also have some radicaly adjustable toe angles to go with it.

I understand that much about attaching the moving linkage to a fixed chassis location, but is there a more permanent way, such as just using straight axles, as opposed to CV shafts?

That's why I'm asking, because I don't know what's available, or what's possible for better alternatives.

why would you want straight axles? Keep the CV's, keep the independant suspension. Thats a good thing.

Many cars these days have "tie rods" on the rear wheels. they are simply fixed to the chasis. It makes alignment adjustments easy. Its a good system. You can buy a large array of heim joints to suit your needs for this.

why would you want straight axles? Keep the CV's, keep the independant suspension. Thats a good thing.

Many cars these days have "tie rods" on the rear wheels. they are simply fixed to the chasis. It makes alignment adjustments easy. Its a good system. You can buy a large array of heim joints to suit your needs for this.

It's not so much that I "want' straight axles, I'm completely open to suggestions, but I'm just thinking that since the engine would be in the rear, and the transmission would be in the rear, all of that torque would be applied pretty harshly to those drive axles, and I wouldn't want one of those rear axles to suddenly make a turn, when it should be a straight drive wheel, especially as I would be driving it!

Thanks, all of you, for your input so far, and I think I'm getting some good ideas, already!

you can get heim joints as big as you want. You can make them bigger than the CV shafts if you like. huge overkill, but you can do it if you want.

You should look at F1 cars. Check out the spindly little bars they have holding that 1500HP and more traction than you'll ever see. Not saying you should go with tiny shafts, but this isn't a big issue, its just a matter of how much safety you wish to design into the system. You can make the "tie rods" the toughest thing in the car if you feel like it.

When Toyota designed the MK1 MR2 (upon which much of the Ferio suspensin design is based, GM copied Toyota after they supposdly copied Lotus, which if you know the suspension on a MK1 MR2 it is pretty clear they didn't) toyota simply took the front subframe out of a Corrolla and stuck it in the back of a wedge shaped chassis.
All the struts, axles, linkages etc, look just like they fell out of the front end of a Corrolla, but instead of a steering rack them simply ran a short 20mm shaft back to a hard mount on the subframe.
(Note, I don't believe the actual parts used in the MR2 and Corrolla are exactly the same, but they are close enough in design its pretty clear they came from the same place).

You dont move the steering setup to the back. what happens is that hub is basically turned into a trailing arm, it moves up and down, but there is no way for it to steer. If you do a good enough job designing it you can attach a bar where the tie rods attach and put them at angles where you create a passive rear stearing where it will change the toe in or out a few degrees while corning to make the car incredably agile.

Upon further investigation, it seems that I won't be the first to do this, as I've been told of a guy that has a '70 Chevelle, with 2 455's and 2 transaxles!

I'm still planning to build the midengine 455 and transaxle in my own, though, anyway.

I'm just going to go buy the donor car that I'll need the transmission from, then I can cut out the parts that I'll need for the suspension and conversion to the full frame car. That will probably be the easiest way.

Uncle Bob, another reason that I was thinking of changing the axles, that I just realized, was that I'd like to use the '70 Buick wheels (now available in Billet Aluminum 16, 17, and 18". I was thinking 18" rear, 16" front, for classic profile).
With the smaller '80s FWD lug pattern, the hubs won't fit the older '70s wheel lug pattern.

That's what I was thinking, I just forgot to mention it.:icon16:

As the lotus driving porcine said, you simple anchor the steering arm to a point on the chassis. i.e. the part of the suspension the steering rack normaly attachs to, simply has a linkage run off it, that is mounted to the chassis in such away that it can move up and down with the suspension, but not allow the strut to turn.
If you use an adjustable linkage then you can also have some radicaly adjustable toe angles to go with it.
Oink!
That's the ticket!
Oink Oink!

there is an obvious problem with straight axles on a FWD tranny....what are you going to use for suspension? IE, WHAT suspension?

You'd have to make the entire drive train unsprung weight.....it wouldn't work.

There isn't much unique anymore when it comes to vehicles and V8's. I knew a guy that shoved a SBC into a kawasaki jet ski once.....Crazy stuff.

there is an obvious problem with straight axles on a FWD tranny....what are you going to use for suspension? IE, WHAT suspension?

