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Discussion Starter · #1 ·
Custom lowered springs, yep that's right, I said custom, and for the HC! :clap:

This is an old topic and a very hot one especially amongst us HC owners, finally a solution is available. I spoke with a bloke from K-Mac Suspension today, explained the car I had, a 1989 HC 929, and asked about the availability of lowered springs for this car, he told me they do make them. I then asked what is the drop below standard and he basically said, what ever you want!

Yee bloody Haa!! You tell them how much lower than standard you want and they make them, within legal guidelines, obviously. The springs they use are progressive and just in case you may not be aware, it basically means they offer more resistance as more load is put on them.

Here's a good explanation for progressive springs...
http://www.tuninglinx.com/html/suspensionsprings.html

This link is to Lovells Suspension's site, which has some handy references to ADRs (Australian Design Rules) regarding modifying a vehicle's suspension.
http://www.lovells.com.au/faq.php

This link has a good springs FAQ with quite a bit of info...
http://www.whiteline.com.au/default.asp?page=/faqsprings.htm

Somewhere buried in this forum someone else made mention of K-Mac springs, but didn't elaborate on them and that was for the HD 929, hopefully this'll be a bit more helpful. Now the best part, they're no where near as expensive as I thought they might've been, for a pair of custom springs they're AUD$165

They're not as cheap as what's available in the US tho', I was looking at the B+G Springs (with only a 1.25" drop), which are just over US$200 and by the time I got them shipped out here it works out to be more than AUD$500, which is still pretty good, but obviously not as good as AUD$330, especially for something that I can choose the height drop for.

If you're interested, K-Mac also make a number of other suspension components that can be made for the 929, such as anti-sway bars, shocks and struts and camber-caster-toe kits. I checked on the anti-sway bars and they're AUD$265.

If you want to check 'em out here's they're site...
http://www.k-mac.com.au/default.htm

I'm going to check with a suspension specialist tomorrow and find out what they reckon would be a good setup for my car. I'm mainly concerned coz I don't want to be scrubbing the tyres on the guards, I'm looking at dropping the front by 2" and the rear by 1.25" to 1.5", if necessary I'll roll the guards, but we'll see.

Cheers
 

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the B&G springs were discontinued.

this is great cause Im deffinetly looking into dropping my HC properly without cut springs.

dropping the front 2 inches is nothing on this car. I chopped 3 coils off the coil and it dropped my down about 3 inches and I still have about a 1 inch gap between the tire and the fender. I havent doen the back but I think a 2.25 inch drop would be perfect, but all this will definetly need a camber kit....
 

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Discussion Starter · #3 ·
I measured the gap between the guard and the top of the tyre and three inches off mine would look pretty slick, but I'm just worried about dragging the tyres on the guards, and as I said previously, rolling the guards is an option, one I'd rather avoid if I could tho'. The springs in my car may have sagged a bit more than yours as well, dunno what the roads are like in your neck of the woods, but where the car came from, Sydney, a lot of roads are absolute crap. Some of the roads where I live are pretty ordinary too :thumbsdown:

Measuring from the centre of your wheel hub to the edge of the guard for your front wheels, what is the current distance (in milimetres would be good)? Do you know what it was before you dropped your springs? What's the current height, using the same measurement for the rear?

On my car, the rear measures at approximately 355mm, the front measures at 385mm. At the rear, the gap between the edge of the guard and the top of the tyre is 1.5", the gap at the front is 2.75". The tyres on my car are 225/45x17s and visually lining them up against the original wheel and tyre combo, the rolling diameter is a poofteenth bigger.

After speaking with the suspension mob I'll post back here what they tell me, I'll also ask about having to use a camber kit as well. I'll get in touch with K-Mac and ask them how much such a kit would cost.

Cheers
 

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Im not exactly sure wat ur talkin about wen u refer to the "tire guards" Is that the mud flaps ?? cause I scrape those on speed bumps all the time and my front lip drags alot but it doesnt really matter cause its plastic...

It looks like your car has sagged a bit, I replaced all my shocks and my rear coils last year so it even out my car alot. it had got pretty bad with time and was dumped in the back and jack up in the front, now it leans the other way.

I cant really get any measurments since my car is being stored and is currently 6000kms away from me.
 

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Discussion Starter · #5 ·
Well that's a pity about your car. What I was referring to is actually called "Eye Brow Heights" as in the pic...



Which measures from the centre of the wheel hub to the underside edge of the wheel arch.

I had to replace the rear shocks probably about 6 to 8 months ago, but the front ones are still original and the springs all around are still original too. I had a drive-on shock test done and the front shocks are roughly about 20% worn, so I'll only replace them when I really need to.

