Effects of Aerodynamics on Suspension

Enzo Ferrari was once quoted for saying, “Aerodynamics are for people who can’t build engines.” Funny guy, that man. Colin Chapman, however, saw aerodynamics as the future of F1, which reflects heavily on the design direction of the F1 cars you’ve seen for the past four decades. It has been used effectively and with amazing results.

If you follow much on the ever-growing Time Attack racing series, you’ll see or hear about aerodynamics. Other than amazing and tractable power that most engines can be tuned for these days, along with a great suspension and tire package, the only way to tick off several tenths of a second from your lap seems to be crazy aero. Incredibly crazy aero. So much so that the cars on track resemble upside down airplanes. Makes me wonder exactly how much downforce these kitted cars are generating.

Top Fuel S2K

This hammerhead shark looking thing comes from the Top Fuel team in Japan. Currently breaking records at Tsukuba and Fuji Speedway. The front splitter and rear wing are waaaaay too wide for use on the street, which this car will probably never see again anyway. Downforce is what’s keeping these fully prepped unibody cars fast (as well as tons of power).

Aerodynamic tuning seems to be a fairly straightforward approach these days, with many people fabricating their own front splitters, canards, flat bottoms, and rear diffusers. While this post is not necessarily about how aerodynamics work both positively and negatively, it is important to know that it is very effective, and it takes more fine tuning of the rest of your vehicle to make the aero work in harmony with your car.

So how does all this extra downforce from aerodynamic gain affect suspension?

Evasive Blue S2K

This Evasive S2000 had a full aero package. Front splitter, flat bottom under tray, & rear wing work together to generate sufficient downforce. Using street tires (treadwear 180) and Evasive Motorsports’ own Evasive-Spec TEIN Super Racing dampers, this Street RWD class Time Attack car broke records at Buttonwillow in Street RWD class events.

When we set up a suspension kit for a vehicle, we have to factor several items prior to deciding which spring rates will work best, followed by how we will valve the dampers depending on what the driver experiences. After all, it is the driver’s confidence we’re trying to build up, which in turn translates into a high performing car if they can do their part behind the wheel.

Evasive GT-R Braking

Believe it or not, this GT-R from Evasive Motorsports has relatively mild aero components. Still, it’s a matter of finding the right balance for the vehicle at differing speeds. For us as a suspension manufacturer, we’re always concerned with how the stability of the car is affected through body dynamics, whether under turning, accelerating, or braking (as in this picture).

We also have to take into account what type of ride height the customer wants to achieve, which in turn affects the damper length, including droop/extension and bump stroke. Keep in mind that your steering geometry must be set for that specific ride height, as you want minimal effect in bump steer.

Evasive S2K Turn

This S2000 going through a turn looks like it is flat relative to the curve. However, you can see that the asphalt is slightly cambered, and the inside wheels/tires need to droop down and maintain contact for greater traction, which it is doing. Otherwise if the wheels were to have lost contact, traction suffers and the balance is thrown off. This car also has relatively mild aero additions.

In its heyday, aero tuning wasn’t understood as it was today. Early reports in F1 stated that the vehicle would oscillate, or “porpoise”, at varying speeds. If the suspension setup was too soft, this problem could be exacerbated by this porpoising phenomenon. This effect disrupts airflow and causes instability as speed increases.

F1 typically has the best examples of the effect of downforce on suspension. For one, F1 cars of today have incredibly stiff suspension. Some control arms actually don’t even have any pivoting point and rely on flexing to provide suspension movement. If you’ve seen an F1 car in action, you’ll know that, for the most part, the circuits they drive on are very smooth. Nevertheless, suspension is still necessary as the car still has to pass through gaps, curbing, etc. However, F1 regulations allow a tire with a really huge sidewall. So this in turn acts as suspension (just without proper damping; also helps create a fairly large contact patch for the tire). If it were tires with a very low aspect ratio (small sidewalls) the car would have to rely on softer suspension, which is what they want to avoid doing.

Still, when you watch an F1 car, you can notice how little body roll there is (it’s noticeable, but not as severe as a street car). The suspension does move, so it is functional. It seems though that the tires, as they deflect and deform through turns, adds to body motion.

sahara f1 kerb

Obviously this Sahara Force India car is going past a curb, which makes the car look like there is some body roll. Of course there is some roll, just very minimal.

