pro's and cons to lowering blocks vs reset leafs?

[Daymo_84]

Just found this, points 4 and 5 and maybe 6
http://www.vicroads.vic.gov.au/NR/rd...340/0/VSI8.pdf

I too have been looking into blocks but seem to be shying away from them based on the last coment. Again this only applies to Vic roads but im sure there are other standards for other states.

[raised by monkeys]

This is quite contraversial, and not to disregard the obvious mechanical knowledge of people on this forum, i would like to hear from an engineer on the legalities and potential damage or risks that blocks may cause.

Often people, including myself, make modifications to cars that pose possible danger to causing damage and thus risk of an accident, so as popular and unpopular as lowering blocks are, im reading just as much negative feedback about lowered leafs as i am blocks.

[mattybarbs]

i have a s2 wag, 1.5 inch lowering blocks you definatly need at least 18 inch rims prob an 18 inch spare (i dont) would be handy, i have 18s plus i lug around tools havent had any problems, i also tow a trailer sometimes. They were really easy to install got the kit off ebay $70 everything included bolted straight on. As for performance havent noticed anything different then stock.

[santb]

blocks are NOT illegal; the only restriction in most states they have to be metal(steel or aluminium).
using blocks to raise or lower anything supporting weight will change the geometry and fulcrums; not such an issue at .5-1inch but over 2.5-3? asking for trouble... axle tramp is not the end of the world if you don't mind constantly fixing suspension or bending axle housings...show cars or non-daily drivers wont matter.. but if you drive to and from work taking every corner in second at 80 k's............... do the math!
dropping cars on their guts looks great but is not really practical for any number of reasons(unless for track); do you want to enjoy driving it or just looking at it???? 20' rims on 4' lowered suspension should be left to the hot-rodders and skyline/commodore wa**kers....
no offense.

reset is the most reliable. plus you get a warranty!


edit: yes i know its over a year since anyone posted on here but some people return to learn....

[XRGhia]

I've got 2.5" blocks in my Wagon (EF though), and it does 1200kms over a normal week of driving to Sydney and back... IMO, blocks aren't that bad unless you reaaaaally drop it down (3.5" and further)....

Its done about 9000km's since i put the blocks in, and have done plenty of (legal) skids and hard take offs with no axle tramp, nor have I damaged an axle housing...

[santb]

Originally Posted by xrghiawagon

I've got 2.5" blocks in my Wagon (EF though), and it does 1200kms over a normal week of driving to Sydney and back... IMO, blocks aren't that bad unless you reaaaaally drop it down (3.5" and further)....

Its done about 9000km's since i put the blocks in, and have done plenty of (legal) skids and hard take offs with no axle tramp, nor have I damaged an axle housing...

thats cool...i had a couple XA/XB/XC's in my youth and all were on their guts!
never had probs either; but now bit older, bit more safety/value conscious..
only point is to remove all doubt: take to an expert and do it right first time.....
most of my k's are hiway so blocks wouldn't worry me until under load.. i'm in XG now and occasionally have the thing loaded up beyond capacity
and yes, i did mean that getting down REALLY LOW with huge rims and no rubber (the kids forget that the rubber is an important part of suspension, braking, steering AND drifting!) and deliberately hooning...
not commenting on the moral/legal stuff but some of them seem to want to be forking out every $$ on a single new tyre or axle or diff....
ahhh to be young again and LIVE for that new tyre.........

[Grobbo]

I might give these blocks a go, they're not illegal here in Vic and it's seems fairly easily reversible... But alas, I only have the 17 inch BA XR rims on my BA wagon - can I only go down an inch then? Would prefer an inch and a half to match 'sport low' springs up front. (XR minus 15mm)

[XP6]

Reset leafs arent the best either because they are flatter than standard they become softer and have way less load capability and stalbillity, this can be over come with helper leaf's(which can raise it back up...)or you can run airbags/poly airsprings(good compromise). Lowering blocks do not have this problem the only handling problem they cause is increased touque leverage against the spring... nothing slapper bars wont fix.

Blocks are not dangerous at all and dont not effect cornering ablity of your car but reset leaves do...

