HELP! Coilover Choice!

[rextreme]

Ok guys.

Here in Japan I have access to about 300 different types of coilovers.

I have read all different stuff and seen different things on DVDs and stuff.

I\'ll be running mostly in the mountains, with a bit of track use. i can put up with a little stiffness. I have Kei Office 14K now and its a bit bouncy on the street but they are in need of an overhaul.

I have extra grip on the front. 255 and 255 rears Neova high grip radials but not S Tyre (semi slicks.)

Most track cars in Japan run 18F/18R or 16F/14R about pan rate for the track with 17" S-Tyres

They then use this rate or higher on the cars in the Touge Battle DVD\'s
16F/18R with 17" 255 radial tyres or more recently 18F/18R

Other people have stated that less pan rate is better for handling

I am guessing to allow for squat and bite.
Amemiya recommends long stroke is best. But I can\'t afford RE-Spec Quantums.

I am totally confused by the choice.

More expensive shocks usually have higher pan rates

Japanese makers Like Tein Super Racing , RE-A and Feed all make between 16K and 18K pan rate spring shock sets but these are track focussed.

So I am guessing some where around the 10-12 mark would be ok.

Tein equivilant is Tein Mono Flex. HKS is Hipermax II Sport

I had old Hipermax on my old car and they were crap on the circuit.

Ive read mixed reviews about Aragosta. Good ride but damping is not great.

Any recommendations....

HKS Pro pfr ?
Zeal Function X
Tein Mono Flex
Apexi Evolution
Ohlins DFV
JIC FL TAR

etc

Nothing is really out of the question.

Russ.

[shaunwil]

2nd time I\'ve mentioned this thread today :p

http://www.rx7club.com/showthread.php?t=723617

Shaun

[rextreme]

It\'s a good thread

I have read a lot of stuff. from him last night. in other posts also.

I am still a bit confused for choice though.

Why does every Jap tuner run high rates?? They Recommend them for S-Tyres and Circuit use mainly. I guess these cars run a lot of aero and most other components are changed.

Miguel runs custom bilsteins that stick like glue. I\'ve driven this car a lot and it does handle extemely well. Spring rate is lower also.

I have a bit of aero on the car.

After reading... I am thinking about these and some sway bars.

Trust Greddy Type S 10F/8R with Rubber Upper and electrically adjustable from in the car.

But they are gas filled -- not OIL? whats the difference?

Bonus... I can get them very cheap.

Others I considered and looked at. But these all a little different. Most have pillow tops which have been stated as unnecessary.

Aragosta standard 10.3F/7.8R  Expensive
Tein Super Street 8F/7R  
Auto Exe STS 12F/8R
RG JTC-N1 10F/8R
Endless Function X 11F/10R Katayama SPL
Endless Function X 11F/10R
Apexi EVOlution Street 12F/10R
HKS Hypermax III Sport 12F/10R
HKS Hypermax III  8F/8R
Tein Mono Flex 10F/10R
Buddy Club Jr 10F/10R
Buddy Club Racing Spec 10F/10R

[rextreme]

I just checked.

disregard gas oil statement...

Trust Greddy Damper type S are the exact same and re-branded as
RE-Amemiya new Street Damper Series.

I think I will get them.

Russ.

[shaunwil]

I do remember reading somewhere that the Japanese racers preferred the stiffer suspension because of the interest in drifting on and off the track.

I\'d Love to go for some better coil overs but I\'d definitely get something that had a range of springs available. Alot of stuff like whiteline usually have a vast array of spring heights and rates available too.

Shaun

[Nik da Greek]

It seems from my admittedly limited experience that Jap springs tend to be linear in rate, that is they deflect the same amount at the start of their travel as at the end, and the same amount of force deflects the spring the same distance no matter where in the shocks travlel force is applied.
 
European dampers tend towards progressive rate springs, more like motorbike suspension, where the spring deflects comparatively easily to begin with, but resists more strongly the more it is compressed. This means that small bumps are absorbed very compliantly, but larger bumps will compress the suspension into the harder range of it\'s travel.
 
