Street Porting Question
 

I ordered some street ported Irons for my s4 Turbo II. Well the question is ... Are the middle housings supposed to be ported??

Only your supplier can anser that.

If only the secondary ports are enlarged, the idle and low end will be more like stock depending on how much the exhaust is ported.

If the primary ports are also enlarged, you idle and low end will not be as smooth or strong.

which are the primary???

Intermediate (center) housing.

B

Good stuff to know. I am having some irons ported, and elected to go with a mild port on the primaries to keep some low end to push around my heavy 'vert.

Am I sacrificing some top end here? If so, no biggie- I will be driving this daily and prefer not to have a sketchy idle.

Oh, yeah, sorry about the threadjack (at least I stayed on topic! :D )

tell me more please

https://www.rx7club.com/showthread.p...1&page=1&pp=15
here is a link with the pics of the ports please gived me feed back

anybody help check the link

By the looks of that picture, the center plate looks more smoothed out for flow rather than ported for timing. It looks like the stock port size for a s4t2 center plate, best way to know is really ask that guy you bought them from.

but the other posts are opened up. oh I asked the guy and he didnt know

this is not true, if you find someone who thoroughly knows the importance of proper porting and cares enough to take their time you will not have this problem. the 12A in my car has has each of its intake ports opened to an extend port (similar to Judge Ito's large secondary). I am talking about both the primary and seconandary ports.... all opened to be huge.

Brian may recall seeing my RX-3 at rev. it idles at a lumpy 700 rpm, with off idle torque... makes a great autoX engine... even coming out of the corners under load. it pulls great. with some playing with the idle adjust screws it will maintain enough air velocity to sit at 400 rpm.

A TII engine i just finished for a friend will idle at 150 RPM... I couldnt believe it either.....

my point is, don't let someone who shouldn't be porting in the first place get one over on you by saying that porting the primary ports will greatly affect low RPM and Idle.

exactly.

streetports, even larger ones, can idle smoothly and still be very friendly from a dead stop on a steep hill. it depends on who you get to port the engine and then who you get to tune it once running.

well I know my irons were ported from atkins. What I have found out so far about the irons I bought was. They were in a rx7 with a to4e and was a high rev monster