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Hi everyone.
My mechanic says my brick has too much mumbo for the gearbox to continually handle, resulting in yet another catastrophic failure.
Any way they can be upgraded or modified in order to strengthen them ?
Would a shift kit help ?
Any ideas appreciated, at $NZ3k a pop to recondition mumsy is getting understandably fractious...
Cheers Mike
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1989 744ti, 51k kms, 13psi, boost gauge, turbo timer, exhaust mods, airbox/induction mods, rear spoiler - kiwis fly !!
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The tranny isn't right (well duh!)
It should be able to stand upright to your minor mods.
Find out either what is wrong, or find Dave Barton's web site via www.turbobricks.com. Dave is www.linkline.com/personal/dbarton (or close)..
He does the Art Carr number (and he uses a good synthetic juice...)
--
http://www.fidalgo.net/~brook4/oilslubesfilters.html
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posted by
someone claiming to be philip bradley
on
Tue Dec 24 02:22 CST 2002 [ RELATED]
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Mike,
I would source a used late model low mileage AW71 with the revised tailshaft bushing (around 1992-1993), and use that with (1) synthetic fluid and (2) a filter in the hose/pipe to/from the cooler and (3) a larger external cooler and (4) the basic shift kit modification outlined by Mike Poulson in the archives at the Turbobricks website (you'll have to search for it but there are even photos).
Running a 14.8 at 90 does not suggest 250 hp. I ran a 14.6 at 94 and calculated maybe 230 hp. There are plenty of formulas available if yo want to search for them and start crunching numbers. Just determine whether they are for wheel hp or crank hp; any trap speed calculation will be based on wheel hp unless it is accompanied by a second calc for either manual or auto trans to obtain crank hp.
If you use a higher stall converter, you will be more likely to make the AW71 slip. In such a case, you need more serious valve body modifications. Someone I communicate with did the basic shift kit mod and still blew a rebuilt AW71 on the dyno at 18 psi with a big exhaust, sport compressor turbo and performance cam. Serious valve body mods might be done by a shop familiar with the older Toyotas, which also used the AW71. I had this done in the US by Level 10 Transmissions (search for the website) in New Jersey for about $600. The shop said that stronger clutches alone would not be sufficient in the long term. They said that ideally both the clutches and the valve body work should be done, at a cost of about $2000 USD, but if only one was done, the valve body work would be the better bet. So far so good. I have had it in for about 3 years with the high stall converter and have run up to 18 psi in daily driving, over at least 50,000 miles.
The next year will be the real test, as I have built a higher performance engine that I expect will push the AW71 to its breaking point. I have not decided what to do then, but I am inclined to go with an M90, BMW Gretrag or Toyota W58 conversion.
For you, I would recommend finding a rod shop in AU. Dick Prince in AU could help you with a manual conversion, as could Dellow. And I am sure that with some searching you could find a Toyota shop familiar with the AW71. Anthony Hyde in AU is another good source. Both have websites and you can find them by searching for their names and Volvo.
Philip Bradley
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Hi Philip
Thanks for the info provided, it tells me a lot in regards to what needs to be done.
Numbers mentioned were at 15 pounds, at this boost rear wheel hp was 177, on the dyno. I did the rough conversion myself. Is there an accurate formula ?
Quarter mile times were also at 15psi.
Again thanks for your help.
Cheers Mike
--
1989 744ti, 51k kms, 13psi, boost gauge, turbo timer, exhaust mods, airbox/induction mods, rear spoiler - kiwis fly !!
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posted by
someone claiming to be philip bradley
on
Tue Dec 24 14:20 CST 2002 [ RELATED]
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I have read the formulas many times, and have them somewhere, but do not know them off the top of my head. You have two numbers to work with, so get both formulas - the trap speed to wheel hp and the wheel hp to crank hp. I think you will find the formulas pretty accurate as you have two references to use. Very roughly, crank hp on an automatic will be wheel hp plus 20%. Your 177 whp figure would be about 212 crank hp. That is what I would have guessed based on my recollection of how crank hp on an automatic relates to trap speed, also. I know of one person who ran a 90 mph trap speed at 11 or 12 psi in a stock 88 or 89 745T with AW71. He should be 20 hp down on you, which could be attributable to hot weather where you are or less ideal tuning on your part.
Anyway, at your power levels, the stock trans should be fine. If you are doing a lot of power braking or dropping the trans into gear from park or neutral, you are destroying your trans. The former cause can be addressed; the latter cannot.
Philip
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posted by
someone claiming to be JohnB
on
Tue Dec 24 00:46 CST 2002 [ RELATED]
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I'd get another box before I'd pay the guy to 'recondition' your box.
Also, when you get the new box make sure the fluid is clean and preferably flush it to a synthetic ATF, amsoil comes to mind.
I've run 15-17psi boost with no problem for some 40K...trans shifts smoothly and no burnt synthetic fluid (still change the fluid every 50K!).
OTOH, if you're power braking at launch and/or dropping it into Drive at 4K rpm...nothing is going to hold up.
While you have the box out, you might consider putting in a high stall torque converter.
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Gidday John
Have been actually running at 15psi.
No neutral bombs but plenty of power launches and rubber laying.
Clearly we have a solution...
Cheers Mike
--
1989 744ti, 51k kms, 13psi, boost gauge, turbo timer, exhaust mods, airbox/induction mods, rear spoiler - kiwis fly !!
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Hmm... I wonder if you could put a AW72 in it.... mine seems very solid... always shifts nice and firm... and maybe even a little heavier duty... not to mention the different gearing..
Cliff Scott
89 740 16v
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posted by
someone claiming to be philip bradley
on
Tue Dec 24 14:23 CST 2002 [ RELATED]
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I have studied the possibility of an AW72 conversion. It appears to be a good trans, as strong or stronger than the AW71, with a good converter and good torque multiplication. It is a lockup, which may not be as durable or smooth with a turbo. Worth considering further. I don't know how soft Volvo set the valve body; it could be that you would need valve body modifications. If I got one cheap and needed a trans, I would give it a try.
Philip
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The lockup doesn't engage until around 52 MPH... Oh, and at least on my AW72, i get a shift that breaks the tires 1-2 at WOT (really gotta watch out for that in the rain)....
Oh, and for even more gusto, if you find a AW72 in a 16v, it will also have the 4.10 rear axle
Cliff Scott
89 740 16v
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Gidday Cliff
This would seem worthy of some consideration.
Could you tell me what models/years they came in.
Believe it or not we have an automotive dismantler with a hundred or so bricks only 10k up the road...
Cheers Mike
--
1989 744ti, 51k kms, 13psi, boost gauge, turbo timer, exhaust mods, airbox/induction mods, rear spoiler - kiwis fly !!
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as far as i know, you would need to get a AW72 from a 16v... I saw somewhere that they came with the PRV6, but even if it did, it wouldn't bolt up anyways would it?..... and I'm not sure if it would have to be only a B234 for the AW72, if you're in a country where they have them you might also check for a car with a B204FT/GT but that's a stretch...
Cliff Scott
89 740 16v
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At the risk of sounding like a smartass, have you considered turning down the boost?
Bob
--
91 740 Ti 173K
82 intercooled turbowagon 237K
67 122 wagon
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Hi Bob
Fair enough, but then I can`t beat the V8`s and boy racer types...
Cheers Mike
--
1989 744ti, 51k kms, 13psi, boost gauge, turbo timer, exhaust mods, airbox/induction mods, rear spoiler - kiwis fly !!
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