2021 T50 suspension rules question

[eclip5e]

I have Ohlins Road & Track coilovers on my vehicle. This means, custom springs, with dampers that are rebound-adjustable, include front camber plates, and they allow me to adjust the ride height. Not sure if these are considered 2-way or 3-way adjustable. I'm unclear how to take points for the springs as well.

reading the 2021 rules, i think i should take 2 points for the coilovers...
2pts: Non-Factory Trim 2-way adjustable shocks, struts, dampers

and either 2 or 3pts for the springs?
2pts: Non-adjustable non-Factory Trim coil springs, leaf springs, or torsion bars (or non-modified factory height adjustment)
3pts: Height adjustable non-Factory Trim coil springs, leaf springs, or torsion bars (or springs with modified factory height adjustment)


Also, i do drift events, and need increased steering angle, so i'm considering a modified front knuckle that gives me increased steering angle for drifting, but doesn't change the geometry for racing as those angles generally mean you've gone-done-screwed-up.

Would that deserve to count as a points-worthy advantage in a time trial? The only change is the extension on the pickup where the tie rod ends connect.

Heres how the knuckle is modified: (circled)

[dtlemoine]

Steward here, hoping others will chime in as well. I believe this should be 5 points total.

Making an assumption about your shocks that they only allow rebound adjustment? And not compression? There's only a single attribute that you can adjust, right? These would be 1-way adjustable, 1 point.

Re: springs - ride height adjustable for 3 points.

The camber hats add 1 point for the following rule: Non-Factory Trim/modified suspension components which enable alignment settings
beyond Factory Trim capability.

The knuckle... Assuming the only change is your ability to adjust alignment, you're covered by the 1 point already in the rule above. Would love others to weigh in on this specific point.

Thoughts??

[eclip5e]

That assessment looks reasonable to me, however, as for the camber plates, my worksheet says:

Non-Factory Trim/Modified Control Arms or Non-Factory Trim/Modified Trailing or Camber Arms of different dimensions than Factory Trim

perhaps my sheet is out of date, but camber plates aren't "control arms/trailing or camber arms", but they could be argued they seem to fall within the spirit of the rule.

The knuckle... Assuming the only change is your ability to adjust alignment, you're covered by the 1 point already in the rule above. Would love others to weigh in on this specific point.

the knuckle is modified only to allow increased steering angle, it does not affect camber, caster or toe:

[DanB]

Looks like 5 points.
1 point for aftermarket 0- or 1-way shocks/struts (line 10)
3 points for springs and height-adjustable coilovers (line 15)
1 point for camber plates which allow alignment beyond factory capability (line 27)

Line 27 also should cover any different geometry nuances with steering angle due to different steering knuckle.

Welcome to the jungle
Sorry I called you Ryan at Thompson!
"Play Summer of '69!"

[TroyV]

Well.. He does look like a Ryan.

[eclip5e]

I'm a white dude, we all look like "Ryan"

[DanB]

Oh yeah, so exactly what Lemoine said!

[paultg]

Looks like 5 points.
1 point for aftermarket 0- or 1-way shocks/struts (line 10)
3 points for springs and height-adjustable coilovers (line 15)
1 point for camber plates which allow alignment beyond factory capability (line 27)

Line 27 also should cover any different geometry nuances with steering angle due to different steering knuckle.

Welcome to the jungle
Sorry I called you Ryan at Thompson!
"Play Summer of '69!"

These seems correct to me and similar to what I have for MX5.
The modified knuckle is a bit of a gray area. The increased steering angle could be considered a performance improvement.
I would need to understand it better.
Please remember to review other lines on the sheet: ie sway bars, bushing changes, etc.

Don’t forget the spreadsheet is a tool to help with classing, not the actual rule book. - Paul G.

[paultg]

I looked again; the chart in the rule and excel sheet says nothing about modified knuckles / hubs.
I think you are fine there. Taking the (1) point for modified alignment settings covers it and the camber plates in my opinion. - Paul G.

