warning regarding lowering springs

over the last few weeks ive learned a hell of a lot with regard to suspension setups etc.
something thats of very relative importance to those using lowering springs on stock type struts, so il pass on to you what ive learned and upto you's whether you think im talking out my arse or not lol

ok after recently fitting a set of gabs with lowering springs to my track/road based car i took it back to a motorsport company to have all the alignment etc setup again, only to get a call from them a couple hours later saying he had set it up best he could but advised me to pop down so he could show me a crucial defect in the system.
so of course i was now very curious as to what could possibly be wrong
so heres what ive learnt and seen with my own eyes so know its not a load of bull

basically all standard type struts fitted to a pulsar / sunny are designed for rally use with high springs and long outer casings.
they are designed to run with high stock springs (as standard ride height shows) to allow for compression of the centre damping rod of strut (squish i think he said its called) this is basically the amount the spring compresses when the weight of the car is on the springs.

now when you fit lowering springs to said struts you only leave around 1''1/2 of rod compression before car hits the bump stops (ive never noticed this before) now with gabs or other similar adjustable damping suspension you can stiffen the damping which does help with rebound but its still far from correct.

for those that are not aware of what im talking about or trying to put across.....as soon as the bumpstop bottoms out (either on hard road driving or circuit)
you just as well have four lumps of wood as suspension as the car will break free and lose grip completely which is obviously far from ideal and could be dangerous!

if you look at a set of coilovers and compare the bodies to a set of stock struts, gabs, konis, kyb etc you will see that the bodies are around one and half inches shorter to allow for more damping rod movement, plus the squish on them (weight of car) is only around 2'' compared to about 4'' on lowering springs so basically they are built for purpose.

theres a lot of cars running round with lowering springs on standard type struts but you are hugely compromising handling and car stability by having these fitted, its certainly made me think about going this route now that ive seen what he means with my own eyes.
he said ideally if he were designing a strut for this type of car (taking into account the weight of car with 4wd system) he would have made the stock housings around 2'' shorter for road and circuit use

so make of this what you will gents, just be carefull and aware if your nailing your car round the twisties on the road, if you hit a dip or pothole it could all end in tears!!!

having said all the above ive just done fastest time ive ever done on circuit in a pulsar with gabs and lowering springs but it still doesnt alter the facts above.

i am using stock shocks with whiteline springs and mine as seemed ok for years though the whiteline dont seem that low still a decent gap between wheel and arch

you need to look at the rod lengh through the spring with car sitting on the ground.
you will see that theres only around 1' 1/2'' of rod travel before your hitting on the bump stops which is what im getting at

Totally agree with what bob has wrote why do you think even on small cheap cars like corsa's etc well any kind for that matter when you buy a suspension kit its lowering spings and shortend stiffened shocks.buy a set of lowering springs and stick them on standard shocks and watch them bottom out and most cases burst the seals maybe they dont burst on a pulsar because there a better built shock.This takes me back years when my bro first passed and lowered his nova alot of his mates said he was stupid for buying a full kit spending all the extra he should just buy springs. untill weeks and months later when we were changing there burst standard shocks and his were fine for all the few year he had the car

Tried to explain this thing to you before bob, the issue is also the shock will be in the wrong part of its stroke as the angle of the suspension changes so damping rates are not linear, the thing where the car is sitting on its springs and compressing them is called "sag" and the distance the wheel drops when you jack the car up is called "droop", mark turbo had a very in depth discussion with a suspension company and apparently the gtir needs suspension travel to be able to move around as such and the after market shocks from a lot of places are too short to allow this too, so it seems that white line and Koni new what they were doing more so than tien or others.......glad I have a brand new set of Koni to go on the car over winter.

yeah as said dan im just going by what was explained to me and yep sag and the rest of it is correct lol, but you know what i mean!

i have none the less learned a lot with regard to suspension and il now be setting my own car up rather than pay through the nose for others to do it, same as i did with my old black one which i had setup lovely through my own trial and error.

