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-   -   PT Rear camber Adjustment 0/3 pt (https://www.rx7club.com/race-car-tech-103/pt-rear-camber-adjustment-0-3-pt-1008656/)

wlfpkrcn 08-17-12 03:44 PM

PT Rear camber Adjustment 0/3 pt
 
After Greg decided that the rear camber links needed to take points, I have been trying to figure out a way to get the camber adjustable without taking additional points. We take 3 points for metallic/spherical bushings/bearings.

I came up with machining a bushing for the upper trailing arm and slotting it. The next obstacle was the DTSS. We ended up fitting a spherical bearing in place of the DTSS. I also made a set of solid shock mounts with a bearing.

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wlfpkrcn 08-17-12 04:14 PM

Here is the info from Greg on the points for either the "center camber link" Or the "Outer links"

1) The center "control link" functions as a sub-frame brace and sub-frame mount. You can modify (replace) this brace for the +3 points under rule 5.3.F.4)
Add or modify other chassis stiffening devices or fabricated parts (such as lower strut braces or lower arm braces (with greater than two attachment points), subframe connectors, subframe braces, subframe mounts/bushings, etc) +3

Slotting the chassis bolt holes for this link would have the same effect, so would take the same +3 point assessment. It would not be considered an alteration of suspension mounting points, but would be, as stated above, considered a modification of a subframe mount. If this +3 points assessment is taken, then the other aspects of this rule can also be taken advantage of (more chassis stiffening devices, etc).

2) The "outside" links that connect the subframe to the trailing arms are considered either part of the subframe suspension mounting points, or are considered part of the trailing arms, whichever will be to the benefit of the competitor. Modifying or replacing them will result in either a +6 point assessment for relocation of suspension mounting points (5.3.E.17), or a +4 point assessment for control arm modification (5.3.E.9). If there are spherical joints involved in the upgrade, then the additional +3 point assessment under rule 5.3.E.24) applies. If the competitor is already taking points for either 5.3.E.17) or 5.3.E.9) for other modifications, then there would be no additional assessment for replacing these links. If neither of those assessments is already taken, then replacing these links would result in the lower +4 point assessment for control arm modification (5.3.E.9). As well, all control arms on the vehicle could them be modified without additional assessment.

3) Slotting of the bolt holes in the trailing arm that the "outside" links use to connect the trailing arms to the subframe are permitted under the No-Points assessment within rule 5.3.E.9)--with or without the use of eccentric bolts or bushings.

C. Ludwig 08-17-12 04:19 PM

Take the stock camber rod out, cut it to desired length, weld it up, grind/sand/bead blast welds down smooth. Paint. Roll it around in some dirt and grease. Re-install.

Replace the bushings with something solid while you're at it.

wlfpkrcn 08-17-12 04:27 PM

OOOOH... Now you make it simple! :lol:

I wanted something adjustable as well.

jgrewe 08-17-12 05:08 PM

Make a few of them.

eage8 08-17-12 11:04 PM

wouldn't the whiteline camber adjusters work just as well? the main problem with them is you can't use solid DTSS eliminators. but if you're already replacing them with sphericals they should be fine.

I'm just not a big fan of slots... they tend to slip.

wlfpkrcn 08-18-12 09:16 AM

If I remember correctly those bushings were expensive. These just cost me time. Initially I drilled just the offset hole and almost left it alone. We wanted some adjustability to dial in the camber. I can always make another set with a single hole or I can drill and tap the trailing arm and bushing and run a 6mm bolt up against the bolt to keep it from shifting negative

Do you slotted camber plates in front slip

SCCAITS 08-18-12 09:19 AM


Originally Posted by wlfpkrcn (Post 11191980)
Here is the info from Greg on the points for either the "center camber link" Or the "Outer links"

And there is your problem. One guy making all the rules that are subject to his often flawed interpretations. Challenge him and you will be censored. The PT points based classing system is overly complicated and overly flawed. I am speaking from first hand experience, 37 races in PT trim before I left. It's fine for time trialers but not for racing.

The single camber adjuster should be a 0 point free mod as it does nothing more than simple camber adjustment, which according to PT philosophy is allowed and the intent of the rules. The single adjusters should be free as well, stock dog bones are already a bearing mount. Problem with single adjusters is they require spherical bearing outer control arm bushings which are a performance advantage and should take points.

