STX Rules and Setup Questions

[Wepeel]

Originally Posted by SubiePig

So... What is everyone thinking on tires since the RS3 seems to not be able to be found. R1R or ZII.

I've heard that the Z2 wasn't great as a 245 on the 9" rim - possibly it being too stiff (they seem to be very good squeezed, like a 235 on a 7" in CStreet). I know the Rival didn't work great at Nationals but it seemed to work well locally and for tours. I'm thinking I might give the Rivals a go in 245 or 255. I liked them on my STU STI and in the few events I did on the BRZ in RTR (225).

[Kido1986]

Z2s are the choice right now IMO, with RS3s not available. I'm loving mine, just having to spray the piss out of them every run after 3rd

Edit: didn't realize I was in the STX thread, was thinking CS. Still believe RS3 is the best answer for STX. With camber, those rule in 245. Z2s are better when you can't camber and I can't

[SubiePig]

Originally Posted by Wepeel

I've heard that the Z2 wasn't great as a 245 on the 9" rim - possibly it being too stiff (they seem to be very good squeezed, like a 235 on a 7" in CStreet). I know the Rival didn't work great at Nationals but it seemed to work well locally and for tours. I'm thinking I might give the Rivals a go in 245 or 255. I liked them on my STU STI and in the few events I did on the BRZ in RTR (225).

Totally forgot about the rival in my post.

R1R is only good for this year, but this in the year that matters right now.

I am between R1R and Rival, then its 255/245 and if I go with the R1R the 245 has 3 different sidewalls.

[piknockout]

I'm betting the new RS3 will be available in time to be legal for the year. Barring that, the ZII or Rival. Toyos for Nationals.

[Itsjusdame]

Hey guys thanks for all the good input. I Just ran my rivials for the second time this weekend . They grip great and i feel they reach max grip faster than RS-3 which is good for me since in normally a one driver car. When i got home when i was storing them away i noticed about of unused tread on the inside. Im only running 1 degrees in the front and about 2 in the back. Question : should i be running more camber ?? Im kinda of intimidated to mess with my camber plates after alignment .

[MTCRX]

Originally Posted by FastWhite

R1R's are only good for this year. 140 tread wear.
ZII's apparently will fit the stock rim In a 235/40/17.
Chime in if that is a no no.
As that is what I was going for on my next set of tires.
My current Rival's are holding up well and are a blast.
But change is good right.


Sent from my iPhone using Tapatalk

I used 235/40/17 on stock rims last year and thought they felt great. I mostly race on asphalt courses and in relatively cooler weather regions. The sidewalls are very stiff and I never felt like the tires were squirmy, the tires always reacted like I expected. Until I got to Nationals. I think they were too worn by then, close to the wear bars. They felt slick on the concrete, but I bet a newer set would have been much better. With that said, don't all you RS3 buyers switch to Dunlops and cause a run on them at the warehouses! I still prefer the Dunlops and will be getting another set this year, but 245's on 9" rims this time (STX). They are also great in the wet.

[Thorpedo]

Originally Posted by Kido1986

Correct. Or you can delete the primary cat (most aftermarket headers) as long as you have a secondary in stock location, as it is within 6" of the OEM primary

@Ranatsu

You can delete both cats but you must have a cat within 6" of the rear most stock location.

No one seemed to notice these posts conflict with eachother. My understanding was that it had to be within 6" of the rear cat.

I don't think the two cats are within 6" of eachother, so I don't think we can just run a catted header. Can anyone confirm this please?

[SubiePig]

I feel the R1R might be faster than the Rival but not last as many runs in optimal condition. I need to order tires this week so I have them for Dixie and College Station. I won't be doing any other big events until Nationals and Blythville, unless someone wants a co-driver. Stuck on tire choice of grip vs gearing. I figured out the max speed at redline for what is out there. I realize I am talking about thousands in time but if I am spending money on tires for those events I want to get the right thing.
R1R
255/40 - 59.69 MPH - 9.6" tread width - $804
245/35 - 56.82 MPH - 9.4" tread width - $728
245/40 - 58.97 MPH - 8.9" tread width - $672
245/45 - 62.08 MPH - 9.3" tread width - $756
RIVAL
245/40 - 58.97 MPH - 9.1" tread width - $692
255/40 - 59.69 MPH - 9.5" tread width - $812

[Kido1986]

At Nats, everyone's Rivals were like that. We all discovered that Rivals really dont like driving on top of a thick layer of purple crack.

If you're doing Dunlop on a 9", I'd suggest the 255s. Sidewalls are MORE than stiff enough for a 255.

[Kido1986]

Originally Posted by Thorpedo

@Ranatsu

No one seemed to notice these posts conflict with eachother. My understanding was that it had to be within 6" of the rear cat.

I don't think the two cats are within 6" of eachother, so I don't think we can just run a catted header. Can anyone confirm this please?

It's been researched and determined that a catted overpipie is close enough to the header to suffice.

