STX Rules and Setup Questions

[Thorpedo]

Originally Posted by Kido1986

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



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)

Oh god I don't know how I came to the conclusion that it was referring to the second one. You're absolutely right about which cat it is talking about. It seems to me the best solution for STX would be go with a catless over/front pipe (Stock front pipe contains the cat FWIW) and get a catted header. That way you avoid the CEL issues and remain legal.

Now I haven't personally measured the distance between the cats, but FWIW I would say it is more than 6".

[piknockout]

Edit: Doh, didn't realize it had been answered while doing my research.

[TallTerror13]

Why do you want to keep the cat so close to the engine anyways? Correct me if I'm wrong, but I come from a wrx state of mind and that is to keep the cat as far away as possible so that the airflow is not so turbulent making it pass the the cat with ease.

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[Kido1986]

Well I guess I was wrong. Looking back, the rulebook I had bookmarked was from a while ago :/

[Wepeel]

Originally Posted by Thorpedo

Oh god I don't know how I came to the conclusion that it was referring to the second one. You're absolutely right about which cat it is talking about. It seems to me the best solution for STX would be go with a catless over/front pipe (Stock front pipe contains the cat FWIW) and get a catted header. That way you avoid the CEL issues and remain legal.

Now I haven't personally measured the distance between the cats, but FWIW I would say it is more than 6".

Well for "full prep" cars it is probably preferable to go with a catless header and a catted front pipe - they will be running a tune anyway which will take care of the CEL, and removing the header cat is probably better for power/temps and it's getting rid of weight in a better place.

[Thorpedo]

Originally Posted by Kido1986

Well I guess I was wrong. Looking back, the rulebook I had bookmarked was from a while ago :/

LOL there ya go.

[MTCRX]

Originally Posted by Wepeel

Well for "full prep" cars it is probably preferable to go with a catless header and a catted front pipe - they will be running a tune anyway which will take care of the CEL, and removing the header cat is probably better for power/temps and it's getting rid of weight in a better place.

I like the idea of catalytic converter placement to avoid CEL issues, and it is away from the header collector tube at least a little bit. Along the lines of header discussion, conventional thinking has been to use equal length headers for low end torque. Does that apply to these engines too? Looking at the dyno numbers from UEL and EL headers, they look pretty comparable. I will be racing autocross and would like to help the low end torque as much as possible. Call me a heretic, but I would prefer NOT to have the boxer rumble, thus my favoring of EL headers, although FT86 SpeedFactories UEL with cat doesn't sound too bad. Any thoughts?

[Wepeel]

Originally Posted by MTCRX

I like the idea of catalytic converter placement to avoid CEL issues, and it is away from the header collector tube at least a little bit. Along the lines of header discussion, conventional thinking has been to use equal length headers for low end torque. Does that apply to these engines too? Looking at the dyno numbers from UEL and EL headers, they look pretty comparable. I will be racing autocross and would like to help the low end torque as much as possible. Call me a heretic, but I would prefer NOT to have the boxer rumble, thus my favoring of EL headers, although FT86 SpeedFactories UEL with cat doesn't sound too bad. Any thoughts?

I've seen it both ways for these cars (EL vs UEL), just based on threads I see here. Of course the header results I see are mainly from vendor-generated threads so

I think either way it's close between the two and probably more dependent on tune. Seems though a header+tune on pump will be worth about 20 whp in general.

[finch1750]

Originally Posted by MTCRX

I like the idea of catalytic converter placement to avoid CEL issues, and it is away from the header collector tube at least a little bit. Along the lines of header discussion, conventional thinking has been to use equal length headers for low end torque. Does that apply to these engines too? Looking at the dyno numbers from UEL and EL headers, they look pretty comparable. I will be racing autocross and would like to help the low end torque as much as possible. Call me a heretic, but I would prefer NOT to have the boxer rumble, thus my favoring of EL headers, although FT86 SpeedFactories UEL with cat doesn't sound too bad. Any thoughts?

Originally Posted by Wepeel

I've seen it both ways for these cars (EL vs UEL), just based on threads I see here. Of course the header results I see are mainly from vendor-generated threads so

I think either way it's close between the two and probably more dependent on tune. Seems though a header+tune on pump will be worth about 20 whp in general.

Drift Office did pulls and tunes with various headers and they were all pretty close. I am on my phone or I would find links but if you seatch for threads they created I would consider it a good neutral comparison. Fwiw I remember uels made more power and tq than everything but HKS EL, but not sure if low end was better on one versus the other

[Wepeel]

Originally Posted by finch1750

Drift Office did pulls and tunes with various headers and they were all pretty close. I am on my phone or I would find links but if you seatch for threads they created I would consider it a good neutral comparison. Fwiw I remember uels made more power and tq than everything but HKS EL, but not sure if low end was better on one versus the other

For the few actual cars I've known of personally, the HKS seemed to make the most power. It's also $$$. Looking forward to the real world results for the upcoming releases - Nameless, OFH, ft86club... etc

[piknockout]

Running STX in Dixie next month. This is gonna be fun.

[Wepeel]

Originally Posted by piknockout

Running STX in Dixie next month. This is gonna be fun.

Good luck. So how far have you gotten with setup?

[SubiePig]

I will be there too!

Tires come in today. Mounting them and scrubbing them in next weekend and trying out the new setup and see if I need to adjust anything. Still have about 100 lbs. I plan to remove from the car, corner balance, realign, test event the weekend before Dixie to test changes and go! Have to order my muffler and build my exhuast too.

[Thorpedo]

My I ask your secret in weight removal, @SubiePig?