ISC-N1 Coilovers

[bradc]

The rear tyres on his Galant are some old Dunlop DZ101's and at the front there are some newer GSD3's. Basically the DZ101's have less grip.

 

[Guest]

As an update, I now have my coilovers in the Galant. These coilovers are made by the same manufacturer as the ISC coilovers and as such, apart from the branding, the are exactly the same as the ISC-N1 coilovers you would buy.

Mine have spring rates of 12kg front and 8kg Rear.

Presently the car has no weight reduction (other than the flywheel) and so this spring rate combination is designed to reflect the weight distribution of about 60%/40% front/rear respectively.

Preload is set as far as I can do up the spring perches without using anything to assist other than the supplied spanner.

I have dropped the car probably close on 30mm. This isn't a lot and the car doesn't look like it has been lowered a great amount. The reason I didn't lower it further is because I have found in the past that the handling actually gets worse, presumably due to the suspension being outside the optimal operating parameters.

Damper settings front and rear are 4/32 and 3/32 respectively. For street use I have them low for comfort. I want them just strong enough to stop the car feeling like it is bouncing. I also want to ensure that the springs will be used to absorb bumps and potholes rather than having the shock transmitted through to the top hats and into the chassis.
With some more driving on different roads this may change, but for now 4/3 is ideal.


The result...
Comfort is very close to standard. Over large variances in the road it becomes obvious that the car isn't moving as much on the vertical plane, however there is no jarring or bouncing.

Handling is great. Very little body roll and plenty of predictable grip. When the back steps out a little it is very easy to bring it back in line with a small amount of correction.

One thing I have yet to test is the anti-dive characteristics under heavy braking.

i've got a similar setup..
12.7kg fronts, 11kg rear. mine can still be a little floaty under hard braking however, i've managed to get 3 AYC lights up under brakes.

definately needs a set of sway bars still though, and the recaro's are a necessity too, i almost fell out the window trying to corner in rhys' standard seats.

 

[Madhav]

i almost fell out the window trying to corner in rhys' standard seats.

Ha ha, I remember that feeling...

 

[jungle]

I've got Evo 5 seats, they suit perfectly. Especially if you have the carbon-look interior.

For interest's sake, I'll get the part number of the Bilsteins that my Galant came with and I'll see if I can find out what springs they have. Always good to have more info on the table to work off.

Sweet Paul, love to have a look, you around this coming week??

I"ll be in Sydney Sunday evening for hopefully only 2 days

 

[aiwasaki]

Hi Kenneth

I have a set of ISC's and with the same spring rates as yours and are set up with the spring just captive (ie when the car is on a lift the spring measures just under 180mm) and my car seems very low. So low that I scrape over pretty much every gutter/driveway and from what one garage said the height is illegally low.

Do you know what the length of your front springs are when the car is on a jack ie when there is no weight on the wheel ? I am wanting to raise my car a bit and thinking (based on the height drop you describe) that if I tighten the front springs a bit I can add a bit of height.

Thanks

 

[aiwasaki]

As an update, I now have my coilovers in the Galant. These coilovers are made by the same manufacturer as the ISC coilovers and as such, apart from the branding, the are exactly the same as the ISC-N1 coilovers you would buy.

Mine have spring rates of 12kg front and 8kg Rear.

Presently the car has no weight reduction (other than the flywheel) and so this spring rate combination is designed to reflect the weight distribution of about 60%/40% front/rear respectively.

Preload is set as far as I can do up the spring perches without using anything to assist other than the supplied spanner.

I have dropped the car probably close on 30mm. This isn't a lot and the car doesn't look like it has been lowered a great amount. The reason I didn't lower it further is because I have found in the past that the handling actually gets worse, presumably due to the suspension being outside the optimal operating parameters.

Damper settings front and rear are 4/32 and 3/32 respectively. For street use I have them low for comfort. I want them just strong enough to stop the car feeling like it is bouncing. I also want to ensure that the springs will be used to absorb bumps and potholes rather than having the shock transmitted through to the top hats and into the chassis.
With some more driving on different roads this may change, but for now 4/3 is ideal.


The result...
Comfort is very close to standard. Over large variances in the road it becomes obvious that the car isn't moving as much on the vertical plane, however there is no jarring or bouncing.

