Scooter Posted July 21, 2015 Share Posted July 21, 2015 I won't be any different really just faster, but I only make the point as you seem to hint at your disappointment if things didn't turn out like your old car just faster. If you push the boundaries of the W58 and stock NA compression ratio you are moving closer to playing with fire and ultimately to potential disappointment. I 'think' a NA-T with the same power as a TT possibly has more torque and torque is apparently what kills a W58, ie a hard pull in third at sensible rpm rather than a high rev antics. I'm just saying after all this time being happy with the NA why jump to almost double the power and open yourself up for possible reliability issues? A missed shift, a hard launch or third gear pull and bye bye W58 and you won't find another with your sort of mileage/provenance easily or cheaply. The w58 won't just wear faster it has the possibility of failing catastrophically and if it did you'd have big costs to get it back on the road AND almost certainly would take the boost down to save the replacement ie arguably be back where you should have started. Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted July 21, 2015 Author Share Posted July 21, 2015 I won't be any different really just faster, but I only make the point as you seem to hint at your disappointment if things didn't turn out like your old car just faster. If you push the boundaries of the W58 and stock NA compression ratio you are moving closer to playing with fire and ultimately to potential disappointment. I 'think' a NA-T with the same power as a TT possibly has more torque and torque is apparently what kills a W58, ie a hard pull in third at sensible rpm rather than a high rev antics. I'm just saying after all this time being happy with the NA why jump to almost double the power and open yourself up for possible reliability issues? A missed shift, a hard launch or third gear pull and bye bye W58 and you won't find another with your sort of mileage/provenance easily or cheaply. The w58 won't just wear faster it has the possibility of failing catastrophically and if it did you'd have big costs to get it back on the road AND almost certainly would take the boost down to save the replacement ie arguably be back where you should have started. Hi Scooter, there are several members now on this club with the NA/T's and they have good reports, also many of the cars are double my mileage, i also don't push the car unless i need to , sort of not lashing it on every outing. If the box does go i will buy a 6 speed, all be it i will be well pis---d off. Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted July 21, 2015 Share Posted July 21, 2015 Look on the Facebook Supra parts page for comments about NA-T. Plenty of people have wrecked their W58 boxes at 400hp. One guy destroyed 3 before going R154. The NA auto is a better base car for NA-T. Quote Link to comment Share on other sites More sharing options...
Scooter Posted July 21, 2015 Share Posted July 21, 2015 Hi Scooter, there are several members now on this club with the NA/T's and they have good reports, also many of the cars are double my mileage, i also don't push the car unless i need to , sort of not lashing it on every outing. If the box does go i will buy a 6 speed, all be it i will be well pis---d off. I'm not anti NA-T just don't see the need to push things in your circumstances, mileage doesn't really matter as too high a peak load would mash even a brand new one. But you are going in with your eyes almost wide open and it's obviously completely up to you how far up the power/risk scale you want to go, best of luck with it all Quote Link to comment Share on other sites More sharing options...
Mike2JZ Posted July 21, 2015 Share Posted July 21, 2015 I have seen 3 W58 boxes go in the last 6 months on a variety of road/track orientated 2JZ/1JZ turbo cars. 1JZ Drift Car pushing 400hp on W58, suddenly lost second and third whilst going round the track after 6 months of abuse TT BPU Transplant in an N/A, was at SantaPod on dragstrip, dropped the clutch at 5k+ and bye bye gearbox. TT BPU, was leaving a car meet and second gear shit itself as he left. In theory driving in a mild manner with a boosted setup will preserve your W58 gearbox, but all it takes is one slip or one adrenaline filled moment and it can be over in seconds. From what I've seen you either need conservative boost settings and play it safe, or you need to find a clutch that isn't going to be that harsh on the drivetrain. I can't remember what clutch someone recommended to me once, but it their experience it had a slight bit of slip and they had been running a boosted setup on the same W58 for 4 years with no hassles. Either way, I'd still say go for it if thats what you want. Just have some cash ready for an alternative gearbox incase yours go's so you aren't caught with your pants down. Quote Link to comment Share on other sites More sharing options...
bignum Posted July 21, 2015 Share Posted July 21, 2015 My bro did 3x 58`s before going r154. Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted July 21, 2015 Author Share Posted July 21, 2015 Hi Guys, Are we saying that i cannot get at the potential horse power and torque without risking the w58? or are the failures reported based on some abuse.? Also what is a R154 and how much fitted.? many thanks. Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted July 21, 2015 Author Share Posted July 21, 2015 (edited) Hi Guys, Are we saying that i cannot get at the potential horse power and torque without risking the w58? or are the failures reported based on some abuse.? sort of dropping the clutch and pushing hard through the gears.? Also what is a R154 and how many gears,why is this box so much stronger.? is it close ratio. and how much fitted.? many thanks. Edited July 21, 2015 by herbiemercman added extra text. (see edit history) Quote Link to comment Share on other sites More sharing options...
Scooter Posted July 21, 2015 Share Posted July 21, 2015 Hi Guys, Are we saying that i cannot get at the potential horse power and torque without risking the w58? or are the failures reported based on some abuse.? Also what is a R154 and how much fitted.? many thanks. Just from going on the stories on here, 320bhp should be fine....beyond 380 and it sounds borderline and in between is well somewhere in between! It goes without saying you'll need to be using all that 380-400 to break things but then if it's there at some point you are going to aren't you? An R154 is an older but stronger 5 speed. The thing with 'just' replacing a gearbox is it isn't just that you need a different prop or to modify the shifter etc fine for a committed diy'er but I'm thinking hassle you just don't want? Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted July 21, 2015 Author Share Posted July 21, 2015 must admit i am sruggling to accept this as if the box failures are plenty, then surely the NA/T conversions are mega flawed, so how come so many have been done and no faults reported.? Quote Link to comment Share on other sites More sharing options...
