Yet another ride height thread... and brake options

I just acquired an 818 a few days ago. Picked it up in California and trailered it back to Houston. I'm a Subaru nerd. I have 2 WRX wagons, a turbo Baja, and a high cube container full of parts from my younger days with bigger turbos and more nitrous. Back to the topic.

1) My 818 needs more ground clearance. With the coilovers adjusted to approximately midway, there's no chance of me making the transition from the driveway to the street without dragging. I can't get enough of an angle in a single car wide driveway to prevent it. If I adjust the springs to their highest setting, and hit the driveway at just the right angle, it'll clear with a fraction of an inch, BUT rides like log wagon. I have 350# front springs, 500# rear springs, riding on 18's with 30 series rubber. I have not tried running the rear at 'normal' height and just raising the front, but I suspect that it would ride alot better. The spring rate isn't THAT much different, but it was significantly more difficult to run the springs up in the rear, which leads me to believe I was preloading them more than the fronts.

Has anyone actually installed air cups from some place like stance parts? I technically would only need them on the front. Lift up the front, back down the driveway, lower it back down. That would allow me to set the ride height back to the midrange.

Has anyone toyed with softer springs in the rear and more preload? I'd have to run around higher all the time, but this is possibly cheaper and easier to implement.

I may eventually get over to MSR for a track day eventually, but to be honest, it'll probably be a few years before I do. I have 3 kids. They like to get dropped off at school and their activities in a cool car. Before the 818, it was the CJ7... which, coincidentally, rides smoother than the 818 when the springs are adjusted all the way up.

2) I may start another thread for this question, but I'll ask here anyway. Does anyone have any experience with the wilwood 6 pot front / 4 pot rear performance compared to the subaru 4 pot front 2 pot rear? Will they stop the car a bit easier, as in provide more clamping for the same amount of pedal pressure? Or are they more for racing application to reduce fade over extended use? As stated above, I have ALOT of subaru parts. I have a set of wilwood 6 pot fronts and 4 pot rears sitting in a box... complete... ready to go... just itching to be installed on something. My 818 currently has subaru 4 pot fronts / 2 pot rears, and no power booster. It does NOT stop on a dime. People are talking about adding ABS, but I couldn't push the pedal hard enough to lock up the brakes with the current setup. Maybe I'm just getting soft in my old age.

It's tough to know where you're at without a bit more info. What is your static ride height? Taken at the 4 corners from the square side frame tubes.
I have 300#/400#, F/R springs and run at 4.5" ride height. I drag a bit here and there but that's with a 4" splitter.
Are the suspension components mounted to the S (as opposed to R) holes/attachment points.?

Welcome to FFR Forum
I have a 2014 vintage 818 that was not finished. I bought it from builder #2 to take my Ferrari Dino body.
I have sold the Subaru power and installed an Acura 3.2 V6 and six speed. I adapted the Acura control arm suspension and aluminum subframe.
I replaced the original 275lb rear springs with 500lb. My old springs are available.
I had too much ride height. I bought the Koni low height shock rod eyes and replaced the one inch extended eyes. Are yours extended?
Common practice here has been four inch ride height ground to frame rail.
My five speed transaxle is also available.
jim

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5-1/4" driver side both front and rear. 5" passenger side both front and rear. Measurements are with a half tank of gas (front mounted fuel cell) and nobody in the car. The shocks are in the S (lower mounting hole) position, which should provide more ground clearance. I have full aero but the front splitter and rear diffuser are currently removed. The rear diffuser for muffler modification reasons. The front splitter, because a snowflake has a better chance in houston summer than the splitter making it down my driveway.

The car has an sti 6speed. It's significantly heavier than the 5mt, but it is also significantly stronger. Given the power it's making, I'm not sure the 5mt could hold up. Possibly interested in the 275# springs and longer rod eyes though. How much you looking to get? How can I tell if the ones I have are extended or not?

Brite,
The FFR rear shock as configured is pictured in the assembly maual on page 129/130. My long configuration picture below.
There is room to fabricate it longer with effort.
My Hyperco 500# cost me $137 ++. I would sell the 275lb pair for $80+ shipping from SE WI. I estimate UPS at $25-30, whatever they charge.
jim

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Front engine cars want more front brake than rear. There is considerable weight shift. My 818 is about 35/65 front rear and it doesn't nose dive under braking as the Subaru would. The FFR Wilwood big brake setup has a lot more brake up front than in the rear just like you'd want in a Cobra. Doing a lot of reading here on the list, I found that a lot of people were complaining that they had to turn down the front brakes to get a good balance which negates the advantage of large front brakes. That and complaints of high pedal force for poor braking performance.

Stealing an idea from somebody who had done it, I used Cadillac ATS Brembo calipers and STI rotors front and rear and turned down the rear brakes one turn on the balance valve to avoid rear lock up. I had to make my own backing plates to mount the rear calipers. I also used a higher pick point on the brake pedal than FFR calls for to reduce pedal effort. I'm really happy with the setup. The brakes stop the car quickly and more pedal force stops it quicker without much more pedal movement. Just like you'd expect in a race car. I never have to stand on it to get it stopped. Boosted brakes just feel soft at the pedal. Don't like. With the STI front rotors, there is no E-brake so I used Wilwood cable actuated calipers for that.

