Tokico D-Spec?
05-18-2007, 06:41 PM
#1
Tokico D-Spec?
Hi, I have silkroad coilovers with 10kg front and 8kg rears...I am not to fond of them, and I am thinking of going with Tokico D specs with swift springs...What is the stiffest spring rate you can run on these...would they be a complete downgrade from silkroads? My 350z is mainly for drift, but I occasionally do Autox and Roadcourse
05-19-2007, 08:01 AM
#3
I have the shock dyno graphs for the DU3742 and DU3743 (front) and the DU3744 (rear). At full stiff they're between 3,000 and 3,500n at .3mps so I think you can run around 550 lb. in. You do start losing digression at settings above the mid-point adjustment and rebound develops a nose that might pack down the springs on a bumpy track. Also, the rears are slightly softer in rebound then the fronts and significantly softer in compression (both good things in my mind).
05-19-2007, 10:39 PM
#4
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On the same subject, who makes a higher rate spring to run with these. basically i'm looking for something with a close to stock ride height ( no more than 1/2 inch) and in the 400 to 425 lb range.
05-20-2007, 07:44 AM
#5
From my post in the Spring Question thread:
Aftermarket suspension manufacturers are a surprisingly conservative bunch. For 95% of their customers, maintaining or slightly increasing understeer while lowering the car to give it the "racer" look is the best way to go. If I was building and selling a street suspension kit, that's what I would do. You never know how really inept and litigeous your customers are.
In 2006 Nissan changed the suspension balance on the 350Z by increasing the rear spring rate to 427 (look for a spring with two red and one purple dot) thereby decreasing the basic understeer in the chassis. Unfortunately, all of the aftermarket spring manufacturers I've contacted are selling the same 2003 through 2005 spring set for the 2006 models. That just makes things worse. H&R is the only one that i know of that even acknowledges the spring rate difference in the 2006 models. Their sport springs have a working rate of 370 front and 400 rear (I've got a set here I'll sell for $250 if anyone wants it).
Personally, I'm probably going to have National Spring spin me up a set with 390 front and 530 rear rates as a test to see if keeping the 25% rear bias at a higher rate works for the car.
In 2006 Nissan changed the suspension balance on the 350Z by increasing the rear spring rate to 427 (look for a spring with two red and one purple dot) thereby decreasing the basic understeer in the chassis. Unfortunately, all of the aftermarket spring manufacturers I've contacted are selling the same 2003 through 2005 spring set for the 2006 models. That just makes things worse. H&R is the only one that i know of that even acknowledges the spring rate difference in the 2006 models. Their sport springs have a working rate of 370 front and 400 rear (I've got a set here I'll sell for $250 if anyone wants it).
Personally, I'm probably going to have National Spring spin me up a set with 390 front and 530 rear rates as a test to see if keeping the 25% rear bias at a higher rate works for the car.
05-20-2007, 08:41 AM
#6
Originally Posted by betamotorsports
I have the shock dyno graphs for the DU3742 and DU3743 (front) and the DU3744 (rear). At full stiff they're between 3,000 and 3,500n at .3mps so I think you can run around 550 lb. in. You do start losing digression at settings above the mid-point adjustment and rebound develops a nose that might pack down the springs on a bumpy track. Also, the rears are slightly softer in rebound then the fronts and significantly softer in compression (both good things in my mind).
John, would you be game to dyno Koni sport SA's? I am running them on the rear, but I can sub some other shocks to send you a complete set of Koni's. I'd love to see a graph of both shocks each at 1/2 and full settings. Please let me know, I'll pay for shipping.
05-20-2007, 09:06 AM
#7
Originally Posted by terrasmak
On the same subject, who makes a higher rate spring to run with these. basically i'm looking for something with a close to stock ride height ( no more than 1/2 inch) and in the 400 to 425 lb range.
And you would not want to run such a setup on oem dampners.
I do know of a way that you can have a 448/427 setup that would be within the ride height range your looking for. It would involve Tein tapered springs in the front and oem 04.5+ rear springs. For the Tein springs to work you would want to either run Koni sports or Tokico D-specs.
