Gaz Spring Poundage Issue

[lemmingzappa 75 1 Cars]

I recently bought a GHA Gaz Coilover kit, and the springs GAZ recommended me were 250lb for fast road use. My car will be running a 309 rear beam with standard size torsion bar.

 

But now i've recieved the kit (including springs) a couple of members have told me that 250lb springs will be way too hard for road use, and that I should be using something like 150lb instead.

 

I e-mailed GAZ about this, and recieved a phonecall this morning telling me that 150lb will be useless and that 250lb is fine to use. He pretty much insisted that he knew what he was talking about and that it has something to do with preloaded springs ?

 

The trouble is i'm now stuck with these 250lb springs and I have no idea what to do as i'm getting mixed opinions.

[welshpug 1,657]

amusing that 150 lbs/in is said to be useless but standard springs are about 100 lbs/in, are standard springs useless? I very much doubt it when coupled with standard rear torsion bars, which you have in effect, marginal upgrade in the spring rate of the 309 torsion bars as they are longer.

 

that said, the damper rate is designed for a spring around the 250 lb/in rate, so quite likely that they wont be particularly good with a 150 spring, much to overdamped.

Edited February 16, 2010 by welshpug

[Baz 421]

Sorry i haven't teplied to your text yet Josh! Essentially;

 

amusing that 150 lbs/in is said to be useless but standard springs are about 100 lbs/in, are standard springs useless? I very much doubt it when coupled with standard rear torsion bars, which you have in effect, marginal upgrade in the spring rate of the 309 torsion bars as they are longer.

 

that said, the damper rate is designed for a spring around the 250 lb/in rate, so quite likely that they wont be particularly good with a 150 spring, much to overdamped.

 

that's what i was going to say. Not sure about the 'preload' bit, apart from also as WP says, could be he meant the fact that the damping rate is probably tuned to that sort of spring rate.

 

But yes, at this point i'd say anything less than 250, or even 200lb would be much better!

 

You're the customer, they should be giving you what you want, not arguing it...

[Anthony 1,003]

It's not so much that it's too hard for road use, but rather that it will be mis-matched with the standard 309 GTi 20mm rear torsion bars and be quite understeery on the limit as a result. Higher poundage springs on the front need thicker torsion bars (thus higher rear spring rate) to keep it balanced.

 

If I remember correctly, the standard OE springs are something like 90-100lb (I'm sure someone has the accurate figures) to give you some idea.

 

As you've already got the 250lb springs, you might as well give them a try and see how you get on, as different setups suit different driving styles. If nothing else, atleast you'll have a feel for it and know roughly what to change the springs for - replacement springs are pretty cheap, so it's not the end of the world if they're wrong.

[custard-rallye 25]

i got some recently aswell for my rallye and got 225lb springs and they are fine dont get bumpsteer ect....

Edited February 16, 2010 by custard-rallye

[Baz 421]

Agreed, 90-100lb standard iirc.

 

It's not so much the suck-it and see aspect, but more the fact that the dampers will have to come back off the car and the springs changed aswel as the ride height set again for another set of springs.

 

IMO why not use the advantages of having so many people's previous experiences and opinions and fit a more-suitable rate of spring first/once.

[Baz 421]

i got some recently aswell for my rallye and got 225lb springs and they are fine dont get bumpsteer ect....

 

225's are what i had on mine. Coupled with quite low ride height/less suspension travel and standard rear torsion bars, a throttle bodied Mi16 and a plate diff it was understeer-tastic. Suffice to say they didn't last long...

[lemmingzappa 75 1 Cars]

Sorry i haven't teplied to your text yet Josh! Essentially;

 

Haha I'm not actually being pushy by the way, before you regret giving me your phone number

 

Well I sent the guy an e-mail anyway, i'll let you know what happens.

[custard-rallye 25]

mine is set as high as they can go as the back of mine isnt lowered yet thats probally why i dont get much bumpsteer

[shalmaneser 26]

I've got some 240s on my car ATM and it's definitely too hard for a road car IMO. I'm still running the standard rear beam (although not by the end of the week hopefully...) and the balance is definitely toward understeer. Also, I'm not happy with the level of rebound damping on the front even though it's wound up nearly the whole way, it still feels too bouncy to me.

 

However I'm running the non-coilover Gaz adjustable dampers so spring choice is fairly limited (how i wish I'd bought coilovers...) but I'm going to put some Eibach springs on the front end this week hopefully too which should restore some balance. I think Gaz (although they're progressive) are around the 150+lb mark, although this is from memory.

 

Does anyone know the rough 'poundage' change from standard rear TBs to 309 TBs?

 

I should also mention that fitting a strut brace really improved turn in and general control after I fitted new springs; these old French cars can be a bit bendy I think. Might be worth bearing in mind.

[lemmingzappa 75 1 Cars]

I've done alot of reading around strut braces, and I dont think they're worth it.

[shalmaneser 26]

I've done alot of reading around strut braces, and I dont think they're worth it.

