Just curious, to know what would happen if I just switch them ? Do I absolutely need a tune ?

Thanks in advance.

 

i would say you would only need a tune if you werent running over 25psi of boost on the 18psi actuator...

but if you ran less then 25psi, your gonna need a tune since you just increased your boost

 

If you are tuned at, say, 28psi with the 18psi actuator your boost will taper off more rapidly than with the 25psi actuator. So, yes, you may need a tune.

Do you have a W/B? Do you have the knock light mod? If so, simply drive carefully and keep a close eye on the W/B and knock light.

If you want to do a WOT data log, keep a very close eye on the W/B and knock light, and let off of it if/when it starts to lean out in the upper RPM range.

If it starts to lean out at, say, 6,000 rpm, then simply lower your rev limiter until you can get properly tuned.

 

the boost taper will also depend on how much boost he has. i went from a stock actuator to a 25psi and the boost taper stayed the same. the turbo can only flow so much, but that was at like 30psi

but i agree with the above post. def log the car just to be sure

 

Depends on the quality of your tune. I would normally say no you don't need a re-tune, but that's on the basis of a quality tune. If you have a poor tune/tuner, you likely will.

 

yes you will. just AFR tho most likely. a 25psi gate is going to creep to sometimes 30psi, and more airflow requires more fuel to keep the mixture from overly leaning out. on my personal car i have a fp 25psi gate, if i run off the gate i creep to 29psi by 6500rpm.. not the same on all setups but just giving you an example.

either way the AFR should be cleaned up since you're going from 18psi to 25psi. thats 7psi.. thats quite a bit.

You can pm me if you have proper logger equipt and ill fix you up very cheap if its just AFR.

 

I forgot to mention, this info might help ..

Im running a Vi-pec v44 ecu / EBC. /tuned at 499whp (FP red 30psi)

 

It depends how well the Vi-Pec can compensate for air/fuel correction.. it may correct itself for you.. some EMS's do that.

That EMS is very easy to work with.

 

If you are using ECU boost, yes you would need a retune..
i dont know about other conditions though