I am going with a new set of Penske 8300 coilovers and considering spring rate selection so wanted to see what people are using. My intended use is kind of all over the map: track days is maybe the most "serious" use, some autocrossing, Tail of the Dragon type drives, and the occasional ice cream run.

Thoughts?

 

Lots of discussion here.

https://www.rx7club.com/3rd-gen-gene...man+suspension

 

The rates available for the Sakebomb Ohlins should be a good starting point:

https://www.sakebombgarage.com/fpspe...dfv-fd3s-rx-7/

I wouldn't go any higher than 10k for a car that sees street duty, personally.

 

One data point for a similar use-case: Spic Racer GT40R Penske 8300 w. 800F/700R.

 

It was good to define the usage, but when asking spring rates, you also need to outline what tire make/model and size you are running, what swaybar, any aero, power level, etc... to better frame your setup for better spring rate recommendations.

0.02

 

IMHO unless you are looking for the last 10/10ths on the track, go with the Tein Flex Z or the Ohlins if you feel more spendy.

Absolutely love my Flex Z's, also love that if the shock fails I can just buy a new one from Apexi, bolt it on, and I'm back on the road.

Also still VERY interested in getting the EDFC for it, it's really supposed to be a game changer with dynamically adjusting the ride as you drive. Comfy for cruising, stiff for the corners, all on the fly.

Dale

 

IMO the EDFC is over-rated. It's a neat novelty but once you've used it and dial in your desired street/performance setup (which makes doing so much quicker) it's not that much work to pop the trunk and hood and adjust your settings for the task at hand. Off the shelf Ohlins are too soft for anything other than a daily driver.

 

I should have been more specific - the new EDFC Active Pro -

https://www.tein.com/products/edfc_active_pro.html

It will dynamically adjust the dampers while driving depending on G forces. Phil, who runs Deals Gap, got it a while back and said it's just an amazing game changer - you can feel the car tighten up automatically in corners then smooth out for cruising through town.

Dale

 

EDIT: Penske might be a bit of an overkill. I kind of looked into a set recently and they are really made for track use only. They need rebuilds a lot more often than a set of Ohlins for example. Penkes are the best of the best if you're exclusively tracking it, but it can get expensive if you're putting miles on the car.

The quality and tuning of the shocks make a huge difference too. My FD sits on 10k-8k Zeal coil overs, but they feel much more smooth on the street than my friends car which sits on Cusco coil overs with the same spring rate. Zeals are made by the same company who makes Endless brakes. The 10k-8k Zeals feel a lot like a stock R1

The link has 11k/10k but I'll bet they ride nicely too.

https://www.vividracing.com/zeal-fun...5-p-23539.html

 

These are nice for as long as they last.

(I am on my third set.)

https://cdnyauction.buyee.jp/images....sc1t889419.jpg

https://buyee.jp/item/yahoo/auction/...owsing_history

They were the selling feature of the 2001 Type R Bathurst R.

Often sold with Tien Tech S.

Jesse Streeter is sending me a set as we speak.

Stock springs are referred to as "normal" .so likely the same as Type RB and Type RS (and even, possibly the springs for Spirit R).

The shocks are "Showa Harmonic Drive" and were used in the NSX in period.

.

 

I run these with Tein S springs (~8kg/6kg)
Street with some track days and drag.
On summer performance street tires (245/255) on RZ BBS wheels.
Front RB sway bar, rear stock 93 (19mm) after the rear RB bent.
Racingbrake 4 wheel BBK.

First time I hear (read) stock Ohlins being too soft, don't they run 11/11kg springs? I was under the impression that 8/6 is a sweet spot, 10/8 the practical streetable limit amd anything stiffer would remove your tooth fillings outside of the track 😅

I have yet to surpass my car's abilities with my setup. I think anyone should just drive as they want to drive, find the limits and upgrade from there.

 

I was running 11k on my ohlins and they felt great for the street but at the track they were a little too soft as i would often bottom them out on tight turns when the car was at the desired height.

I changed my setup to 18k/16k now. I dont love them on the street, they are a little stiffer for everyday use but not horrible. I can live with them

they really do shine at the track though. a 16k/14k might have been a better compromise to better favor the street driving conditions

meanwhile the spring rates themselves behave different on different coil overs. For example i couldnt stand the 8k(if memory serves)on the hks hipermax drag coils-overs but the 11k were far superior on the ohlins setup

 

Before I modified my car for serious autocross duty, I used to run Zeal Function B6 coilovers with 11k/10k springs which is 616lbs/560lbs. The ride on the streets were great, not too harsh and it handle well. Now, the car is a dedicated autocross vehicle with an occasional jaunt on the street. Then, I upgraded with Koni 2812 double adjustable coilovers racing shocks with 1000lbsF/850lbsR springs which is about 18k/15k. The car is more stable with Hoosier A7s 315s on 18x11" wheels on course with even tire wear. However, the car ride on the street is much harsher. Now, I have upgraded to Penske 8300 double adjustable with remote cannister coilovers racing shocks with 22k/18k springs which is about 1232lbsF/1008lbsR. I have a test-n-tune and autocross next month. I expect the handling to be better with the Penskes especially during transition in the slaloms and off-set gates. This is the same shocks and spring rates used on another FD RX-7 that won SCCA Solo Nationals in ASP in 2021 and 2022.

 

Is it too obvious to state that a coilover is a system? The Spring "supports" the car and the Shock dampens. Within the damper's effective design range, the system complements each constituent without the tyranny of either over the other. My stock Mazdaspeed Miata's Bilstein was a poster child for despotic dampers' heinous ride (until the coup that crowned my FM Fox coilovers). So to the point, what's the performance cost of too much spring without revalving the dampers?

