Apexi just released a more affordable coilover system. These should give Tein a run for their money at a cheaper price.

http://www.rx7store.net/index.asp?Pa...ROD&ProdID=899

Just thought I would pass the info on.

Jason

 

Those look pretty nice, wonder if they are any good.

-Rob

 

What are the spring rate/shock rate specs?

Jeremy

 

Very interesting!

 

whenever i get the time/money to do suspension upgrades, i'm probably going to go with these. mind was set on the tein ss, but these are the same price and also include upper mounts! so many parts, so little money.

chris

 

Jason...have any info on the specs for the A'pexi coilover?

Also, are you going to carry any Endless products? I'm interested in the Zeal coilovers.

 

Do they mention the difference between these and they more costly units.

 

Man I just blew $600+ w/ you Jason.... Oh well what's another grand......LOL
Seriously though very nice.. Can't wait for some feedback on em.....

 

I would like to know as well. Also what about the spring diameter size, have any info there?

 

These are now in my garage!

They are 7inch 12kg/mm front and rear (672 lb/in) and they're 3.5 in dia.

Very nice quality! I'm very happy with them, so far.

I will soon have a set of HKS Hyper-D coilovers for sale! (pm me if interested)

 

I have the spec sheet at work and will post it.
I can get endless products, shoot me an email and I will send over some pricing.

Jason

 

You know you could use a nice set of coilovers.

Jason

 

the most important aspect of an aftermarket coil-over is:

SPRING RATE.

get it wrong and you will be very unhappy.

i remember my chassis guy flying home to his shop to get a 425 pound spring for my right front corner during the 4 hours between practice and qualifying at IRP. he got back in time to make the swap. i sat on the pole, won the race and broke a 6 year track record. the spring we replaced had a 450 pound rate!!!!

all that for 25 pounds on one corner of the car!

the right spring rate is magic. the wrong rate is...

With regard to the fd….

the stock spring rate of the fd is 263 front and 195 rear.

should you wish to just change springs a few options i recommend are:

tein s tech---------------440 front------320 rear
tein h tech---------------390 front-------290 rear
eibach pro kit------------350 front-------255 rear

i have heard lots of people tell me that just upping the rate with any of the above options literally transformed their car.... some say it is their favorite mod. The above springs work very well with the excellent non R1 OEM shocks. By far the best bang for the buck. BTW, I have a shock dyno so I am not guessing when I talk shocks.

taking it up a notch to coil overs...

i run RS*Rs... no longer available 432 front and 378 rear. i consider that rate to be close to optimum for combo street and track.

as it turns out, RS*Rs were just rebadged Tein HAs. which are now Tein Flex. 560 front and 450 rear is the current Flex rate. Jason offers Tein.

i consider 560/450 to be the upper end of an acceptable aggressive street/track spring rate.

if you want to run something higher than that rate try pumping up your tires to 75 pounds and go for a drive. it won't be pretty. It also will not be fast.

Stiff is not fast. Stiff is sliding around, overheating/grinding up your tires, or having your tires see alot of air time as they bounce over the bumps. An overly stiffly sprung car might give the appearance of fast as it responds faster to steering inputs but as soon as the suspension loads the tire is in over it’s head and loses grip.

Increased roll stiffness from higher spring rate does not change the amount of lateral load transfer in a corner. It merely speeds up the time in which the load transfers making it more difficult for the driver to drive at the edge of control. Watch the restart of NASCAR race as the drivers warm up their tires… notice how free the cars are, how they roll…

The fd has a true racecar suspension. Double unequal length A arms front and rear. As such, when the wheels go into bump, negative camber is increased to offset body roll maintaining the original static camber setting.

Not true w greatly inferior Macpherson strut cars. No negative camber gain- so when they roll in a corner 3 degrees the outside front tire rolls 3 degrees positive from it’s static setting! That’s why they have to run way too stiff shocks unlike the fd.

Back to coil overs and spring rates.

I was looking over Jason’s broad product line. All the coil-overs look alike… sure some are green, some red, you’d almost think you might buy your favorite color.

Of course they differ as night and day…

So here’s the info you really need to make the right choice.

