S7 Chassis Modifications?

[Guest Tocca]

Been reading up on the S7 for a couple of hours before I pick it up tomorrow and it seems I'm going to have to modify the chassis to make it stronger. Anyone got any pictures of the mods they have added? Much appreciated

 

Andrew

 

 

[Big Jim]

It all depends on what you mean by *S7* People called most of the monocoques S7's, but they are different models, and therefore different tubs.

[Guest mower man]

There are quite a few mods and some issue with the mono cars all are possible to mod ,reengineer and cure ,where are you ? there will be some one local to you who can help ,join the club and post your location some one out there will help -- mower man

[Snapperpaul]

The tub itself is ok as long as you have the gearbox crossmember in place and perhaps some forward running supports under the seat.

The rest is the roll bar, seatbelt mounts and steering support hoop.

This info is for an S3, similar construction to an Exmo.....

 

The S7 has some particular issues which have to be addressed for IVA.

The rear mount point is to low

I welded a roll bar tube across the roll bar at the correct height the belts from the rear now go over that to the seat

Floor outer mounts need reinforcing with steel plate and captive nuts

Inner floor mounts are ok if they have steel plate and captive nuts

Rear upper mount is a steel angle along the rear boot, I put angle from the rear bar to the roll bar down tube and a second from the roll bar to the seat belt mount hole at an angle, triangulating from the rear bar to the roll bar.

I put plate under the roll bar legs to stop it punching through in a roll

I used crush tubes through the roll bar and bolted to the tub with load spreading washers not just the exhaust clamps used on most Monocoques

My seat belts passed, the roll bar was part of the structure and assesed for strength as the seatbelts used it for the upper effective mounting point and as strengthening for the rear mount.

Edited May 2, 2012 by Snapperpaul

[Guest Tocca]

I'm pretty sure it's a mark 2, did you take any pics of yours after the mods?

 

I'm located in South Wales.

 

 

[Snapperpaul]

Just a few of the rear seatbelt mounting bar to roll bar the rest is pretty self explanitary

The steering support hoop is to flexible so I ran 2 bars from the steering mounting bolts back to the scuttle.

In the IVA test the tester will pull and push front back and side to side the steering wheel if it moves to much its a fail

[Guest Tocca]

Would you be able to send me the pictures? Would be much appreciated.

 

Where you mention the upper and lower mounts do you mean the mounting points for the seatbelt/harness?

 

Thanks, Andrew

[knights_templar]

would advise you have a visit to your local test station and get their view on a monocoque

 

last I heard they would not accept them for IVA, unless you could demonstrate the strength, either with computer simulation, or crash testing, which is a little final. a professional builder I spoke to a while back at Newark show, said he got one through at Nottingham, but only after building a space frame chassis into it.

 

All hearsay, which is why I suggest you talk to the people who interpretate the current regulations, might save some work and money.

[Snapperpaul]

Don't be to conserved the monocoque has passed SVA & IVA the aluminium lightweight has been an issue.

We used Norwich VOSA but yes we'll worth asking VOSA there thoughts.

I have not heard of a steel monocoque failing due to chassis strength, I have heard of one lightweight failing and it was not constructed properly from the start, the lightweights that have passed needed some strengthening, now well documented on this Forum.

The strengthening I did was mainly fit the seatbelt mounts and the roll bar with some forward underfloor angle, the only thing I would consider further was to run angle along the tunnel top from the diff mounts to the front scuttle, adds strength and provides a place for cables and pipes to run front to back.

A dummy tunnel top to cover and no one would know, however you could remove to show the tester.

If you send me a message with your email I will send what photos I have.

[Guest Tocca]

Hi mate your messages are full I think?

[Guest Tocca]

Also the plan was to get it as a rolling chassis minus engine and box etc and take it to visa and see what they say?

[Snapperpaul]

That's a new one on me, you will still have to pay a fee they won't test without engine and box

Messenger cleared

Edited May 3, 2012 by Snapperpaul