 

massa ferrari

This older spec Ferrari shows just a bit more body roll at turn-in.

But, on straightaways, it is clear that F1 car suspension is working. Thankfully this has been made clear in the 2015 regulations as all cars must use a titanium skid plate. And when this skid plate makes contact with the ground, it makes an amazing shower of sparks seen coming out the car’s back end. Why is this helpful? because clearly the car is making enough downforce to cause the skid plate to scrape along the ground.

lotus f1 sparks

We kinda dig the show current F1 cars put on, especially with their titanium skid plates.

This is a factor that is still important with street cars set up for racing. You may find a need for super stiff suspension, but for the most part we don’t have, or get, to drive on super smooth circuits like F1 cars do. That means we need a suspension that can track the road surface better and help maintain good traction. Super stiff suspension with very little droop travel with literally be skipping off the curbs and bumps. It wouldn’t take a whole lot to make the car feel unsettling. So, therein lies the problem. Then, once you add aero parts like a front splitter, flat bottom, rear diffuser, & rear wing, you’re compounding the problem. It’s a balancing act.

For the most part, our Super Racing dampers are designed and valved with some specific spring rates in mind for each application. In fact, some of our sponsored teams, like SportCar Motion and Evasive Motorsports here in the U.S., have pretty aggressive aero on their Time Attack vehicles, yet they still use our recommended spring rates. Really aggressive aero, and even a change in stickier tires, may require a small change in spring rate, maybe something slightly stiffer (+2kg/mm), and that is more than enough.

Ultimately, it is best to try a suspension kit as-is at our recommendations, do your testing, work on any other additional modifications you make to the vehicle, continue testing, then you can assess what changes you need to make to your suspension. It can be as simple as damping force changes, ride height changes, or spring rate change. Starting with an out-of-the-box setup is at least a good baseline. Just as with any other modification you make to your car, modifications to suspension can also be made. We’ve already spent the time to engineer the the suspension kit for your specific application (albeit a relatively stock vehicle), so that gives you a great baseline to start with.

Since I brought up what Enzo Ferrari said- “Aerodynamics are for people who can’t build engines”, how about this new engine for the 488 GTB:

ferrari-488-gtb-engine-image

Damn, that looks sexy.

 

One extra thought- while it’s nice to try and pioneer your own aero setup for your car, sometimes it’s best to go with a tested/developed setup for your car. Piecing together components from different manufacturers, although looking very similar and wanting to create similar effects, may not net the results you are looking for. Aerodynamic tuning can be very tricky to get right, depending on what you want to achieve.

CFD-ANSYS-BMW-SauberF1

“Yeah, I’ve got a set of TEIN Coils”

Whenever we hear that (blog title), we tend to understand that a customer has a set of our lowering springs. However, for some strange reason, people online or that call us are referring to our suspension kits as coils, whether it be a complete suspension kit like a STREET FLEX or STREET BASIS,  even a SUPER RACING setup.

We must ask- WHY ARE YOU REFERRING TO THEM AS “COILS”?!

We’re just as guilty, using different terminology than what some people may understand. For example, saying “coilover” implies simply that- a coil over a damper. This is how most people know of our product since our height adjustable setups are typically coilover, but is this a coilover?:

stfa z33

STREET FLEX for 2003-2009 Nissan 350Z

As pictured above, this “coilover” kit uses our Height Adjust System (H.A.S.) for the rear, as pictured on the left. So it is in fact not a “coilover” with exception of the fronts (pictured on the right). We’re wrong for ever referring to such kits as a coilover package. Instead, this is a suspension kit. But, for simplicity’s sake, and in acknowledging what are customers know us for, we continue to call them coilovers. It’s easy, and it won’t confuse our customers.

There are other things/terminology we may use that may be either incorrect to some, or just named differently. For example, the name “Shock Absorber”. It is in fact a “Damper”. Shock Absorber is incorrect because it isn’t absorbing shock. What it is doing is turning kinetic energy (the up and down motion of the vehicle and unsprung mass) and converting it into thermal (heat) energy. Nothing is really being absorbed. It is a transfer of energy from one form to another. However, most people understand them to be Shock Absorbers, so we just roll with it.