The second can go away completely, IF you have one within 6" of the first one. It just happens that the overpipe is close enough to fall within this rule.

[Thorpedo]

Originally Posted by Kido1986

It's been researched and determined that a catted overpipie is close enough to the header to suffice.

The second can go away completely, IF you have one within 6" of the first one. It just happens that the overpipe is close enough to fall within this rule.

Bare with me here, but im still confused. It is the front pipe that is catted, not the overpipe. Of course the header is catted as well.

In the rulebook (last time I read it, not long ago) it stated it had to be within 6" of the REAR cat, not the front. Given the front and rear cat are further than 6" apart, I can't see what you said being true.

I will be running at the Canadian nationals, and I don't think "close enough" is going to cut it unless there is a specific section in the rules saying the FRS/BRZ actually are "close enough".

Edit: Not trying to be a douche here, just trying to nail this down 100%.

[Wepeel]

Originally Posted by SubiePig

I feel the R1R might be faster than the Rival but not last as many runs in optimal condition. I need to order tires this week so I have them for Dixie and College Station. I won't be doing any other big events until Nationals and Blythville, unless someone wants a co-driver. Stuck on tire choice of grip vs gearing. I figured out the max speed at redline for what is out there. I realize I am talking about thousands in time but if I am spending money on tires for those events I want to get the right thing.
R1R
255/40 - 59.69 MPH - 9.6" tread width - $804
245/35 - 56.82 MPH - 9.4" tread width - $728
245/40 - 58.97 MPH - 8.9" tread width - $672
245/45 - 62.08 MPH - 9.3" tread width - $756
RIVAL
245/40 - 58.97 MPH - 9.1" tread width - $692
255/40 - 59.69 MPH - 9.5" tread width - $812

I think that's the general consensus - and even on a light-ish car like the twins the Toyo may be fastest in the first run or two. I'm looking to DD the tire as well so that would favor a non-Toyo.

How often are twins hitting the limiters in STX at the stock 7400 RPM limit? I hit it a lot on my STI (59 mph) but that also had gobs of torque and AWD traction.

Originally Posted by Kido1986

At Nats, everyone's Rivals were like that. We all discovered that Rivals really dont like driving on top of a thick layer of purple crack.

If you're doing Dunlop on a 9", I'd suggest the 255s. Sidewalls are MORE than stiff enough for a 255.

That's the recommendation on the Dunlop I've gotten as well. But the 255 Z2's are heavy compared to the 245 Z2 and the 255 Rival.

[Kido1986]

Originally Posted by Thorpedo

Bare with me here, but im still confused. It is the front pipe that is catted, not the overpipe. Of course the header is catted as well.

In the rulebook (last time I read it, not long ago) it stated it had to be within 6" of the REAR cat, not the front. Given the front and rear cat are further than 6" apart, I can't see what you said being true.

I will be running at the Canadian nationals, and I don't think "close enough" is going to cut it unless there is a specific section in the rules saying the FRS/BRZ actually are "close enough".

Edit: Not trying to be a douche here, just trying to nail this down 100%.

Understand, no douchery taken. However, here is the rule copy/pasted from the rulebook

High flow catalytic converters are allowed, but must attach within six inches of the original unit. Multiple catalytic converters may be replaced by a single unit, provided the single unit is within six inches of the original primary unit. The resultant configuration must meet Federal emissions standards at normal vehicle operating temperature.

It may be the front pipe and not the overpipe I'm thinking of. I run Stock/Street so I haven't replaced mine, I just know that wherever the secondary is, you CAN use it inplace of the primary in this car due to the closeness of the inlet of secondary in relation to the outlet of the primary (when discussing OEM)

[mrazny]

online pdf's have search functions. It took me 30 seconds to get to the text I wanted:

"E. Catalytic converters: Any catalytic converters are allowed, but must
attach within 6” of the original unit. Multiple catalytic converters may
be replaced by a single unit. The inlet of the single replacement converter
may be located no further downstream than 6” (152.4mm)
along the piping flow path from the original exit of the final OE converter.
The extents of an OE converter are defined by the expansion
chamber in which the catalyst is contained, regardless of placement
within larger exhaust sections. Replacement converters must have
a minimum catalyst density of 100 cells per inch and minimum substrate
length of 3” (76.2mm)."

Start with the language most applicable and go from there (the bold).

Everyone works with the same language. Definitively it can be no further downstream than 6" from the final. As to the space between, what do you think the rules say here, and what do you think a Protest Committee thinks the rules say? At a minimum the single converter can be 6" upstream or downstream from either location. the space between 6" downstream from the header and 6" upstream from the secondary? The clarifying sentence says it can be there. The first sentence seems to imply it can't.

AKA depends on the committee. Also would depend on someone in class first throwing paper. If someone thinks you won because you put a cat further upstream than allowed and further downstream than allowed *at the same time*, goddamn that's a frivolous protest.