IM Roadster D Sway Barr

Depending if you have the 900 series front end or a beam front end those questions you should get answers from Intermeccanica as to what they used. IMO...

Can we actually get answers from Intermeccanica these days?

That’s the problem.  Apparently Intermeccanica has closed and there’s nobody there to supply answers.

They are kind of asleep at this time but Henry is on Facebook.

@Gary B., do you know what kind of a front end you have?  If it is a beam front end it seems like a VW sway bar would work.

He has IRS rear end but what engine?  What front end ?  

@Gary B.

Since Henry just arrived in Tuscany with his family at his vacation home, he might not be answering posts.  Here’s what to do:

Get under the front end of your car with a phone/camera.  Take a photo of the inside of the wheel (either one) where the suspension/trailing arms are attached to the front wheel.  It may be easier to get it jacked up a bit - If you can’t do that, even getting the front wheels up on a curb on the side of a street or parking lot would give a little more room to get under there for a better shot.   Then, post your photo(s) on here.

That photo will tell us what type of front suspension you have and we can then recommend a front anti-sway bar.  They are pretty generic, and there’s no need to try to get Henry involved (although I’m sure he would be pleased to help).

I have a question, though - Why do you wish to add a front anti-sway bar?   Not being critical, just curious and that will also help me recommend a specific size/spring rate for you.

Gordon

Everybody's got a different take, but I understand why @Gary B. would want a sway-bar with an IRS rear end. He'd like to corner more like a sportscar. I've got one front and back. It's just what we expect.

If you have a VW beam, there are only 2 sizes of sway-bar commercially available - 1/2" VW and 3/4" EMPI. The 1/2" bar is what almost everybody (except me and a few other hardheads) run. In the absence of pretty aggressive driving, it's probably the right size. 5/8" would be the sweet spot, but they're NLA.

Gordon is right. Jack up the front of the car and snap a picture or two of the suspension. We'll be able to tell you what you need before we drift off into talking about the weather in sub-Saharan Africa or the benefits of argon vs. helium for shielding gas when Tig welding. Eventually, someone may talk about pot pie, but you'll get an answer before then.

Thanks everybody for your replies and I’ve been talking to a few people outside this site.  It seems I need to reevaluate why I want a sway bar.  It may not be what I need.  I don’t race or track the car and at one point 2 years ago during the build Henry said I didn’t need it.  I’m looking for a little more front end stability or “road grab”.  Somebody suggested stiffer shocks which I had already replaced and they helped a lot.  I can get pictures on Thursday and I’ll post.  In the meantime I’ll be listening to everyone’s thoughts.  Thanks!!

@Gary B. posted:

Thanks everybody for your replies and I’ve been talking to a few people outside this site.  It seems I need to reevaluate why I want a sway bar.  It may not be what I need.  I don’t race or track the car and at one point 2 years ago during the build Henry said I didn’t need it.  I’m looking for a little more front end stability or “road grab”.  Somebody suggested stiffer shocks which I had already replaced and they helped a lot.  I can get pictures on Thursday and I’ll post.  In the meantime I’ll be listening to everyone’s thoughts.  Thanks!!

Queue up the tire pressure comments.

Gentlemen, start your engines.

@Stan Galat posted:

Queue up the tire pressure comments.

Gentlemen, start your engines.

You obviously were reading my mind Stanley I was typing one of those while I was at work and apparently I forgot to hit "send".

I would start with tire pressure if I wanted more bite. If you're going off of the sidewall tire pressure recommendation it is going to be too high. The front of these cars is much lighter than the Beetle for which those tire pressures or any other car for which they are recommended. Many here run 18-20psi in the front and 20-24 in the rear. Try that and see if it improves your front bite.

One of the options in my build was “Custom front transaxle cross member with 911 OEM mounts”.  Does this give anybody any thoughts on what I have on my front end suspension?

No  What kind of engine?   How many gears do you have 4 or 5?   How about a picture of the engine and interior of the trunk.

It’s a CB Performance 2010cc with twin Weber 44 carbs.  4 forward gears.  I’ll post some pictures on Thursday.

Now we have to ask what front suspension you have to know more but, we now know you do have a normal VW Type 1  tranny and vw type 1 engine so we are getting closer to knowing but for the rear you have access to sway bars for VW for sure.

For the Front once we know what you have we can comment.

Do you have the full build sheet for your car?  If so post it for us, without prices of course.  

Your IM most likely has the 900 (911/914) front torsion bar suspension.  It looks like this:

If so it would take a 911/914 front sway bar.  It looks like this BUT you probably will have to reinforce with steel/aluminum where it got thru inner wheel well to the other side.

Why do you assume that, Greg? He's got a T1 engine/trans. The transaxle mount was for wheel hop.

