Dai Yoshihara's Team Falken/Discount Tire 2011 Formula D Ride

Is that a rocket bunny in my pants? No but close...

The new car is wicked looking. I really do like that FD is forcing teams to work with stock suspension setups. Hopefully the development will produce new parts for the every man's car. Mike would this suspension setup be good for a road race/autocross car too? It looks like all of this would be beneficial to every 240 out there.

That car is sick! I love the attention to detail!

I love reading these articles on race cars that go beyond whats on the surface. Keep it up.

Whats an inverted drift?

The LS2 punched out essentially to an LS7!

That beautiful oval exhaust! I keep wanting someone, myself included, to increase the oval, side-exit, race car exhaust look on modern rides.

3" bump travel while looking slammed! Kind of reminded me of trophy trucks.

Mike, you guys have created a thing of beauty and I look forward to your season. I hope you guys and the controversial motor rocket through the year in FD!

er, what's an inverted drift?

I think Mike means backwards drift/entry, past 90 degrees?

Love the exhaust, and good idea with rotating the camber plates.

Am I missing something with the rear subframe? Looks like the lower control arm front mounting point is lowered in this picture:

http://motoiq.smugmug.com/MotoIQ/Features/Dais-2011-car-preview/IMG0578/1241612695_SqyRb-L.jpg

DEF, I made a mistake on the calipers, I should know better, I have superlights on one of my own race cars.

Beaters, the car is really good at grip driving, it's how we won Gymkhana, this thing would kill in autocross and in Time Attack if we put aero on it and changed a few set up details.

Shifter, an inverted drift is past 90 degrees from the axis of the turn.

Miro, that is the old subframe, it was not clear if we would have to go back to the S13 subframe until FD's final decision this last weekend. Since that picture was taken, we do indeed now have an unaltered pivot S13 subframe in the car.

Rotating the camber plates is clever. There are a couple companies that make camber plates with castor slots as well, so is there any advatanges of what you guys did or was it a combination of funding issues and a "good enough" mentality?

Was Dai running the solid spool diff at the gymkanha?

I'm also curious to what type of anti/prosquat changes you guys made to the subframe if any.

I like the 5" oval exhaust. It certainly is a well built & clean car.

The reason why we rotated the plates is because FD rules will not allow us to use a weld in type of camber caster plate and we tune the steering axis with caster. We also adjust caster from below.

Dai ran a spool at Gymkhana if you can tune for some inside wheel unloading it's not such a disadvantage for grip driving.

Formula D does not allow changes in suspension geometry anymore that is not done through links and spindles. On an S chassis you cannot affect anti very much through the spindle, only a sight amount and it was not worth fabricating a spindle for that.

We can tilt the subframe slightly in stock limits and we did that but it doesn't make that much difference as it doesn't affect forward IC location which is important.

I was looking for a "K" in front of the 5840 on the side of the Winters diff housing. Alas, it's missing, so it's not the magnesium version of the housing. Still incredibly cool, especially because it's a quick-change IRS housing instead of a live axle.

neat! see you this weekend

We don't need a mag case because under the new Formula D minimal weight rules, the car has to weigh no less than 2600lbs with driver.

Formula D's 2011 rules are trying to prevent cars from getting too far away from their street roots.

This car is stanced and when we get the final wheels it will be hella flush as well! It has a rocket bunny kit, too bad it has a V8 or it would be a fanboi's dream.

Stanced and hella flush can work if the car is designed for it!

What the heck is a bunny rocket?

Mike - can you comment a little more on the mister that was fabricated for additional cooling? Were there off the shelf parts used? I made one for my car using a spare reservoir & windshield washer pump but had issues with the nozzles used. Are you using a higher pressure pump and specialized spray bar? Thanks!

Always been a fan of this car and this team, best of luck with the 2011 season.

are the rear dampers not inverted types like the front? the resevoir attachment point is on the top for the front, but bottem at the rear, just courious why. also, Is it just the pickup points that must not change? were you allowed to clearance the front crossmember for your oil pan?

Finally you mentioned in a previous article that the new motor was stock except for the intake and a few other things. The changes you mention at the beginning of this article, are those the differences between the old LS1 and the new LS7? for example you didn't bore and stroke your old motor to get the new specs correct?