Coil over spring rates

Tein
Front Rear
Basic Damper----------------unadj shock------670---------560
Super Street--------------------------------------670---------560
Flex--------------------16 shock adj-------------560---------450--------------MY PICK
RA---------------------------------------------------900---------900----are they nuts?????????
RE---------------------------------------------------900---------900----------ditto

Tanabe
Sustec Pro-----------------------------------------447---------335----nice…

JIC Magic
SF1---no adj---------------------------------------558-----------391-----nice
FLT A2--------------------------------------------- -670------------503----too much rate

HKS
Hiper-----------------------------------------no rate given as progressive. I don’t like progressive as they are always changing rates in the middle of a corner. linear is where it’s at.

Apex
N1--------------------- I believe you can interchange different rated springs with these which is what you should require as you get toward $2000.

N1Exv-------------32 adj-------------------------------670-----------670 too stiff

Notice the rate is the same for the front and rear…the rear should be softer.
the primary challenge for all front engined rear drive cars is to hook up the rear… that’s because the rear tires not only have to stick and support roughly half the car’s weight but they also have all the power feeding through them. It is all about rear stick. That’s why you run larger rear tires, less rear air pressure, less or no rear swaybar and softer rear springs and shocks. Notice all of the above springsets excepting the Exv, are lower rated in the rear. If you run even rated springs in an fd the rear end will be all over the place.

Give the very attractive price of the Exv and the fact that they are offered by Apexi, a truly premium vendor, I would be very interested as to looking into a swap…finding another set of, say 450/350 or 550/450 springs that would fit.

Unless I was planning to just use them on a drift car I would not run them at 670/670.

Another item re coil overs… “Pillowball mounts”

the entire corner weight of the car sits on the upper spring. Mazda wisely added an approx 3/8 inch rubber insulator between the car and the spring to absorb the incredible amount of roadshock.

“pillowball” upper mounts remove all the insulation and replace it with solid steel. Since the suspension geometry is scribed by the A arms and has nothing to do with the upper spring mounting there will be no measureable positive effect performance-wise. There will be slightly less compliance which will reduce traction.

For this you get a huge amount of transmitted NVH. Skip pillowballs.


This is all offered constructively so forum members are better able to make the right choice. The FD is a great car and it does respond to a bit more spring rate.

Unlike horsepower, too much spring is not a happy situation and is slower on a roadcourse or aggressive street driving.

Jason has an excellent broad line of product. Pick the rate that fits your application.

Good luck,

Howard Coleman

 

i was always told, especially in drag racing that contrary to popular belief, you don't want to run a softer spring rate in the rear. with a stiff spring the weight and gravity of the car is pushing the tires to the ground, where as with a soft spring gravity is forcing the tires into the suspension and car itself. that's why my HKS DRAG coilovers are so stiff in the rear, with soft springs in the front you allow the nose of the car to lift and shift weight to the rear where the stiff spring push the wheels down.

 

Even spring rate = drifting/show setup. If you want to do anything else I agree with Howard, get something that is 20% or so stiffer in the front. For autocross I've seen folks have a lot of sucess with the FLT-A2s, I'm not certain about track applications or if they would have done better with the slightly lower rate of the Flex or SF1s.

 

Fantastic post Howard

 

FYI, the fastest track Rx7s I've been around ran around 900lb springs in the front!!! I was amazed how well this drove on the street with Koni yellows.

 

my comments relate to street. aggressive street and road course only. there are many on the forum that are highly accomplished as to autocross, drag racing and drifting. i invite any comments from them with regard to the very different suspension requirements.

howard coleman

 

Nice info howard, I guess I made the right choice going with the flexs

 

Amazing post Howard. You=The Suspension Master!

 

I just rated this thread. Thank you Howard. Now how bout someone puts this over in advanced tech for easier access...

 

Thanks for the advice howard

 

I always wondered what the big deal was about regarding "pillow ball mounts" myself. Quite a few guys were recommending them when I was shopping for coilovers, but after checking them out, I saw no real advantage to the pillow ball mounts for my usage, which is what Howard was referring to (street/roadcourse).

I'm perfectly happy with my Koni yellows at 550/450 on the street and occasional track day (actually, more like rare lately... )

 

Howard what do you think about Zeal/Endless suspension setups?

Such as the S6
(http://www.endlessusa.com/products/p...24&cid=14&pg=2)

and the b6 model
(http://www.endlessusa.com/products/p...19&cid=11&pg=3)

What spring rate would you go with? they offer either (9 kg/mm / 8 kg/mm) or (11 kg/mm / 10 kg/mm)

 

Once again the FC owners dont get a corresponding model