Have you tested the slotted bushing on track? Did it hold?

wlfpkrcn 08-18-12 09:37 AM

Nope. That's why I have a plan to lock it or build one with a single hole. If it does slip. For the record my preference was/is a single offset hole. I just need to know where to put that hole. The slotted bushing will allow me to dial in the adjustment. I can machine 2 more bushings if needed

RockLobster 08-21-12 07:32 PM

It's a good thing none of this is actually enforced at any level including nationals...

I gave up and went back to the stock inner trailing arm links. I was playing with the idea of trying some crash style cam bolts for the mounts or slotting the subframe side opening and using a cam headed bolt similar to the toe adjustment.

For now the car actually works pretty good with the ride height and tires we use with the higher degree of negative camber. Especially since we use the stock sway bars. It's not ideal from a drivability standpoint but it seems pretty fast.

Josh18_2k 08-21-12 11:34 PM

can you just shorten the dogbones? is anyone gonna notice.. lol
thats how i set my camber, after too many failed adjustable links

wlfpkrcn 08-23-12 11:58 AM

Update- I did the alignment last night. The camber adjustment range is now -.5* to -2.5*. We will see how it goes at the next race.

gkmccready 08-25-12 12:47 AM


Originally Posted by wlfpkrcn (Post 11197870)
Update- I did the alignment last night. The camber adjustment range is now -.5* to -2.5*. We will see how it goes at the next race.

When are you guys out again? WERC in September? My RX7 motor is still getting built, but I've been running the Miata all year -- leading PTE points in NorCal right now! :-)

wlfpkrcn 08-25-12 07:42 PM

Yup we are signed up for WERC. Congrats on leading points. Glad its not a SM!

gkmccready 08-25-12 10:13 PM


Originally Posted by wlfpkrcn (Post 11200296)
Yup we are signed up for WERC. Congrats on leading points. Glad its not a SM!

Good to hear. I'm trying to see if I can line up crew for the WERC race. The points lead is entirely through attendance, otherwise Bruce and Kurt would be kicking my butt. :-) Definitely not an SM. Three top in PTE are two PTE Miatas and Kurt in an ex-Pro7 1st gen.

I did hear from Haag recently so hopefully the RX7 dynos soon!

I like how you're working the PT rules!

wlfpkrcn 08-26-12 09:55 AM

Try contacting RJ Racing. They were offering VIP/Crew for enduros previously. Not sure if they still do

Good luck on the engine

Thanks, we need to do everything we can to try and catch the 949 guys. They have far more money, resources and track time

Gian 09-01-12 01:04 AM


Originally Posted by gkmccready (Post 11199621)
When are you guys out again? WERC in September? My RX7 motor is still getting built, but I've been running the Miata all year -- leading PTE points in NorCal right now! :-)

If your doing it in SoCal. I maybe able to help you out.

088 09-05-12 05:10 PM


Originally Posted by gkmccready (Post 11200438)
Three top in PTE are two PTE Miatas and Kurt in an ex-Pro7 1st gen.

Damn those Miatas. :P Yeah, the one time I beat Kurt in my PTD car, I considered it a victory. :P


Originally Posted by gkmccready
I did hear from Haag recently so hopefully the RX7 dynos soon!

Are you talking about that tII that Haag and Colicchio have been working on forever?

088 09-05-12 05:13 PM


Originally Posted by SCCAITS (Post 11192557)
And there is your problem. One guy making all the rules that are subject to his often flawed interpretations. Challenge him and you will be censored. The PT points based classing system is overly complicated and overly flawed.

Amen.


Originally Posted by SCCAITS (Post 11192557)
The single camber adjuster should be a 0 point free mod as it does nothing more than simple camber adjustment, which according to PT philosophy is allowed and the intent of the rules.

Amen again.

gkmccready 09-13-12 09:18 PM


Originally Posted by 088 (Post 11211628)
Are you talking about that tII that Haag and Colicchio have been working on forever?

Yup. That's the one. Haag says end of September for the motor back in and tuned. Maybe. Car has missed yet another season...

Gian 09-14-12 12:37 PM


Originally Posted by gkmccready (Post 11221235)
Yup. That's the one. Haag says end of September for the motor back in and tuned. Maybe. Car has missed yet another season...

Just an FWI. My motor stayed together after Nats and is making good power. 137 whp. I'm a happy camper.
:nod:

wlfpkrcn 10-12-12 06:04 PM

Update-

We ran a 3 hour enduro a couple weekends ago. The Adjusters did not slip/move. The car ran the entire 3 hours without any problems other than a flat from a Legends car hitting us.

Next up-Some more suspension tweaking and a new engine!

RockLobster 10-15-12 09:04 AM

Nice! We almost finished P1 overall at road america last weekend...granted only like 8 cars started lol.


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