Advanced Suspension Mods

[Advancedynamix]

I don't currently have a set to measure (off a car that is). The 36mm bilstein coilover sleeves fit snugly on the bodies though, if that helps.

[Dragonhealer]

I wouldn't know a 36mm Bilstein if it bit me in the ass, but I'll check against our Bilstein race shocks.....

[Advancedynamix]

36mm aka "small body" bilstein is what they commonly use on the smaller roundy pounders. Midgets, dwarfs, minisprints, that sort of thing. Probably commonplace on old formula cars too.

[Dragonhealer]

OK, These are too big in that case.

[skeeters_keeper]

I was privileged to ride in Tweek and also drive Pedro at Madness. Let me tell you, these setups are insane!

I've had a few festivas rolling pretty quick at 100+mph with stock or slightly modified suspension. It's usually a little scary. Tweek was solid as a rock at speeds that were way, way higher than that. If I wouldn't have known we were nearly at redline in 5th we could have been cruising along at 90mph for how stable the car felt. Coming around an on ramp at 130 felt like doing 55 on stock suspension.

Driving Pedro was also excellent. The soft-ish spring rates with better damped shocks make the handling flat, but still absorb bumps in the road better than stock. Body roll, even with the stock festiva rear beam and front sway bar was minimal. Pedro still has the stock transmission, and is putting out somewhere around 120hp, and there was essentially NO torque steer. I've driven B6t and BP cars with the stock transmission before and I wouldn't have thought that was possible. Usually you punch it and have to struggle just to keep the thing in your lane. Not so with Pedro!

I think having a decent set of suspension on a festiva is probably the best thing you can do. Having more power is a lot of fun, but being able to whip it around corners is the kind of fun you can have even with a stock engine.

Just figured I'd put my first hand experience out there - Charlie knows his stuff

[Advancedynamix]

Thanks Nate! If Tweak was still mine I would have tossed you the keys for a solo run, it gets even better with only 1 person in the car. Lol.

[cliferton]

I've been running the suspension setup all summer on stock power. I am running 160 lb in the front and 140 lb in the rear. Daily driving all in all is really good. The rear is a little stiff in a gutted car, but the faster you go the better it gets. In autox it does well. I'm usually in first by 2-5 seconds in my class and am running top 3 awd times at our autox. On the track the 60ish hp to the ground is the limiting factor ever on 700 treadwear tires. I am running charlies setup with a modified rear top hats that I will get drawings with measurements posted up soon.

[cliferton]

I also got to take a ride in tweak when charlie and his festiva gang stopped by our shop oh their way home from madness. Great group of guys with great taste in cars

Tweak is a beast that's all you can say. It is stupid fast but super smooth it dosent really feel like a turbo car. But your instantly over 100 but think your doing 60. The car is on rails too I can feel the difference that moving the motor for and and doing the front body brace give. I've been working on a tweakish clone, but when you get to ride in one you get in more of a hurry to get it finished. Every festiva should be like tweak lol

[Advancedynamix]

All 4 of the cars in that photo have the suspension that's outlined in this thread. Thanks for posting Clif!

[TominMO]

Charlie, I went thru this whole thread and didn't see the answers to a few questions I had.

1. I have '01 Rio front struts with stock Festy springs cut one coil. To replace the Festy springs with 150# Black Magics, would I use the 2 9/16" diameter springs from SW Speed? Should I go with 10", 12" or 14" long, to end up with the same ride height as my slightly-cut front springs? Am I even on the right track here?

2. For the Festy's rear, I have the 93 VW Cabriolet Bilsteins. They are noticeably thicker than the KYBs for the same application. What diameter threaded sleeve/nut do I need for the Bilstein and also for the KYB? (The VW KYBs are on the Aspire.)

3. Is there a thinner strut bellow available to protect the strut shaft from dirt when using the 1 7/8" springs?

4. What's the name of the guy you suggested we talk to at SW Speed? (I don't want to go back thru your whole thread to find it!)

I'm gonna go with 10" long, 1 7/8" diameter, 105# and 120# for the Festy and Aspire rears, respectively, since the Aspire is a heavier car.

[TominMO]

I figured out that I can't fit 1 7/8" springs to the Bilsteins, since the shock body diameter is 2"! Can't use either the 36mm or 46mm threaded sleeves and nuts. Guess I'll have to call SW Auto and figure it out with them. They do have other sleeves, for Porsche Carreras. Maybe they'll work.

However, it looks like for the Aspire's KYBs I can use 'em, with 46mm sleeves. The strut body is 1 5/8" thick, which equates to ~41.3mm. The 1 7/8" springs equate to ~47.6mm, which sounds perfect for the 46mm sleeves; .8mm clearance on each side.

For the front struts on both cars, I may have to go with the 5" OD rear springs, which come in 11, 13 and 16" lengths, and all sorts of weights in a useful range for us.

[TominMO]

Just talked to Toby @ SW Speed about my order, and made some changes. He said that I needed the 46mm sleeve/nut and the 2 1/2" (2 9/16") spring size for the KYBs, not 1 7/8"; so I ordered that with their lightest 12" spring, 120#. Twelve inches will give me some adjustability up and down, vs. being maxed out at the top.

For the Bilsteins, he didn't think he had anything in stock, sleeve-wise, to accommodate the 2"-diameter body, and suggested I contact Bilstein somewhere in Calif.