You'd have to make the entire drive train unsprung weight.....it wouldn't work.

There isn't much unique anymore when it comes to vehicles and V8's. I knew a guy that shoved a SBC into a kawasaki jet ski once.....Crazy stuff.

Now you're asking the same question that I'M asking!:banghead::grinno:

WHAT suspension CAN I use, for a FWD trans, converted to straight axles, as a Midengine application?

I have seen it done already, with a FWD TH425 ('70 Olds Toronado) trans, using straight axles, midengine, and I think it was using standard RWD suspension (shocks, springs, upper/lower control arms), which is how I got the idea in the first place!
I don't remember where I saw it, in a Hot Rod magazine, or on the internet, but I saw it, and it worked with the car that the guy built!
At the time, I wasn't even thinking about building my own vehicle like this, but now that I am, I need to research the chassis and suspension more.

If I can figure out, specifically, which suspension that I can use, then I can build the chassis, and the rest will come easy after that!

Maybe I shouldn't say that I want to build a "unique" vehicle. Maybe "unconventional" would be more appropriate.:wink:

If you want to use a solid rear axle with a fwd tranny your going to have to hinge the entire motor and tranny so that it all moves, it would just be easier to use the cv axles like everyone keeps saying. If you cant understand this you shouldnt be doing this project.

and I think it was using standard RWD suspension

Define standard RWD suspension?
IRS has been in common use since the 60s, but the live axle continued common use untill..... well its still in common use (which IMO is says something sad about the manufactors who still use it).

Maybe I shouldn't say that I want to build a "unique" vehicle. Maybe "unconventional" would be more appropriate.:wink:

by unconventional do you mean "wrong because you don't know what you're doing"?

WHAT suspension CAN I use, for a FWD trans, converted to straight axles, as a Midengine application?

:
Fwd trans + Midengine = either an independent suspension or De dion suspension.
Independent is either double A-arms type, multi link, Mcpherson strut (including conventional strut, or tri-link).
All these type require a double articulated half-shaft (driveshaft) on either side with "plunge"(length changing ability) incorporated into their design.
The older Corvettes, newer Corvairs and Jag XK-Es had an IRS where the upper A-arm was replaced by the half shaft, and a no plunge type shaft was required.
A weirder design with some really ugly limitations is the "de Dion" where a solid beam running under the transaxle or differential connects the right and left side wheel hubs. Fully articulated half shafts are used, with plunge.
Therefore you get a beam axle effect without adding the weight of the drivetrain to the unsprung weight.
I.E. the powerplant and transmission stay affixed to the car, and the wheels bob up and down together rather like the live axle on cousin Fred's '67 Camaro.
These can work pretty good, except if you start dumping serious power and tire width into the equation--then the whole rear axle system can go into a "tramp" (low frequency, high amplitude vibration) mode.
Jim Hall tried it in a later Chaparral Can-Am car--and it sucked, and Ferrari tried it (very briefly) in a 312T F-1 car--and it didn't pass muster.
A de Dion axle could be called a "straight axle". But it's better to call it a "de Dion", because if you mix mid-engine with "straight axle", it really messes peoples minds up.
Oink!

All these type require a double articulated half-shaft (driveshaft) on either side with "plunge"(length changing ability)


Not all independant set ups need a length changing axle/driveshaft, its quite possible to enginer geometery into them that keeps everything equal length through the suspension travel.
Although its generaly easier to have plunging shaft.

The older Corvettes, newer Corvairs and Jag XK-Es had an IRS where the upper A-arm was replaced by the half shaft, and a no plunge type shaft was required.

Oink!
Also Jag XJSs.
One must also not forget the Mercedes Benz "low-pivot swing axle".
Well, OK maybe we should.

by unconventional do you mean "wrong because you don't know what you're doing"?

By unconventional, I mean "I'd rather build a car, with the appearance and performance that I want, rather than just go buy a car that looks and runs like every other Japanese Plastic Eggmobile that you see on the road everyday, that I don't want!

I don't have to know what I'm doing.
I just have to know what someone else who's already done it, did, so I can do the same thing, and maybe add my own upgrades or improvements.

