5 Spd tranny, max hp?

[chu77]

How much can the stock n/a 5 spd handle?

[trufanatic]

safely and reliably people say 450 maz. i've heard quite a few pull off 5-600 but not for long.

[Mr Ree NZ]

probably less...more like 350whp treated nicely all the time, no launches, no flat shifting etc with nice oil :)

Im not keen enough to wind my boost up to find its limits, ill just enjoy it at 8psi until all the r154 bits are in my lap for the swap ;)

[gottaloveit]

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[pilotman]

i was also interested on hp numbers for the w58 as well. i have consistantly heard 450 whp is really the max you can run safely. dose anyone have any numbers that they have ran for a considerable amout of time and not having any problems.

[LexusFTW]

There are a few guys that claim 600+ whp without launching the car and doing soft highway pulls without slamming the gears.

[pilotman]

what would you recomend running on that transmission. i would like to pull 500, but i,m kind of nervous because of destroying the trans.

[LexusFTW]

From what I've seen it's hit or miss on whether your transmission will hold the power. If you take it easy, I think you can pull off 500 reliably.

[pilotman]

thanks for your advise and your time. i will look into having that set up the next time i have it tuned. thanks again

[Mr Ree NZ]

The best thing to do if you plan on running 500hp is to start sourcing the parts for an R154 swap. If you decide to do this then you want to buy the remote shfter box with JZ bellhouing from a JZZ30 or JZX90/100 to make the conversion alot easier. The boxes are newer too and have had less abuse than old 7MGTE boxes etc. Also look at buying a few upgrade parts from driftmotion, they sell all the Marlin Crawler stuff and it has been proven to cope with abuse. There is no point in going to all the time and expense and not upgrade the known weak link of the box.

Im about to place an order soon and will be replacing the thrust washer, bearing retainer, all synchros, seals, o-rings, shifter cup etc. With a nice carbon full face clutch to ensure as little shock loading as possible as this is what kills gearboxes at the end of the day.

[pilotman]

thanks for the info. right now i,m running a little over 400whp. and that seems to do ok with the tranny. i would like to go with a getrag setup. but they are so expensive. i have entertained the R154 for awile now. but i don,t know enough to do something like this on my own. i wanted to pull 500 to the wheels but i know thats the danger zone for the w58 even under the best of driving circumstances, no launching, etc.

[Mr Ree NZ]

Dont be too intimidated with the R154 swap as if you buy the right one, its a direct bolt in. A shop wouldnt charge too much to swap it for you provided you do your homework first and make sure to have everything for them. FYI There is all the info you need in a thread on this site too. :)

[pilotman]

thanks for your help ree. do you know a reputable person or place to get one. like anyone i am concerned about buying a used transmission from a complete stranger. let me know if you have any leads on where to begin this project. thanks, take care

[Mr Ree NZ]

Sorry mate but Im the wrong person to ask as I live in New Zealand. I would ask around some american car forums for the contact details for good wrecking yards that have a good repuation for not stiffing their clients. A warranty would be nice too.