Ground clearance height issues below 100mm LVTA??

[BrentNZ 44]

Curious what height people are running at lowest point?

I've got the car sitting on 195/50R15 Tyres, XYZ Coilovers wound down to roughly where I want them, the sump is 60mm off the ground. I know you can get cert under 100mm but I think this low is going to cause quite a few issues that I'm not yet aware of.
Options are;
Taller tyre, 195/55 or 205/50-15 but I think that will cause turning clearance issues plus additional width at guards which is marginal as well.
Raise the coilovers heights 10-15mm 
And both of the above?

Suggestions or current clearance heights with a LVTA cert?

[hotwire 352]

205/55- 15 is the factory size tyre for E30

We run as a control tyre in the BMW Race Series 205/50 - 15

[LemonHunter 583]

My sump was about that low on me E30 320.  It got removed and folded under the chassis with the exhaust manifold by a manhole that was sitting too high. 10/10 wouldn't do again.

[gjm 3258]

It depends what you're after. If a super-low look is your goal, then yes - a cert will be needed for <100mm ground clearance. (And for the adjustable height.)

If you want to drive it, enjoy it, and not worry about pebbles on the road, you need more height. 100mm is actually very low as a static height - suspension compression is going to see it go (much?) lower than that.

 

[zero 1162]

Before you do much else I would install a sump guard.

 

And by running the tyres you have, the speedometer will need re-calibrating which is expensive, so maybe look at getting a wheel and tyre combination that has the correct diameter.

 

Can you put up a pic of your car?

[Herbmiester 923]

I know low is all about the look but 60mm is just asking for trouble. I would go 100mm min and allow the suspension some chance of doing its job. I assume you realise that when you go super low the factory geometry is all out of whack, handling goes out the window and bumps that normal sport height can handle can throw you off the road?

[Matth5 471]

I get about 11cm of clearance at the front with the KWV2s on my E92. I'm pushing the limits in some car park buildings and driveways. Any non-sealed road requires extreme caution. 

I'd agree with post above suggesting 100mm as a minimum, any lower and you''ll have major hassles getting around. 

And a sump as the lowest hanging part... lol I would not be comfortable with that. At least on mine it's the chassis and exhaust depending on the area so I can afford to have it touch the ground on occasion.

Edited May 22, 2018 by Matth5

[BrentNZ 44]

Will post some pic's again when back at car.

Very familiar with running low clearance on my vehicles, but yeah this will be too low, just checking if there was a number under 100mm for the cert minimum. Will wind it up some over the weekend to get some more clearance and check guard gaps.

Will look into a sump guard... thanks people.

[M3_Power 636]

Did you read the new rules at all (been around since 2016) about suspension modifications?

I’ve just had my car certified and I can tell you the new rules are lot more comprehensive and has already done away with the 100mm clearance requirement. (i’ve had no less than 5 cars lvvt certified since 1997) and the rules have changed significantly since back then.

It is now about having sufficient suspension travel - the gist of it requires at least 40mm travel or at least 1/3 of original non modified suspension travel, amongst other things. When it lands on the bump stop it cannot contact any part of the vehicle body or shield ect.

 

So with 60mm clearance I am willing to wager you will fail the cert period.

There’s also extensive rules now about alignment and camber and castor angles - an alignment read out has to be provided to the certifier with suspension modifications - at least in my case.

The car is scrutinised right down to the nuts and bolts used and suspension arm angle and binding, steering arm angle ect.

 

For sump clearance - dry sump it : )

Edited May 23, 2018 by M3_Power

[Herbmiester 923]

Hopefully this will help deal with those stupid "slammed" cars that rest on the bump stops. People do dumb sh*t just to try and look cool.

[Matth5 471]

2 hours ago, Herbmiester said:

Hopefully this will help deal with those stupid "slammed" cars that rest on the bump stops. People do dumb sh*t just to try and look cool.

Do those people even bother with certs? I thought they just try to avoid getting caught...

[BrentNZ 44]

Thanks all, yeah had read about the suspension travel requirements, also I certed a car last year and I had to supply wheel alignment report within certain tolerances of the factory spec's... like 1/2 a degree I think?
Need to make a decision on what size 15" tyre I'm going to change too... 205/50R15 or 205/55r15