As it is tho' it rides brilliantly, very comfortable and no bangs or knocks anywhere, but I would say the passenger side front spring is showing signs of wear, coz when I hit right hand corners hard, particularly going thru roundabouts (lots of them where I live), the front left tyre just rubs somewhere. I have to be reasonably careful when there's a passenger in the front coz it rubs without much effort then.

At first I just put this down to the bigger wheels and tyres coz I didn't encounter that with the original wheels, but I don't get that problem on the driver's side (right hand side), which is a good indication that the front right spring is weak. The back end is fine tho', no probs there.

Cheers
 

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Discussion Starter · #6 ·
I spoke with suspension specialist today and he had a look at my car and from the size of the tyres on it, a two inch drop would be stretching the friendship. The tyres would end up buggering up the guards by dropping them that much, if I didn't have to turn the wheels and everything was perfectly flat then two inches would be good, but of course that ain't the way it is. A 1.5" drop in the rear would be too close as well.

He suggested I see if I can find out what the original height should be so I can then work out correctly how much I can drop it, so I did. I contacted one spring manufacturer (Pedders) and they only had a measurement from the lip of the rim (where the rim meets the tyre bead and measured from the bottom of course) to the underside edge of the guard. And their measurements for the stock height (with 17" rims) are;

Front = 620mm
Rear = 595mm

To work out for 15" rims basically knock off 25mm

As it turns out, mine measures just about spot on. So it would seem that the springs haven't really sagged at all. I checked with another spring manufacturer (King Springs) and with their stock springs fitted the Eye Brow Height measurments were;

Front = 400mm
Rear = 340mm

Somehow tho' this doesn't add up, coz if these measurements were right then the car would be getting around like a boat, nose high. I got springs from this mob before for my '84 929 and with the ones that were supplied the heights were completely wrong, front and rear, so I'm inclined to disregard the measurements from them.

Anyway, based on the first lot of measurements, a drop of 1.25" in the rear would leave a visible gap from the top of the tyre to the underside edge of the wheel arch of 13mm, or 0.5". Dropping the front by 1.5" would leave a visible gap of 27mm, just over an inch. A 1.75" drop would leave a gap of 20mm and a 2" drop, a gap of 14mm.

So I think in the interest of not having to roll the guards or pump them out, a big job including repainting the whole guard, I think the 1.5" drop is the logical decision, especially as I drive this car all the time. I suppose one way to minimise the movement in the front is to fit a heavier anti-sway bar, which is certainly something I'm looking at anyway. Dropping it lower is a bit of a concern considering the wider tyres of 245/45 are more at risk of hitting the guards, something to bear in mind if you're looking at changing yours later.

I contacted K-Mac for further info and am waiting for a reply, which I should receive in a day or so. I have also asked them about the price for a Camber and Caster adjuster kit. The suspension bloke I spoke with today tells me tho' that I probably won't need a kit for my car.

I shall post back soon.

Cheers.
 

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dude as if lowering your HC 2 inches up front is going to be too low. ive lowered mine 2.5 inches up front and 3 inches at the rear. i have no scrubbing. none of my guards have been rolled or flared. i sometimes scrape but its nothing serious.

the first time i lowered the HC was 1.5 inches and it was still way too high, this was with pedders springs which was said to be lowest that they would go. so i went to an industrial spring manufacurer and got em to do me my new spring set up for me with custom made 2.5 inch springs for front and 3inch for the rear.

with my front springs i have a very small gap between the top of my tyre and the guard. its like 1-2 cms. with my rear springs i have about half of the rear tyre profile sittin inside the guards this is with 245/40/R18 tyres. and with people sittin in the back seats the rear of the car goes down another inch. so thats 4 inches lower than standard when i got people in it and i still dont have rubbing or big scraping problems.
so yeh all im sayin is really check out how low you can go. i have spent a lot of money trying out different spring heights and shockers and am now finally happy with it. i know i have the different model HC 929 to you but the standard heights of each car should probs be about the same. but yeh thats all im sayin. coz u can go way lower than that safely. and if you need to, havin ur guards rolled isnt that expensive.

james.
 

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take a page outta VIP styling and get better wheel fitamet then drop that bitch properly and roll fenders if needed, the more you dump this car the better it looks/handles...
 

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Discussion Starter · #9 ·
Originally posted by 6929er@Sep 29 2005, 07:00 AM
dude as if lowering your HC 2 inches up front is going to be too low. ive lowered mine 2.5 inches up front and 3 inches at the rear. i have no scrubbing. none of my guards have been rolled or flared. i sometimes scrape but its nothing serious.


[snapback]308354[/snapback]​
OK, so now I'm really confused :wacko: Basically what you're both telling me is to totally disregard what the physical gap currently is coz this won't have any bearing on when I put another set of springs on, would that be right?