Anyway, I didn't come here for debates or definitions.

I'm capable of building the vehicle, as long as I get the correct answers from the qualified people that have them (hopefully someone who's already done this conversion, as I know there are a few)!

I know that the FWD TH425 ('70 Olds Toronado) has been successfully converted into a Rear Axle (no CV's! Straight left and right Axles, direct from gears to hub/wheel!)/RWD Suspension (Coil Springs, Shocks, Upper/Lower Control Arms), because I've seen it done!

I may just stick this FWD/Midengine Big Block concoction into the bed of an S10 pickup truck, add a tonneau cover, and call it done! Maybe that would be even easier yet! All the parts are available, anyway, either cheap or Free!
Depends who you know.

I know that the FWD TH425 ('70 Olds Toronado) has been successfully converted into a Rear Axle (no CV's! Straight left and right Axles, direct from gears to hub/wheel!)/RWD Suspension (Coil Springs, Shocks, Upper/Lower Control Arms), because I've seen it done!




Of course its possible, but if there is no moving linkage between the engine and the wheels, then either there was no Suspension travel, or the whole engine had to move when the wheels moved.
Neither is going to make the car useable on anything but a very large flat surface with no need to go around corners.

Of course its possible, but if there is no moving linkage between the engine and the wheels, then either there was no Suspension travel, or the whole engine had to move when the wheels moved.
Neither is going to make the car useable on anything but a very large flat surface with no need to go around corners.:1:

I don't have to know what I'm doing.

uh huh...

I just have to know what someone else who's already done it,
I'm capable of building the vehicle, as long as I get the correct answers from the qualified people that have them (hopefully someone who's already done this conversion, as I know there are a few)!

I know that the FWD TH425 ('70 Olds Toronado) has been successfully converted into a Rear Axle (no CV's! Straight left and right Axles, direct from gears to hub/wheel!)/RWD Suspension (Coil Springs, Shocks, Upper/Lower Control Arms), because I've seen it done!


I think you need to visit these chaps----
http://www.fiero.nl/cgi-bin/fiero/Ultimate.cgi?action=intro&BypassCookie=true

I don't have to know what I'm doing.




Im one of the few who will sort of agree with you, but be aware it will help, and could save you lots of money.

Im one of the few who will sort of agree with you, but be aware it will help, and could save you lots of money.

Thanks for your advice, Mop, but I'm one of the few that doesn't let money concern me, when I'm investing into my own cars. That's why most people refer to them as "toys", because they're just for Fun, nothing more.

I have a professional chassis shop that will build the frame for me, as I don't have the tube bending equipment to do it, myself, so it will be easier to have them do it, and it will also save me time that I can get the engine and transmission ready to install, as soon as we figure out the suspension.

I'm sorry if most of you have misunderstood my question, as I wasn't asking the Differences between the 2 types of suspensions, but rather how it's possible to Combine them, as I've already seen it done!

Thanks to all of you that have tried to participate, but I've found a partial answer to what I was looking for, Thanks to Black Lotus, through the guys that have already done it with the Fiero conversions!

I'll take it from here, now.

Why do I get the feeling he didn't really understand the basic issue with straight axles?

Oh well....I guess he'll figure it out soon enough....

Why do I get the feeling he didn't really understand the basic issue with straight axles?

Oh well....I guess he'll figure it out soon enough....

UncleBob,
I guess I will "figure it out, soon enough", as soon as I buy the transaxle, and build the frame, and start driving it!

Like I said, I just want to build it, and drive it! I'm not trying to win an Engineering Award, and I'm not building it to compete with a Lamborghini or Ferrari, either. I just want to build my own car, using parts that I already have, and don't have to find or buy (except for the transaxle).

Again, I never said I "had" to use straight axles, I said I'd "prefer" to use them, so I could fit the larger RWD wheels, instead of the smaller FWD wheels!
Thank you for helping me remember, because now that I think about it, the guy who built the other vehicle just used the original axles from the RWD, and had them shortened and resplined, so they replaced the CVs in the FWD transaxle! That was how he did it, and that's what I was trying to remember as part of the answer I was looking for!

