ok heres a question. how come most people choose to use the t3/t4 on thier hondas over the t3.

i kno the obvious answer is that the t3/t4 makes more power cuz its bigger. but that doesnt make sense to me. cuz boost is boost. from the motor's point of view if u are 8psi of boost in the intake manifold from a t3 its the same as getting a t3/t4. right?

the other advantage of the t3/t4 is that it maxes out at a higher HP. but its like the t3 maxes out at like 300-400. n i don thtink most people run more than that in a street car.

so i guess my question is:
is there any advantage of the t3/t4 over a straight t3 in a street set up when ur pushin less that like 350 hp

thanks

 

its about efficiency. if you look at the compressor maps the t4 compressors are more efficient for our motors.

 

Simple concept really..
Say you have a t3 turbo running 8psi for instance produce about +75hp gain...

Same with t3/t4 turbo working hard same, but to get +75hp this turbo only does 6psi....

Cause t3/t4 is bigger, but not really more power..Name of turbo is just big turbo, how hard it working...

Example take the wheel, take big wheel and small wheel...who runs faster in same speed of pedaling?? Too bigger of turbo can produce much stronger power, but how hard it take you to pedal that big wheel..??? Hard right and slow right, but when you pick up it much stronger cause it bigger wheel....

All power not come in bigger turbo, power come from good tuning and timing air/fuel ratio...What it do if you got that thing running but cant mix it air to match your fuel to make power..(tuning is the best idea)...

 

the bigger turbo flows more air..all boost isnt created equal, or i'd get a lil t25 and push 500whp@22psi and start spooling at like 2k...LOL thatyd be the shitz

 

hmm ok im still a lil confused. when u are refering to 8psi from the t3 and 6psi spining the t3/t4, u are refering to wat the spring in the wastegate is set at right?

so more boost is used to spin the turbo but the amount of air that reaches the motor is still the same right?

but im speaking completely purely from the motors point of view. i kno the t4 is more efficient but as long as the t3 isnt maxing out then it doesnt make a difference right?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GOLDBERG &raquo;</TD></TR><TR><TD CLASS="quote">the bigger turbo flows more air..all boost isnt created equal, or i'd get a lil t25 and push 500whp@22psi and start spooling at like 2k...LOL thatyd be the shitz</TD></TR></TABLE>

This isn't exactly true. It's not flowing more CFM, but the same at a lower temperature because it has to work less. If you keep stepping up to a larger and larger turbo you will make more and more power, but with SIGNIFICANTLY diminishing returns, ie. t3-&gt;t3/t4 may gain 5-10hp at 12psi, let's say, and then stepping up to some behemoth may gain another 3-5hp because of slightly cooler air. However, it will take more effort to spool the larger turbo and higher rpm, making it less useable for anything but an all-out race application. The idea, IMO, is to get the largest turbo you can that will spool-up by the rpm you want it. Umm, yeah.

 

[QUOTE=gsrbruin
but im speaking completely purely from the motors point of view. i kno the t4 is more efficient but as long as the t3 isnt maxing out then it doesnt make a difference right?[/QUOTE]

If you are running low boost (ie. both compressors are in their MAXIMUM efficiency range, then no. You would want to go with the smaller turbo at &lt;10psi, let's say, since it will spool up faster.