Revisions in suspension Astra Mk2??

[Vinci]

I am in need of new rear springs for my Astra Mk2 and now I saw there are two types of original height springs. I know there is a model for anything under 1.8 liter engines and a type for the GTE redtop models, but the main thing I am wondering about is if anybody could tell me the exact difference?

Why?

For starters I don't use my GTE for racing and I like to keep it as original as possible, secondly I go on camping trips with it abroad and like it to be able to handle a little more load than usual. Last trip to France I bent one of my Spidan rear springs on a bumpy road. (passenger side) I was probably driving too fast with too much load, anyways I had a free single sided lowering kit as a result...lmao Then I had a friend ship me a pair of used springs over, original GM, but as we were all packed and ready to drive back I noticed there was barely any suspension left, they were much weaker!!

Since there is hardly any specification of the strength of the new springs available anywhere, only what model they are made for it started to make me wonder if they just vary from brand to brand? Or were the weaker ones sent over just too old? If I look at the approved max. load the smaller engine models are allowed to ship a little more cargo, but perhaps that is just a simple result of total approved max. weight for the chassis minus the weight of the engine and whole suspension? Naturally with a smaller engine there will then be more left over...

Maybe someone can point me towards a suspension specialist?

I have some Bilstein B6 shock absorbers fitted and I had a new set of Spidan original spec. springs and I was really happy with the way it behaved on the road actually!

Perhaps I should fit some support springs before each time I go on a camping trip with it?

I am a noob on the subject, so please be gentle!

[Vinci]

Figured out a few things...

There have originally been two types of standard springs, anything up to 1.8 liter engines had long springs and the 2.0 liter GTE models and earlier 1.8 GTE were standard 20mm lowered. So in fact if you buy 30mm lowering springs your GTE will actually be lowered only 10mm!

The smaller engine springs have been redesigned later on because they were simply too weak. So nowadays we know three types of standars springs.

Then there are all kinds of brands that made/make them and all have their differences in specifications.

I have been very very pleased with the performance of my Spidan original spec. GTE springs, excellent road behaviour and even under heavy load I never heard a whistle! These have order nr. 48722. I now have ordered TC-TECH springs from Germany since these are so cheap I can't skip on trying them. They are roughly €80 including shipping towards the Netherlands, where the Spidan springs would cost me around €200....

I have been using the Spidan springs for a little longer than a year and one possible down side is the coating on them was cracked here and there, maybe that's normal, don't know.... Will compare this to the cheaper springs and make a write up here about my experiences.

[Frisco]

The spring coating cracking usually means its been painted rather than powder coated which TBH is generally a sign of cheap springs

[Vinci]

Thanks, but they're powdercoated alright, and my experience with powdercoating is it cracks just as well... And these were the expensive springs.....

[DarrenH]

i think you are right, maximum authroised mass includes the cars weight so it would make sense that a 1.3 merit might legally be able to carry more cargo than a gte16v.

however thats just goverment legislation, the first thing that happens on commercial vehicles is they increase spring rates on the rear, exactly as you would for a sports model. so i would argue that a gte would be safer.

you are also right GM springs there were small block versions (1.2 through 1.6 and 1.8 luxury models), gte/gsi versions, then a version for gte/gsi 16v.

i dissagree that specifc 30mm lowering springs for a gte16v only lower it 10mm. but agree that if it was a spring set for all models 1.8 through 2.0 16v, then it would lower base models more.

eibach website specify axle loads with their pairs of springs, which give you an idea of spring rates or the intended application. for instance 1.2 kadett E springs have less axle load than gte/gsi16v, and gte/gsi16v has less axle load than the mk3 astra (astra-3) gsi.

[Vinci]

Very interesting and helpful post there Darren, thanks! So perhaps it is better to go for a set of MK3 springs next time then?

The net lowering of -10mm with a -30mm set I was informed by a guy that does only vauxhall engine conversions professionally and he knows his vauxhall. I still see no reason to doubt that, or perhaps that's also manufacturer spec dependent....

[Gordo]

The only way ypou can 'bend' a spring, so it takes a set, within it's designed working range is if it was crap in the first place.
Sorry, can't help you on the selection of a replacement, except maybe not Spidan - depending what their service claims...

[Tathan]

I'd have thought it would bind before it damaged tbh.

OE was Boge on them wasn't it? Just fling a pair of 16v standard ones on.

[Vinci]

Never expected it to bend in either, maybe the rubber top and bottom dampers were crap, which I think are supposed to prevent such damage. I have ordered new ones for them already. But I have to admit it was not under normal circumstances, I was driving with a roof box completely filled up, wife and kid and all the gear, then dunno if you guys know French roads? And I was doing about 100km/h there.. Then I hit a hole in the road, not really a pothole, but deep enough to bring the weight of the whole car on one wheel for a short moment... Can't really blame the spring to be honest...

I am actually planning on molding some bump-stops myself in a cone shape so the suspension is going very progressive at some point.

The car was doing great on the way back with the bent spring on the other end and both springs filled up with thick foam rubber pieces stuck in between (still there, can shoot a pic of that...) But now with no load on the back it's a little too high and stiff....

[Vinci]

Okay, after another dissapointment with some new springs I've been driving around with the old springs combined with support springs. Worked fairly well, but today I was walking arounbd ojn the scrapyard and saw a BMW 3-series which had some rear springs that looked exactly the same. It is a much heavier car though, so I figured the springs would be stronger as well.... They looked brandnew, so I took them and I'm gonna try how they work out!