 

lets not open that can of worms! a few here disagree...http://forum.205gtidrivers.com/index.php?showtopic=113056&hl=strut+brace

 

either way it's up to you, but re. the original post in my experience 250lb front springs would be excessive.

[Baz 421]

Does anyone know the rough 'poundage' change from standard rear TBs to 309 TBs?

 

Not a lot considering they're also longer, as said above!

[Jrod 7]

I used 160lb springs with 20mm Torsion bars (on a 205 beam!) and that was fantastic for the road with a TU engine, maybe a touch soft for an XU.

[taylorspug 7]

What engine is in the car at the moment? You will run the risk of the springs going coilbound on the road with 150lbs and an XU lump. I had 185lb springs on my Gaz coilovers, admittedly with a Gti6 lump, but even so they would go coilbound over even the smallest bumps most insignificant bumps. Ok standard 100lb spring dont do this, but there is an awful lot more travel before coil meets coil with them! From my conversations with Gaz they do seem to go a bit overboard with their springs, id imagine to cover a variety of use and also protect them against potentially dangerous bottoming out issues. If you ever go in a car which goes coilbound over bumps you will see what i mean, its literally like hitting a brick wall with every bump.

 

You should really be matching the spring rate with the rear end, which will always be a compromise on standard 309 torsion bars as they are around the 130lb mark IIRC. As mentioned you should also be matching the spring rate to the dampers and also the weight being applied to them, they are supporting the car afterall! Id personally not venture below 185lb if you have a standard 8v lump, and 200lb with a 16v. Ok this could make the car understeer more, but this can be effectively countered using bigger torsion bars and/or ARB. I dont think you can get away with putting front end upgrades like this on and completely ignoring the rear (kind of like porting a head and leaving the standard cams in!), so at the very least a chopped down 306 24mm ARB is a must, it will certainly restore any lost handling balance.

 

Im on 275lb fronts now, 24mm rear bars and 21mm ARB with Leda dampers and although it will be harsh, the suspension is working in a controlled manner within the parameters given to it (ie not bouncing off the bumpstops all the time, and using the spring and damper rates properly to control movement). My previous 225lb front end setup wasnt bad at all, but im expecting the new lot to be so much better once i ignore the slightly jarring low speed ride comfort!

[lemmingzappa 75 1 Cars]

There's currently an 8v in the car.

 

GAZ agreed to swap the springs, they will be sending me something between 150-175.

[MerlinGTI 3]

I run 180lb on my Gaz's with a STD rear beam, its perfect.

[lemmingzappa 75 1 Cars]

Is there a way of finding out what poundage the springs are without asking the manufacturer ?

 

They'll probably turn up without stickers on so i'd be wondering what they decided to send me in the end.

[Anthony 1,003]

Just ask them for a specific poundage spring rather than letting them send whatever; normally they're available in 10lb steps at that sort of poundage, namely 150lb, 160lb, 170lb, 180lb, 190lb, 200lb.

 

Given what else has been said on this thread, 180lb is probably a good starting point if you're staying 8v.

[dino20vt 3]

I received 8" 250lbs springs, I'm guessing this will be quite harsh for a road going/occasional track day alloy 16v 1.9?

 

Trouble is if I return them for softer springs will they be mis matched to the dampers as they would have been 'valved' for the 250lbs springs?

 

But if I stick with the springs I'm going to need some f@cking thick/expensive TB's and ARB to match.

 

What to do?

Edited February 19, 2010 by dino20vt

[lemmingzappa 75 1 Cars]

I went for the cheaper option and asked to swap them for 180lb springs. I dont think it will be an issue using different types of springs as I think they might be set up generically ?

[Cameron 16]

Those Gaz GHA shocks have rebound adjustability to cope with different weight springs. The bump setting is fixed to suit the springs they supplied you with (250lb/in) so it won't be optimal for your 180lb/in springs but to be honest there won't be much difference and I doubt you would notice.

 

I think the people at Gaz are pretty keen for customers to trust that they know their stuff, so maybe that's why he was a bit funny with you and said 180lb would be no good. My guess is they assume you're also upgrading torsion bars as 250lb/in is quite a jump from standard spring rate, and as Anthony said you're going to upset the balance by having that much spring rate increase at the front, with nothing at the rear.

 

Also, in my opinion 180lb/in is too soft for any kind of track use. If it's purely a road car then it should be fine, but you'll find that it may roll a little too much on track.

Edited February 20, 2010 by Cameron

[Tom Fenton 1,542]

I have got 225 lb front springs on my car, with 23mm 309 rear bars, I think I could do with going up a bit to maybe 250's or 275's at the front now, but its certainly pretty good as it is, in my opinion anyway.

[blandy 29]

Without wishing to start a new topic is there a standard spring size they supply with gha's.

 

I have a gti6 engine with 23mm tbs and 24.8mm Arb. The front appears very soft so looking to go for a spring to suit the rear but haven't a clue where to start

[petert 588]

Depends what you use it for and what sort of tyres.