I'm now running a Super T70 on my stock engine and I want to change my secondaries to be safe. As the title says, is it overkill to put 1600cc as secondaries ? (I will keep my 550cc primaries).

- Is the duty cycle will be too low on the 1600cc's ?

- BTW, how much boost stock internals can take with a single turbo setup ?

I have a Power FC, Supra TT fuel pump, Greddy frontmount intercooler and an upgraded radiator. I will aslo change my fuel pressure regulator.

Thanks a lot guys !
- Carl

 

no its not overkill. I would actually reccomend it if your going with a T70. The transition between the 550's and 1600's is probably going to be more noticable than if you were to run a 850/1600 setup though. I am in the process installing a 850/1600 setup on my t04r setup.

There are people with stock internals running high levels of boost. The key is in the tuning. What are your goals?

 

I would like to have 375-400 RWHP.

 

Almost everyone runs "stock internals" because there really isn't too much to change. I know of cars that have run stock seals with 20-30 psi with no problems. I will be running 26 psi with mazda seals. The bottom line is that these motors simply don't last that long at 25+ psi boost. But having 1600cc injectors is definately not overkill. With these cars, its only a matter of time until your 300rwhp feels slow and you want 350...then...400...then 450...its a viscious cycle really, you'll use the 1600cc injectors, and as Backyard said tuning is key.

 

I have 1000cc and 1680cc injectors.

I'd have to say the only complaint i have is idle, the 1000cc primaries do not respond at such low duty,. I wind up with a 12.5 afr at best.

 

my internals are all stock (not that there are really any internals to upgrade other than seals and springs...) and i run 550 primary 1600 secondary injectors. I have also run close to 2 bar of boost on my t78 turbo. Not overkill whatsoever