how many people have them and how can they be removed and would they give any performance gains

 

The main reason for removing them is so that you can grind out the exhaust port. I am not 100% sure, but I think you can swap them out for the turbo part.

 

So if you're doing some port work and porting your exhaust ports on an n/a, you should just grind those out?

 

from what I have heard it is very difficult to grind them out. I do think it is better to swap them with 4 port sleeves or else use turbo rotor housings.

 

i'd go for the turbo rotor housing, i've read of exhaust problems causing loss in power from taking them out.

 

Yes, it's easier to just use a turbo housing. You pretty much have to cut them out with a torch and then grind everything smooth, or you can try to drill the pins out (not very easy)

 

So the Turbo rotor housings are the same then? I'm not too familiar with housing differences, but I am going to be rebuilding/porting my motor this summer. Just seems like since the Turbo is 4port and n/a is 6port they'd be different, but I guess I am wrong?

 

None of the ports are on the housing, so it doesn't matter. However, the TII's have a coolant passage on the rear rotor, that goes into the intake manifold. The N/A's do not, so be sure to get front tII housings, or be sure to use a rubber o-ring and seal that passage up to the N/A manifold (not sure if that's even possible, but that's how the tII's do it)

 

Ah ok, that makes sense then. So the templates for porting, say the racing beat ones for example, the ones specifically for the exhaust port, are the templates having you leave in the diffusers then? Or do those templates expect you to torch/grind them out?

 

Let me look real quick. For most porting I would suspect you'd want to remove them. When I ported my Turbo engine I just port matched the front lip of the housing to the exhaust insert (as there's quite a bit of material that overhangs), and just smoothed it all out. This kept me with a fast spool and seemed to help keep my boost from falling off, I'd consider it a very mild port. For an N/A however, I'm not sure what you'd aim for in porting it, so I'd just ask them directly.

 

So far I've decided that I'm going to take the intake ports as big as I can but still in the "streetport" category. Basically following the streetport template at first and then going a little larger. The exhaust I'm still trying to figure out, though. Because after the rebuild/porting and it is all broken in, I'll be starting my turbo'd 6port project On this I'm looking to run 10-13 psi and have quick spool still, so maybe I should leave the porting on the exhaust mild?

 

Well, I've got a 6 port turbo, and let me tell you that damn thing spools QUICKLY. If this is the route you're going to aim for, I'd just do like I did and match the exhaust port insert, I've got some pictures I can PM you a link to somewhere, let me dig them up.

 

Alright cool, that sounds great. And yes this will be my eventual route. The plan is, save up money to do a koyo radiator, lightweight flywheel, port/rebuild, and RB street oil pressure regulator all at once since I'll have the motor out (it'll make all of it easier to work with). Also while it's out I'll go back and clean up my intake manifold porting and see if I can go any bigger on them in any area (I think I left some with a little more to be had). After all that is said and done, the breakin will begin and the gathering of parts for the turbo project will commense. Hopefully by winter time it will be done or nearing completion, and it can go in for a new paint job at the end of winter, and be ready for spring/summer

 

i used a turbo housing in my 88 N/A because it was the first cheap, usable housing i came across. it's a pain in the *** to get that cooling port to seal up... o-rings leak against the intake gasket and freeze plugs won't fit tightly enough because it's an oddly shaped and sized hole. i blew a high mile side seal, which i re-used and am currently rebuilding it and now that i have the chance i'm going to use both N/A housings.

as far as the diffusers go, i removed the N/A one to match the turbo housing by getting a hack saw's blade in there, putting it back on the saw, and very carefully sawing it off, then grinding it down with a dremel. it was a pain, but worked.