A 2021 can still have a front end made for a T1 front end just saying… so if we have no picts we are still in the dark unless the build sheet is shared.  Everything else is supposition as our resident Cyrano mentioned.

I’ve requested more specific build sheets than the ones I have, but I’ll share what I have on Thursday, along with pictures.  I appreciate all of your interest and it’s helping me learn more about the car.

In the meantime I like the idea of lowering the tire pressure for road grab.  I’m going to try that.

@Gary B. posted:

In the meantime I like the idea of lowering the tire pressure for road grab.  I’m going to try that.

A few pounds of pressure removed, usually helps with what you are concerned about.

Front tires, of course.

18-20 front 28-32 rear is what I used in my original with 2010cc engine like yours and still the same with my newer one with a Subie.

I take it then that it wasn’t built for you and so you are the second owner?  

Btw some have added 30-40lbs to the front end in lead bars or nuggets to help with the front lightness.

It would be Good to see a picture of your Frunk to see the space you have in it as it might be an easier way to know if you have the 914 front end if they gave you the big trunk option. Just saying

BTW. I like the overider bars.

Okay, here we go.  I’m going to try to attach pictures and 4 pages of build sheets.  Originally, I opted for the “Custom front transaxle cross member” which is listed under Options -Mechanical on the third page.  The factory said I didn’t need it so I had deleted it from my options.  But my build sheet shows I have it, so I’m not sure if I do or not.  If anyone needs a new or different picture just let me know.

Any Custom front transaxle cross member would be in the rear of the car.

Your photos show a VW front beam and any VW sway could be used.  Typically, that requires modification of the bumper supports although I don't know if bumper supports on an IM are different from VS, CMC, etc.

Build sheets

Thanks for posting those picts and sheets.

So this car was custom built for you congratulations. It’s very nice and you made some really nice choices. The car is as original or as close to replica as you can get.  So we can now confirm that you have a full type one engine transmission and front end, 3:44 tranny  which means that a swaybar could be placed in front and in back if you so desire.

The brackets suggested by Michael in the prior post would not work because the bumpers and attachments are very different on your car.  

Your bumper is attached exactly as the originals as it has the original support bars as well.

“Somebody suggested stiffer shocks which I had already replaced and they helped a lot.  “

Did you really change out the front shocks?

Henry had installed gas front shocks.

some on the list have suggested using KOni for a more original feel but your issue is standard weight and tire pressure related.

My 2004 IM had exactly your configuration but it had front and rear sway bars so you can rest assured that you can do it to your car.

I did drop the front tire pressure to 25, and, although I took only a short drive, I thought I could notice a slight improvement in handling.  A longer drive will give me more information.

You need to be at 20lbs at least or you will find it too stiff still when you have time post some pictures from the inside.

Robert must’ve given you a manual and the manual has a spec sheet for what tire pressure you should use. Do you have the manual?

here is the standard tube frame you have

I do have the manual.

So... I'm going to offer some plain talk from flyover country:

the weak link on how these cars feel in the front is the 1930s design of the front "beam" suspension. Henry installed 914 and 911 front ends on some of his cars, and those cars feel a lot more "planted", but a lot of them were built with the original-style front beam. Yours was one of them, and so was mine. A lot of that feel (where the car doesn't feel "planted") is baked in the cake. We do things to minimize it, but it's always going to be there.

From Vancouver, my car had a full stack of torsion leaves in the beam, Koni adjustable shocks (set full soft), and an EMPI 3/4" sway-bar. I lowered the car as far as I dared, and I've been trying to help the front end ever since.

Stiffer shocks seem like the wrong direction to me, as the front is already oversprung for the  weight of the car. Some guys have added weight to the front end, and others recommend cheap EMPI oil shocks to soften the suspension. This winter I pulled some leaves out of the top tube of my beam to try to soften it up. I'm going to test if the shocks are part of the problem by removing them completely for a short drive to see if the ride is better without than with - if it is, I may buy some cheap shocks as well.

Reduced tire pressure helps the car feel softer, and like the tires are getting a better bite - but nothing comes for free. The tire is actually becoming a part of the initial compliance in the suspension, but it's rolling laterally on the sidewalls in aggressive cornering. Most 185/65R15 tires are rock hard A/S donuts. A nicer tire with a compliant sidewall rides worlds better. Alas, the Vredestein Sportaks that worked so nicely are NLA. 

Being a guy interested in cornering flat and aggressively, I'm a firm believer in sway-bars, which is why I had my car built with the heaviest sway-bar available. Carey at Beck doesn't feel like speedsters benefit that much from them, and he may be onto something. I may have gone too far with mine - I'd like to see how it worked with a 1/2" stock bar.

