Spec Your Build With Us

Every set we build is valved for one car and one driver — there is no shelf stock to pull from. Tell us what you run and what you want it to do, and we will come back with a spring rate range, a valving direction, and an honest read on whether TL-ONE or TL-PRO fits your program.

Free, no commitment, answered within 24 hours by a person. Five fields below is enough to get a useful reply — if you have tire, aero, or weight detail handy, open Add detail and our first answer gets sharper.

Send a build brief
The single most useful thing you can tell us. A 200TW street tire and a Hoosier want meaningfully different damping.
Add detail Optional. Aero, weight, what you run now, what you want to change — the more you give us, the more specific our first reply is.
The car
E46, S13, ZZW30, R53 — if you know it.
M vs non-M, 2WD vs AWD, base vs Track Pack.
How you use it
Daily driven? Trailered? Tell us.
Series, region, home track.
Lead time is 4–6 weeks plus 5–10 business days shipping.
Current setup
With driver if you have it.
Understeer on entry, floating over kerbs, no adjustment range left — be blunt.
Scope and contact
Some specs are faster to sort out on a call.
Reservoir mounting, camber plate requirements, ride height targets, past builds.

We reply within 24 hours, from a person, with an actual recommendation — not an auto-quote.

What Happens Next

  1. We read it and reply.

    Within 24 hours you get a response from our team with a spring rate range, a valving direction for your tire and aero package, and a straight answer on which line fits your program.

  2. We work the spec out together.

    Email or a 15-minute call, whichever you prefer. This is where ride height targets, reservoir mounting, camber plate requirements, and spring brand get settled.

  3. You get an invoice for exactly that build.

    No configurator guesswork. The order matches the spec we agreed on.

  4. We build it.

    4–6 weeks, hand-assembled, then 5–10 business days to your door. Shipping is free to the US, Canada, Mexico, and Central America.

  5. Your dyno graphs ship with it.

    Every set includes CVP and PVP plots. You'll know exactly what your dampers do before you bolt them on.

What You're Buying

TL-ONE

46mm monotube dampers (inverted monotubes on select applications) with 20-click rebound adjustment, spherical bearing top mounts, and camber plates on platforms that support them. Electroplated bodies and collars for corrosion resistance. Fully rebuildable and re-valvable, with a documented upgrade path to a 3-way reservoir system later.

TL-PRO

The 3-way adjustable platform, with independent high-speed and low-speed compression plus rebound. For programs where the setup changes between sessions and the driver knows what they're chasing.

Both lines use check valves and our piston technology, and both ship with CVP and PVP dyno documentation. Specs vary by chassis — we'll confirm exactly what your platform gets when we reply.

Common Questions

Is this really free?

Yes. You're not buying a consultation — you're getting the conversation that should happen before you spend $2,000+ on parts built specifically for your car.

I'm not ready to buy for a few months. Should I still send this?

Send it. Knowing what your build needs well ahead of time is better than sorting it out three weeks before your first event. We'll keep the brief on file.

My platform isn't listed on your site. Can you still build it?

Usually. We build custom-spec sets for platforms that aren't in the catalog — tell us the chassis and we'll tell you honestly whether we can do it well.

Do I need corner weights before I contact you?

No. Helpful, not required. We can work from vehicle weight, tire size, ride height targets, and sway bar configuration.

Can these be valved for street use?

Yes. Every kit can be valved specifically for the street. Even track-oriented valving usually rides well, because controlling the platform better also controls body motion better on the road.

What's the lead time on a build?

4 to 6 weeks for hand assembly, plus 5 to 10 business days shipping. Shipping is free to the US, Canada, Mexico, and Central America.

What's the warranty?

6 months, covering defects and unreasonable wear. Track damage is not covered.

I already know exactly what I want. Can I just order?

Go ahead — every product page has a direct checkout. We'll still confirm your spec before we build.

Racing on Thunder Lane suspension in Time Attack, Hill Climb, or wheel-to-wheel competition? Ask us about product credit through the 2026 contingency program when you send your brief.

Not sure this is the right starting point? Browse fitment by platform or read the tech tips archive.