Streetline Or Sprintline

[Adi 0]

As I said on the PSOOC forum......the Sprintlines everytime as long as you don't mind the lumpier ride and the extra cost.

 

The Sprints and Streetline dampers are TOTALLY different. In fact the valving used on the Sprints/Sports are is totally different to most dampers made for the road and that includes the Koni Sports.

 

In top line motorsports inc F1, WRC etc....the dampers use "digressive" valving. It is too deep to go into fully now.......but basically digressive valving gives more control at low shaft speed......i.e. cornering, braking. It also gives a smoother ride at higher shaft speeds like hitting sharp bumps and potholes. The only reason why the Sprints/Sports will be at all firmer than say the Konis......is the Sprint/Sports use high gas pressure. Now they have what is a called a "nose" force....which means it takes more force to create the initial movement of the damper stroke due to that higher gas pressure.

 

I have heard many times complaints associated with dampers like Konis. They are " that floaty feeling" when encountering brows of hills etc. That is due to the type of valving used......and it been a linear valving in the damper. The digressive valving as in the Bilstein Sport/Sprint gets round those problems.

 

The good thing with the Sport/Sprints is the ride is more fidgety on normal roads. But when driving on motorways......the ride smooths out.....so giving a more relaxing ride.

 

The Sprint has a short stroke to go with -25mm springs and the Sport has a full stroke to go with longer springs.

[DrSeuss 0]

Digressive valving. Go on do explain. I'm guessing but does it use a non linear valve spacing, to lower the rate of flow at small displacements?

[Adi 0]

Digressive valving. Go on do explain

 

The valving is quite different to linear or progressive valving.

 

There are more passages and routes for the oil to flow depending on the shaft speed.

 

At lower pressure (lower shaft speed) the oil will flow thru the main piston. At higher pressure thus shaft speed.......larger amounts of oil needs to be dumped, so the shim stacks open.

This is how greater low shaft speed control is gained......whilst higher shaft speed comfort is maintained (hitting potholes etc)......thru the greater amount of oil flow. A normal damper valving would create a harsh ride due to the near lock up effect of the valving on the damper shaft.

[Ted 0]

The Sprints and Streetline dampers are TOTALLY different. In fact the valving used on the Sprints/Sports are is totally different to most dampers made for the road and that includes the Koni Sports.

 

are the dampers used in the sprintline kit different much to the Sport dampers ?

[Adi 0]

are the dampers used in the sprintline kit different much to the Sport dampers ?

 

The only difference between the Sport and Sprint dampers is the Sprint has a shortened stroke for shorter springs.

[Dino 3]

now I am totally confused......

 

- my Konis never had a 'floaty feeling' they were just hard - period (as the Americans say!)

- I want to lower the car whilst keeping a (fairly) good ride

- I don't want to knock my fillings out with every bump and pothole

- I will only ever do the occasional track day, other than that it is mostly London roads mixed with A and B roads......

 

In that case why would I choose the Sprintlines if they are firmer than Koni sports?!!??! By that rationale the Streetlines mated with Eibach springs would be perfect wouldn't they?

[fiji bob 0]

floaty over hill crests where damper movement will be relatively slow

[Adi 0]

I want to lower the car whilst keeping a (fairly) good ride

 

A standard car will have softer springs and lots of suspension travel. As the suspension travel is shortened......the spring/damper rate has to increase. As the rates increase......the ride gets worse.

So to lower the car......and keep the ride quality.......is a bit of contradiction.

 

In that case why would I choose the Sprintlines if they are firmer than Koni sports?!!??!

 

Any adjustable damper gives the all round tuning ability to change the ride/handling qualities for road and track.

But unless you are using the car in such varying conditions.....adjustable dampers are not much use.

Like I mentioned before.......there are many different needs from a damper. Ride quality is just one. But the Sprint dampers are superior in other areas where more control is wanted.

 

By that rationale the Streetlines mated with Eibach springs would be perfect wouldn't they?

 

If ride quality is of major importance.......then the Streeline dampers will suit you well. But they won't be best suited for the track. That doesn't mean they won't cope.

[Alan_M 66 1 Cars]

Adi,

 

You may know that i run Sprints on my 205 with the springs that come with the kit.

 

After getting a good deal on 309 wishbones (touch of neg. camber) and a 309 rear beam (Stiffer ARB's and wider width), i plan on fitting these to my 205 along with some Eibach springs.

 

Question is;

 

Do you think it'll be worth gaining a stiffer front ARB from a 309GTi?

 

At the moment, i find it quite easy to get the car to understeer round a corner/roundabout. Now, if i fit a stiffer ARB, surely this will make things worse?

 

From what i've read on here, fitting the 309 stiffer ARB is meant to help balance a 205 GTi with 309 wishbones & rear beam.

 

May seem a simple question, but i'm in a dilemma!

[fiji bob 0]

well going by adis previous posts fitting the 309 rear beam should balance things out because of the stiffer torsion bars and anti roll bar, i noticed the same thing when i lowered the car on a particular corner the car felt quite neutral and you could get a bit of drifting going on but with the eibach springs that feel stiffer the car understeers slightly

Edited January 9, 2004 by fiji bob

[Adi 0]

Do you think it'll be worth gaining a stiffer front ARB from a 309GTi?

 

I have known in certain situations for a stiffer front roll bar to help front end traction. That is cos it is reducing front end roll and helping the front tyres stay flatter.

However.....in most situation....the stiffer front bar will create quicker front weight transfer which will either lessen oversteer....or increase understeer.

 

On the roundabouts....the understeer is likely to be more down to an open diff and spinning of the inside wheel.

 

i plan on fitting these to my 205 along with some Eibach springs.

 

The front will become stiffer and stay flatter which can again increase front end grip. The balance of the car is likely to favour understeer again though, as you aren't stiffening the rear the same amount as the front.

 

fitting the 309 stiffer ARB is meant to help balance a 205 GTi with 309 wishbones & rear beam.

 

The problem that a few people have encountered with the wider rear axle is more oversteer thru using the standard rear axle bushes. So by fitting uprated rear axle bushes will get rid of the trailing throttle rear end movement and will leave the balance down to steering input and suspension settings...rather than the axle twist.

 

Even though the 309 rear beam may have thicker bars......you may need to uprate these further to get the desired balance.

I would say AT LEAST 21mm rear torsion bars and/or 23mm anti roll bar. The problem will be finding these bars for the wider 309 axle.

 

Another tip is to widen the rear axle even further using spacers to match the front track. From the info I've got......the front axle will be 54.4" The widest the rear will be is 54".

54" = 1371mm/rear 54.4 = 1382mm/front

 

It will help slightly by fitting 5mm spacers to both rear wheels which as long as there is 7 turns of the wheels bolts before fully tight.....you won't need longer studs.

[fiji bob 0]

im not sure fitting spacers to the rear is an option considering how close the tyres are to the arches