And yes, it is “Damper” and not “Dampener”. They may share some similarities in meaning, but they’re in fact used differently. Dampener is typically used to describe a wet or moist condition. But it can also be used to describe a deadening or depressing. Damper, on the other hand, is mainly used to describe a reduction in oscillation or amplitude of force.

We also hear people ask for “Pillar Ball Mounts”, which is easily understood to be (how we know it) Pillowball Mounts. Not a big deal.

Another one that we hear is when people refer to our Seat Locks and Spring Seats (where you can adjust a spring’s setting and vehicle ride height) simply as “rings”. Sometimes we hear them being called “collars”. We use collars, but they are usually much smaller and are used as a spacer in our upper mount assemblies.

That’s another one- upper mounts being referred to as “top hats”. Not really a big deal, and some upper mounts kind of look like top hats. So, [top] hats off to you for using that description!

Willy-Wonka

Willy Wonka wears a Top Hat. He can also be condescending sometimes.

There are some less obvious things that we cannot fault a person for. For example, our inverted dampers for strut type monotube setups, like our older MONO FLEX and our SUPER RACING. People will refer to the shiny part of the damper assembly as the piston or piston shaft. Again, although that is incorrect, we cannot fault the customer for that. Since the damper is inverted, the whole assembly is upside down. The piston shaft is now on the bottom side and inside of the threaded shell case.

mflp gdb

MONO FLEX for 2002-2007 Subaru WRX

In the above picture, the shiny rod coming out of the threaded shell case (black) is in fact the damper body and not the piston shaft. The piston shaft is itself inside the threaded shell case and completely out of view.

There’s also the use of the name “Serration Bolts” which we use for the studs in our upper mounts (that secure the upper mount assembly into the strut or shock tower). We realize that confuses a lot of people when they need replacements of these components. Sorry!

The use of “Strut” may also be confusing for some. The above picture of the MONO FLEX for Subaru WRX shows struts, which this chassis of Subaru uses for front and rear. When we say strut, we’re referring to the MacPherson Strut design, which other than being a damper, also serves as a structural member of the suspension by supporting the knuckle assembly. The knuckle assembly comprises of the wheel and brake components. Struts have to be a bit larger in size and be able to handle large side forces/loads.

In comparison, a “SA” type of damper (short for “Shock Absorber”), which is used in Double Wishbone or Multi-link type suspensions, doesn’t have to support such side loads. They are used strictly to control vehicle motion. This is also why we don’t make camber adjustable upper mounts for our SA dampers. It’s position or angle will have no affect on wheel camber.

img01img02   Can you see the difference between these two suspension designs?

 

 

 

 

 

For sure there are other things we hear from customers, but this covers a majority of terminology we hear.

Hopefully that helps break down some of our terminology for suspension components!

The New, More Affordable STREET BASIS Z & STREET ADVANCE Z Coilovers!!!

As we had already mentioned, development has started on our FLEX Z coilovers, a more affordable offering of our popular STREET FLEX coilovers. But, we haven’t stopped there with new products for 2015!

At around the same time we start bringing in our FLEX Z coilovers (mid-Spring), we should also have a few applications of our STREET BASIS Z & STREET ADVANCE Z coilovers! However, we’re not too sure the timing, as the new STREET BASIS Z & STREET ADVANCE Z will be coming from our newly established TEIN China plant.

The difference between current STREET BASIS and STREET ADVANCE coilovers from the new “Z” line is that the Z line are non-rebuildable coilovers. Again, this follows in suit to the STREET FLEX -> FLEX Z changes. All other features of the two entry-level coilover lines are the same.

STREET BASIS Z is strictly a ride height adjustable kit. This makes it a perfect setup for the daily driver looking for an increase in handling performance without compromising comfort for everyday use. For many of you considering a lowering spring + performance shock absorber combination, the STREET BASIS Z makes even more sense as we select appropriate spring rates and valve our dampers to match. No guesswork on the end-users part in trying to match one brand of springs to another brand of shock absorbers. The added height adjustment feature allows the end-user the ability to adjust ride height to their preference, something that lowering springs lack. Being that most vehicles are slightly unbalanced from left to right sides, that means you can easily adjust the ride height so that each corner is even from their opposing sides.