Below are a couple of pics of how the springs sit now, the front on the left and the rear on the right...



James, there must be some difference between your model and mine, with the 225/45x17s I can't fit my finger between the spring saddle on the front struts on either the top or the side of the tyre. How do your 245/40x18s fit? :huh:

This pics shows what I mean...



Unless the offset on your wheels is different, but then they wouldn't fit under the guards :blink: Does yours have the active suspension setup? Mine doesn't. I know on the old HB 929 the saddle mounts were in different positions between one with the active setup and the one without.

Unfortunately I don't have the readies to play around with different spring heights so I need to get it right first go, and rolling the guards would mean more dollars. So referring back to my first question, what you're telling me is to forget about what it looks like to determine how new springs will fit, and to just go by what you and 9ine Deuce have already experienced, is that right? That'd be logical enough.

K-Mac got back to me and suggest I plan a day to go down to them in Sydney then I can discuss with them exactly where I want the car to sit and they can manufacture and fit the springs while I wait. I think this sounds like a good idea :thumbsup:

They also tell me that the standard 30mm anti-sway bar is sufficient and that after fitting the springs then we can determine if a camber kit is needed.

Your input is appreciated.

Cheers
 

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because you never replaced your rear coil springs and they are the original ones, the car will be lower in the rear by quiet a bit
 

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hey al. yeh i had to go for 225/40/18's for the front wheels. and yeh they only just miss the front struts by about 1 cm hehe. ive only got the 245's on the rear.

but yeh i wouldnt say to disregard what K Mac or any other suspension places say coz im no suspension specialist. i just know thru a lot of trial and error how low u can get these cars. goin from ur pics it looks like ur cars factory suspension may be a little bit lower than what mine is. but yeh how low do u wanna go? if you want it just moderately low and not slammed then maybe 1.5 inches would be good for ya.

this is a pic of where my rear springs are sittin now. the car has the independant rear suspension too so when i put the car into gear it sinks down just a little bit more :D




anyways its quite possible for you to get ur car to this kinda height. maybe even lower. but it could take a bit of trial and error to get it perfect so be prepared. it took me three attempts to finally get my car where its sittin now.
it all depends on where u want ur car to sit but if you want the car to sit pretty low and look good i would say lowering it 2.5 inches all round would be sweet. that way you will have some room for the front wheells so u can turn without many dramas and the rears will be nicely sittin inside the guards a little. u may need to have ur rear guards rolled or flared but it shouldnt cost u too much. around here most places charge about $50 a corner.

anyways hoped that helped.
james.
 

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Discussion Starter · #12 ·
Yes that does help, thanks. I like your wheels by the way, they really suit your car :)

A bit of light has been shed on the subject, it gives me some idea of how to determine how low I should go and will help me make a decision when I see the dudes at K-Mac, hopefully within a couple of months, which won't be soon enough.

Cheers.
 

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i recently got a new luce, and put rx7 struts in it. 6929er, your cars low mate, but fuck u should see mine hahah. I cant go over speed bumps.
 

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is it as low as your last luce in ur signature? coz damn thats low dude! i can only just get over speed bumps in mine hehe.

james.
 

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how hard was it to mod the struts ? is it the top hats on the front and rear ?
 

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easy to mod the struts, just put the top hats from the luce onto the rx7 struts (front and rear). Its time consuming tho, because u have to use spring compressors all the time. Takes long to do but is worth it if u want it fully sacked out. Yea its as low as that basically.
 

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Discussion Starter · #17 ·
Hey mr hcfs, that's damn low :blink: What are your wheel/tyre sizes? Have you had to modify your guards so your front wheels don't catch when the steering is at lock?

Mate, how do the RX-7 struts cope with the extra weight? The 929 is over 200Kgs heavier than the RX-7.
 

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wheels are 17inch, x 7.5 in the front and 8.5 in the rear. 205/40/17R tyres all round. I had to roll the gaurds in the front, and it still scrapes against them every now and then. The rx7 struts seem to cope great, the handleing is awesome. Very bumpy ride though, and i seem to bottom out alot. Its not exactly a convenient height, definately looks good though. Im going to raise the back abit hopefully that will help abit, because i had to use cut rx7 springs in the back, because the standard springs dont lower it really.
 

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did you end up gettin the K Mac springs ?

Im seriously looking into this if they are good to deal with. im looking drop of 3.4" front and 2.75" rear
 

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there is a company here in OZ (Queensland) called KingSpringsthey will be able to make custom springs for anything, they already make standard replacement springs for HC there is nothing stopping them making lower ones

you give them measuremnts and they will wind you a set :)

what interests me most is that there are Rx7 struts on the HC..... i can get my grabby little hands on a set of MS fully ajustable coilovers, now i'm interested if that would work.... hhhmmm
 
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