I'm currently rebuilding my 13BT. I just received RB intake porting template and I have some questions. Is this template only good for secondary ports or it's also good for primaries ? Is it too big for primaries ? Can I port bigger than this template or it's not recommended ?

Thanks all!

 

You can always go bigger - but if you go TOO big, then you'll need to fill the water-jacket for the area you've just ground a huge hole into

 

you can fill the water jacket?

 

Is RB template wild or mild ? Cause I would like something enough wild. What do I do with primaries ?

 

I haven't done it myself, but I know that you can fill the section of water jacket where you need to cut into (but it never lasts that long)

The RB template is mild, it's just to give you an idea on what to do really. Just extend them as far as you dare. Practise on some dead housings to see how far you can go before you cut into the water jacket, and experiment with tequniques and shapes as well

 

Do I have to increase the size of runners ? In the RB instruction that came with the template, they told that I should not increase it. What do you guys think ?

 

an increase in runner size decreases the velocity of the fuel mixture into the engine (velocity = torque), but it allows a greater amount of air into the engine at higher RPM.

So you have an offset advantage of losing torque, but gaining Bhp. But I'd reccomend NOT doing this on your 1st attempt, just try to smooth it out a little

 

ok i will take your advice

 

I have used the RB templates, on the primary, do not attempt to make the hole runner the size of the template hole, keep the intake runner the same size, but blend the runner to the shape of the template on the housing face...
The port shape is pretty tame for the secondaries, be forewarned though that with the exhuast ported to their template and teh primaries done with their template, the engine lopes pretty good at idle(950 rpm), my car has developed a pretty neat rocking motion with that idle and the exhaust note vibrates every car sitting around it.... I don't know if it would pass emmissions or not, and also its probably to much for the stock ecu to contend with, without some piggy back for fueling...
All that being said, it spools the turbo significantly faster, and it likes way more fuel under boost...max

 

I have used the RB street port intake templet on my 87TII. You Definitely want to port your primary's along with the secondary, where's the advantage if you don't. You want to make sure as you port to stay shallow as you walk away from the existing stock port, because the casting will thin out toward the end of the port (walking on thin ice). Give it a nice taper.

I used the RB street port intake with RB race port exhaust and had very good results. I used it with the stock turbo boost spiking 10-12 pounds in most gears.
I barely managed to get it to pass emission.

 

Hehe, emissions aint NO problem for me, I'll just cap my PP and the secondary, and just run one rotor, whilst having the other one pump fresh-air round (weakens the exhaust readings).

Then when it's passed, I'll just re-connect the carbs, and away I go!

 

haha nice

 

I suppose this could be done with the stock setup as well, but you'd have to get a spare NIkki carb to mess with.


Remove the link-arm to the diaphragm for the secondaries, and then cover it over with epoxy to seal itand remove the insert for that barrell as well.

Put a bolt into the hole that the insert came out of to stop fuel from pouring out everywhere.

remove the inserts and fillthe holes for them in the same way for the ports feeding the 2nd rotor.

Get 2 spare HT leads, and modify them in some way, so that they won't work at all (or just get some rubber pipe that looks the same after some modifications to the ends).

This will make it so that you'll only be running on your primaries - using less fuel, and also pumping in fresh-air as well