STBZ

STREET ADVANCE Z takes the ride height adjustability of the STREET BASIS Z line and adds 16-way damping adjustment. So, not only do you get a matched spring and damper setting, you now have the ability to tune the dampers to meet your driving conditions. Roads seem a bit rough? Soften up the damping. Glass smooth highways? Crank the damping to a stiffer setting. You get all that and everything in between.  STREET ADVANCE Z is also compatible with our EDFC systems (some STREET ADVANCE Z coilover kits may require extension kits for compatibility), giving you a completely adaptable suspension kit based on your driving conditions/characteristics! That’s a feature that not even all sports luxury cars have, and our setup is at a much more affordable price!!!

STAZ

Like the FLEX Z line, these new STREET BASIS Z  & STREET ADVANCE Z coilovers have a very appealing starting price! STREET BASIS Z comes in at $400 while STREET ADVANCE Z comes in at $500!!! Those are unheard of starting prices for a TEIN coilover!

And, just like the FLEX Z coilovers, replacement parts will be made readily available! If your STREET BASIS Z or STREET ADVANCE Z dampers start feeling worn, you can purchase replacement dampers! No need to send them into us for a rebuild since these are fully sealed, non-rebuildable dampers! That will save you some money, and most importantly, extended downtime! We’ll help to get your car back on the road as quickly as possible!

Again, the only major difference is that the new “Z” line of dampers are non-rebuildable.

Internally, we continue to use our ADVANCE NEEDLE for increased per-click damping adjustment. This translates into greater damping change for each click of the 16-way adjuster, making it easier to find the perfect damping setting. Our high performance damper oil, the same kind we use in our race dampers (Gr.N, Super Racing, N1) provides excellent anti-foaming and viscosity characteristics under heavy cyclic rate, giving you repeatable damping feel and performance for the life of the damper.

advance_needle_technology

ADVANCE NEEDLE provides wide-range damping force change per click.

oil

Proprietary damper oil exhibits excellent anti-foaming and viscosity characteristics for stable damping force under extended use.

We will still retain our exclusive damper coatings, too. Our shot blasted, zinc plated high strength STKM13C steel damper bodies are treated to our patented 2-layer/1-bake powdercoating procedure. This gives our dampers excellent protection against corrosion in harsh environments, especially in areas with heavy snowfall. Our patented ZT coating is applied to our threaded adjustment tubes (inside and out), and contribute to smooth height adjustment, and outstanding adhesion to the steel threads. This ZT coating will not peel or flake off even after repeated adjustment. This is due to the ZT coatings’ low friction coefficient. Essentially, it acts as a dry lubricant. That makes every external component of the steel bodied damper completely protected from the unforgiving environments we subject them to, and we expect our dampers to perform at their very best year after year after year…

the bare surface of our dampers are treated to a double shot peening adding surface strength and also prepares it for zinc coating.

the bare surface of our dampers are treated to a double shot peening adding surface strength and also prepares it for zinc coating.

stbn_003

stbn_004

We’ve also updated our spring seats and seat locks for increased durability under heavy vehicle loads and smooth height adjustment. Instead of using a rubber spring seat, we’ve added a Delrin thrust washer atop the new, wider spring seats.

sp seat w delrin

Coilover springs will continue to be made from cold-wound SAE 9254 Vanadium alloy. After cold winding and setting, we heat treat the springs prior to grinding end coils to proper dimensions. Before powdercoating, we subject every spring to double shot-peening which aids in increased spring life and fatigue strength. Some coilover applications may have application-specific spring windings and shapes, such as our barrel springs or taper springs.

We will also continue to provide our 1-year warranty against manufacturer’s defects. Even at this new starting price, we will stand behind our products!

So now you’ve got the highest available quality and performance at an extremely low price, and backed with a manufacturers warranty. Unfortunately, we still haven’t made it easier for you to decide with TEIN suspension system you want. So we ask you to please give our sales staff a call at 562-861-9161 for assistance in getting you into the proper TEIN suspension kit for your needs!

 

We’re In The Anime Business Now!

No, not really. I’m just kidding.

But, we did put a short cartoon out regarding our EDFC Active Pro. In the cartoon, it shows the benefits of active damping force while going around a long sweeper.

