105 Rear Suspension Ride Height

[njh1964]

Hi All,

I have a "fast road" suspension set up on my GT1300 Junior, and I'm very happy with the ride and handling on nice smooth road surfaces. However, on rougher surfaces and over bumps, speed humps, etc it's just too low in the rear end. Bottoming out is a real issue, particular if I put anything heavier than a picnic basket and a bottle of prosecco in the boot :-)

From pavement to the top lip of the rear wheel arches measures 590-595mm. I'd like to lift that ride height by 40-60mm to provide a little extra ground clearance. I assume I'll either need to install spacers or replace the existing rear coil springs, but I'm hoping I won't also have to replace the rear shock absorbers. The existing shock absorbers (Koni Reds) are not that old and appear to be working fine, but of course they can't stop the rear end from bottoming out on their own.

Can anyone suggest a spring/spacer combination that would give me the extra 40-60mm rear ride height, hopefully without having to replace the existing rear shock absorbers? A local supplier in Melbourne would be preferable.

[Paul Gulliver]

Springs are a lot cheaper than shockers, so I would be starting there. Check and see if the springs have been chopped and if so by how much.

[njh1964]

Hi Paul,

Thanks for the response. My existing rear springs haven't been chopped as such, they are lower/fast road suspension spec springs. The problem is that they're just too low for my general driving usage.

I'd like to avoid a convoluted trial-and-error fitting process if possible, so I'm hoping someone can recommend a supplier and/or part number for a pair of rear springs that will give me an additional 40-60mm of rear ride height... perhaps a pair of factory standard springs?

As you can imagine, I don't want to buy a pair of springs, fit them, drop the car and find that I'm still too low (or too high), and then have to remove and return the new springs.

Cheers,


Nick

[Colin Byrne]

hi nick, are you happy with the actually spring rate? if so a spacer may be an easier option, and will give you the same ride height change as the spacer, so no trial and error. Unlikely the dampers will run out of travel if they are standard, infact sounds like you'll move them back into their correct working range. 

[njh1964]

Hi Colin,

I reckon the spring rate is okay because the car rides and handles really well on smooth surface roads. I suspect the problem is there's just not enough suspension travel available to avoid bottoming out.

If fitting spacers can get me an additional 40-60mm of rear suspension ride height, that would be ideal. Any advice as to where I can buy suitable spacers? Also, do the spacers fit at the top or bottom of the rear springs... or both ends?

Regards,


Nick

[Colin Byrne]

Not sure about availability, I made some for my car, fitted at the top. How about just putting standard springs back in, at least a known quantity then? Just to confuse the issue I did have a set of konies that failed in a way that made it feal like the car was bottoming out on speed humps ect. Do the bump stops look like they have been getting a hard time?

[njh1964]

Unfortunately, I don't have the original factory springs anymore, so I would need to buy new factory spec springs to see if that increases the ride height. The bump stops do have contact marks, so the rear end is actually bottoming out.

[njh1964]

Has anyone fitted the below "standard height" King Springs rear coil springs to a 105 coupe? If so, what was the ride height (ie from ground to under the lip of the rear wheel arch) after fitting?

https://automotivesuperstore.com.au/king-springs-kars-04?gclid=CjwKCAiAmNbwBRBOEiwAqcwwpUPZtQS6bd6-AkuJH7IQ3dzZTA1TfPWeORngb6YTGfnavLhzBBr4wBoCZ0YQAvD_BwE

[GG105]

I have standard front and rear springs on my stepnose Junior. They have never been replaced.

If you like, i'll take measurements on Saturday.

Cheers
John

[njh1964]

Hi John,

Thanks... I would be interest in the rear ride height from the ground to the underside of the rear wheel arch lip.

Regards,


Nick

[GG105]

Hi Nick, I have measured the height from floor to wheelarch lip on my car. It is 66cm.

I've also taken a picture fyi.

For those interested I also measured the height from the floor to wheelarch lip of my Giulia sedan. Its not standard, but hasn't had the wheel arches stretched and runs 5.5" steel wheels. its 54cm.

Cheers
John

[njh1964]

Thanks, John. As mentioned, my rear ride height measurement is about 59cm, without anyone or any luggage in the car. I'm thinking a height of around 63cm might be a good compromise between good handling and not bottoming out. I'm currently investigating rear spring spacers to see if that does the trick before possibly changing the rear springs.