Im going to street port my 12A, what else would i need to do to my car. Im talking fuel pump carb etc. Maybe a parts list would be nice. Any help on this subject would be great.

 

depending on how big the streetport is, you could get a modded nikki or go a little bigger. but a well done nikki should flow enough for even a big streetport.

 

Freeflowing headers and exhaust. Needs to go hand in hand with a nice SP.

 

go with the biggest street port possible anything other than this is just a waste of time and money. you will need bigger jets in the nikki carb. start with #100 in the primary and #180 in the secondary.

 

85psi oil pressure regulator helps it live longer, cheap insurance.

rebuild or replace the oil metering pump

high flowing carb and exhaust so you'll get the most out of the motor's potential.

light flywheel goes hand and hand with the streetport. thats what i did, RB light steel fw. 2nd thought woulda done the ligher aluminum one. revvs REAL GOOD.

better grabbing clutch. i personally like the Centerforce II.

4.444 gears help out lots too but not necessary.

suspension upgrade so it'll handle as well as it accelerates.

roll cage
helmet
drivers suit
competition license
(just kidding but that's the route i'm heading)

 

I have a question....with a modded nikki and a RB header and exhaust....does anyone have any hp numbers for this setup with no other modifications?

 

Look here:

http://www.yawpower.com/12ptdyn.html

 

rotariesrule : i dont agree with your statement of making the port as big as possible.If he then wants to bridgeport in future,the area available for the bridge will be to small,and he will be forced to get other housings.

Rather do a moderate streetport,so that there will be room for improvement,if he decides on it.

My opinion.

I would also suggest ` adjustable FPR ,and then also a higher capacity fuel pump

Karis

 

I'm with karism on this one. That is the single biggest performance error that everyone makes. The Nikki can't flow anywhere near the potential of a large streetport. Not even a modified Nikki. On Paul Yaw's website he asks: "What is the point of having a port that flows well at 9000 rpm when the carb stalls out at 8000?" Streetport it as large as possible only when your intake, exhaust, carb, etc can handle it. Bigger is not always better. Some people never understand this. The truth that everyone needs to learn is velocity not volume is faster.

 

Rotarygod,

I understand that Yaw has been taken at face value for a while, but there is a carb in the works that is putting up impressive enough numbers to feed a SP just fine - and it's a modified Nikki...

 

i agree. if you wanna go with street port, then go all the way. except, if you are to spend $$$, then I would rather have you spend it on a 48 ida. just my $0.02.

yes, its true that there is no turning back once the cut is made but he didnt say that he wants to do a bridge port.

 

Plates are relatively easy to find and pretty cheap, most 12a core engine plates can either be machined or are ok and 12a cores are like a 100 bux. I would go big street port 48 IDA, and a good header exhaust, light fly wheel, underdrive pullys, electric fan. At 8500-9k you should make almost 190 or mabe a little more at the fly wheel. Pretty fun lengine with a good lifspan.

CJG

 

yeah, i had some trouble with a modified nikki so just went for the 48 mm IDA... totally depends on the money source... hows the fuel pump holding?? mine was shocking, had to get a series 6 one put in... hmm ROTORS OUT IN NZ YEAH BABY!!! sorry... yeah, totally a muney thing

 

I think he should first decide if he would want to upgrade in the future to a BP. If he wants to,then i would suggest a smaller streetport.

If not,then he could go a bit bigger.

Nikki`s can be modified flow lots more than standard,but they do have there limits.

Example : + - 400 CFM for a nikki (dont flame me,i`am going on memory here)

48 IDA 37 venturi : 510 CFM
48 IDA 40 venturi : 560 CFM
48 IDA 45 venturi: 600cfm

Offcourse a 48 IDA with 40 venturies will be total overkill,and not very driveable on a SP

Like Rotarygod said...velocity is just as important,if not more,than port size.

Bigger without good velocity is a waste of time.It will make it less pleasurable to drive,and so on.


Do some research on different streetport layouts.

I would suggest having a look at more year specific templates as well.The front,intermediate and rear housing port sizes differ alot from eachother

 

i doubt it. i have both the street port template and a bridge port template from racing beat. they look the same a far as intake opening on the stock port. if the port was too big as you say, then the seals would get stuck on just the street port. i still say make the port close as late as possible and remove lots of metal to give a good area of flow. i have tried the late closing, long duration port without a big area of flow and it was not nearly as good as the big area. when i say area i mean the depth of the port from the face (shiny) side up, going toward the water jacket. you should leave the runners inside the housing alone.

 

Mmmm... The area available for the bridge on my housings was too thin. (runner side)

I wasnt going to throw away another engine because of a cracked bridge.

I didnt know that housings are that cheap in USA ,if so,then i would suggest that you port bigger,if the cost of different housings arent a problem

Karis

 

I disagree with the above....i dont even use a 40 venturies. i play between 43-45 depending which i wanna play on the fwy or track. IMHO, a 43 is ideal for street and track. 44-45, low end sucks but top end is great.

BTW, my set up: was in the 85 GSL but now in the RX-3.
13-B big 4port street port (balanced, e-shaft modified, rotors pinned blah blah blah) done by sidepex in california, GSL-SE internals, 48 ida, 4puck/3500 lbs pressure plate.

 

There is a big difference in engine demand between a 13B and a 12A. The 13B needs much more intake

 

You have to make the mixture very weak for the engine to work good with that size venturi. What size fuel and air jets are you using ?

Karis

 

150 air/75 idle jet/240 main. runs low 13s