This is also a cheap way of achieving high and low speed damping characteristics without introducing loads of different shim stack profiles. (High and low speed refers to the speed with which the shock is compressed, not the speed of the vehicle!) High speed is the deflection of a large, sudden bump, low speed is the absorption of cornering forces that may compress the shock just as much, but not so violently.
 
Bottom line is, have linear springs if you do loads of track work, where the surface is smooth and the primary concern is control of cornering forces. If you live down a rutted cart track and drive through massive potholes every day, get something progressive. And don\'t worry too much about separate high and low speed compression damping adjustment unless you do loads of track work.
 
Not all shocks are the same, even from the same manufacturer. The Ohlins shocks made in Japan are nothing like the genuine Swedish ones (Ohlins is owned by Yamaha, but not all that glitters is gold, if you know what I mean).
 
I think the main appeal of gas filled dampers is that it makes it easier for control of the damping degradation through heat (friction) and oil breakdown (long-chain molecules being mashed up by getting fired through small holes in shims), giving more consistent and predictable damping.

[rextreme]

Yes, almost all are linear in the above selection

Anyway, I do want to have fun so I do want a little tail sliding. so 10/8 should be a good compromise.

Thats why I DONT have semi slicks. I borrowed some and it was so boring to drive. No wheel spin at all.

A bit like my old WRX. Too much grip to be any fun. except in the wet. Then it\'s just a bit scary when you can\'t stop. hehe.

I have Kei Office now with 14/14 and it\'s fine. But a little bumpy.

Most Japanese mountain roads are excellent!
But the Wangan and C1 are bumpy... there are so many joins in the road.
da dum da dum etc.

Anyway... thanks for the help.. with reading and research. I think you can make educated choices these days.

Russ.

[Jake]

There are a bunch of people talking up the Zeal Function X on RX-7 club for their street and circuit balance.  With the Function X you can choose the spring rate as well and they valve them accordingly.  They are meant to ride very well.  A guy on their who tracks got 11kg/8kg as apparently the standard rates can give too much overstear.  I think he got them revalved after a while as he said there wasn\'t enough rebound and they could feel a little floaty on track.  There was talk that Endless were going to make his valving standard but I don\'t know if that happened.  He\'s put up chassis dyno plots of them before the change.  Do a search on Zeal Function X and you should find all the info. in a number of threads.

[rextreme]

I have seen many nasty bushes on second hand ZEAL.

I have been browsing yahoo for some time.

Kei office and Zeal have bad bushings in the bottom of the front shocks.
These are just ok, but many are split.



Thats the problem I have at the moment.
Front bushes are toasted.

Endless Zeal Function X 11F/10R Katayama SPL -
                                Katayama is 787B Le mans driver.
Endless Zeal Function X 11F/10R

[rextreme]

BEWARE

[rextreme]

Yahoo can tell you a lot about used parts.

Zeal are not so great.



puts you off doesn\'t it

Here is Kei Office.. mine are similar. as are most other

Thats why they are out of business.

Don\'t ever buy DG5 or anything from Keiichi Tsuchiya!

They may actually be the same... not sure.

[Nik da Greek]

That\'s nasty! Dread to think what they\'d be like on a car in the UK, with our corrosive salt bath roads we get four months of the year. Hmmm, maybe I\'ll go out to the garage and check my coilover bushes...

[Jake]

Bloody \'ell That\'s scary...maybe Zeal are off the shopping list then...You still set on the RE Amemiya street spec?

[rextreme]

new Zeal may have different bushings...

I am not sure... but those pics are real cases!

I am thinking of the Greddy Type S version actually.
The RE-A have a price premium for their sticker. about $500 more for the exact same product... different colour only

They have had good reviews from Tarzan Yamada.

Price is good.

RE-A


Greddy Type S

[ashc]

great data - looking into this myself at the mo - let us know how you get on