Suspension advice please; 2,400 lbs., street legal
 

Seasons Greetings All,

I haven't started a build thread yet, want to get suspension figured out first. I'm building a street legal, gutted, 99 base. About 2,400 lbs., less after about 2 years. So, about 50 lbs. less than SpecB minimum.
75%? autocross/25%? street suspension. But driven mostly on the street on rural back roads that are in excellent shape. No traffic. No in town driving. Purely for pleasure driving. Corners, corners, corners. Don't care about top end or competing. No rules. Fast into corners.

$3,000.00+ suspension budget first year ($300.00 month). $3k - 5k second year and so on. The big crimp is doing it over time. $10k-ish total?

I'm assuming that EVERYTHING is worn out and it all needs refurbishing. It will need coilovers since it keeps rising the more the weight is removed. I'm only familiar with Koni Sport with custom adj. springs and Koni dbl. adj. race shocks (loved but out of my price range). This is my first Porsche. I'll do my own alignments. Fwiw, was comfortable with 2.35 - 2.5 hz. suspension and RA1s on last street project, could go a little bit higher with proper dampers.

Here's what I'm thinking for first year;
PSS9s - would prefer a step up but budget. Can get these for $2k. Has availability improved?
Front camber plate, rear upper shock mounts (front camber to eventually assist GT3 lower arms for more track?) $1,000.00
Maybe another $500.00 for stock tranny/motor mounts, other stock bushings due to cost. Upgrade later.

2nd Year;
Square setup with Toyo RA1 235/40/17 (24.4"x 9"- run wide), Jongbloed SpecBoxster 17x8.5, $349.00. Or maybe Yoko A052, etc. Will 9" tread be enough with 13/1 whp/lb. dry?
Drop about 100-115mm?, plus 3/10' drop from tire diameter. About -3 camber, -2.5, etc.
GT3 arms, etc., etc..

After first 2 year phase will drop weight more and will also be doing extensive body changes - purists run now!

Thanks for reading, your feedback is most appreciated.

is there a question?

PSS9 are being discontinued and have always been a pretty big compromise in performance. If you want to get serious about suspension go JRZ. A huge leap in tunability over most budget coilover options.

GT3 A-arms are a must have IMO

Yes, thanks, I'm asking if I'm headed in the right direction. Perhaps alternative suggestions.

I looked at JRZs and am also waiting to hear back from TrueChoice re. dbl. adj. Konis Sports since dbl. adj. race Konis aren't available. I'd have to wait a good while due to budget constraints but something to consider. I slotted GT3 arms for second year when also purchasing RA1s when lots of neg. camber is required. Thanks.

not sure what tires you plan to run your first year, but you will not enjoy yourself on R comps without the added camber. Buying camber plates would be a waste imho.

Get yourself the GT3 arms. I'm personally very pleased with the Feal coilovers I run. You can set them up with whatever spring rate you like and while not MCS or Ohlins level quality, for my car, I'm more than happy at the $1700 I paid.

The rear of the car has more than enough camber adjustment as is, so I wouldn't buy adjustable rear plates. if you lower the car though, you will need adjustable toe links. I went megan racing and they are fine for the price.

So for $3600, I would do the following:

Feal road race coilovers (they come with front and rear camber plates). 550lb front, 600 rear springs $1,700
GT3 front control arms. $1200 or so all in
Adjustable rear Toe link: $200 to $400
New meyle control arms rear and new thrust arms all around $500

With a good alignment, that will be all you need to do serious work on the street or track. Ride will be firm but not hateful.

2nd year, I'd add some adjustable tarret swaybars and better endlinks

+1 This is an excellent solution.

The GT-3 adj lower control arms are a must-have ($1200).
Any coilover will require the adj rear toe link ($400)
Use the remaining budget to buy the best set of coilovers you can find for the remaining $2,000.

No, wouldn't do Rs on low camber, would use my current crappy old potenzas. No camber plate for rears; Tarrett/Elephant type with monoballs.

