Class this Car TOO, please . . .

[arniecoleman]

'03 Infinit G35 Coupe

Aftermarket shocks, springs
Front & Rear Sway bars
Aftermarket exhaust incl. headers
Cold Air Intake
Slotted Rotors
Stainless Steel Brake Lines

Thanks!

[lmichael]

Sounds like STX on street tires (depending on whether the wheels are 8 inches wide or less), and ESP on race tires.

[russjnco]

Yep, straight to ESP for that car.

[fsmtnbiker]

Does the aftermarket headers/exhaust still retain the factory cats? Or cats in the original locations?

[arniecoleman]

Does the aftermarket headers/exhaust still retain the factory cats? Or cats in the original locations?

I think the answer to both is "No"

[fsmtnbiker]

I would concur with Russ, ESP it is.

Other than the cats, all the modifications are ST* legal.

[lmichael]

I would concur with Russ, ESP it is.

Other than the cats, all the modifications are ST* legal.

Headers and replacement high flow cat(s) are allowable modifications in STX, and I assume STU. Come take a look at my car this weekend....

I assume that this person has a car that can pass emissions and be licensed in Colorado. Based on that assumption, they do have at least one functioning catalytic converter and oxygen sensor, and most probably at least a pre and post cat oxygen sensor.

In STX, and I assume in STU as well, OEM catalytic converters are allowed to be replaced with a single high-flow unit. Therefore, without seeing the exhaust system, my assumption is that this car is legal in STX or STU (depending on wheel width). It does not need to "go straight to ESP" if it's on 140+ rated street tires.

[00 SS]

Yep, ESP is right. Would be nice to see more kinds of cars in the class at local events.

[fsmtnbiker]

Headers and replacement high flow cat(s) are allowable modifications in STX, and I assume STU. Come take a look at my car this weekend....


That depends entirely on how you interpret (or choose not to) the most recent BoD 'Clarification' of the ST* emissions requirements. Nobody seems to know exactly what is required.

I assumed the opposite that you did - that the car is without cats entirely. I know test pipes are a relatively popular mod among the G35/350Z crowd. No cats = ESP, Cats of any kind = STU or STX, as stated, dependant on wheel width.

My car could stand to go on a serious exhaust diet, I'll definitely check out your setup this weekend.

[BDoggPrelude]

The base model G35 Coupe has 17x7's and the Sport Coupe model came with 18x8's in 2003. Assuming it has the appropriate cat setup it would fit in STX.

[BobDixon]

The base model G35 Coupe has 17x7's and the Sport Coupe model came with 18x8's in 2003. Assuming it has the appropriate cat setup it would fit in STX.

17x8 max for STX