only bad Auto I found was the Original Defect with it's blistering 69 horsepower... on the road the lack of power would be dangerous!

however rebuild it and stick it behind a Hot A14/A15 and it'd be good fun...

good thing is from 1000's/1200's to Patrols the 3N71 was fitted to everything Nissan...

i have a couple of the dellow conversions with celica box, i think it's T5 not T50 though, they are great, tough, good shift, and great ratios

the condition of the gearbox is obviously going to determine the likely hood of failure, if you rebuild a 60 series your gonna get a good life span out of it even behind a really tough a-series

there's a good reason why there is limited experience racing auto's on ashphalt, cause just driving one around town you can tell it's a really crappy idea

I blew up a 60a 4 speed behind my a15 ,it always crunched into second gear if I revved it out

It crunched in second on day and chipped a tooth which then went through the rest of the gear set and locked the back wheels up in the process.

So I bought another one that had reverse gone and made a good one out off 2 ,cost me 40 bucks for the new box then 7 for gasket goo

Only time ive seen them pop is if you are rough when changing gears

Also are t50 yota boxes any good ,can it be.used behind an a series ,I've got one but dunno what its good for ,came out of an ae86

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I've raced an auto behind a 2J, does that count? I've also raced a Getrag 6spd 2J. Both stock with cat-back (around 185rwkw). Not many A series or L series turbos are going to make that. And there was not a single place that the auto could keep up with the manual, but I suspect if you ran them both at Mt Cotton hillclimb the auto might just beat the manual. Just because of the slippery launch pad where an auto can be gentler on the launch, the 2 real slow 1st gear corners where the tall 1st gear and particualrly the stall are an advantage, and the steep hills you need to upshift on. But I didn't run them both there... On the fast flowing Lakeside track, the manual was 1.9sec faster, but on lesser rubber - KU36s vs the auto on FZ201. You could easily add another second for that (at least!)

Your budget is totally unrealistic as well. A built manualised Jatco will set you back more like 3K than $1200!

They are rare and old hard to find parts for now cant be clearer than that.

you always seem to describe a-series boxes as weak... why

i haven't found this to be the case

if the box isn't in bad condition to start with it's gonna put up with a lot of grief from any a-series

i've seen a few a-series powered rally cars over the years with a-series gearboxes competing for years without problem

we stuffed one once, but it was well worn when we got it

otherwise if your not doing burn outs and roll backs i dont see why you would consider them weak

even seen/had them behind turbo a-series without problem

None here have raced autos on the ashphalt behind a powerful A or L series.

For the street there are free mods that can be made to the accumulator springs, then money thrown at the stall converter and a fully manualised kit but its not an expensive exercise to do on the 3n71.

Given a choice atm Id choose a well prepped Jatco for $800-1200 than blow 60 series 4 speeds which are now rare.

thanks L18_B110, the wise words of someone who has built and raced these things

there's heaps of discussion about it in the 13seconds for $1300 thread

but you are absolutely right, the "autos" for drag cars are nothing like what comes in a production vehicle

the whole idea of using an auto in dirt/drift etc is also only applicable to massive power and masive budget vehicles,

there's no way you could extract good performance from a auto datto built on a budget, the clutch control for compression braking and lock ups and also the control of putting the power down through gear changes is absolutely mandatory to maintain corner speed

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massive generalisation. It's not true for lower power applications. Rob's 240Z (tripple 40mm sloex L28 at 2850cc) ran 12.9 at a low 105mph with the manual. That's a very good time for the mph. All the drag racing gurus told him an auto would be the best way to go faster, but after many attempts with a built Jatco, various stall and diff gears, he couldn't get within 5mph and 3 tenths of his PB. Its not like it wasn't properly built or that he didn't try the right combo, it just couldn't match the well driven manual. There's a big difference between eeking out every little bit of a low powered car and dedicated drag racing rotaries, so be a bit careful applying generalised drag racing wisdom that autos are better to a little <1600cc 4cyl... even with turbo

How much power do you (realisticly!) think your turbo A series will make? 3spd auto and mid 3 diff gears behind a turbo A series beat a manual equivalent down the quarter? only if the manual breaks, which is a good chance I suppose... Unless you're going to be running low 12's there's not going to be a performance advantage to be had from an auto, other than consistency.

then there's the cost of this manualised auto!

Totally agree the 60 series is a no go, the sillibox is a no go and theres not much left that isnt rare and chased by everyone else. A 3.7, 3.545 or 3.31 will be perfect behind a modded tricked 3n71 for most duties behind a boosted A.

Love a sequential 4 speed with 2.6, 1.75, 1:1 and .75 as strong as a T50 yota box
but it will only happen if there is a new racing class to suit it.