exgr

Hello, anybody have suspension photos from the RTR TSX? They had raced the 1st gen and 2nd get TSX. Looking for ANY and ALL photos. Please share. Lets learn and discuss this chassis.

exgr

Mid-Ohio

Mid-Ohio 2006

Kaan

iTrader: (3)

Follow @johnwhitaker88 on instagram... he has a collection of RTR cars.

exgr

Cool thanks for the note. But it appears he has the 2nd gen TSX...

Does anyone know if the suspension of gen 2 TSX is similar to gen 1?

"

sjg88

Also interested in learning more about these chassis

IIRC, a source of mine told me the original TSX that RTR used required a bit of massaging to get right.

Whether or not a bolt on setup is adequate for a HPDE and or H2/H2 race car is something I'd like to know or get details on

exgr

I also have photos of the SuperTouring Accord from Europe. Not sure if I should start a separate thread for that or just keep it here. Thoughts.

TheShodan

iTrader: (14)

As a previous owner of a Gen1, yes, the suspension is different from axGen 2.

see the AJR spoon CL9 to see photos of race suspension

boxedfox

The suspension of the RTR 1st gen TSX was a closely guarded secret. They changed all of the mounting points of the control arms so they could run the ride heights and travel that they needed.

Their 2nd gen GTS class car, on the other hand, used the stock mounting points with aftermarket arms. They used high dollar suspension dampers and had sphericals instead of bushings, but aside from that it was a setup that you could easily reproduce if you wanted to.

Greyout

The first car I tracked was an '06 TSX. Granted I never got out of the 'intermediate' group, but the car did wonderful against mediocre drivers.

When I go back and watch this video after a few years of tracking my S2000, it seems painfully slow. However, when I went to this same track with my stock S2000 (also on all-seasons) I was 2 seconds slower than my best lap in the TSX.

Video from my first ever track event. Editing has some 3/10 lols and I was obviously too proud of myself.


Later, I went by muself and got some respectable pointbys

exgr

I was asking PD about gen 1 WC TSX suspension.secrets. First he said, nothing special, full custom stuff, but using all stock location pick up points. Since he said nothing special, then I asked him for photos of it. Then he changed tone and said he can't show them to me... sounds a little fishy... I mean, the program is more than a decade ago.

boxedfox

I think you're right to be suspicious. There's no way they were doing what they're doing using stock pickup points and just custom arms / uprights. The geometry of the CL9 Accord / TSX is very well known. It was actually one of the first cars I studied when I started getting into suspension engineering. The suspension system on the car does not behave the way the RTR cars did. There was a visible difference that you could see from the TV coverage and photos.

I really wish I could find old videos of the RTR car. Now that I know a lot more about how suspension systems work, I think I could make a much more educated guess as to what they were doing than I did at the time. Unfortunately I lost all of my Speed World Challenge footage in a hard drive crash in '09 and haven't been able to find the footage since.

exgr

Hmm!!! Don't tease us, tell us what you really think. I never watched SWC races back then... so I have no idea. But I have always heard the RTR TSX had trick *** suspension setup. Trick how? No clue. I'm going to guess they got some creative ways to circumvent the rule book, or maybe they did things that were grey area and thus, still want to keep it hush hush after all these years.

boxedfox

Turns out we don't need to guess. A former mechanic at RTR (and apparently, a Honda-Tech member) took a bunch of photos of the TSX when he worked there and put them up on his photobucket for everyone to see.

Note: See reply below for a more complete, summarized analysis of these photos.

Being that they are 10 year old digital camera photos they aren't exactly high-res, but they're good enough that you can see out a lot of the trick parts they used.

Front Suspension:

Check out the lower control arm. That looks nothing like the stock TSX part. The front lower control arm mounting point is visibly higher than stock and they appear to be running a relatively tall extended ball joint.


It's hard to tell because of the perspective, but if you straighten this photo you can see just how short the upper control arms are. The shocks are also tiled inwards at an extreme angle, indicating that they moved the upper mounting point further into the shock tower.



You can see the driver's side lower control arm from above here. The back half of it looks like it is a cast steel part, which makes me wonder if this was a fully custom part or if they modified a lower control arm off of a different car.



The top surface of the shock towers have been replaced entirely. There's a set of mounting ears for the front tower bar where you would expect the front shocks to poke into the engine bay. I suspect that those ears extend down into the wheel well, and that's what the front shocks are bolted into. They also cut big holes on the outsides of the shock towers so the upper control arm can extend into the engine bay when the car hits big bumps.

Rear Suspension:

The obvious difference here is that they've installed a massive antiroll bar and relocated the mounting points so that it goes under the rear toe arm. The suspension arms are all adjustable length pieces with heim joints, which is how they were able to run the cars with so little negative camber in the back. For the most part, the control arm mounting points are in a similar location to stock. However, it does look like they might have moved the inner mounting point for the rear upper arm upwards to compensate for the low ride height.



