Okay so i want to know the main differences of a large street port versus a mild street port. what would be the pros and cons of both what is more reliable or better for DD to make more power.

 

Reliability depends on the quality of the person using the tools to port the engine and build it.

The difference between power levels will depend on other mods. Obviously bigger flows more air but at a higher RPM. DDability will depend on tuning as well.

 

Here's a nice little reference.
http://www.mazdarotary.net/porting.htm

 

well a bridgeport isn't necessarily good for DD, but a street port obviously is, the downfall of bridgeport is louder, more gas consumption, and shorter engine life? i have the option to buy either a bridgeport n/a or a streetport turbo II it is my first seven so I'm going to lean towards the street port since it is probably more logical to go with something less advance such as a bridgeport build.


yeah I've been there a few times thanks.

 

Just wanted to chime in and say that guide is EXTREMELY helpful for someone who hasn't seen ports before. I kind of knew what they were, but now I've SEEN them :P

/newb moment

 

Yes, they do give good photo's of each engine port and gives a great detailed description for each type of port.

 

You asked about Mild vs Large Streetport. You didn't mention Bridgeport in your original post unless I'm going blind....

You don't want a bridgeport for a DD. Your "downfall"s are accurate. Plus you'll never, ever stand a chance at passing an emissions test.

 

yeah that was my mistake idk why i even mentioned it i think bcus i was talking to my friend about it when i was going to post, and i ended up just writing random shxt. lol

 

From what I've read I heard the more extreme you port the emmsions are pretty bad , gas milage isn't that great and the engine life is shortened. Like peripheral port are mostly used in track cars and rarely if ever seen on street cars.

 

emissions are hardly affected with any streetport. emissions are largely affected by a bridge.

it just depends what part of the RPM range you plan on using more and where you need that power curve to be.

in essence:
stock port- lower RPM power range
mild street port- mid RPM range
large streetport- mid to upper RPM range
bridges- high RPM range



the higher you go with the RPM range shift the less the car likes to drive in the lower RPM ranges, mainly true of bridges because that is a rather radical step in port timing/volume.

with a turbo car porting is mainly to aid in your chosen RPM range but porting isn't even necessary with a turbo car. people have made more than usable power with stock ported motors and the turbo can be scaled accordingly for your power and RPM range goals. basically if you want to squeeze out maybe 5% more power from your turbo then porting will help with that, or to help your stocker flow to redline, for example.

a few have made over 700whp on stock blocks for reference. and how many people can realistically use that much power? porting aim just helps you reach your goal with the engine a tiny bit easier, i rarely even push portwork anymore because the gains i have noticed have been much more minimal than most people think. shops that claim 10-15% more peak power from a streetport are full of ****.