I Brought the Gaz road kit which is my first set of coilovers and its been a bit of a journey that has still not ended, not owning coilovers before i have come across a few problems and experiences i was not expecting, which has lead me to do some research and experimenting of my own including three visits to Gaz themselves.
The first problem was the supplied 8" 425lb front springs dislocate on full droop at std ride height(m.o.t fail), I made a number of phone calls/emails about this to Julian at balance motorsport and he said i must have the ride height to low as the test kit never dislocated at std ride height.
So after the endless emails and checking the ride height,the options I was given were to shorten the stroke of the damper or to use a helper spring.
My knowledge about suspension at this point was limited,(still is) and one of the mechanics at Gaz told me that shortening the stroke has "no effect on the travel" and that helper springs "just get in the way" so I took his advice went to Gaz and got the stroke shortened.
So this lead me on to my second problem, which is a definite decrease in traction since switching to the Gaz set up,which kind of makes sense to me now.
The std front spring is a soft long spring with loads of travel, soft springs follow bumps etc better than hard, also when you accelerate and the weight transfer makes the back of the car squat and the nose of the car rise the tyre stays on the ground.(think about when you jack a std car up,how long before the wheel comes of the ground)
The Gaz kit uses a Stiff short 8" front spring which dislocates on full droop, also the rear spring poundage is softer than the front,so when you accelerate the back squats and its easier for the front spring to become unloaded giving less traction.
The stroke reducing modification they did, gave me a total of 2.5" of travel, 2" of droop and 1/2" of bump which means I had 1/2" before I hit the bump stops and 2" before the wheel comes of the floor.
So my initial solution was to take the stroke reducement off (which Gaz charged me £100)and after talking to Jimbo about his setup and researching,i decided to try a dual rate set up with a shorter stiff main spring and a progressive tender spring,the main reasons for this were to give me a softer ride and more overall spring length so there is no dislocation on droop.
This then showed me a third problem, the body of the Gaz damper is so wide that the spring cup platform used to separate the two springs,is so close to the threaded part of the damper it rubs away at the thread when you hit bumps! it is impossible for the cup sizes to be bigger as they have to hold the 2.5"spring, so you have to use a single spring or a long main and a short helper so the platform is not near the threaded body.
The fourth is the balance motorsport caster top mount bearings, they have intermitantly knocked after a few months of owning them, Barbz has also confirmed there is play in them and when he was doing my geometry it was changing due to the play in the bearings, granted Julian did say i could return them to be looked at, but because the knock is intermitant i have never got round to doing it, but I would say there is a question mark over the quality/longevity of the bearings.
also one of the benefits of more caster is the more lock you apply the more camber you get, meaning you don't have to run to much static camber, but Barbz could only just get it into negative camber, now I don't know if its a problem with my camber bolts or the design of the strut, I have not tried other camber bolts, another thing is some people use the bravo top mounts for coilovers,to give a softer ride but barbz implied the rod on the Gaz is to big to fit through the hole in the bravo top mounts.
My fifth point is the ride/handling, some of this is my personal view, but what I wanted from this kit when i first brought it was a set of coilovers that was at std height (so I could run a lower brace without hitting speed bumps/grounding out on country roads) which is stiff enough not to have to much body roll/alter the geometry but still supple enough to blast down country roads,then the dampers could be turned up for track days.
Don't get me wrong I new the ride would be firm,but in my opinion this setup is FAR to stiff for the road,you get lots of wheel spin in lower gears especially in the wet and pot holes etc feel like you have no suspension at all,you would definitely be faster down bumpy/wet roads on std suspension, also if you turn the damper down to make the ride better you get so much bounce and float in dips you have to slow down.
The positives are it handles very flat with little roll and on ultra smooth roads/track and with sticky rubber it would be good, but it its meant to be a road/track kit and they do a full track kit already.
The Sixth point is that other makes of coilover come with adjustable rear spring conversion platforms,so you can change the height and poundage of the rear springs.
The Gaz kit comes with a fixed std style springs so you cant change rear corner weights and if you want to change the rear spring rates you cant just pick generic ones out of a catalouge you have to get them specially made.
Also its worth mentioning that they don't come with rod covers so they are exposed to the elements,Gaz claim they have a special seal that cleans the rod to stop it getting pitted etc, Nigel mentioned some routinely service you should carry out on them if your using them on the road but as he said "its hardly a fit and forget item",and some of my "hard plating" round the damper body were there bolted on is coming off already.
So were am i at now? well I have spent to much money to give up, and after looking on the net and talking to people the common opinion with Fwd cars is you want a softer front and a stiff rear,this gives you traction and stops the weight transfer when you accelerate, the same theory applies to arb's stiff rear soft front.
Now the problem with this is if you tip the balance to far,you end up with lots of lift off oversteer, so i have gone with caution and only gone 25lb softer on the front, some people suggest 100lb softer on track spec .
Going softer also means you can run a longer spring with out raising the ride height this calculator is very usefull
spring calculator So now I have kept the supplied 375lb rear and added a single 9" 350lb front,which has improved the car no end,it is still very flat and on b roads it feels like the suspension actually works now, also there is loads of grip,chucking it into round about's you have to go in very deep to get it to understeer.
I have only driven it spiritedly on the road not on track but it feels very neutral with no real sign of lift off oversteer but with good turn in,this is with a std front arb and a 22mm rear arb, Barbz also commented on how good the car felt and how neutral it was.
But for me I think it could go softer, the ride is still very firm and i am still looking for more traction from the front, the dampers are very stiff and I think I would rather have even softer longer springs and turn up the dampers,i'm still only on about 6 out of 15 clicks,I am happy to stick with the front to rear ratio but drop the poundage evenly to a 10" 300lb front and 325lb rear.
So for me personally the kit is not finished and not right for a road kit, but there are option's round the problems,you can the change spring rates to suit (rear more difficult) also you can buy dust covers for the pistons from demon tweeks, Barbz said he can get the top mounts machined with higher quality bearings and also machine the damper holes using special washers for more camber.
If asked I would not buy the kit again,I would buy the Ozravs either with std springs and uprated arb's or Eibach springs and get the front subframe welded so you don't have to run a lower brace.