If you have the big Wilwoods already, consider getting another set for the back and figure out what rotors to use for the rears. In the interim, look at the pick point on the brake pedal. If you can raise it, it will reduce pedal force.

Ed

Quote:

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Originally Posted by Bicyclops

Front engine cars want more front brake than rear.
Ed

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I'm with you that the WRX balance is WAY different than the 818. But I'm thinking the fronts still do most of the work. My 818 at 42/58% isn't far off the Cayman at 44/56% and the Cayman has massive front brakes. Given that, the CG of the Porsche is likely a higher than the 818, causing more weight shift.

I definitely had to use the Wilwood balance bar to make the rears work harder. I like the idea of going with more caliper at the rear.

I'm one of the guys complaining about high brake effort. I'm thinking about different compounds, master cyl size and modifying the pedal.
Ed, is it the Subaru brake pedal that you modified? I haven't really looked at how to do it on the Wilwood.

Yeah, I used the Subaru pedal box. The problem of course is geometry. With a booster, the rod going to the master cylinder wants to be lower which gives more pedal travel but the booster does the hard work. With that gone, we don't want travel, we want pressure and we have to make it ourselves. Higher up on the pedal gives more mechanical advantage to the foot. The FFR destructions called for a hole to be drilled maybe 3/4" higher than the stock one. I think they speced there because that's about as high as you can get and stay below the structure of the pedal carrier. I tried it there and the foot force required was way high. I would put everything I had into it and it wasn't stopping like I wanted. I went back in there and used a long drill bit right through the carrier and pedal. A lot of fun climbing under the dash and getting the clevis pin in. The brake rod enters the master at a high angle. Any higher up and it would rub on the body of the MC. It has a round end and fits into a socket and doesn't seem to have any problem with binding. I have a proportioning valve which I plumbed inline with the rear brakes. I turned it down one full turn and that seems about right. I did some reading about using different diameter master cylinders which would have been my next move if the higher pick point hadn't worked. As far as brake compound goes, I'm using the stock Delco CTS pads. I thought about more aggressive pads, but stopping isn't a problem so I haven't bothered.

Not sure what the Wilwood pedal box looks like, but there should be some way to increase pedal mechanical advantage.

Ed

Correction: I looked at the FFR destructions for the pedal box mod for manual brakes again. The hole they specified is 1/2" above the stock location. I think I went a little higher and then put in another hole higher yet for luck. That is the one I'm in now. I know that I calculated the pedal ratio, but I don't recall what it was. Here's a pic or two of my rear brake setup also:

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I looked at the Wilwood site: https://www.wilwood.com/Pedals/Pedals

They have pedal boxes in 6.25 and 7:1 ratios. You might look into which you have. Might be fairly easy to switch out to the higher ratio box.

Ed

Quote:

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Originally Posted by Bicyclops

I looked at the Wilwood site: https://www.wilwood.com/Pedals/Pedals

They have pedal boxes in 6.25 and 7:1 ratios. You might look into which you have. Might be fairly easy to switch out to the higher ratio box.

Ed

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Wow, didn't know about that. (kind of a duh! for me, lol)
Thanks!

FFR missed the boat with a lot of their engineering decisions on the 818. Their thinking on the big brake package for one, in my opinion. Perhaps they specified or Wilwood suggested the 6.25 ratio box and that never got revisited. Ask Wilwood what ratio they supplied. FFR certainly didn't seem to be interested in improving the design much other than a revamp of the front of the body and then later abandoned us.

Ed

Fwiw I went a little higher than the specified hole location, but otherwise built per the manual (reduction valve on front) with a 07 wrx donor brake system.

Pedal effort is high but I've never had an issue locking up (usually unintentionally) at autocross. And I don't particularly notice it when daily driving.

This is with hawk hps pads and Fallen RT660+'s. 215 front and 245 rear. Maybe experience with something stickier and/or wider would be different.

Sorry y'all. I disappeared for a bit. Work and family things.

The 275# springs up front and 350# springs in the back at a ride height of 5" make the car ride like a dream compared to before. I can barely get out of the driveway using a couple of old fence pickets as buffers.

That said, braking IS an issue. This thing accelerates stupid fast, but I'm pretty sure my '02 WRX wagon with stock calipers and EBC reds stops faster. If I was built like the beast, I'm sure the 818 could stop faster, I just can't physically push the pedal hard enough. I went to an empty parking lot, got it up to 30 and stomped as hard as I could and the brakes didn't lock up. I should note that I have 315 wide rubber in the rear and 285 up front.

I may try to move where the MC rod attaches to the pedal. That seems to be the path of least resistance from what I've read so far. Apparently the windshield and alot of other things have to come off to add a vacuum booster, which sounds about right, because I'm not sure how you even add brake fluid without a pump given the reservoir location.