It's unusual to find decent coilovers for $1,700, especially with top plates but will check them out.

Ok, I'll look into this approach, Quad, thanks.

Thanks, thstone, any other coilovers I should check out?. For that price Fortune Auto has very decent stuff. Asian parts that they custom for you here. They have them for a lot of Porsches but was surprised to find nothing for older Boxsters.

Also, thanks Jon, for getting me started. :)

I bought a set of "raceworks" coilovers. They're around $1500-ish, as I recall. I've not yet installed them but on inspection they seem to be quality items.
They received high reviews from several people I trust.
Two-way damping adjustment, etc.

Fwiw

Sent from my SM-G970U using Tapatalk

You're doing pretty much what I did to mine. (I've got a thread that might be helpful, if you're interested.) Mine started out as a budget track car project.

With my car COMPLETELY gutted, and a roll bar welded in, it's still just a bit over 2400lbs. And I mean completely gutted; all carpets, sound insulation, even the whole dash assembly gone (gauges zip-tied to the steering column, that sort of gutted.) Just food for thought.

You wanna do this on a budget? I run Godspeed coilovers off ebay for under $900. Done multiple races, and for a budget build, they're incredible bang for the buck. That's all I've done to the suspension on mine, and at the track and pushing hard, I don't feel left wanting. Adjustable spring rate, dampening, ride height, and the fronts have camber plates.

As for tires, Federal 595 SS or the 595 RS-RR. Yes, there are better tires out there, but not for the price. Performance per dollar is great, especially with their longevity.

Both of those things will save you some cash, so if I may, allow me to suggest some alternatives. The biggest would be a proper seat. In my experience, the stock seats on the 986 allow you to slide around a good bit. That, as well as a quality short shifter and a suede wheel in slightly smaller than stock diameter tie the driving position down.

I'll check them out Maytag, thanks. What size springs?

I've followed your build all along, and it's been very helpful. No engine swaps for me, though!
Familiar with Godspeeds from watching other builds. What size springs?
Seat, steering wheel, shifter and linkage are in another budget category and seriously needed.
Lowering the weight is one of my obsessions so that is a fun project.
Thanks, WS.

Hah, yeah, don't worry about that. That's just me getting carried away.

Godspeed springs? No clue, whatever came on them.

Lowering the weight is definitely addicting, especially in regards to performance per dollar.

I got exited of these after your above writing... untill I receive quote from Godspeed for the SHIPPING ONLY of set of 4 coilovers to Finland - costing $450 USD...!!! I wonder if they reserve one flight ticket in an airplane for the delivery guy both ways across the Atlantic to deliver these :eek::confused:

holy cow.... that's insane. Then again, Godspeed is a California company. For Finland, one of the Euro companies might be less expensive.

Although, even at $1350 USD including shipping, ($900 + 450 shipping) that's still not bad. Weigh your options, make the best choice.

Godspeed does not list coilovers for Boxsters and Amazon lists them as No Longer Available.

RaceWorks 400/450 are about $1300 with camber plates.

Since I haven't found coilovers under $3000 I'd be satisfied with, going with $1300 RaceWorks would really free the budget up by about $1500 since top plates are included. RaceWorks used to specialize in 986/987s when they were RennenWerke. Even if they aren't awesome, they would at least allow for height correction for bodywork. If they're fine, so much the better..... I smell GT3 arms in the near future. :)

By the way, windshield and frame is coming off eventually. Probably a bikini for this upcoming summer.

Hmm, not sure why they're not on their website. I found them on ebay, however, if you're still interested in them. https://www.ebay.com/itm/Godspeed-MMX3830-MonoMAXX-Coilovers-Suspension-Kit-For-Porsche-Boxster-986-96-04-/352304658612

Exact same ones I have.