Now, if I can just remember what I read about how he did the suspension for it, or I'll have to find the article about it, again...

However I build it, I just know that a midengine big block, rear transaxle, rear wheel drive, 1 or 2 seat, open frame type vehicle is going to be fast enough to have fun with, anyway! I don't care about debating the details of the engineering, I just want it sitting in my driveway, ready to drive, just to take it out for some high speed blasts on the highway once in a while!

Buddy, we're trying to help you. No one has said that its not feasible to use straight axles, but every single one of us said it has some severe issues. From your responses, I don't think you understand what we are even saying.

No, you don't have to be a master engineer to do these kinds of projects, but you should at least study the disadvantages before you set your heart on doing it a certain way. You keep saying "someone has done it before"....I have no doubt on that. That doesn't mean its a good idea!

So again, how exactly are you going to work the rear suspension? Do you even have a plan? Aren't you interested in having ANY rear suspension? Ever ridden a car with no suspension? Trust me, its a TREAT!

Buddy, we're trying to help you. No one has said that its not feasible to use straight axles, but every single one of us said it has some severe issues. From your responses, I don't think you understand what we are even saying.

No, you don't have to be a master engineer to do these kinds of projects, but you should at least study the disadvantages before you set your heart on doing it a certain way. You keep saying "someone has done it before"....I have no doubt on that. That doesn't mean its a good idea!

So again, how exactly are you going to work the rear suspension? Do you even have a plan? Aren't you interested in having ANY rear suspension? Ever ridden a car with no suspension? Trust me, its a TREAT!

I know you're trying to help, and I appreciate it, I do!

Basically, I'm just trying to remember the details of what I saw for the other guy's vehicle, about what type of suspension that HE used!

Even from this discussion, you just helped me remember that he removed the original axles from the RWD diff, sent them to Currie Enterprises (differential specialists), who shortened them and resplined them to fit into the FWD transaxle, so he could use the RWD wheels with the larger bolt patterns, instead of the FWD wheels. That's how he was using the straight axles, that I was trying to explain, but maybe just didn't explain clearly enough, because I couldn't remember the details.

I do understand everything that we've discussed here, with no confusion, as I'm familiar with the different suspension systems, as I've either seen, or worked on, most of them used in factory cars, Hot Rods, Musclecars, Street Machines, Exotic Cars, and as many other vehicles that I've studied, researched, driven, and enjoyed.

I've only seen the one type of system that I'm trying to use, with available GM parts, without having to overengineer or completely fabricate something that would be impractical to maintain or repair.

To answer your questions:
I don't know how I'm going to do the rear suspension, because I don't remember how the one was built, as I saw it. That's been my question all along, is HOW did he do it? It could have been that the engine and transaxle might have been in some type of subframe, that allowed the suspension to be functional, by having a pivot point on the frame, if I remember, too.

My plan, currently, is to attach the engine that I already have built and ready to use, to the transaxle that I'll be using, and build the frame around it, using the suspension that it already has, until I can learn from my first vehicle how to improve or change it for the next one.

Yes, I am planning on having a rear suspension, but I'm trying to keep it as a "performance" vehicle, at the same time, not just for a "comfortable" ride.
I'd like it to have a somewhat stiffer suspension, for better acceleration and handling, but not too stiff that it feels like a solid framed car with no shock absorbtion.

No, I never have ridden in a car with no suspension, but I'm not planning on it, either, and I'll take your word for it, and not find out for myself.:wink:

To answer your questions:
I don't know how I'm going to do the rear suspension, because I don't remember how the one was built, as I saw it. That's been my question all along, is HOW did he do it? It could have been that the engine and transaxle might have been in some type of subframe, that allowed the suspension to be functional, by having a pivot point on the frame, if I remember, too.


Having the entire drive train pivot is almost as bad as no suspension. Thats what we're trying to tell you. The best suspension is when you have very low unsprung weight vs sprung weight. You're talking about an assembly that could be over 800 pounds being your unsprung rear suspension component. It will not handle at all, it will not react to bumps at all. It will not hook up at all.

There IS no other way to deal with this situation. Either there is no suspension, or you move the entire drive train. Thats it without CV's, or seperate the differential from the drive train.