Although it is a very short video, what it is trying to explain is how our EDFC Active  Control Unit will make adjustments based on the vehicle’s dynamics. Within the controller we have an accelerometer that adjusts damping based on g-force loading. There is also an available speed-based damping force setting using either the optional GPS Kit (especially for the EDFC Active) or by obtaining the speed signal from the vehicle’s ECU (this feature is available on the EDFC Active Pro only).

In the video, the driver who starts falling behind complains about roll understeer. Initially, he believes the leading car has their suspension tuned only for low-speed damping (which would mean a compromise in high speed damping force control). However, with EDFC Active/EDFC Active Pro, we’re able to negate the side effects of such one-setting tuning. Now you can have a suspension kit fully adaptable to your driving conditions!

We’ll be putting out more videos to show the other benefits of our system and why a racing enthusiast such as yourself may find our product suitable for you!

In the meantime, if you have any questions regarding our EDFC Active and/or EDFC Active Pro, please give our sales staff a call at 562-861-9161 or email us at tus_sales@tein.com for assistance! We’ll be glad to answer any questions you may have!

Porsche 997 GT3 Coilover Testing

You’ve read that correctly- we’re now testing on a 997 GT3 Porsche with our very own 3-way adjustable dampers! While Porsche’s aren’t necessarily anything new for us, we’ve only made a name for ourselves developing and producing products for the Japanese vehicle market (JDM, if you will). But, with increasing demands for products internationally, the TEIN group has branched out into other vehicle markets and made some unique suspension setups, specifically for rally and off-road. Our expertise doesn’t stop there, however. We love road racing, too. This latest example is no exception.

This past year, the TEIN group has been working with a few customers (997 GT3 customers, specifically) wanting better suspension than what the car comes with, and what was currently available as aftermarket. Off the lot, the GT3 is pretty hard to beat, or in this case, make better. So that sounded like a great challenge for TEIN engineering!

So, while TEIN Japan was taking care of overseas inquiries on this, the TEIN USA group had a customer who was just as interested. It turns out our good friends at Evasive Motorsports had a 997 GT3 and were going to start developing the car for track duty. That was a good coincidence!

Anyway, we finally got the prototype 3-way adjustable dampers in from Japan and headed over to Evasive Motorsports to do the install. So far, so good! First reports from the owner is that the car’s ride quality has improved! Next up is some track testing, which we’ll report on soon. So stay with us as we get more updates!

Here are a few pics of the install with Evasive Motorsports for now!

3-way adjustable dampers, made through our Specialized Damper Program

3-way adjustable dampers, made through our Specialized Damper Program

IMG_6389 (Custom)

The factory supplied dampers are quite nice. But, that TEIN Green, though......

The factory supplied dampers are quite nice. But, that TEIN Green, though……

Fronts installed

Fronts installed

 

Rears on

Rears on

 

Looking good so far!

Looking good so far!

 

Japanese Spec Vs. US Spec Coil-overs

Recently I have noticed that a lot of consumers and dealers of ours inquire about the differences between a Japanese-spec coilover kit and a U.S.-spec coilover kit. Relax, grab a cup of coffee, and let me do some explaining. It’s actually quite simple.

One of the main differences between these kits is the valving and in some cases spring rates. The U.S.-spec coilover kit comes with a more aggressive valving. The reason behind this is because consumers in the U.S. prefer a slightly more aggressive coilover in comparison to consumers in Japan. U.S. vehicle’s may also have some manufacturing differences opposed to the ones released overseas.

But as mentioned earlier, another factor is the spring rates. Some of the U.S.-spec coilover’s come with a stiffer spring to match the aggressive valving of the dampers. Of course there are other differences between the dampers besides the valving and spring rate. Damper designs may vary from U.S. to Japanese kits such as damper mounting points, damper body and stroke lengths, and required OEM parts.

As a side note- some U.S. applications may be compatible with Japanese dampers with no modifications whatsoever. But we recommended to verify with TEIN prior to purchasing these kits.

In conclusion, regardless if the coilover kit is Japanese or US spec they both come down to one thing- they both cater to different markets which is a matter of consumer preference. However, TEIN is able to assist with customization of your TEIN dampers through our Overhaul and Revalving service available Stateside through our in-house service departments in the East Coast and West Coast facilities. As a performance suspension manufacturer for a global market, we realize it is difficult to appease all customers. But we can definitely assist our customers in dialing in their suspension for their specific needs, all of which is for your driving pleasure!