[TXBDan]

The camber plates fall under this rule:
Non-Factory Trim/modified suspension components which enable alignment settings beyond Factory Trim capability (does not apply to coil springs, leaf springs, or torsion bars); note - additional points may need to be taken for specific non-Factory Trim suspension components if listed elsewhere in this section

Not this one:
Non-Factory Trim/Modified Control Arms or Non-Factory Trim/Modified Trailing or Camber Arms of different dimensions than Factory Trim


Other can check me, but if the camber plate uses a spherical bearing and the factory mount does not, then you also need to take a point for:
Non-Factory Trim suspension bushings or spherical bearings, except rubber or polyurethane

[eclip5e]

Heres how i've assessed myself for the recent few events, given my Ohlins Road & Trail coilovers:


5pts total.

here are the coilovers in question:



My personal assessment:

1pts Non-Factory Trim 1-way adjustable shocks, struts, dampers

The actual coilover dampers

3pts Height adjustable non-Factory Trim coil springs, leaf springs, or torsion bars (or springs with modified factory height adjustment)

the springs

1pts Non-Factory Trim/Modified Control Arms or Non-Factory Trim/Modified Trailing or Camber Arms of different dimensions than Factory Trim

I'd argue that camber plates aren't control arms, trailing arms, or camber arms, so i'd debate this if protested.

1pts Non-Factory Trim suspension bushings or spherical bearings, except rubber or polyurethane

this accounts for the the camber plates w/spherical bearings

0pts Custom Alignment settings, including caster, camber, or toe, regardless of factory recommendations; note: modifications to Factory-trim suspension components for the purposes of alignment adjustment must be assessed separately

my alignment, 0 points.

2pts Modification of wishbone suspension upright

This is what i'm asking about. I'd like to challenge this ruling and exclude increases in wheel steering angle as a competitive advantage. From the factory, the Toyota 86 & Subaru BRZ have a very wide horizontally opposed engine, which places the engine frame very wide. The wheel wells are relatively tight, which constrain the factory steering angle to 35º of steering lock-to-lock, much tighter than say, the Miata.

Given the narrow steering angle, I'd like to run extended tie-rods, wheel spacers, a narrower 8" wheel and 215 tire, and a modified knuckle to increase this steering angle for drift events. These changes give the wheel more room inside the wheel well to turn when the car gets sideways.

I wouldn't run the wheel spacers, 8" wheel, and small tires at track & time trial events like COM, only during drift days. At track days and time trial i run without the spacers on a 9" wheel on 235 tires. This itself would negate the modifications to the knuckle because the bigger wheel & tire rub on the inner wheel well at max angle... and in racing, we don't care about max-angle unless we've **** up really badly.

The goal here is a competitive T50 car that can also do drift events.

[paultg]

You are missing this point which covers the camber plate - camber gain advantage. - Paul G.

[dtlemoine]

You are missing this point which covers the camber plate - camber gain advantage. - Paul G.

This is correct. Need to take the point for the camber adjustment component of the camber hat, in addition to the spherical bushing.

Everyone is in agreement that the following point is unnecessary for your build: 1pts Non-Factory Trim/Modified Control Arms or Non-Factory Trim/Modified Trailing or Camber Arms of different dimensions than Factory Trim

To summarize:
1 point for 1-way shock
3 points for ride height adjustable springs
1 point camber hat (rule Paul cites above)
1 point spherical bushing
0 points steering knuckle - no need to challenge anything, there was not a ruling made, everyone is in agreement the knuckle is free

For a total of 6 suspension points. Nothing to be challenged or debated on the 6 point assessment, this is a super common setup many competitors have taken historically.

[eclip5e]

This is all great, thanks for all the input, i've adjusted accordingly for 6pts and i'm very happy with the results.

[TunaNoCrust]

Here is a picture of my factory Toyota 86 top hats we were talking about at NHMS