From a distance it's really hard to tell how much work they've done to the rear suspension. If you were casually passing by you'd probably only notice the wacky rear antiroll bar and miss all of the subtle changes that they made to the suspension geometry.


Completed Car on jack stands:

I was always surprised at how much droop travel these cars had, especially in the front. Can't tell if this was intended or a happy coincidence, but I'm guessing this is partly why they could attack kerbs so aggressively.


Original source with additional photos:
RTR by Travis Watry | Photobucket

It also turns out that the World Challenge TV youtube channel also has some older videos where you can see the car in action:

exgr

gosh what horrible resolution... can't see ****. but thanks for digging them up and sharing. droop is no accident. my prototype 2 way suspension for EG/DC chassis will have more droop than most aftermarket suspension. it is by design.

boxedfox

Yeah, it took a lot of playing with filters and lighting in Photoshop to make out the details. Anyway, for the benefit of everyone who is having trouble understanding my comments on the photos, here's a more complete analysis of what I see in this suspension setup:

Design Philosophy

It's pretty clear that RTR was following a very traditional FWD racecar setup philosophy for this car. The priorities were to:

• Run as stiff a spring rate as possible to keep a stable platform that can transition quickly between acceleration, cornering, and braking
• Get as much dynamic camber in the front while having as close to 0 deg static camber in the rear
• Make the rear tyres work as hard as possible by running as much rear roll stiffness as reasonable
• Lower the ride height as much as reasonably possible to maximize the car's aerodynamic performance in the limited ruleset of the cars

While it seems a little old fashioned noawadays, this was a very popular setup philosophy at the time.

A lot of it had to do with the tyres that they were running. From 2003 to 2007, the World Challenge TC class mandated the use of Toyo RA1s, a DOT R compound with soft sidewalls that works best with tons of negative camber. The best way to get that amount of negative camber is to run very short upper control arms, which will not only give you a good deal of static camber, but will maximize the amount of camber that the suspension gains as you compress it through its travel. In order to make sure the alignment stayed the way they wanted it to, they replaced every stamped steel control arm with a tubular unit and replaced every rubber bushing with a steel bearing.

Like most World Challenge teams, RTR wanted to run their car as close to the ground as possible so they could get the maximum amount of front downforce from their stubby rules-limited splitter. In order to make sure that the suspension geometry wasn't compromised by the low ride height, they fabricated custom lower control arms with extremely tall lower ball joints so they could maintain reasonable geometry and keep bumpsteer under control. They also cut windows into the front shock towers so the super-short upper control arms could swing into the engine bay when the suspension compressed. The front tower bar shock not only keeps alignment in check, but it also ensures the shock towers wouldn't flex under load.

In the rear, they tried to keep the rear tyres as close to 0 camber as possible to keep the rear end stable under hard braking. A consequence of this is that the rear tyres would visibly go into positive camber during the initial turn-in phase of each corner. This sounds like a bad thing, but it's actually very helpful in getting FWD race cars to rotate. Similar to the front, RTR changed the lengths of all of the rear suspension arms and lowered the mounting points on the knuckcle to get a more favorable camber curve whlie still running their super-low ride height.


Springs and Damping

Most World Challenge cars of that era ran springs in the 2500 lb-f/in to 3500 lb-f/in range, and in all likelihood these RTR TSX's were no different. My suspicion is that the front springs on the RTR TSX were on the stiffer side of that spectrum.

This is due to the fact that RTR relocated the upper mount for the front dampers inwards from its stock location in order to get the front camber that they wanted. This means that the front coilovers are leaned in at a much larger angle than they are stock. The larger the installation angle of the spring and shock, the less effective they are, so it's safe to assume that they needed to run some very stiff springs and damping up front to compensate.

That said I don't think the rears were much softer. With the way those cars launched off the line and the way they behaved mid-corner, I would think the rears were in the 3000 lb-f/in - 3200 lb-f/in range at most tracks. And that's not including that gigantic speedway style rear antiroll bar hanging off the back.

Their solution for controlling these super high spring rates were to use 3-way adjustable Motons. In 2008 they cost somewhere between $8000 - $11,000 just for the shocks. While this might sound expensive, it isn't that bad when you consider everything else required hundreds of hours of R&D and custom fabrication work to build.


Why are they keeping it a secret?

I need to find a copy of the SCCA Pro Racing rulebook from that era to confirm, but I don't think it was explicitly stated that you could relocate the upper shock mounting points the way that they did.

Everything else including the custom control arms and the tower bar are allowed under exceptions in the World Challenge VTS for the TSX. But those front shocks look like they are well into a grey area of the rulebook. They might have even been illegal.

Should you copy their setup?