S300 inspired/replica Engine Brace - Group Buy?

[Erikl]

I am thinking of having a friends S300 engine brace and mount bungs copied at a fabrication shop near his house in Minnesota USA.

They have to build a jig so there are some up front costs.

We will not know exactly what they look like until they are done so there would be a non-refundable deposit.

There is substantial effort required to install the mount bungs on the chassis so keep that in mind.

If anybody is interested in the $1K US range please reach out.  Shipping over the pond would be terrible I am sure.  

If anybody knows of a place that can knock out an engine bay brace please let me know before I order.

Cheers!

 

 

  

[Jacques]

Erik,

I think it should be somewhat updated, as the Sp300 engine brace aluminium part is really heavy. I am sure, a carbon fiber version with high strength and stiffness, could be made and resemble the aluminium part in shape and form. I would certainly like to have such a version for my car. I can take a few pics if need be?

Kind regards,

Jacques

[Erikl]

This Fabrication facility only works in metals.

[Jacques]

Okay, so we need to have it scanned or measured up and spoken to a carbon specialist.

I will try to see if I can find someone around here, who could possibly so some of that.

Kind regards,

Jacques

[Erikl]

Update - the fab shop will do 3 for $900 each (plus shipping).  I will probably do something a little different with a fab shop close to me (similar to back half of X180R cage) if we dont get 3 buyers.  Since the motor has to come out and the body jacked up to install mount bungs either way, might as well get exactly what I want.  

[Jacques]

The x180r cage - rear - is far stiffer than the Sp300 solution.

Kind regards,

Jacques

[Jacques]

So, if you can copy that, and the body is off, and you'll use the car for tracking, do the cage instead. I would in that case, meaning ability to run stiffer springs etc.

Kind regards,

Jacques

[Erikl]

Thinking something like this, but the hoop inside the engine compartment right behind the engine compartment window.  The legs of the hoop would mount the same as the front mount bungs, they would be a bit of a funky shape for sure.  

[Jacques]

Looking good and good thoughts on the matter. I think there was a scheme showing the stiffness for a variety of cars, incl. the normal Esprit, the Sport300 as well as the X180R, where you can see, that the stiffness in chassis on the X180R is just a lot higher.

And...  if you see or hear about an EMCO or Holloway set, please notify me asap, and I'll sell my GTO (higher geared still) set to you if you still want one by that time.

Kind regards,

Jacques

[plumdeplakmuis]

If this tread is still active. 

I'm in for increasing the stiffness of my Esprit GT3 chassis. Either chassis brace as per the Sport 300, or full cage even better. As long as I can keep the original interior and use it as a 2 seat road car. How difficult would it be to organize a group development/buy for a bolt in roll cage?

[Erikl]

Hey Jaap, I am still working on a local solution for a "copy" of the X180R cage.  Have talked with several fab shops that were not interested.  Have a couple more that I need to get the details too.

That said I talked to Lotus Bits in the UK, they indicated they had experience with such things.  I immediately asked a couple of other questions and they stopped responding.  I think they stay very busy.  

I think they would be able to produce what I want and ship it to us if they had the resources.  

I will reach out again and let them know we might be in for two or 3.

 

[plumdeplakmuis]

Hi Erik, 

I know Lotus bits have experience with racing their sunbeams, but racing Esprits I'm not sure. 

The original X180 were made by safetydevices in the UK. http://www.safetydevices.com/ but I don't think they have any data. 

This cage was a bolt in cage, https://www.classicandracing.co.uk/projects/lotus-esprit-turbo-race-car/   but difficult to judge if it is compatible useful for a roadcar. Nevertheless it would be a great base for road cage. 

I build a custom cage in my Esprit S1 racecar, but that process would mess up the interior and only works if there is a body of restoration. 

If you have any idea to make a kit that can be fitted in a car with remaining most of the interior that would be great.

Otherwise i think it is just as easy to make a custom unit for each individual car by a local company if you take the engine and interior out.    

[Giniw]

 

[Erikl]

Yeah that is the data that convinced me to go with a full cage and not just the rear brace.

[plumdeplakmuis]

Hi Erik, any news on your search for a cage solution?

[Erikl]

Hey,

I am sort of working parallel paths on this at the moment.  The gent who posted the above Gt2 video is working on a cage design for his track car.  I may have his cage fabrcator make a copy for me when he builds his cage.  Assuming the designer and fabricator are willing and everything went perfectly.

I also have a cage/chassis fabricator a couple of hours from me that has looked at my car and the photos and may be able to take on a custom solution In December.

My plan is for the bolt in solution I use to be "inspired by" the X180R cage - but using modern bolted joints and possibly some smaller bars in some areas so its less intrusive in the cockpit.  The solution I am planning will retain most of the interior and be "streetable".  The version I am planning now will have the main hoop inside the cockpit and not in the engine compartment as i was considering at one time (see above).