Scooter Posted July 21, 2015 Share Posted July 21, 2015 They are not flawed exactly, but everything has it's limitations. The stock head gasket and high compression limits the boost/Power you can have. The gearboxes strength limits the power you can have. It just so happens the gearbox limit is slightly lower than the compression/power limit. The W58 is if you like the weak link, but that doesn't mean it won't happily deal with stock TT power levels day in day out and frankly I can't see why you wouldn't be happy with 320bhp mated to the low geared 5 speed, or somehow regard that as a flawed? A low mile TT6 would cost well north of £10K and once done yours should feel to all intents and purposes the same at a fraction of the cost. Quote Link to comment Share on other sites More sharing options...
Mike2JZ Posted July 21, 2015 Share Posted July 21, 2015 must admit i am sruggling to accept this as if the box failures are plenty, then surely the NA/T conversions are mega flawed, so how come so many have been done and no faults reported.? A lot of the N/A-T guys are running auto boxes as well, which can take more than the W58 Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted July 21, 2015 Share Posted July 21, 2015 must admit i am sruggling to accept this as if the box failures are plenty, then surely the NA/T conversions are mega flawed, so how come so many have been done and no faults reported.? There are plenty of documented w58 failures if you do a search on Google. But what you usually find with people going NA-T or NA-TT with a 5 speed is they don't listen to the warnings, and when the box goes they usually keep it pretty quiet. As has been said, the auto is much stronger, and the R154 5 speed manual swap is a common swap as it is much tougher than the w58. Quote Link to comment Share on other sites More sharing options...
supra_aero Posted July 21, 2015 Share Posted July 21, 2015 So the na auto isn't all that bad is it Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted July 21, 2015 Share Posted July 21, 2015 If you're going NA-T, sure... Quote Link to comment Share on other sites More sharing options...
Scooter Posted July 21, 2015 Share Posted July 21, 2015 I think the auto box needs some tweaks to make it last doesn't it? Line pressure and valves? Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted July 22, 2015 Author Share Posted July 22, 2015 Thanks guys some good info, i will most likely end up with the 320 level of bhp, i am forgetting that 100 bhp more must be well satisfying. I am speaking to the "doctor" (Craig) today and no doubt he will say what levels he advises. I will post accordingly. Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted July 22, 2015 Author Share Posted July 22, 2015 The "doctor" just told me if you drive with reasonable concern for your gearbox everything should be ok, it's the torque which takes the box out, not the actual rpm, to me this means if you do not do too many jerk off take offs and flooring the pedal, sort of applying the power normally, not in one big hit. Anyway i am with him on this and going for the full monty, 400 bhp. Wish me luck, at the worst i can chuck another box in it if i am unlucky. I still appreciate all your comments. Will keep you posted. Quote Link to comment Share on other sites More sharing options...
Hitbox Junkie Posted July 22, 2015 Share Posted July 22, 2015 Its not bhp that breaks the boxes its the Torque. they just come hand in hand. If it were me id be going auto or 6 speed for security. ( or R154 ) as for costs there was a full V8 and R154 conversion kit for sale on the us forum it was linked somewhere on here cost I think was around £1500 ) Quote Link to comment Share on other sites More sharing options...
LasseV Posted July 22, 2015 Share Posted July 22, 2015 Rebuild w58 and make it stronger? http://www.ppgearbox.com.au/page.asp?productid=42 Quote Link to comment Share on other sites More sharing options...
bignum Posted July 22, 2015 Share Posted July 22, 2015 Rebuild w58 and make it stronger? http://www.ppgearbox.com.au/page.asp?productid=42 Judging by the price of the other makes gearsets (they don`t list toyota) you could buy a new 6 speed gearbox... x2 Quote Link to comment Share on other sites More sharing options...
berg Posted July 22, 2015 Share Posted July 22, 2015 I ran 17psi through my w58 for over a year without problems, was a tad over 400hp it now currently lives in another na-t running 393hp and has done for the past 18 months, still going strong If you abuse the crap out of it. you may have problems, but same rule can apply to anything I never once drove my car worrying about breaking the box, if it broke then it broke, it just never did I just think theres no point in spending all that money on upping the power, then have to drive it like a wussy so the gearbox don't blow up Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted July 23, 2015 Author Share Posted July 23, 2015 Rebuild w58 and make it stronger? http://www.ppgearbox.com.au/page.asp?productid=42 Hi LasseV, many thanks good link, i have made a note of it. Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted July 23, 2015 Author Share Posted July 23, 2015 Hi berg, I know what you mean but i mean i won't be knocking S.H one T out of it all the time, just when it's needed, and even then you can without abuse. also like you, if it does dip out on me i will get it sorted. Quote Link to comment Share on other sites More sharing options...
Noz Posted July 23, 2015 Share Posted July 23, 2015 Thanks guys some good info, i will most likely end up with the 320 level of bhp, i am forgetting that 100 bhp more must be well satisfying. I am speaking to the "doctor" (Craig) today and no doubt he will say what levels he advises. I will post accordingly. If you go NA-t expect more like 360-400. Lowest boost spring on pretty much 99% of NA-t wastegates will hit that figure. I've never seen one below 350hp (that didn't have boosting problems). A NA-t or TT conversion on a w58 is on borrowed time compared to any other option on the market. It's a gamble, that's been proven. Some win, many don't. Risk it you take your chances. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.