That's a lot of rubber! I've got 255s rear and 215s front and those rub when I turn the wheel towards lock. Do you have large spacers behind the wheels? Post some pix of your car please.

Braking, like cornering, depends on tire patch. If those are really your tire sizes, you've got a lot more patch than I do. Gonna be hard to lock under any circumstances. I haven't seriously tried to lock mine since I went to the higher pick point on the pedal and turned down the rears one turn. My car stops really well. It does require significant pedal force if I'm breaking super hard, but in normal driving the force is fairly light. I wouldn't want boosted brakes on this car. It would make for too much pedal movement and spongy feel. Try moving the MC actuating rod up the pedal as high as you can get it without impinging. You should be happier with that. Another move would be to reduce MC piston diameter and trade off longer throw for less pedal effort. If you end up messing with your master cylinder, you might want to put a remote reservoir on it before the windscreen goes back on.

Ed

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I bought the green one that was for sale here a few months ago. It has been 'widebodied' to accommodate the larger tires. She's thick. As wide, if not wider than, my 02 WRX, just a few feet shorter in length and a foot shorter in height. The tire does occasionally rub up front on the passenger side, but I think I've found the issue and can remedy it.

The car exterior is a 9/10. The interior is a 6/10. The dash pad is bubbling, and peeling in areas. At some point, I'm going to want to redo the wiring as well. I'm not sure what/who was in there, but as an engineer, just knowing what it looks like behind the dash causes me grief. Include the remote reservoir suggestion, and the reasons to pull the windshield are starting to add up.

Just for giggles, has anyone tried an electric brake booster? They're kinda pricey, but if you could dial in the brakes, might be worth it. I don't mean the electric vacuum pump type. The kind that would hook up without a vacuum booster.

Nice looking car. I'm burning alcohol too. I like it. I did manage to lock my brakes from about 40 today. I was in traffic so I just did it once. It felt like the fronts and rears locked at the same time, but I'll need to play with it more. I was pushing the pedal hard, but I didn't feel as if it was everything I could do and the car was stopping very short before the wheels skidded. I'd go after the pedal ratio first before going for any sort of boosted brakes. Getting to the pedal to change the pick point probably won't be easy. Not a lot of room to get in there. If you can get under the dash somehow (maybe pull the seat?), an angle drill and a six inch long bit is what it'll take to drill right through the structure supporting the pedal. This is assuming Subaru pedal box. If it's Wilwood, it might be easier to replace it with one that has better pedal ratio.

Since yours is a hardtop, it won't be as simple as removing the windshield to get to the master cylinder. I think the glass is glued into the hardtop. I don't know what pulling the top would entail.
Ed

I think I have found the problem. If I'm not mistaken, the factory location is being used for the master cylinder rod....

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Yup. This is Hindsight's build thread post #1090:

I spent this evening and yesterday working on this and believe I have come up with the perfect brake pedal hole location: 7/8" up from the OEM hole, center to center. I tried a whopping 1 1/4" and while the car was easy to stop, the brake pedal travel was too much and the brakes felt mushy. At 7/8", it feels like a great balance. I would like the pedal to be a bit more firm, but doing so would mean increasing effort. So I think 7/8" is the magic number. I am quite happy to have this behind me. Removing and replacing the pedal assembly with the windshield in place is a serious pain in the ***! I have done it twice now in two days. To get the 1 1/4" hole, I had to remove the brake pedal from the pedal cluster. I don't think you'd be able to drill the 7/8" hole without removing the pedal either, but you can just barely remove the pin at that hole height.

Before I claim total victory, I would like to run the car on the track again but as of right now, I'm quite happy with how the brakes feel.
End quote.

He also mentions using different diameter master cylinders. I haven't measured mine lately and I can't find any pictures, but I am definitely higher than the FFR 1/2" higher than stock. Might be about an inch.
Ed

I see from the Green Car post that your brakes are 4/2 pot. Once you get your pedal ratio setup better, you may find that you'll be locking rears or have to turn down the bias on the fronts, which to me seems to defeat the purpose of having larger brakes and might be part of why you have excessive pedal force to stop. I went with equal (oversize) brakes front and rear and put the bias valve in the rear circuit.
Ed

Thanks Ed for all your help. I have no doubt the pick point needs to be changed. I have pulled the seat once already, looks like I'll be doing it again. I was hoping to pull the pedal box, but after reviewing the manual, that's not gonna happen! I'll try drilling in place as you suggested.

Let's get the pedal force down, then focus on bias. The dynamics of this car are completely different than the donor vehicle. Significantly lighter, but weight is biased to the rear. More weight over the fatter tires, but less caliper. Front tires have more contact patch than any donor possibly could have had, more caliper, but less weight. Too many variables...

Moved the pick point up approximately 3/4". It definitely improved the braking. I probably should have gone higher, but I couldn't get the drill any higher. Didn't have to remove the seat, but it was royal PITA. Couldn't get at it from the clutch side, so had to remove the gas pedal and squeeze myself further in to drill from that side. Extreme limited visibility due the steering column on that side.

Improvement is good. Being able to stop is a good thing.
Ed