Fuergrissa, the fronts are a MacPherson configuration which have fairly high bending loads, so the dampers are inverted for higher stiffness and lower friction. The rear isn't a MacPherson config and doesn't have the same bending loads, so an inverted damper isn't necessary.

@ Fuergrissa: I'm pretty certain that this motor is a reworking of last years motor (Bored a little more, stroked a little further) to achieve the 427CI displacement. Matt Powers started with an LS7 from scratch. I'm sure Mike will chime in and correct me if I've got it wrong.

Back when I first got a look at this thing I was actually a little surprised to see the fronts were inverted. Some of the other KW competition shocks look inverted but are not. Instead they use a big reinforcement sleeve that rides on linear bearings and goes over a regular piston rod.

Fly'n: your right, I'm mixing up the builds, thanks.

Cool car. Thanks for sharing Mike !
I know you're a die-hard fan of the KW, I'm sure they work wonder when setup correctly; but there are few other great companies out there that make great coilovers: Moton, JRZ, Penske, Koni, just to name a few. And as you probably already know, their customer service and support are top notch.
Anyway, good luck !

Keith, the spray bar is an old blank fuel rail with home depot patio misters. The water pump is the older AEM water injection pump from Project EVO.

Fuergrissa, the rear shocks are not inverted. FD allows very minor clearancing of the front cross member for the oil pan. Tow generations ago we ran a basically stock motor but this is the third iteration of that motor. Currently the motor is very much like an LS7 with higher compression and a bigger cam.

JDMized, I am not a fan of anything nor do I have an emotional attachment to a particular brand. I simply use what is logically the best set up for my customers price point. I use KW a lot because their stuff works really well and they have a full time support engineer, Chris Marion who helps me with re valving, special parts I sometimes need to do things with shock dynamics, rebuilding and repairs.

KW also provides race support by sending Chris with us. KW is the logical choice for us for these reasons. I have also used Penske and Moton but I like KW better because of their base valves which gives really good frequency response and has less tire shock, plus because of the support they give my race programs. KW has a wide model line up and the best performance at any price point.

I will not ever use Penske after their tech guy told me he was too busy to deal with my tech questions because he had better things to do like service his WRC and F1 customers then hung up on me. What is even more irritating is that I don't ask stupid questions and am a technical professional. Penske obviously doesn't need my business nor anyone who I consult for.

Its how I use Cosworth and Pectel for engine internals because it comes with Eric's expertise, JE because Chuck Johnson helps me, Motec because of Nate and Steve Mitchell and other brands. Its a lot to do with the the level of tech expertise you can get and support that you need to get good results that customers demand.

You just hit the future of business on its head...
Almost any part can be built anywhere and shipped to your door but its Customer Service that is keen on different industry surviving...

Anyways BTT

Nice Rightup on the car. this has been my fav team for since the days of Millens old GTO... I love the mix of JDM, USDM, and EDM to create a Superior product that is Cheaper than the rest. Pics and details of the New Wheels Once they go on please...

"Dai ran a spool at Gymkhana if you can tune for some inside wheel unloading it's not such a disadvantage for grip driving."

I interpret this as running a stiffer roll bar or stiffer springs, but practicality tells me this will only make the oversteering issue worse as the outside laden tires gets overloaded.

Mostly wide front and narrow rear track.

I see that the car has quite a bit of ackerman angle, and you're saying that it's actually better. What would be the consiquences of modifying the geometry so there's close to 0 ackerman at full lock, wouldn't a lot of ackerman at drift scrub a lot of tire/speed from the front?
I've been doing some search on this topic lately and your input would be appreciated because you actually know what you're doing unlike myself here.

Thanks,
Mike

Mike, thanks for the more-than clear explanation. I appreciate it.

Mike,

In my opinion zero Ackerman doesn't work well on a drift car. A lot of the Japanese tuners use it but I find that it lacks self steering and has poor driver feedback. It tends to stick at lock. The car also wants to straighten up which makes it feel unstable in drift.

The premise of zero Ackermann makes sense from the standpoint of predictability, because the geometric change in tire angle would be the same regardless of the amount of steer angle. That's the only reason (that I can think of) that would be an advantage though, and it would be outweighed by all of the multiple benefits of having Ackermann.

Zero Ackerman makes the car LESS predictable and less stable.

anyone know how asabo's scion TC was converted to RWD without violating the rules for suspension/subframe modifications?

Probably by petitioning to get an exception to the rules.