Quick Click Fixes

The TEIN adjustable damping force coilover click adjuster is commonly misdiagnosed part. Misdiagnosed because many customers with stuck or broken adjustment knobs (click assembly) think that repair or replacement requires the damper to be sent to us for repair. For many stuck adjustment knobs a new replacement click assembly is not required. Here are some tips you can use if you encounter a stuck click adjuster or are looking to replace a broken unit.

Click adjuster or Adjustment knob may be located at the top and/or bottom of your coilover depending on type.

Stuck or seized Click Assembly

A click assembly that does not turn smoothly or turn at all may be a quick and easy fix IF there is enough space to work on the unit.  The problem is usually caused by debris getting lodged in between the knob and knob base.  Between the two halves there is a spring loaded ball bearing (located under the knob) moves into machined divets (located on the knob base). Debris can stop the movement of the ball or become lodged into the divets. Another cause could be moisture build up inside the coilover piston rod causing the small hex bolt to seize. THE FIXES:

1) Try to use compressed air to dislodge any dirt or debris between the two halves of the click assembly.

2) Remove the click assembly. Then clean and re-lubricate the hex bolt.

A TEIN Click Assembly Wrench (black), Part #SST01-F1126, MSRP $5 can be purchased from our online store.

To do the second fix you will need a TEIN 8mm wrench or a modified standard 8mm wrench (grinded to 3mm thickness). Use the 8mm thin wrench to remove the click assembly (see image below). A crescent wrench can be used to keep the piston shaft from spinning (be sure not to damage the threads on the piston shaft). Next use the click adjustment tool or a 3mm allen wrench to remove the hex bolt (see image below).

Using the TEIN Click Assembly Wrench and a crescent wrench to remove the click assembly.

After the click assembly is removed use the click adjustment tool to remove the small hex screw inside the piston shaft.

Both click assembly and hex bolt can be cleaned with some mild parts cleaner.

Scroll to the bottom on instructions for re-assembly.

Note: TEIN coilover kits do include a rubber add cap to prevent moisture and debris from forming but I would still recommend checking the assembly once in a while.

Replacing a broken click assembly

The click assembly can break in two different places. One, the top half of the knob (knurled section). Second, is the bottom tip of the click assembly (resembles hex bit or allen key).

Replacing a broken click assembly may be a little more work if bottom tip has broken off inside the piston shaft. This may require the coilover to be removed from the vehicle if it cannot be easily removed.

First remove the click assembly using the same method stated above.

This is what the click assembly looks like when the top half is missing.

After the click assembly is removed inspect it to see if the bottom tip is intact or not.

This is a complete Click Assembly (silver) with Hex Bolt (black).

You can see the click assembly has a knurled top section, 8mm hex and threaded section and bottom 3mm hex tip.

This exact assembly can be purchased on our online shop, Part #SPS12-G0047.

If the bottom tip has broken off extract it with a pick tool or magnet. If the tip is stuck in the hex screw you may need to use lubricant and lightly tap the piston shaft to help dislodge it. In this case the plastic end of a screw driver or plastic hammer works well. Be careful when using a tool to extract the lodged piece as the inner and outer threads can be damaged. Use Caution.

Broken piece of the bottom tip of the click assembly.

Installation of Click Assembly and Hex Bolt

With the click assembly off the piston shaft and hex bolt removed. Clean and lightly lube the threads inside the piston rod with light grease. When installing the new click assembly and hex bolt, you can use the click assembly, click adjustment tool, or allen key to thread in the hex bolt. We recommended to insert the hex bolt about 3/4 of the way to allow the click assembly to catch the hex.

Insert the bottom tip of the click assembly into the hex bolt and screw in.

Tightening the click assembly to 12 inch pounds torque or snug (do not over torque).

Check to make sure the click knob can rotate smoothly in both directions. Then adjust click knob to desired setting. Remember turn the click knob to full clockwise position (Zero setting or stiffest setting), then turn counter-clockwise to desired position (16 setting or softest position). Click assembly may click more than 16 times but going past 16 clicks does nothing for adjustment and repeatedly exceeding 16 clicks may cause internal shock damage.

If the click assembly or hex bolt can not be removed it may be required to send in the damper to determine condition and have the parts removed. Worst case scenario would be a new piston rod with overhaul (this is a rare case scenario).