Having a hard time finding anything. I am under the impression that the 99 spec turbos waste gate is a few mm larger than the standard previous version. The spring rate is a little stronger also so running off the spring should result in 8-9 psi vs 6-7psi.
we are getting ready to fire things up and just wondering what to expect. I am actually going to try and break this motor in like a pansy. Like off boost for 500 miles and probably no more than 4k.
I guess I will take the mid pipe off and put the hi flow back on for now. Boost will be controlled via apexi solenoid through pfc. No idea how well this will work (I have heard mixed reviews).
I assume boost creep regardless, but if the creep is minor I may put mid pipe on for tune and/or consider a restrictor plate. Or might just put the hi flow back and leave it.
I have my own reasons for not wanting to port the waste gate.
Anyone have 1st hand knowledge between the 2?

 

Not sure. I know stock for stock the 99 spec 280hp cars run more boost, but I'm not sure if it's due to the wastegate or just the factory boost control running more boost.

If the actual wastegate ports are larger it's pretty minimal. There's still material that can be removed to make it bigger - I ported my 99 turbos when I put them on ages ago.

It's always a good idea to put plenty of break-in miles on an engine and drive with no/low boost so you're fine there. The big thing is if the turbos are already installed or not.

Dale

 

Thanks for the response Dale. I was told these 3KAI have a bigger one. Not sure if these 99spec "sp" or whatever you want to call them are any different than the regular 99 spec regarding the spring or size of the waste gate.
I assume boost creep would be expected regardless. I am excited to get this thing back!
I will do 500miles off boost 4k max, maybe 1000 miles 6k max and off the spring for boost (8-9psi from what I am told).

 

probably not going to help you much but.......here's a copy of the mazda sales brochure listing differences in the new turbo vs old design. I can't read Japanese but from picture, it list differences in turbo housing and compressor wheels diameter. Maybe there's something in the content if you get it translated?

 

Thanks,

I forgot Mike posted this awhile back also.
i guess I am kind of looking for 1st hand experience if anyone is running a mid pipe with minimal creep, but I am kind of doubting that.