The Tein tapered spring allows you to run the oem upper shock mounts, but they cannot sit in a oem based lower spring seat. You will need Koni threaded coilover parts ($115). And you'll need to make a adaptor ring the allow's you to sit a 70mm I.D. spring on a 65mm I.D. seat*. On Koni shocks the Koni coilover parts sit on the shock where the removeable spring perch sits. On Tokico shocks you use a dremel and reduce the diameter of the metal collar that sit's at the very top of the shock body, non issue since the reducing it's size alter's nothing functionaly. Then the Koni threaded part sit's on the upper portion of the lower spring seat of the D-spec shock.
Here's the setup with Koni front shocks
Koni shock without it's lower spring seat
Koni theaded coilover part
70mm to 65mm adaptor I made out of 6061
Tein tapered spring
show's why the adaptor part is required
shows how the Tein tapered spring cannot sit on the oem lower spring seat
installed on the car
*Bit of important advise. The adaptor ring needs to be machined better then I did in my garage. Mine has some play to it around the Koni coilover parts and is the source of in a clicking noise I would get now and then.
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05-20-2007, 09:41 AM
#8
Originally Posted by betamotorsports
From my post in the Spring Question thread:
H&R is the only one that i know of that even acknowledges the spring rate difference in the 2006 models. Their sport springs have a working rate of 370 front and 400 rear (I've got a set here I'll sell for $250 if anyone wants it).
H&R is the only one that i know of that even acknowledges the spring rate difference in the 2006 models. Their sport springs have a working rate of 370 front and 400 rear (I've got a set here I'll sell for $250 if anyone wants it).
Uhg, all those progressive coil's for a pretty wide rate spread, must have at least 125lbs between inital and final. How did you end up with them, kind of puzzled
I avoid progressive springs at all costs, certainly nothing that binds to change rate or has a wide spread.
05-21-2007, 07:08 AM
#9
How did you end up with them, kind of puzzled I avoid progressive springs at all costs, certainly nothing that binds to change rate or has a wide spread.
In general I'm OK with progressive springs on a car that's driven on the street. As you do, I avoid them for track cars mainly because I sometimes end up chasing my tail when adjusting to the track, driver, or some handling problem.
Regarding the dynoing the Koni Sports - I don't have a shock dyno myself but I'll call Gordon at Koni to see if he has a chart.
05-30-2007, 02:03 AM
#11
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Originally Posted by betamotorsports
In 2006 Nissan changed the suspension balance on the 350Z by increasing the rear spring rate to 427 (look for a spring with two red and one purple dot) thereby decreasing the basic understeer in the chassis. Unfortunately, all of the aftermarket spring manufacturers I've contacted are selling the same 2003 through 2005 spring set for the 2006 models. That just makes things worse. H&R is the only one that i know of that even acknowledges the spring rate difference in the 2006 models. Their sport springs have a working rate of 370 front and 400 rear (I've got a set here I'll sell for $250 if anyone wants it).
What kind of problems will you run into if you use '03-05 springs on the '06-07 models? Would the aftermarket springs cause the car to have more understeer than the stock suspension.
Last edited by Sensi09; 05-30-2007 at 02:31 AM.
05-30-2007, 08:01 AM
#12
What do mean makes things worse. More understeer
What kind of problems will you run into if you use '03-05 springs on the '06-07 models? Would the aftermarket springs cause the car to have more understeer than the stock suspension
I don't think you would have any problems, the car would just exhibit more understeer at the limit. Also, please keep my suggestions in context. I'm always talking about driving a car at 10/10ths on a race track lap after lap. That's where the balance differences we're discussing here really stand out.
Pretty much any car can feel good at 8/10ths with an upgrade in springs, ARBs, and shocks. That's what most aftermarket manufacturers shoot for and its the correct thing to do. The car feels better, is more neutral, and transitions better at that level of driving. But at the tire's limits, when you're at the top of the slip angle curve, most of the "Sport" aftermarket setups kinda give up and the car rides on the bump stops. That puts the car in a basic understeering mode as designed by Nissan.
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