If it were mine, I would simply shorten the CV axles out of the orginal setup. Its the exact same thing as shortening solid axles. You can make it any length you want, although if you make them too short, you will have to reduce your suspension travel to prevent from breaking the CV's due to the hard angle it would create.

Having the entire drive train pivot is almost as bad as no suspension. Thats what we're trying to tell you. The best suspension is when you have very low unsprung weight vs sprung weight. You're talking about an assembly that could be over 800 pounds being your unsprung rear suspension component. It will not handle at all, it will not react to bumps at all. It will not hook up at all.

There IS no other way to deal with this situation. Either there is no suspension, or you move the entire drive train. Thats it without CV's, or seperate the differential from the drive train.

If it were mine, I would simply shorten the CV axles out of the orginal setup. Its the exact same thing as shortening solid axles. You can make it any length you want, although if you make them too short, you will have to reduce your suspension travel to prevent from breaking the CV's due to the hard angle it would create.

I understand that, too. That's what's making this a challenge, to build it completely from scratch, without having the experience of having already built one, and having to learn on the prototype.

It's nothing more than a garage experiment, really, just to see how it turns out, as a Frankenstein vehicle (pieced together from all the new old parts that have just been sitting for years, waiting for something to do with them.)

My only concern is using a 455 with such a weak transmission, that uses CV joints and small wheels, but I'm going to chance it, anyway, just to see if it will take abuse, and be able to transfer the torque to the ground.

If possible, I may not modify anything, at first, just to see how it's all going to go together, and drive. When I pick up the donor car for the transaxle, I may just install the 455 in it, and drive it that way, just to find out how it handles, to have something to compare to, after it's removed and replaced into the rear of the scratchbuilt vehicle.

Would you recommend that, as a good place to start?

Yes, I am planning on having a rear suspension, but I'm trying to keep it as a "performance" vehicle, at the same time, not just for a "comfortable" ride.

this is the bit I don't understand.
you appear to be saying that the rear suspension of a car is there for comfort, that it has no effects on performance and hence unneccesary at this point. The whole point of independent rear suspension set ups (of which no one has mentioned trailing arms for location yet...) is that it should afford you better tyre/road contact
i.e it improves performance.

in order to make it a better performance vehicle, you NEED to have a decent rear suspension set up.

this is the bit I don't understand.
you appear to be saying that the rear suspension of a car is there for comfort, that it has no effects on performance and hence unneccesary at this point. The whole point of independent rear suspension set ups (of which no one has mentioned trailing arms for location yet...) is that it should afford you better tyre/road contact
i.e it improves performance.

in order to make it a better performance vehicle, you NEED to have a decent rear suspension set up.

I think I'm on the right track, now, as I looked up Lamborghini rear suspension, which uses the same configuration that I'll be trying to build for this vehicle (Longitudinal engine mount, with rear transaxle).

It uses what they refer to as a "wishbone" suspension, which is similar to GM's upper and lower A-arms.

With so many aftermarket tubular A-arms available, I'm thinking Hotchkis Performance tubular A-arms, that would allowing adjustment and stability, by using the CV axles!

That way, the engine and transmission are mounted securely to the frame, in the rear. The only moving parts of the suspension would be the Control Arms, Springs/Shocks, CV axles, and Wheels, as it should be!

This sounds much better, and now that I've actually had something to reference to, I think it will help my build go much easier, with something to compare with!

See? Good things can come from discussion!

I think I'm more on the right track, now...

I think I'm on the right track, now, as I looked up Lamborghini rear suspension, which uses the same configuration that I'll be trying to build for this vehicle (Longitudinal engine mount, with rear transaxle).

A Fiero needs to have the body stretched behind the firewall to accomodate a longitudinal engine/clutch/gearbox package.
In other words, it won't fit with the stock body panels.

A Fiero needs to have the body stretched behind the firewall to accomodate a longitudinal engine/clutch/gearbox package.
In other words, it won't fit with the stock body panels.

I'm not using a Fiero, at all!

I'm only using the Fiero links as REFERENCE material!