Also, Lotus Bits did come up with a workable proposal for a near exact copy of an X180R cage.  They have access to one of the original cars and the car was going to be in their shop (owner was willing).  They also have a bear shell,  they were going to design a cage off the original and send the bare shell to a cage specialist they work with.  They were prepared to make copies.  The cost was just out of my comfort zone before shipping.  If we could have found 4 or 5 people interested the cost would have come down but I was only able to find 2 or 3 people tentatively interested world wide.  I did not persue.   

    

[plumdeplakmuis]

I'm interested but not sure if shipping from the US will make sense

[Jacques]

I am not sure about that stress analysis of the Esprit. There seems at the point I first saw it, to be missing some things in the chassis parts/setup. I remember the front stays that are welded in on my chassis, and when servo'ed they are bolted in.

Then there's the Sport300 center plate welded and bolted in, which later on became standard.

Then there's the inversed U-shaped square thin plate metal bar bolted in right under the boot floor. The gentlemen in Germany who builds race Esprits, have done some versions of this that is way stiffer - less flex.

In Denmark, it's very very hard to get permission to bolt in a propper cage. Just saying. So I cannot do it on mine. Would be über nice though.

So for now, I am still looking for a place where I can lift the body off and have the 4 bolting points welded in. And re-galvanized. And the stronger/stiffer bar I mentioned in the above.

Meanwhile, as another approach to this whole scenario, I am still working on lightening my car for a lot more kilos.

Kind regards.

Jacques

[Giniw]

Hi Jacques!

27 minutes ago, Jacques said:

Then there's the Sport300 center plate welded and bolted in, which later on became standard.

He has added it too after the initial analysis though?

 

 

 

 

 

As for the U section bolted between the springs upper cups, I would be wary about using a bigger one. It can't be worse in rigidity, but is it any useful, I don't know.

Generally speaking, a lot of people are very happy with their "uprated" things just because it's bigger. Uprated ARB (aka stiffer), stiffer springs, harder shocks, and so on. But often it's not based on anything proven. I mean, some people install stiffeners bars between the M100 rear upper spring cups in the boot. Some basic knowledge about the M100 chassis structure is enough to assume it's totally pointless.

So, as for the bigger U bar in the Esprit, I certainly would not trust anyone pretending it's useful without a serious analysis like the youtube video guy "Jon Himself" has made.

 

[Jacques]

I for one cannot perform such things. That central point is in the middle of the long chassis tunnel, and is cut open to allow the gearmaster. There seem to be a stress point here, and some cars will show cracks here. Lotus did this modification.

I do the mods to my car as I feel the drive. That's what I can do. It only takes you to ride in the car to see what it does for you. Right, hard is not for the sake of hard alone, as that would be pointless. As the chassis is a bit weak (at least compared to what an Elise shows as has been mentioned), that is one limiting factor to what suspension can be installed. The suspension cannot be what hardness you may want because of roads, comfort, tires, chassis twist etc. If you stiffen the chassis, there is a bit more to work with.

As far as I remember, I believe the rear tubular section of the chassis on the SPort350 was made a bit thicker (I may be wrong of course), but  unfortunately I cannot do that legally.

The geometry as I mentioned earlier on my Esprit is a pro-dive. Not an anti-dive setup. Lotus themselves changed a bit forth and back between this, as the continuos development were made to the Esprit. For road cars, that brought the stiffening pieces at the front of the chassis, the strenghening around the cut out for the gearmaster and the SP300 tubular and bar-brace, plus of course the front arb. That was at first thin as we know, then became thicker as in 1990 SE, then thinner again as on the S4/V8 and then thicker again as on the SP350, which is the same as the 1990 SE.

Where I believe Lotus was experts, was for example their ability to combine road holding with comfort. As one introduces comfort to a car, there is a trade off in suspension etc. as to what can be done. Personally, I am not into comfort, and I believe I have said that before. For me, there is a very wellcome lesser comfort in say my car. For example Lotus spent a long time developing/experimenting with the Bilstein damper/Eibach  spring option that is available today, to maintain comfort. That is not of my interest. I am willing to give that up, for having a little to work with on the spring/damper side. Then comes in the chassis limitations as others have described. Numbers or not. It can be felt. To help the chassis, there must be made some mods, some probably, note that, more effective than others.

So that includes a little bit here and there to aid that; after all, my goal is not a pure track machine. Lotus also said they spent a long time experimenting with the shore value on their bushing programme. They are definitely not as hard as some non-lotus options out there. But in that case, there was also the matter, that some options were split bushes. That may represent a compromise, which I am not willing to take. So Lotus' LOTAC bushings it was. I did though want less roll in corners as an important thing for me. The stiffer front arb is one, non-original SJ purple front arb middle bushings is another one, while Nitron for me at least, not that I have installed it and used it for a while, is also a noteworthy change in comparison to the Lotus LOTAC damper/spring option, which I find too soft and gives a bit too much roll and comfort etc. I looked at for example Öhlins, as they have made some very very very good dampers and spring for me, for another project, and they have ultra little stiction, and super polished internals, as was demonstrated to me, at a development facility by Öhlins themselves. But they would need my car for a long time, and being abroad and also very expensive, I felt that the Nitron option was a worthwhile compromise. I discussed the spring option with Nitron a few times, and we agreed to try the "standard " middle spring option as a start. That is fine, but a bit too soft for me. But I think to be able to use a number harder springs, I need to look at all of the chassis, including but not only, the points made earlier.