Even though it's a performance hit to Dai's car, I still like that Formula D is taking steps to keep the cars relevant to its fan base. Pretty cool that anybody can build a near pro-level suspension system for drifting (of course, finding proper settings for all that is probably even more of a challenge).

At the same time, I do like that they still allow V8 transplants. In my mind, this allows the a multitude of chassis to compete together, where it would otherwise not be possible (or cost prohibitive). In a way, it helps equalize the power side of things and lets a S13 be competitive against a Challenger or Mustang, and lets the chassis & driver stand out.

I've just watched the qualifing and I'm totally amazed by you guys. Even though you had to go back to the stock subframe, it seems like the car got even faster.
How the hell did you do that, and how can you make it hookup so good with that much anti-squat?

Mike,

Thank you very much for sharing this car with us. I follow your builds very closely. Looks like changing back to the S13 subframe did not hurt much, as I saw Dia qualified second with the fastest entry speed. I would love to ask you some questions about the set up, but I believe you have stated that you can't tell us everything. Some things must be kept secret. I understand. Maybe if I catch you in the pits once this year.
Good luck tomorrow.

I can answer some general questions but particulars on what we did to get Dai's car to work, even with tons of antisquat must remain secret. We might patent some of the things we did.

The car might be even better than before.

I totally respect that, but it makes me even more curious how you did it.
I guess it just shows what can be done when there's a genius at work together with a top team. Can't wait to see how Dai does in the battles tonight.

Thank you for understanding!

Hi Mike! Nice build! Lots of experience is here.
could you tell me where can I get those brake kit?
"SPD sells this brake set up for S chassis builders"
nothing about it on their website.
Thanks

Dai finishes 3rd at Long Beach

Willy give SPD a call. They have a bunch of the brackets.

"This part keeps the Ackerman angle correct and bumpsteer in a range where it can be adjusted. There is only about 1/8" of bumpsteer."

Is the bumpsteer (outer pickup vertical height) optimized/adjusted for high steering angles at all? Do you adjust rack height at all?

When you say 'correct' Ackerman, are you referring to traditional 'correctness' (with steering arms coinciding with the rear axle centerline) or 'correct' for your application?

Can we get more info on the specs / details of the cooling system?

What size is the radiator and how many cfm's do those fans pull?

Really look forward to seeing the 2012 prep work for this car!

quick question,

Why do you guys run such extreme reverse rake? Or is it just bodywork playing tricks on me.

The car is actually level.

how much does it cost to build this car?

Hey Mike,

First of all, thank you for taking the time to post articles like this one and the other suspension set up articles. I've gained so much knowledge from your atricles that I always used to wonder about.

I've still got a few questions on my mind. I'm in the process of building a S14. So, much of the suspension is relatively the same as Dai's S13. And I completely understand not wanting to give away secrets. So if there is a question you choose to not answer, just say pass.

Now my first question is, how great of an offset has been built into those inner tie rod spacers? ___mm forward, and ___mm out? I've come to the conclusion from reading your articles that positive caster is the way to go for drifting, from it's influence on self steer and what not. And running these spacers helps correct over centering of the tie rod at full lock do to the increased amounts of caster?

My second question is, I've been looking at knuckles to get some ideas of what works best. The PBM ones seem to be most popular because of their roll center correction. But, just by looking at the pictures, it seems like they have lowered the lca mounting point on the spindle alot more than you guys have. What is this going to change geometry wise? And it also looks like the knuckles you guys run have slightly more amount of ackerman built into them.

My third question is, and I'll make this my last for now haha, the rear subframe will want to be rotated back (lowered in the rear, raised in the front) to level out the way the suspension travels, to reduce anti-squat? I've dealt with anti dive when I built the front end of my truck, and to get rid of it I rotated the uca mounts forward to level the arm out and eliminated caster gain throughout the travel.

Sorry for all the questions. This stuff fascinates me, and I'd love to learn more about suspension geometry and how it effects handling characteristics.

Thanks Mike!

Actually, the more research I did, it seems like you would want to do the exact opposite as I said with the rear subframe. You would want it higher(closer to the frame) in the rear and lower(closer to stock position) in the front to reduce anti squat?

Hey mike, where do I procure a set of these famed "haraguchi" knuckles? Thanx & keep up the good work writing great articles!! You're suspension series is like crack! Lol!! Thanx for any info on those knuckles