I will be connecting a Buick 455, that I already have, to a GM TH325 transaxle, to find out what measurements that they have as a combined unit, and then build a full tube frame around it.

No clutch, it's an automatic transmission, with overdrive. More reliable, more consistent that way, in my opinion.

I think I'm on the right track, now, as I looked up Lamborghini rear suspension, which uses the same configuration that I'll be trying to build for this vehicle (Longitudinal engine mount, with rear transaxle).

It uses what they refer to as a "wishbone" suspension, which is similar to GM's upper and lower A-arms.

With so many aftermarket tubular A-arms available, I'm thinking Hotchkis Performance tubular A-arms, that would allowing adjustment and stability, by using the CV axles!

That way, the engine and transmission are mounted securely to the frame, in the rear. The only moving parts of the suspension would be the Control Arms, Springs/Shocks, CV axles, and Wheels, as it should be!

This sounds much better, and now that I've actually had something to reference to, I think it will help my build go much easier, with something to compare with!

See? Good things can come from discussion!

I think I'm more on the right track, now...


Are you really this fucking stupid? Every person that has replied to this damn thread as told you to do that, you dont even fucking know what the differnt types of suspension are called. Now you say what everyone else has said and think your an expert? Now your on the right track? I dont even think your anywhere close to anything that resembles a track.

Relax TSC, there is no need to lay into the kid.

Remember we were all young and niave once, I used to think a Holden Comadore was the worlds best car.

....i'm not even going to ask whether he knows the slightest thing about suspension geometry and that it isn't as simple as saying "
I'm thinking Hotchkis Performance tubular A-arms, that would allowing adjustment and stability, by using the CV axles!

oh darn it, I just did.

....i'm not even going to ask whether he knows the slightest thing about suspension geometry and that it isn't as simple as saying "


oh darn it, I just did.
And there you go.........satisfied?
;)

no..... i have this.... hollow feeling inside me now....

That may be indigestion.

no..... i have this.... hollow feeling inside me now....
Oh, you're just being a pessimist. Things will get better when we get around to the front suspension.........

Don't even go there my Chapman loving porcine friend, because you know the next step will be AWD, with a solid front axle. Steering will be by a centre pivot in the axle, and a couple of ropes tied to each end of the axle.

Forgive me for not being as booksmart as you, TSC, but I've just never had any desire to study Front Wheel Drive anything, until I recently realized that I can convert it to a more practical application as a Rear Wheel Drive transaxle, for my own purpose.:2cents:

Just because I have a better understanding of what I was trying to figure out in the first place, does not make me an expert, and I never said that it did!
Obviously, you aren't such an expert, either, or you wouldn't just tell me the differences between a CV axle and a straight or solid axle, which I already know, but you'd be able to tell me how to Interchange them, and use them with a suspension that isn't intended to work, but does!

I never asked your opinion of whether it's practical or not, I just asked how it can be done! And, you don't know, because you've never done it, either!

Thanks for your approval to go ahead with my project, as I've already started it, anyway!:disappoin :rolleyes:

Now, rope steering...?
Hmm.
Multipurpose uses, as:
- emergency belt replacement
- tow line to pull other vehicles
- power winch
Jack rear wheels above ground (don't forget to use jackstands, for safety), tie one end to U-joint of driveshaft, and other end to object that you want to pull, shift into Drive, slowly accelerate for rope to wrap around driveshaft.
If vehicle starts moving sideways, then reposition vehicle between 2 trees for more secure leverage...:icon16:

Moppie, you have potential Redneck Engineering qualities...:lol:

I'm proud to be a City boy!:grinyes:

You may not have asked for it, but this is a forum, you get whats coming to you.

You may not have asked for it, but this is a forum, you get whats coming to you.


Down boy!

:uhoh: :uhoh:



!
Obviously, you aren't such an expert, either, or you wouldn't just tell me the differences between a CV axle and a straight or solid axle, which I already know, but you'd be able to tell me how to Interchange them, and use them with a suspension that isn't intended to work, but does!

I never asked your opinion of whether it's practical or not, I just asked how it can be done! And, you don't know, because you've never done it, either!




