Quote Originally Posted by arraydude View Post
I've built it for drag/street purposes, regarding the plenum volume really i don't know it was made by my mechanic.

Currently i'm building 8-9 psi and something like 400whp, in these days i'll go to the dyno and go a little up with the boost.



Most challenging parts are almost all, haha it's very complex and expensive building here a car.

Actually, regarding my gearbox i don't know what to do... maybe you can help me...

I want a street car with 5xx whp
Over time, we have collectively noted several components that add to transmission failure on Honda K-series transmissions: Poor maintenance for fluid changes, HARD shifting, HARD launching with slicks/drag radials, non-upgraded motor mounts, and failure to pre-load the transmission when launching (axles are affected greatly by this as well). Also, over 400ft-lbs of torque seems to be the breaking line for OEM Honda 3rd/4th gears. This doesn't mean that less than 400ft-lb of torque won't be an issue, or that over 400ft-lbs definitely is an issue. We've simply noted that over 400ft-lbs of torque is when people break considerably faster across all forums and chassis. These motors make a lot of power with forced induction, so we expect the transmissions to be the weak link. Ultimately, it is not "if" transmission parts break, but "when" they break. We can, however, treat the transmissions well and they will last quite long. There have been many daily drivers noted across forums over the years with 500+whp. So, there is hope.

Luckily, you have several options for building your transmission - all based on time and money. For example, if you break 4th gear, you can simply replace it with another OEM Honda 4th gear for cheap if you do the work yourself. Alternatively, you can purchase stronger gears. These include Gear-X (may fit well based on your power goals), Mfactory, Albins, and PPG. The last two are by far the most expensive but also the strongest. We recommend you do not use OBX gears, as they have shown to be of very poor quality. Again, this is based on your power goals.

My advice? Enjoy the car as-is. Have money set aside for transmission issues, and address them when you arrive at them. Until then, drive the car well and have fun!