street porting! how much hp increse?
 

i am installing a new street ported motor in my 86 gxl. i have no catz, custom duel exhaust that runs straight to dues borla mufflers, a pacesetter header, 8mm plug wires and a cone reactive filter with heat shield. how much power will my engine now put out? i have beaten many a honda with my regular motor and i have also beaten stock 7's in my area. i just want to know ho much a street ported motor will give me. it cost me 3700 bucks for the motor, new clutch and install was it worth it?

You can expect 10-15% from the streetport...depending on the size and shape.

i would say 20-25-30% increase if done right

does street port refer to porting the intake manifolds?

i heard about 20 to 25 percent. i hope alot though the wheels cause i got about the same setup as you. i only have about 800 miles on mine though. still dont have full power

I think 20-30% is pretty unrealistic. 10-15%, maybe. There are a bunch of other things that will factor into your gains.

you may not even get 10-15% unless it's a monster street port w/ lots of overlap. porting has less of an effect on na motors than turbo ones, where every little improvement in airflow gets you lots of hp.

i am talking about the port plus exhaust porting.. thats where most of your power will be

Must be a pretty awesome street port to gain a 30% increase:) I've never seen that big of an increase...

i was looking for my rotary preformance book becuase i swear i saw somwthing like that in there! oh well! lets just say street port = fun times :)

Bridge da bitch!!!!.

Re: street porting! how much hp increse?
 

There're alot of variables in SP. port timing, shape of the port, size of the port, runner size, runner smoothness...etc... Everybody has their own versions of SP so its hard to say. If I have to give you a %, I would say from -10% to +15%. I did say -10% because you can actually hurt the performance if not ported properly.

Re: Re: street porting! how much hp increse?
 

true dat. if you're gonna want any significant hp from an na you're gonna need tons of overlap. most of your hp will be from advancing the mechanical timing as opposed to increased airflow. this means a monster sp. a mild sp will do nothing for you.

A mild port will do wonders for the na, but nothing like a monster street port will do, and if you don't mind replacing the motor a little more often, but make tuns of power Bridge da Bitch

-Chris