 

My thoughts exactly - dampers and springs have to be valved/selected to work with each other. And a weird combo can work fantastically one place, and be horrible at another.
I've had that experience.

 

think of it like this. the spring mostly controls how much the car will pitch and roll in a corner/driver input also how much the suspension compresses in a bump. the damper controls how quickly it happens.

so for instance, if you have looked at the suspension geometry and decided that you want about ~3 degrees of roll in a corner at maximum grip, you can then set the spring rate (including the sway bars) such that you get it. in a sense the spring rate is related to the tires grip. the more grip you have the more spring rate you need/want.
for the ride quality, most of it is the damping. however, when you hit a bump, the suspension moves some amount, and the softer the spring, the more the suspension will move. the more the suspension moves the easier it is to have the dampers right to get a nice ride.

the metric for ride quality is actually Watts, they put a helmet on the driver and when your head moves it generates Watts, the more Watts you have the worse the car is.

 

Thanks for the replies, everyone, much appreciated!

More info on my car:After reading through the thread started by Dale (thanks for the link, DaveW and good read!) I am thinking something like 12kg (~650lb) front and 10 (~550lb) rear as a compromise. That is an incremental step up from my old setup, which I liked, and was a bit nervous to go too far.
That aligns with the Ohlins street/track setup is on the link from c0rbin9.

I talked to Guy at Ankeny Racing Enterprises (who used to build the Penskes for Tri-Point) and he was thinking 800 (~14 - 15kg) front and 500 (~9kg) rear as more of an all-around use setup as I am thinking. (Which is closer to what you are running, Carlos, with the same shocks.) I wanted to pick everyone's brains here first as he has built some for RX-7s more recently but specifically for autocross and you all have personal experience with a wider range of uses.

Question: are the higher-end shocks like the Penskes better able to control higher spring rates, i.e., that may be why Guy was thinking 800lb in front? Obviously valving them for the springs will make a big difference, but my point is more of is the valving that much better designed and built that they can control the inputs from a stiffer spring so the ride won't be compromised as much as a not-as-pricey shock with the same spring? If so, I might go with something more like Carlos' setup.

And I absolutely agree with the people saying the springs and shock valving need to be matched - that's why i am picking springs first and Guy will valve the shocks accordingly.

 

maybe compromise, so run yours in the front and his in the rear? 650/500, 12/9?

the nice thing is that the FD has good suspension geometry so softer suspension hurts the handling less than some other cars...

 

I just installed long stroke Ohlins with 12k/10k and it feels extremely comfortable going down city roads, and it still firm enough not to bottom out. I removed 10k stance coilovers for these, and the ohlins "feel" softer

 

Context:
1. I've driven the off the shelf / not sakebomb Ohlins on the standard spring rates. I thought they spring rates too much for rough streets. But... I was looking for a more street oriented setup that I can drive across any sort of streets and be comfortable. I was also in my mid 40s at that time for whatever that is worth...
https://www.rx7club.com/suspension-w...setup-1104755/
2. I run Penske shocks on my Spec Miata with 800 lb springs up front. Too stiff for street on that car imo.

If your intended usage is mostly street, err on the side of softer spring rates - softer that what you mentioned.
If your intended usage is more track with 200 tread wear tires, what you mentioned might be ok. maybe decrease it a little depending on your roads and how much stiffness you can tolerate.
If your intended usage is mostly track with slicks (hoosiers, toyo rr), generally might want to go stiffer

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How did the car feel on the old spring rates?

 

I run 8f/6r. Mostly street and occasional track scca day. I have my ride height at 25.5" from the road to bottom of the fender well. I find it to be a great compromise between a decent street ride and still a capable track/fast twisty car.

Prior owner, when I purchased the car, had RE suspension which was cool for the bling factor but it was 18f/16r and you might as well bolt the car to the road. It was so harsh it was not enjoyable to drive unless it would be a dedicated track car.

 

I would love to see this in action! I wish I would have gone with the Teins so I could get the pro kit as well. Would love to hear feedback from someone that has the pro kit.

 

I don't know the specs, but about 15 years ago I drove a friend's Supra with Penske shocks and it felt great in terms of street comfort. It was an autocross car from the southern california region where Guy Ankeny used to attend events, so I assume he is the one who spec'd them out.

 

My friend uses 16 kg springs front and back. They're stiff, but not overly harsh. That's where I would start for a track car.

Mine are 10 kg front and back, and they're a bit soft for pure track use, but they're actually quite comfortable on the street, as far as modified sports cars go. My MR-2 was way stiffer back in the day with 5k/8k springs.

10-12 is perfect for a mixed-use car. If you want to go any softer than that, there is no real reason to use coilovers at all. Get some lowering springs and some Ohlins/Bilstein/Etc. shocks.

Damping will have a bigger effect on comfort and handling than any particular spring rate.

Penske will suggest spring and damping rates for your particular car. Ask them. That's half of the reason you're paying so much!

I don't see a reason to use softer rears unless you are drag racing.

 

I don't see a reason to use softer rears unless you are drag racing

There are basically 2 types of drivers-

1) Drivers who like to drive just under the limit and ease off the inputs when they feel a little understeer. Easing off inputs for oversteer doesnt work, so they need understeer.

2) Drivers who like to drive just over the limit and need oversteer to manage the chassis while doing so. Understeer would cause them to have to ease off the inputs and drop below the limit, they need oversteer.

Each requires a different chassis set-up.