Just wondering out of curiosity, does anyone know how much power a factory Honda 5 speed can handle? My old man and I have been entertaining the idea of souping up a Honda of some variety, but we're just wondering how far you can reliably push a Honda gearbox before needing to beef it up.

 

From what I've read and remember from a few others, somewhere in the 350~400whp range and you start to have issues with a stock manaul trans. There are upgraded gears you can get to go above that.

 

I'm with poorman. About 400. The higher you go the shorter the life.

 

Thanks for the quick answers guys, that's plenty of capability for what we're looking to do.

Since we're on topic, has anyone ever used any additives in their gearbox? I ask because mine simply takes 10W-30 motor oil and there are a ton of additives made for that though I'm not sure if a gearbox would take as well to such things as an engine.

 

Personally I'm not a big fan of "additives".......ok yes I use seafoam in the gas about once a year.

For a manual trans.....if you want something other than engine oil. Either use Honda MTF or there is the Pennzoil Synchromesh.

"Rice" - have you ever run across "extralargenog" on HT? He was running close to 500 whp on a F engine in a 5th gen.

 

No I haven't heard of him. I haven't been on honda-tech in years. The transmissions for 5th gens are so cheap, who cares if you blow them up, $100 or less and you got a few more months of use!

I know there is a company that makes/made a dogbox gearbox for F and H series. Think it was in the $3,000 range if I remember correctly.