Handling is great. Very little body roll and plenty of predictable grip. When the back steps out a little it is very easy to bring it back in line with a small amount of correction.

One thing I have yet to test is the anti-dive characteristics under heavy braking.

Hi Kenneth

I have a set of ISC's and with the same spring rates as yours and are set up with the spring just captive (ie when the car is on a lift the spring measures just under 180mm) and my car seems very low. So low that I scrape over pretty much every gutter/driveway and from what one garage said the height is illegally low.

Do you know what the length of your front springs are when the car is on a jack ie when there is no weight on the wheel ? I am wanting to raise my car a bit and thinking (based on the height drop you describe) that if I tighten the front springs a bit I can add a bit of height.

Thanks

 

[Kenneth]

You should have both height and preload adjustment. Having the spring just captive is the preload and you shouldn't need to do much with that.

Do you know what the shock body adjustment is like? Mine is pretty much at maximum height (don't want it that low due to roll centre changes causing excessive body roll)

I think I have preload on the fronts though, as much as I could get with the spanners by hand. Rear is just captive because otherwise there isn't enough static sag in the rear.

 

[aiwasaki]

Thanks for your reply Kenneth.

My bottom bracket is set to the maximum height. The guy at the garage showed me that this was the case via the hole on the side of the bracket that you can see the thread through.

I was hoping if I wind up the preload a little I can raise the car. Although I am a little concerned with doing this as I don't want the ride to become uncomfortably hard. Perhaps I can counteract this by lowering the damper settings. From memory I have mine set on half way between max/min

 

[Kenneth]

half way between max and min would give quite a hard ride on normal streets. I use 6 front and 4 rear if I recall correctly. That may have been before I moved rural where I need a bit more to stop grazing the bumper on the ground over bumps and stuff.

You can only just see the bottoms of the threads through those holes in mine. if you can see the full thread, it isn't as high as it can go. Be careful to leave enough thread on for safety though.

 

[steveP]

It sounds like your bottom bracket is no where near the max height. They should go higher than stock.

You should never adjust the spring pre-load unless your coilover doesn't have base height adjustability.

 

[aiwasaki]

Yes, you can just see the thread through the holes.

Might try softening the dampers and then increasing the preload. Fingers crossed

 

[aiwasaki]

It sounds like your bottom bracket is no where near the max height. They should go higher than stock.

You should never adjust the spring pre-load unless your coilover doesn't have base height adjustability.

Hi Steve, my bottom bracket is definitely at the top height as I can only just see the thread through the observation hole. There is obsoletely no way these coilovers could go above stock.

Currently the top of my tyre (which is OEM spec - 16 inch etc) is about 25-30mm from the guard.

 

[steveP]

That hole doesn't really mean much. Take the coilovers out and unscrew the bottom until it actually seperates. You will see you have heaps of thread to play with and can see how far you can actually adjust it.

Don't mess with the spring pre-load when it's such a simple solution.

 

[aiwasaki]

That hole doesn't really mean much. Take the coilovers out and unscrew the bottom until it actually seperates. You will see you have heaps of thread to play with and can see how far you can actually adjust it.

Don't mess with the spring pre-load when it's such a simple solution.

Hi Steve, I appreciate your advice, however the hole is actually extremely important as this is the maximum safe (as confirmed by two garages) height you should set your bottom bracket to.

I have a young son and would never take the risk of mucking around with the setup of my suspension beyond the recommended (safe) parameters.

 

[Kenneth]

I can't get to standard height either.

The point in pre-load adjustment is to centre the piston within the shock body. Or better still, to place it in a position which maximises the travel for the use it will encountering.

Real life usually requires some compromise though, so if you need to use preload to get sufficient ground clearance, do so. Just make sure you have sufficient travel left in the shock. I wouldn't want much less that about 75mm of static sag though. (Oh, and often the manufacturers will void the warranty if you use pre-load to set the height)

That and get used to how not to scrape on everything...

 

[aiwasaki]

Thanks Kenneth, I will try out your specs.

 

[hooter]

just ordered some isc coilovers they have a special on at the moment $1199 set

 

[hooter]

and just looked at jonsons site should have checked there first sorry jonson

 

[Black_Ice]

and just looked at jonsons site should have checked there first sorry jonson

Dont worry neale..he already sold those coilovers...

 

[hooter]

thanks Aamir feel better