kmatts

Please excuse this post if this particular subject has been addressed before. I did search and could not find it.
I know for a fact that the 993 3.8RS factory head does NOT have a port for the SAI (secondary air injection).
So my question is this......if anyone has upgraded with the factory 3.8 Euro RS kit, then how did they address this issue. Essentially, with out the SAI a fault code will be registered which will set the MIL indicator lamp and that car will NOT pass emissions. Any thoughts?

Cheers,
Kyle.

Bill Verburg

None of the RoW n/a 993 heads have SAI ports.

I have a RoW vram in my '95 all it needed was a chip and some minor rewiring.

To do that in an 88pin OBD2 compliant '96 up will be more of an issue but it can be done.

kmatts

Bill,
I neglected to give some very important information. The issue is that the car that will be receiving the euro rs heads is indeed an OBD2 car. I am well aware that the SAI does not exist in any of the ROW cars. Indeed the issue is how to make this work in an 88pin OBD2 car. Drilling the heads with the ceramic coating is simply not a possibility. I refuse to even consider it.

Bill Verburg

You can remove(or leave off) the whole SAI pump, you just need to spoof the O sensors into reporting clean air downstream of where the cat is(or supposed to be), this is the same way some use a cat bypass on 88pin cars. I have sen several cars running like this.

The RSR heads are not appropriate for street engines, they are designed for a much higher rpm regime.

kmatts

Bill,
If you did remove the SAI pump I believe this would certainly set the MIL indicator lamp.
"spoofing" the secondary Oxygen sensors (post catalyst) is easly accomplished but I am just not certain that doing that alone would accomplish keeping the MIL light off. I am not concerned that the car will put out poor emissions. In fact if you were to actually use an exhaust analyzer it would likely run very clean. I have done this on my OBD1 1995 with and without a catalyst. The numbers are very very good and well exceed washington state emission requirements.
I should have also mentioned that this particular is indeed primarily a track car but its owner would like to actually be able to drive it on the street. more than likely directly to the track.
Thanks as always for your input Bill.
Kyle.

Bill Verburg

The only connection to between the DME and SAI pump is thru a relay which connects to ground, this energises the pump if the following conditions are met
Specs are dependant on year but for a '95
temp 59F to 158F
for 1 minute only

monitoring is done by differential comparison between upstream and downstream O sensors on '96 up

kmatts

Thanks very much for the info Bill !!!

NineMeister

Beats me why you would want to fit RS heads in the first place. Apart from the cost they have huge ports which do nothing but loose torque across the entire rpm range, you would be better off retaining the stock 993 heads and using them with the RS cams or consider alternative heads, in my opinion.