[madwag]

im happy with mine.
i even did a 200km drive on dirt roads with the car fully loaded and they held up
cant complain one bit about them.

i have 2" blocks in an 18" rim on my BF

[Sox]

Originally Posted by XP6

Reset leafs arent the best either because they are flatter than standard they become softer and have way less load capability and stalbillity, this can be over come with helper leaf's(which can raise it back up...)

Whilst you're correct in saying a flatter spring is softer than an arched spring, the difference isn't way less as you claim.

Also, extra leaves (or helper leaves, as you call them) are almost always added to the spring pack because of this very reason.

So the end result is an excellent spring with the correct height and tension.

Lowering blocks do not have this problem the only handling problem they cause is increased touque leverage against the spring... nothing slapper bars wont fix.

Perhaps so, but with the correct reset and stiffened spring, slapper bars aren't needed. And again, the end result is better.

Blocks are not dangerous at all and dont not effect cornering ablity of your car but reset leaves do...

They do affect the handling, in a bad way.

As for being dangerous, maybe not, but they will cause increased stress on the U-bolts because of the extra leverage. Whether this is a safety issue is debatable. I guess the potential is there.

In any case, why bother with blocks when reset and stiffened leaves are simply better.

[Grobbo]

Originally Posted by Sox

Also, extra leaves are almost always added t

In any case, why bother with blocks when reset and stiffened leaves are simply better.

I've had heaps of quotes and no one said they'd put any extra leaves in with a reset.

People go for blocks coz they're cheaper - like anything really - money talks!

[Grobbo]

Originally Posted by madwag

im happy with mine.
i even did a 200km drive on dirt roads with the car fully loaded and they held up
cant complain one bit about them.

i have 2" blocks in an 18" rim on my BF

image
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Do you reckon I'd be able to do 1.5 inches with 17's? Did you use just basic tools and a jack?

[XRGhia]

After a few months with the blocks in, I think it's easy to say that because the pinion angle hasn't changed, yet the diff position has been pushed up (causing the driveshaft to rub against the floor)...

[Sox]

Originally Posted by Grobbo

I've had heaps of quotes and no one said they'd put any extra leaves in with a reset.

They're probably trying to win the job by quoting it as cheap as possible.
Business is very cut throat these days.

You should ask how much extra it is to throw in another leaf, it may only be $30 or so and is well worth it.

People go for blocks coz they're cheaper - like anything really - money talks!

True enough, but you also get what you pay for....

[XP6]

Sox ask any spring mob if they add extra leafs when resetting, it'll only be at the customers request that they will.
Adeversely effect handling BS blocks dont negatively effect handling as the standard geomertry remains unchanged other than axle height load point on the spring... which is only when traction is lost. Cornering ability is not effected at all.
I've twice removed reset saggers and replaced them with standard leafs and lowering blocks and the handling has improved massively, the biggest plus was being able to carry loads again without cornering ridding on the inside bump stops... talk about bad handling

[Sox]

Originally Posted by XP6

Sox ask any spring mob if they add extra leafs when resetting, it'll only be at the customers request that they will.

All the ones I've dealt with have always discussed it, and recommended an extra leaf.

Adeversely effect handling BS blocks dont negatively effect handling as the standard geomertry remains unchanged other than axle height load point on the spring... which is only when traction is lost. Cornering ability is not effected at all.

Wrong.
Axle tramp is increased, as is bump steer.
Geometry is changed, as the pinion angle is different.

Reset springs can allow for that.

Blocks are the cheap & nasty solution to lowering, always have been.

[madwag]

Originally Posted by Grobbo

Do you reckon I'd be able to do 1.5 inches with 17's? Did you use just basic tools and a jack?

yeah a spanner, and just measure from the shock mount to the rim

[Grobbo]

Originally Posted by Sox

They're probably trying to win the job by quoting it as cheap as possible.
Business is very cut throat these days.

You should ask how much extra it is to throw in another leaf, it may only be $30 or so and is well worth it.

True enough, but you also get what you pay for....

I've had quotes from $400 up to $2200... No one offered them when I lowered my ute either. I'll ask next time tho. :-)

My XR8 ute was as low as it could go simply on reset leaves and it was pretty sweet - put dirtbikes in the back every weekend with no issues.

[XP6]

Agreed axle tramp can be increased due to leverage but not allways, it depends on how stiff the spring rate is.