Unfortunatly you seem to still be missing something.
It maybe a technical language barrier, or it be your lack of experiance, but its the reason there is hostility brewing in this thread, and Im glad your taking it so well.
But, the point is being made, that with with a FWD transaxle you HAVE to have some kind of sectioned driveshafts capable of flexing, i.e. through a C.V. joint if you want to have suspension that will work.
If you use a straight axle, then when the wheel moves up and down the axle will go with it, the transaxle will go with the axle, and the engine goes with the transaxle.
As has been stated it does not produce a suspension set up that is useable. Any car with that sort of set up would have in-surmountable traction problems, and very dangerous handling chararistics.

And you can not build a car capable of traveling at more than about 30kph with out fitting it with a working suspension system.

Quite simply you can not use a straight axle on your project, sorry you can, but the car will kill you and anyone who gets in its way.
Any project you saw with straight axles was either dangeroulsy and badly engineered, or you were misled.

I never asked your opinion of whether it's practical or not, I just asked how it can be done! And, you don't know, because you've never done it, either!

there are reasons why certain things just aren't done.
mostly they are down to common sense. In the cases where it isn't common sense, it is usually down to technical knowledge of the thing being done.

the reason why he had never done it before is because he knows better.

for example:
you might want to put your fingers into fire.
I tell you not to because I say it will, more than likely, hurt.
You ask if I've done it before.
I say "no".
You say:
you don't know, because you've never done it, either!

simple fact here is that everyone has told you not to do what you suggested and have given reasons why you shouldn't. They have also given you ways of doing what you want to do but better which you dismissed. Then you come back and say that you "found" a way of doing it after looking at how lamborghini did it and lo and behold, it was what they've been telling you here all along.

incidentally, you say you've started on this project already.
what have you gotten done?
got any pics of the progress?

Down boy!

:uhoh: :uhoh:

Unfortunatly you seem to still be missing something.
It maybe a technical language barrier, or it be your lack of experiance, but its the reason there is hostility brewing in this thread, and Im glad your taking it so well.
But, the point is being made, that with with a FWD transaxle you HAVE to have some kind of sectioned driveshafts capable of flexing, i.e. through a C.V. joint if you want to have suspension that will work.
If you use a straight axle, then when the wheel moves up and down the axle will go with it, the transaxle will go with the axle, and the engine goes with the transaxle.
As has been stated it does not produce a suspension set up that is useable. Any car with that sort of set up would have in-surmountable traction problems, and very dangerous handling chararistics.

And you can not build a car capable of traveling at more than about 30kph with out fitting it with a working suspension system.

Quite simply you can not use a straight axle on your project, sorry you can, but the car will kill you and anyone who gets in its way.
Any project you saw with straight axles was either dangeroulsy and badly engineered, or you were misled.

I can appreciate this, Moppie, and that has been my whole purpose of asking the question, as an informational discussion only, not as a debate about who has more knowledge, or experience, or skill to do what I'm trying to do, that most likely not many others have even tried, but has been done before.

I have no hostility towards anyone here, especially TSC, and, respectfully, I've appreciated his attention to detail in his technical explanations, such as the Fiberglass 101 tutorial, for example. I've found that to be very informative and useful, and just from that I learned to repair my own Hoods, Hood Scoops, and a couple of other small projects that I was working on at the time.

I've never argued with anyone here about any explanations, as I understand them, and I agree with them! I've just been trying to use the information at a higher level, to actually apply it to the project that I'm working on!

This discussion is only a minor part of what lies ahead for me, with the fabrication, and assembly, compared to what I'm getting myself into, now, by building this vehicle on my own, and I already realize that, before I get more into it, but I'm building it, anyway, just to say that (at this point) I CAN, and (when it's finished) I DID IT!:2cents:

......so why on earth did it take 4 pages for you to accept that you need to have a suspended rear end? Do you really believe that people have been replying without experience with things like this?

......so why on earth did it take 4 pages for you to accept that you need to have a suspended rear end? Do you really believe that people have been replying without experience with things like this?

Let me answer your question, the best way that I can, from my observations here.

I originally asked a question, regarding a specific suspension design that I saw ONCE! I asked how it was possible for this type of suspension to work, as I didn't understand it, myself, but since the owner was driving the car, then it "must have" worked, somehow!