I have a theory ..
I have fitted my cusco strut braces in the past when the wheels are not on the ground (on axle stands)
And when i have put it on it's wheels the car sits really high (maybe 3cm higher) even after driving it for 2k..
fit braces when the car is on the floor and it sits at normal ride height .

so my theory is could you fit stiffer lowering springs and fit braces with car in the air (so lowering from 3cm higher to normal height) and end up with a stiffer car at a standard ride height ?
This would then have the shocks at the correct angle and length etc

You are talking about upper strut braces (sit on top of the turret) im not rubbishing your theory but i cannot see how this would alter the ride i may well be wrong but in effect all it does is rigid the top half of the body to rule out body roll/flex although i do see how up/down while fitting may alter how the dimensions of the body between the turrets but i still would think that is minimal amount not unless your pulsar is rot lol

technically what rob is saying is quite correct because if you fit the upper brace with wheels off the floor then adjust brace so its pushing outwards then effectively you are altering the camber.

if you alter the brace with car on the deck so it pulls inwards on the turrets then it will give slightly more neg camber which will in turn slightly alter the ride height

Yeah i do agree all im saying is it must be minimal amount either way

Dan the Gearboxman wrote:Tried to explain this thing to you before bob, the issue is also the shock will be in the wrong part of its stroke as the angle of the suspension changes so damping rates are not linear, the thing where the car is sitting on its springs and compressing them is called "sag" and the distance the wheel drops when you jack the car up is called "droop", mark turbo had a very in depth discussion with a suspension company and apparently the gtir needs suspension travel to be able to move around as such and the after market shocks from a lot of places are too short to allow this too, so it seems that white line and Koni new what they were doing more so than tien or others.......glad I have a brand new set of Koni to go on the car over winter.

So you think tein and bc etc are the wrong shocks and koni is a better choice? im needing to buy a new set but cant find sellers of koni anywhere, where did you source a set, if you dont mind me asking?

think ive got a set on car ive just bought but not decided yet whether im gonna keep or flog them

gtirus wrote:think ive got a set on car ive just bought but not decided yet whether im gonna keep or flog them

Well let me know how much if you decide to flog them?

Digitalfaze wrote:

Dan the Gearboxman wrote:Tried to explain this thing to you before bob, the issue is also the shock will be in the wrong part of its stroke as the angle of the suspension changes so damping rates are not linear, the thing where the car is sitting on its springs and compressing them is called "sag" and the distance the wheel drops when you jack the car up is called "droop", mark turbo had a very in depth discussion with a suspension company and apparently the gtir needs suspension travel to be able to move around as such and the after market shocks from a lot of places are too short to allow this too, so it seems that white line and Koni new what they were doing more so than tien or others.......glad I have a brand new set of Koni to go on the car over winter.

So you think tein and bc etc are the wrong shocks and koni is a better choice? im needing to buy a new set but cant find sellers of koni anywhere, where did you source a set, if you dont mind me asking?

I would not say wrong but if the car is mainly road use a decent set of springs and shocks are nearly always a better option in my opinion.Dont forget every car handels different suspension is a massive part but handling depends on many things tyres,weight distrobution No two people have the same driving style a car set up perfect for you i could get in and hate the set up and find dangerous

Digitalfaze wrote:

Dan the Gearboxman wrote:Tried to explain this thing to you before bob, the issue is also the shock will be in the wrong part of its stroke as the angle of the suspension changes so damping rates are not linear, the thing where the car is sitting on its springs and compressing them is called "sag" and the distance the wheel drops when you jack the car up is called "droop", mark turbo had a very in depth discussion with a suspension company and apparently the gtir needs suspension travel to be able to move around as such and the after market shocks from a lot of places are too short to allow this too, so it seems that white line and Koni new what they were doing more so than tien or others.......glad I have a brand new set of Koni to go on the car over winter.

So you think tein and bc etc are the wrong shocks and koni is a better choice? im needing to buy a new set but cant find sellers of koni anywhere, where did you source a set, if you dont mind me asking?

I think BC are still good for what they are, and if you fit Koni or others you need either white line springs or another good make with a max lowering of 40 mm from the standard ride height, I sourced my set as new old stock they are a pig to get hold of.

As for tien, and a few other makes I don't rate them at all, but you have to remember you get three different types of tien and two of those were designed for track work only and one was for the street. There is so much that goes into suspension set up....

thanks for the info ill try look at my options when time comes, im running gabs just now on 35mm drop but the front is leaking, i see koni offer the shocks per corner where as bc etc is the full set, is it ok to mix brands? gabs on rear and koni on front with the gab springs or is this not recommended? im not a crazy driver but do push it to the limits round corners on the back roads when im feeling rich.

ive never really put any thought into suspension i just thought if you buy good kit then it will suit you fine