Rebuilding my 6 port S5 motor and was trying to get a hold of a T2 center Iron because everyone say's they're better. After much searching I have been unable to find a clear picture why, except that they can be more heavily ported.



So my question is,

in a completely stock configuration does anyone know how a T2 center iron in a N/A engine would perform.



or does anyone have any info on the gains one would expect from using a ported T2 center hosing on an otherwise stock N/A S5 6 port.



thanks everyone

The ports from the factory are slightly bigger on the turbo iron and you would have to grind out your LIM a little to get it to fit. I wouldn't think there would be much aof a benefit at all. The only way I would see fit to using one is if it was all you had to work with and it was in good shape. Otherwise I wouldn't go out of my way to find one.

Im pretty sure that the 6 port center iron can be ported just as big as the Turbo II one. The Turbo II just starts out bigger, so their is less work to porting it.

the center iron on the na has a the same casting as the turbo one, except the turbo port is ported bigger, if you were to port both plates it woudlnt matter which you used except that the NA you woudl have to port longer since you start out with a smaller port.



this was covered previously, obviosuly u didnt serach well enouf.

Thanks for the help guys,



I never ran across anything that said they were the same castings before. Guess the 6 port parts with a thin casting must be the end housings then?



But has no one ever just rebuilt a stock motor with a turbo II center just for grins to see if they made more power? It has different timming right? I'm asking becuse i don't feel like porting anything and i can get a TII iron easy. Maybe I'll clean the castings up a bit but thats probobly it.

the easy way to make a bit more power is to use a turbo center, but its not gonan be a big diffrence from the na primary.

[quote name='RE87FC' date='Aug 1 2005, 01:18 PM']you would have to grind out your LIM a little to get it to fit.
[/quote]



No you wouldn't The port runners are identical, it is only the port shape that is different.

[quote name='scathcart' date='Aug 2 2005, 02:11 AM']No you wouldn't The port runners are identical, it is only the port shape that is different.


[/quote]



That's right



I didn't have to modify the primary runners at all when I modified a TII LIM to bolt onto a 6 port block

what about EGR valve? or is that only in S4?

[quote name='treceb' date='Aug 2 2005, 11:03 AM']what about EGR valve? or is that only in S4?


[/quote]



I believe S4 NA has the EGR passages in the primary ports S5 NA doesn't S4 TII and S5TII don't either.



From what I have seen S5 TII has later opening primary ports stock- don't know if S5 NA does...