WizardSmokey, I emailed them;

"These coilovers are currently out of stock in U.S warehouse. As Godspeed's authorized dealer we could have it drop ship straight from the manufacture in Taiwan , Will take roughly 7 business days to get to you , we will cover express international shipping ($840 with free shipping) ."

Their springs are 392/692.


I'm still looking at a bunch of options but will go the cautious budget route. Including tires/wheels the suspension will still run 6-7k minimum and will likely be considerably more but that can be stretched out. My original estimate was 10k.

That's an odd spring rate. Look at feal

They are. Raceworks (400/450 lbs.) are the same price as the Feal economy but I'll contact them tomorrow. Thanks.

Hasbro:

With the low weight that you are going to, you are looking at a corner weight of about 540 lb on each front wheel, and 660 lb on each rear wheel.

With these corner weights on the 986 suspension geometry, you only need about 330 lb/in springs in front for a 2.40 Hz frequency, and 430 lb/in rear springs for a 2.56 Hz frequency in the rear.

If you are going to autocross at AMS, I would not go much over a 2.5 Hz frequency as there are some surface changes where you need compliance to avoid upsetting the balance.

If you know what natural frequency you are going to run, you really don't need multi adjustable dampers. Just get some high quality single adjustable dampers set up at around 70% of critical damping force, and you are good to go.

That said, the biggest bang for your buck is going to be camber control. For that, you need either GT3 LCA's or camber plates (or both) along with an adjustable front bar. These McStrut suspensions have awful camber curves, and you must add front bar to stop the dynamic camber change that makes the stock configuration understeer like a pig.

Good luck.

Thanks, LAP1DOUG. In November I spoke with Chuck at Elephant re. their Vonn's non adjustable coilovers. With my budget requiring a drawn out time line I would have to save up for a good while. Not a horrible situation but it would delay some of my other concurrent projects such as bodywork and a ton of refreshing. An economical route would allow me to move on, however, down the line, higher quality parts would be desired. I guess I need to determine my priorities! Therein lies the rub.
I really like tinkering with suspension adjustments so with non adjustables there would still be adjustable bars front and rear?, tire pressure, yada, yada. Maybe go with even lighter springs?

I appreciate your weighing in. My last project involved struts and an engineer on that forum made a wonderful suspension program for that specific model. It was the best tool ever and it taught me a lot so I still want to think in Hertz for starters.

Consider the Vorshlag camber plates. They allow for both camber and castor adjustment. They were great to work with and turnaround time was super quick.

Wow, time has flown!

Thanks to everyone's input I have pretty much narrowed suspension parts down (to start out with) and should be ready to get going here soon. Been saving my pennies in the meantime.

To review, this is for a 2,400 lb. "street rat", for cornering, don't care about top end or fitting into a sanctioned group. On the street, can go into corners fast, not as much emphasis on mph coming out of corners. I'm anticipating a lot of adjusting with the square setup. I'm concerned there won't be enough tread.

- Tires; Toyo Ra1s, 235/40/17, squared. 24.4" diameter, 9" tread (wish I could go wider). Lower gearing, a little lighter in the rear, warm up fast, don't cycle out and handling keeps improving as it wears to the end. Will lower car at least 3/10" without suspension adjustment to help with McPherson's camber problem the more it compresses. They handle a smaller width wheel very well.

- Coilovers; Feals, stock springs for now until weight is attained. Do I need the adjustable bump stops?

- Lower GT# adjustable arms for front for now rears later.

- Adjustable front bar.

- Adjustable rear toe links, front and rear thrust arms, rear control arm links.

- I will also replace tranny, motor mounts.

Sound good?

edit; I also have a paved 1/6 mile "track" that I can play on after hours. Just need to lock the gate. Lots of different cambers and elevation changes. :)

BUMP!

Anyone try the RaceWorks coilovers yet?

They do have an option for 986s now, and you can select different valving, spring rates and spring brands, and adjustable camber plate or pillowball mounts. Prices start at $1,300. I was going to rebuild my H&R's but this is starting to look like a great option.