Pinion angle would be no different between blocks or resets given the same axle height to body, pinion angle has nothing to do with the geometry unless you severely preload the springs, dunno why you would want too do that

Bump steer can be affected by lowering yes but what ever method you use to lower with makes no difference the effect will be the same given the same height!

"Blocks are the cheap & nasty solution to lowering, always have been."
Thats a bit generalised isnt it, should be a little more pacific Yes blocks are not ideal for drag racing where traction is the priority, really should be using a 4 link not leafs
Are they bad on a racing track... who knows until its tested on the individual car

On the street for everyday driving... do you push your car to the absolute limits?
Blocks are better in a load carrying situation as no reset can handle weight, yes you can increase the rate but this means little when the weight pushes the spring past its "ideal" load height... ever seen flat leafs on a ute, just look how much a XR ute is derated compared to a standard XT just for a 2" reduced height.

The thing is leaf springs are not designed to be flat, the curve is what gives them a progressive rate, resets typicaly dont have this option after a 2" drop you can add extra leafs to make them harder to increase load cap a little but this makes them too hard which is not ideal on the street.

Im not saying resets are no good it just depends on what situation they are being used... and the quality of them they are known for sagging a lot quicker than stockys, getting the eyes reversed will lower then a inch or two and still retain the factory curve.

[madwag]

the reason i like it is because 90% of the time i need the suspension travel and height so i don't run blocks, but for the 10% i put em in and my wagon looks dope. i can get them in/out in an hour now

[Sox]

Originally Posted by XP6

Agreed axle tramp can be increased due to leverage but not allways, it depends on how stiff the spring rate is.

No. Axle tramp is always increased by leverage. Always.

Pinion angle would be no different between blocks or resets given the same axle height to body,

No again.
Pinion angle is changed relative to the tailshaft with blocks. The only way this can be rectified is with angled slip plates.

Reset springs can have this angle made correct when pressing.

pinion angle has nothing to do with the geometry unless you severely preload the springs, dunno why you would want too do that

Of course pinion angle is changed with geometry.

Bump steer can be affected by lowering yes but what ever method you use to lower with makes no difference the effect will be the same given the same height!

No. Bump steer can be caused by axle wind up, which is caused by the added leverage that blocks allow.

"Blocks are the cheap & nasty solution to lowering, always have been."
Thats a bit generalised isnt it,

How so? It's the truth. Blocks can work ok in some applications, but compared to reset leaves and/or new lowered springs, they are cheap and nasty and never work as well.

should be a little more pacific Yes blocks are not ideal for drag racing where traction is the priority, really should be using a 4 link not leafs
Are they bad on a racing track... who knows until its tested on the individual car
On the street for everyday driving... do you push your car to the absolute limits?

Nonsense. Blocks are not ideal for anything, but they can work acceptable in some situations.

Blocks are better in a load carrying situation as no reset can handle weight, yes you can increase the rate but this means little when the weight pushes the spring past its "ideal" load height... ever seen flat leafs on a ute, just look how much a XR ute is derated compared to a standard XT just for a 2" reduced height.

Wrong again. XR leaves are different to XL springs. The thick load carrying leaf is not as thick on XR's (and XLS's). That's why it's de-rated.

In any case, I've already said reset leaves can and mostly have an extra leaf (or 2 or 3....) to compensate for the reduced stiffness when flattened. This is a non issue.

The thing is leaf springs are not designed to be flat, the curve is what gives them a progressive rate, resets typicaly dont have this option after a 2" drop you can add extra leafs to make them harder to increase load cap a little but this makes them too hard which is not ideal on the street.

How so? You make them as stiff as required for the application. That may or may not be stiffer than the arched standard spring.

Im not saying resets are no good it just depends on what situation they are being used... and the quality of them they are known for sagging a lot quicker than stockys,

Something which I've never experienced, and shouldn't happen anyhow.
There's nothing about the resetting process which should make them sag any quicker than a standard spring.
If reset springs have sagged, then the original springs were likely already stuffed.

getting the eyes reversed will lower then a inch or two and still retain the factory curve.

True enough, but not strictly required anyhow.

BTW, do you have shares with a lowering block mob??....

[Molloy]

No cons mate just pros, pro= ur car looks prime and u get lots of hotties