James,

It is possible to reach the WG's limit of flow and this in turn forces the boost rise above the preset settings as the extra air flow is forced through the turbine wheel, A check for this is too remove all boost control hoses and just run a single hose from the turbo comp housing to the actuator so it runs just spring pressure boost which will be 9-10 psi, If then you still see it creep up then you will have worked out that the WG is fully open. I have seen this a lot on VF turbo's with P18 exhaust housings on good HP cars.

The fix is to allow the WG to open more, on the TDO turbo there is a threaded rod that you need to make long, this will give the WG more travel. What it also does is allow it to open with less pressure, you need to be sure it still takes at least 7 psi before the waste gate starts to move, boost controllers will still be able to adjust boost and good quality controls will stop boost coming on any slower . With a VF turbo they have a pin that slots into the hole on the WG lever arm, with these you can drill a new hole next to the OEM hole closer to the pivot so as you get the WG to open more for the same travel of rod out of the actuator.

The splitter will work in the open mouth much better than the HKS system, on the new age wrx you can't run a long collector as the steering collum is bigger , the difference is very minor as the new age run larger cams and better inlet ports so make up there for low down power.

If your 94 has the std TDO5 you would just need to make the splitter protrude 22mm into the turbo and allow 12mm as well for it to be welded into the collector, there are specs list in an earlier post i made with regards to placement within the collector.

Michael
http://www.users.bigpond.net.au/msgofast/

 

Thanks for that Michael, I'll give it a go!

James