My 45s:




You can see how there's no choke it's just 45mm straight through with sliding valves instead of venturies.

My 2" exhaust:







You can see how straight it is and it's got one muffler plus an empty catalytic converter. Not sure how legal this is there but if your vehicle is low enough you can get it really straight like mine by going under the diff. No clearance problems yet but mine'll be lower than it is now when it's all said and done. (who am I kidding, when are these things 'done'?)