[Advancedynamix]

Charlie, I went thru this whole thread and didn't see the answers to a few questions I had.

1. I have '01 Rio front struts with stock Festy springs cut one coil. To replace the Festy springs with 150# Black Magics, would I use the 2 9/16" diameter springs from SW Speed? Should I go with 10", 12" or 14" long, to end up with the same ride height as my slightly-cut front springs? Am I even on the right track here?

2. For the Festy's rear, I have the 93 VW Cabriolet Bilsteins. They are noticeably thicker than the KYBs for the same application. What diameter threaded sleeve/nut do I need for the Bilstein and also for the KYB? (The VW KYBs are on the Aspire.)

3. Is there a thinner strut bellow available to protect the strut shaft from dirt when using the 1 7/8" springs?

4. What's the name of the guy you suggested we talk to at SW Speed? (I don't want to go back thru your whole thread to find it!)

I'm gonna go with 10" long, 1 7/8" diameter, 105# and 120# for the Festy and Aspire rears, respectively, since the Aspire is a heavier car.

1. I'm not sure on rate or length for the Rio Struts. Rate depends on length and how much sag you need, also what spring rate rise will match your shocks valving. I've never used the Rio struts, so I'm not sure what kind of rate rise will compliment them. The front spring rate is critical on these cars. Matching the load, rate rise and shock valving is very important.

2. If the bilstein bodies are thicker than the kyb bodies then they won't work with the 1 7/8" sleeves. I don't have any suggestions for a good solution to this. I've only used the KYB shocks. This is good information to keep in mind.

3. I protect the shock shaft with the long vw bump stop on top of the supplied kyb bump stop that's been pressed into the adjuster sleeve. This provides great protection of the shock shaft. The stacked bump stops covers all but 1" of the very top of the shaft at ride height. This 1" will never ride inside the seal of the shock, so it's less critical to keep it covered.

4. I used to talk to AJ, but he hasn't answered the phone the last few times I've called. All the guys are very friendly and helpful.

[TominMO]

1. I'm not sure on rate or length for the Rio Struts. Rate depends on length and how much sag you need, also what spring rate rise will match your shocks valving. I've never used the Rio struts, so I'm not sure what kind of rate rise will compliment them. The front spring rate is critical on these cars. Matching the load, rate rise and shock valving is very important.

2. If the bilstein bodies are thicker than the kyb bodies then they won't work with the 1 7/8" sleeves. I don't have any suggestions for a good solution to this. I've only used the KYB shocks. This is good information to keep in mind.
3. I protect the shock shaft with the long vw bump stop. It provides much more protection than a bellow could, and fits snugly inside the small body sleeve. This covers all but 1" of the very top of the shaft at ride height.
4. I used to talk to AJ, but he hasn't answered the phone the last few times I've called. All the guys are very friendly and helpful.

1. The Rio has 175# front springs, but I want to change out my stock Festy front springs and go to 150s on the Festy--assuming I can find a good solution for the rear Bilsteins. One solution would be to just use Festy fronts of course, but I wanted to go to a narrower spring for tire/wheel clearance reasons.
2. ---
3. Yeah I wondered about just using the bump stop. Good pic there.
4. Toby was very helpful.

I'm gonna hafta come up with a solution for my top hat too. I'm hoping I can just use the rubber spring isolator up there, like we do on stock springs. But we'll see.....I might just test-fit the 12" springs and if they are too short, return them and go with 14s.

[Advancedynamix]

Just talked to Toby @ SW Speed about my order, and made some changes. He said that I needed the 46mm sleeve/nut and the 2 1/2" (2 9/16") spring size for the KYBs, not 1 7/8"; so I ordered that with their lightest 12" spring, 120#. Twelve inches will give me some adjustability up and down, vs. being maxed out at the top.

For the Bilsteins, he didn't think he had anything in stock, sleeve-wise, to accommodate the 2"-diameter body, and suggested I contact Bilstein somewhere in Calif.

The small body 36mm bilstein sleeve fits the rear KYB VW shocks perfectly. I wouldn't suggest using the larger sleeves, because they won't locate on the register ring that's already on the kyb shock. Also, the larger diameter springs will have a different rate rise, so I'm not sure what to suggest for a base rate.

I sand the weld area a bit so the sleeve slides over it, and on these shocks I used a little electrical tape to help snug the sleeve. I typically glue the sleeve with windshield glue, but wanted to be able to take these apart for testing.

The small body 36mm bilstein sleeve from southwest speed then fits over the kyb VW shock nicely and locates perfectly on the register. This all fits like these parts were made for each other.

Then I use a 10" long 1 7/8 diameter springs from southwest speed.
I used 105lb springs on this car, as a test. This spring will allow for 7" wide wheels and 4 degrees of negative camber in the back, while still being able to ride 4 or more inches lower than stock. For a car that's only running 2-3" lower, with a typical festiva load, I'd suggest 120lb springs. For a car being used to tow or carry extra weight in the back I suggest 150lb springs.

The base spring rate effects the rate at which the spring rate rises. Running too stiff a base rate will cause the car to ride too high and feel stiff and bouncy. These VW shocks have a lot of rebound dampening, so 150lb springs won't feel bouncy, but they will give a very firm ride and could cause the car to tend to drift.