OK so I'm currently in the process of building a y7 for boost. I am just curious as to the amount of torque my stock lx trans will hold , as this will determine my power goal.

Is there any common problems with these in high powered cars? Also I know that the ex trans has better gears for performance, but I do a 150 mile round trip commute daily and this will be my daily driver, so I want the longer gears.

 

It's the axles you need to worry about not the trans

 

you shouldnt have a problem of you are running a stock motor .. you start making 300+ hp it would be a good idea to rebuild the trans with cry treated syncros... D series trans do not like higher revs then the stock rev limiter

 

Your bottom end is going to give out well before you even have to look at your transmission, axles, or anything else.

 

as said. and stock clutch likes to slip aroubd 250whp.

 

Clutches don't care about horsepower, they care about torque. That said, the expected torque curve for a 200bhp turbo build will be just right for a stock clutch to hate life - they aren't made for any more than stock.

 

you start making 300+ hp it would be a good idea to rebuild the trans with cry treated syncros

 

I am building a motor for boost, not boosting stock motor. Sorry, should've been more specific. My stocker has 308,000 miles!

And thank you everyone for your input. Any ideas where to look for good axles and cryo treated synchronizers? My budget isn't unlimited but I am willing to pay to keep this thing reliable.

 

Ignore "cryo treated". Get some carbon coated synchros from synchrotech-transmissions.com if you're worried about them (although I personally wouldn't be, given the limitations of a D16).

What kind of power are you building for? If you aren't planning on going past 300, stock axles will suffice. If you're looking past 250-300, get some axles from Drive Shaft Shop. I leave a 50bhp gap there because different people have different wants. I personally have no problem occasionally (maybe once a year) replacing axles, and Autozone/Advanced axles have a lifetime warranty, so it's free with a little bit of your time. DSS makes different axles for different build levels.

 

SOMEone hasn't done his research. You'll run out of engine, built or not, before you run out if transmission.

 

your trans and axles will be fine if you drive it right.

 

If you make enough power you will start shredding 3rd/4th gears. This seems to happen around 350 - 400hp.

The Y8 trans have bigger diff bearings, bigger bottom countershaft bearing and a roller bearing instead of a ball bearing for the middle countershaft bearing. You can use a Y7 gearset and final drive though, or use an HX trans which is also big bearing. I would put some carbon synchros in it either way.

The biggest thing that I've seen happen to D-series transmissions is blown final drives, and it's very much related to wheel hop.

Top pics are from a stock Y8 trans attached to a stock Y8 engine, car never had slicks and was a daily driver.




This was a stock Y7 trans, and as far as I know it was attached to a stock Y7 but I really don't know for sure, it and another transmission were given to a friend of mine. Somehow the ring gear survived unscathed

 

Related to wheel hop, meaning it can be prevented with the proper suspension components, which will be a hell of a lot cheaper than a beefed up transmission.

 

That'll help you some, but the biggest issue is the lack of an LSD and unequal length axles.

 

LSD can be fixed, too

But I get what you're saying. There's a limit. I don't foresee the OP reaching that limit, though.

 

Yup, and so can the axles for that matter (hydro DOHC ZC axles and intermediate shaft, good luck finding them though)

That's the thing though, that carnage I just posted was all behind stock engines. That Y8 was worn out and probably making around 100whp. Chances are if you can drive you'll be alright, but it's not that hard to break stuff if don't know what you're doing or you're rough with stuff.

 

Oh yeah, I definitely won't argue against "stupid breaks things faster than power."

 

Well this info has been very useful. I'm not looking for any crazy amounts of power, something like 250-275whp at the max. I'm not usually really hard on my vehicles, other than my drag toys, but I pretty well know how to handle them, and what they will handle.

Hondas are a whole new world for me. I have spent probably 200+ hours in the past 3 months doing research, but am still pretty much a noob. I really appreciate everyone's help and patience, as I really want to build this car right. It seems like every modified Honda in my area, Cookeville TN, is just an intake and fart can muffler, not my style at all.

 

Personal advice: Buy a Y8 trans, put an MFactory LSD in it, run the LX gearset and final drive if you really want the longer ratios. You could always run the Y8 gearset with the LX final drive as well. 1st, 4th and 5th will be the same as an LX trans, but 2nd and 3rd will be lower. I would also run a set of carbon synchros and Torco MTF.

 

I like the idea of the lx gear set in a y8 trans with a LSD. I really like the gearing I have at the moment. Also gonna get the carbon synchros and good MTF

 

I wouldn't run the LX gear set or FD, both will only make you slower than using a Y8 trans. Cruising RPM with the Y8 trans is perfectly acceptable and will more than likely improve your fuel economy.

The three biggest weakpoints in the D trans are the diff, FD, and shift forks (88-95 only). Using a 96-00 trans takes care of the forks, an MFactory helical LSD and 4.5 FD takes care of the other two and is the most common setup I build for boosted D's.

I can take care of the parts and assembly for you. I'm MFactory's Official North American Installer and am about 3-3.5 hours away from Cookeville.

 

This thread is too far along to be moved, but this question would be better answered in the Forced Induction forum. Not that you haven't gotten your answer, but you'll need to sift through the crap to find it.

Disregard posts like this:

 

OK another question, anyone know approximate rpm at say 75-80 MPH with the y8 trans? I drive about 35 miles of mountain roads and 40 miles of interstate a day, so I can see where the y8 trans would help on the steep curvy roads, but curious about interstate.

 

At 80mph you're looking at around 3500RPM.

 

Use this transmission calculator, you can plot the gearing of using different gears and final drives, different tires, everything. http://www.zealautowerks.com/transcalc.php