Coilover relocation question

[richw2000]

I have a BMW 1 series road/track car going through LVV at the moment.
The original vehicle has a divorce shock and coil setup from the factory.
I’m currently running a full coilover setup in the rear. This was fitted in the UK and is a well-known high-quality brand (Nitron).

The certifier is suggesting that it’s difficult to get approval to run the coilover in this configuration and I should swap back to the original divorced setup.

Just wondering what options I have to keep the current setup?
Any suggestions? I have asked in bimmersport and FB groups and others are running this type of configuration successfully. Although I’m not sure how.

I have also contacted Nitron in the Uk for comment. But I’m not expecting much from them.

I’m not against switching to the divorced setup. But trying to avoid unnecessary cost that doesn’t really achieve anything.

Any help appreciated.

[Chris]

Hi Richard

I understand that the spring load has changed from the OE location to the top and bottom shock absorber mounts meaning there is a change of load path.
The shock absorber mounts will need to suitable for the change from shock absorber loads (low to medium) to carrying the weight of the vehicle including momentary bump loads (high to very high)

The certifier would expect to see reinforcement of these areas and be satisfied the reinforcement is adequate. If there has been no reinforcement of the upper and/or lower mounts, then you would need to provide engineering justification that the factory mounts are suitable for the increased load.
Typically, the engineering justification is considered a complex task and in the past it has been far easier to reinstall a spring to its original location and use the uprated shock absorber part of the coil over in the original shock location (sans springs)

If you are able to provide an engineering justification, I can pass it onto my engineer colleague who can review the report and pass this on to your certifier.

Hope that helps

Chris

[richw2000]

Hi Chris.

Thanks for the response.
I have been in contact with the suspension manufacturer (Nitron) in the Uk.
They can supply a “certificate of Conformance” for EU and Switzerland.
This certifies them for meeting regulations for road use in the EU and Switzerland.

Would this be sufficient for NZ LVV acceptance?

[Chris]

Feb 2, 2022 8:57:34 GMT 12 richw2000 said:

Hi Chris.

Thanks for the response.
I have been in contact with the suspension manufacturer (Nitron) in the Uk.
They can supply a “certificate of Conformance” for EU and Switzerland.
This certifies them for meeting regulations for road use in the EU and Switzerland.

Would this be sufficient for NZ LVV acceptance?

Hi Richard

If that document confirms the factory shock absorber mounts are suitable to support the weight of the vehicle, it could be considered, providing the numbers stack up. Can you please forward a full copy of the document to [e-mail] (in English) Hopefully I will quickly be able to tell you if it is suitable to use as an engineering justification.

Some certificates of conformance only confirm the products meet certain economical requirements for a percentage of locally sourced materials and other similar non engineering type confirmations.

Regards

Chris

[richw2000]

Ok thanks. Will do.
I have to request the cert. So as soon as I receive it, I’ll pass it onto the email provided.


Appreciated.