The thing is, all of this just addresses a part of the issue, which is suspension compliance - it doesn't do anything for why the car feels unstable (not "planted") at higher speeds. There are a lot of things working against the car and you can really start to feel them at speeds from 90 mph on up.

The first problem is the weight of the front end. It's really, really light. My car handles way differently with a full tank of gas and hauling all my tools and spares then it does running on fumes with no extra parts in the nose.

The second problem is the shape of the car. It's an almost perfect wing - curved on the top, flat on the bottom. The more air the car catches, the worse the aerodynamics become. Dropping the car into the weeds would help enormously, but it would take away all of the suspension travel.

The last piece of the puzzle is the design of the front end. In short, it's antique - a 100 year old evolutionary dead-end. There's a reason all production car suspensions settled on A-arms. They just work. Beck's new suspension has them, as did Henry's higher end builds. Rolling on a modern design means not having to fart around trying to make a silk purse out of a sow's ear.

But - it's not what you or I have, so we deal with what we've got. Reduce your front tire pressure to 22 psi, and see what it feels like. Then, remove your front shocks and see if you like how it feels - if you do, then get some cheap oil shocks, if not, then some Konis. The sway-bar is tougher - you're going to need to try one to see if you like it. The easiest way to do this would be to drive somebody else's car who has one. But if not, I'd order a 1/2" bar and bolt it on. Give a stock bar a try to see if it helps.

Nothing is going to be as nice as the ride in the average $20K Kia, though. I wish it were not so, but it is.

Somebody just needs to say it, and I guess it falls to the plainspoken plainsman.

Well there was an education in how 50 year old technology and suspension is what they drove back then and those facts still are the same for us when we dream of an old car...  

Having said that I don't think removing the front shocks would do much but hey it is worth a try.   Weigh is another issue and those who load up the front seem to like the effect and of course tire pressure. ( I run 21-31 )   (My front has a tire tools a jack and a full tank)

I forget how much difference in size front to rear bars have to be for more neutral handling but someone here knows.  

In any case, back to reality, some things can be made better and some things are the visceral experience of the 50 year technology.  

50? It's 2023. 50 years ago was 1973. This suspension was designed 90-ish years ago.

I understand your desire for "a little more front end stability or “road grab” from your description.  As others have said, this is 50+ year old technology and lacks the feel of even a modern low end car.  But with that said, I have made significant improvements in the way the front end rides and handles in my car.  When I first built the car the front end felt really light, unstable and rough.  Lowering the tire pressures softened the ride, but caused it to feel more unstable and spongy when cornering.  I have 185/65R15 tires on 4.5" wide rims which is too wide of a tire for that rim (clearance problems in the rear determined this decision).  If I run less than 26-28 PSI front and 28-30 PSI rear, the car feels spongy in the corners due to sidewall flex.  Therefore lower tire pressure did not work for me.  The things that I changed that made the most difference, in order of significance, were:

1.)  Removed leaves from the upper tube.

2.)  Added a second set of caster shims.  This was a game changer at highway speeds.

3.)  Additional weight in the front.  I have my battery (small Odyssey PC680), spare tire, scissor jack and a few tools/spares.

I'm not sure if the sway bar or shocks make a difference because they have been on the car since I built it. I am running a stock sway bar and cheap, oil filled shocks and have not tried changing.  I still want to get to 5.5" wide rims and then the car should handle reasonably  well.  Hope this helps.

Again, I appreciate all the replies and input that everybody has offered.  My mechanic changed the front hydraulic shocks to KYB gas shocks and it made a world of difference.  Everyone that had driven the car before and after commented on the improvement.  I can’t tell you why it made such a difference, but I was a much happier camper after the change.  This two day exchange of opinions has left me feeling more knowledgeable about my car and the subject.  For now, since I don’t track or drive the car aggressively (I have my wife’s car for that), I will continue to enjoy my 356 as is.

Thanks everybody.

@James - how many leaves did you pull?

James, I do think you have a pan car so that the shims on your car helped.  

I am not sure if that could be easily done or if it has been done before on an IM with the tube frame.  I do know they have front beam height adjusters but it has been a while since I moved on from my  IM 2004 Link here

Gary just Drive it for a while with 21 lbs of air in the front to see how you like it and add a bit of front weight.  You can tell if you have too little air easily if the tires squeel on turning.

Enjoy the car, living with the car is a bit like a women, you can never fully understand them but ...

I have KYB shocks front and rear, 3/4" sway bars front and rear, and one set of caster shims.  I run 18 psi front and 28 psi rear in 175/70 Vred. Sprint Classic tires.

I don't drive as aggressively as Stan and some others.  It would be interesting to let him drive it sometime and get his reaction.