Then it turned into reasons and opinions of why NOT to use the same suspension that he built and used, from theories and common knowledge (only explaining differences, and components, but not explaining how the one guy did it, which is what I was asking).

Everyone has different types of experience.

So, you know the differences between FWD suspension and RWD suspension.
Are you also familiar with Retractable Helicopter Landing Gear?

Would you know how to install it in a Boat, that you'd like to turn into an Amphibious vehicle?

Do you see the point I'm trying to make, here?

Just that I'm trying to take 2 different kinds of vehicles, and combine them, to make a different, performance based car, that most people will never see, but that I will build and own and enjoy, for myself, just for the satisfaction of doing it, myself.
I don't expect it to be easy, but I don't expect it to be impossible, either, and I am confident that I can do this, with parts that I already have, and parts that should be easy to get, or that I can go have made!

I don't need to know WHY it works, just HOW it goes together!

Ok, I think that what ever you saw was either a dangerous abomination of a vechile that should never be allowed on the road, or you were mislead in what you saw.

As has been said so many times, you seem to not be able to grasp, a fixed axle mounted to a transaxle that is then mounted to an engine means you either have no suspension, or whole assembly has to move with the suspension, which make having any suspension pointless to begin with as there is far to much sprung weight for it ever to work safely and effectivly.


There have been very few opinions offered in this thread, but lots of engeering fact. Facts that if you want to build what you claim you are building you need to understand and listen to.

Obviously, you aren't such an expert, either, or you wouldn't just tell me the differences between a CV axle and a straight or solid axle, which I already know, but you'd be able to tell me how to Interchange them, and use them with a suspension that isn't intended to work, but does!

:
Hey!
I wonder if what he was looking at was the fixed length of driveshaft coming off the transaxle that equalises the length of what would normally be two very different length of half- shafts. Helps to cut down on torque steer a bit by keeping the CV joint motion angles closer together.
Don't know if Olds Toro or Caddys have this item, but it's thought. A useless feature if its at the rear 'tho.

An intermediate shaft?
All the Honda B series engines have them, theres a bearing mounted to the engine block that carries the shaft out so the axles on each side are the same length.

It might be what he saw, either a stock one, or a custom built one, which wouldn't be that hard to do.

So, you know the differences between FWD suspension and RWD suspension.
Are you also familiar with Retractable Helicopter Landing Gear?

Would you know how to install it in a Boat, that you'd like to turn into an Amphibious vehicle?

what I know or do not know isn't the point here as i am not the one asking a question and not listening to the replies.
incidentally, i have a pretty good idea of how to use a car engine to ALSO power the prop for an amphibious car. the thing i would humm over would be do i go for sealled hull (and hence pig ugly...) or go for bouyancy aids (and hence pig ugly....).

Then it turned into reasons and opinions of why NOT to use the same suspension that he built and used, from theories and common knowledge (only explaining differences, and components, but not explaining how the one guy did it, which is what I was asking).

so common that you didn't know what they were talking about?
and if you didn't know what they were talking about, how are we to be sure if what you describe is what you even actually saw?

I don't need to know WHY it works, just HOW it goes together!
and i say you do need to know why it works.
like i said (elsewhere) before.
the act of utilising a IRS system isn't as simple as bolting on the wishbones and sticking a damper and spring inbetween them to support the chassis.
To set them up properly, you need to have some sort of knowledge of the numbers involved and the behaviour of your chosen parts under different types of stress.
Any fool can bolt a pair of wishbones onto a tube frame.

And let's put it another way.
People here have explained to you WHY what you suggested on page one won't work. They have also told you HOW to do things that will work.

Which one do you want again?

so, once again, how far have you gotten into this project and what have you gotten done so far?

An intermediate shaft?
All the Honda B series engines have them, theres a bearing mounted to the engine block that carries the shaft out so the axles on each side are the same length.

It might be what he saw, either a stock one, or a custom built one, which wouldn't be that hard to do.

i don't actually recall him telling us what he saw beyond that he knows of a car that had a similar engine transplant to the mid of the car. The solid axle was something he suggested. It might not be what was done to the car he saw.