I hope that the man who made the stress analysis as you refer to, has updated the numbers after adding the few missing bits. That is interesting. My car is a road car, but nearing a track day car point of scale, more than a road car point of scale. There are a few people who have raced Esprits, and their modifications are not always based on computers, but also experience in actually driving the car. Missing out on the computer side of matters, I think it's very interesting for me at least, to see what they did that works. This includes for example the bar just under the boot floor, that I mentioned. I have spoken to a friend who works at the Danish National Technical University about this point and others, and he came up with a solution to this area. I therefore bought a few of this cross member, and are experimenting with this. I have other hobbies, so this takes a vey long time, and I am also limited for weather etc. 

I understand the point about loud in not always better, as in stiffer is not always better, bu in this case, on my car, I once again stress that I am not doing extreme things, just small things here and there and everywhere. It's not a race car, but a road car, and should be able to cope with bumps, cracks, dents, potholes, counter laid asphalt, and what not, and keep the wheels on the terra firma. And I am willing to give up most if not all comfort for this. It makes my body ache to ride in a comfortable car, and I have always been so, also in my other cars and motorcycles. It seriously annoys me to the point that I strive for something different. From my own observations, there is a distance from the standard soft comfort, body roll and keeping the wheels on ground, to the point where alterations will begin to demand better more even surfaced roads, if the wheels should be kept on the ground and mower can be transferred properly. That distance is the one I am working with.

An example. If I cannot stiffen the chassis more (I can), I can work with the weight. Every thing I do to the car, also have this in mind. So far, I removed 74,643 kilo from the car. This means that the chassis is not coping with as much load as before, when accelerating, braking and turning, which also translates into less weight shifts from say rear left to front right - under power and no power. That is noticable as in being more nimble, easier to change direction, acceleration, braking and roll. Much more weight saving is under way. All this while also observing other points as for example brakes. The original brakes on my 1990 non-abs SE car is to put it mildly underperforming. Let's just say as a reference point, that they are working well, with no points of attention to be made. They do not brake well, and do easily fade, as seen on Knutstorp Raceway in Sweden. There is then a whole line of points that can be made to improve on the matter. So I did exactly that, and I am not finished. There is now a world of difference, and I am still testing various components out and have some on the drawing to be made. This point is one where I feel maybe the old influence from Colin was a bit too much. Better brakes is the way for me at least. I am observing the placing of brake components in relation to weight and performance. And I will alter that over time. Lower, lighter, more centralised.

In lowering the car, Lotus removed the thick anti-roadnoise rubber components below the spring perches. It lowers the car some 10mm, and the noise transfer is from what I have been told by owners, not vey much.

As for wheels, I am now running S4s Euro wheels, with light weight outer lips from Radinox. The original aluminium ones are soft and were a tiny bit uneven. They are a slight bit wider, as that was what I could get. It suits the tires very well from the informations I got from Pirelli, for that model of tyre. On my car, there is enough room to run those wheels. The lower sidewall is far less wobbly, which was also something I wanted to eliminate to a point. In my humble view, a wheel is stiffer than a rubber sidewall on a tyre, and by lowering that, I have now a bit less movement in the tires. These wheels are lighter than my V8 wheels, with and without tires. But heavier than the smaller 1990 SE Euro wheels. That is a trade off. But the grip is immense. There is a bit more stress on the hubs, steering etc. Time for gearbox changes, which what I am also doing now, albeit at a halt, as the set I got was not what I was told I would buy, but something else: a track oriented gearset, not an optimised road gear set. Oh well, looking again for an EMCO set. Anyone?

I am also trying to improve on the interface of the car, so I have for example installed Sport300 seats and Sport300 steering wheel with the alcantara option. This gives a better grip on my hands and my body, while lowering the mass (me) I am very aware of not getting heavy myself and be in good health and shape. I usually also wear driving gloves with better grip. I have now prepared most if not all parts for transforming the original 1990 SE gearshift, for the latest more precise ditto Lotus ever made. Less chance of errors. Less chance of damages and accidents. More safety. More stable driving under power.

So far I can say honestly, that I am satisfied with the alterations. Many small streams makes for a bigger river. I can keep the wheels planted and transferring power, and the car is more flat, more responsive, have more traction and better power transfer, that what I started with. But this is definitely not the end point. There are much more that can be tested and possibly done. And no, I cannot make computeranalysis, but I can drive the car. That is my humble way to do things. I could write a lot more of what I am trying to do and how, and why, but I need to go to work now  I'll write in my normal own thread as it happens.

For me at least, it's a compromised way of doing thigs. I do feel results though, and not just hard for the sake of hard, which is silly.

It will be interesting to see what comes out of the wish to make a SP300 brace or semi cage expressed here by Erik.

Kind regards.

[Jacques]

Sorry, there was a typo here. The weight saving is not at 74,643 kilo. That was old info from my file. Weight saving on my Esprit is now at minus 110,700 kilo +/-.

Kind regards.

Jacques