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#1
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Turbo 400 pq
Good afternoon as many of you know I'm slowly restoring my 1970 formula auto with the transmission code pq. It's original to car And worked well well I stopped driving it about 30 years ago. It has 124k original miles. As a young man I read high performance magazine, it was my favorite mag. And learned about stall converters, now I'm thinking that what I was reading was probably for racing quarter mile. I want to have transmission rebuilt. What kit is recommended including brand and what stall converter. I plan on just driving around country roads maybe a road trip with family like my dad use to. I'm learning towards stock components , I was a smooth ride and smooth shift, not to much into the hard gear slamming shift kits. Some good advise is needed on this and recommended kit and stall converter. Im.not sure what stock stall was either. Do I also need to decide on what rear gear ratio before I do transmission? It's either going to be posi 307 or 331. Thanks in advance for reading this. It's the stock transmission.
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#2
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Funny true story.. Took a PQ from a 70TA and the torque converter to a company called TCI Racing Torque converters. Had them rebuild the tranny and asked them to go through the torque converter as I wanted to keep the original. They called me about a week later asking what car this factory torque converter came from. They said the "beefing" up work they do(maybe it was brazing the fins?) on these GM converters was done at the factory and they were just going to weld it back together without doing any work.. Point was, the torque converter,per TCI, that was stock and had never been opened didn't need a thing done to it as this unit had all the good stuff done already as a factory unit. My experience here....you don't need to do a thing to the Torque converter if it is the original one that came with the PQ.....
Unless Pontiac supplied a different converter with the TA vs Formula...I don't know that answer.. |
#3
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Yes it's original torque converter so it's a keeper? They don't do bad I hope
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#4
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The PQ (and PD for GTO's) Ram Air TH400 trans has a good torque convertor from the factory. Though it is a stock low-stall 13" unit, it is beefy with furnace brazed fins. It is recognized by a big "5-5" paint stamp on the body perimeter along with 6 furnace brazed mounds on the sleeve side about midway on the body. I, like 70RAIII, had my factory "5-5" convertor checked out and reused in my RAIII Formula. If you have your original convertor, have it opened up to check the condition, most likely good if the trans was never burnt up and beat to death. I would stick with the factory convertor if your engine is going to remain fairly stock with good low end torque, especially with your 3.31 (or 3.07) gears.
Dennis |
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#5
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I run 2800 rpm one, and it helps with the 2.73 rear gear set up I believe. The more Torque, the better high gears work IMO. So while it sounds like a weird set up, it works well in spite of out of the norm. But I don't think it would work as well with a 400 vs 455 I have. To answer your question I would probably bump the stall up from stock a bit. 2200 / 2400 (?).......... I defer to the experts however......
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72 Bird |
#6
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I'll echo others - the PQ, as built and "calibrated" by GM, is a fantastic street trans. No need to change anything other than freshening up worn out parts if required.
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keith k 70 Trans Am RA III / T400 / Lucerne Blue / Bright Blue 70 Trans Am RA III / M20 / Lucerne Blue / Sandalwood 70 Formula RA III / M21 / Lucerne Blue / Bright Blue |
#7
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well car been sitting for 30 years is there a recommended rebuild kit? i want new clutches should be around 13 in there and seals, pump inspected, planatary gear and value body cleaned up too. My dad always said the same but tranny has 124k miles and it hasnt moved in 30 years. not a good idea to put in without getting rebuilt. Just thought someone might recomment a good overhaul kit. not building a drad car but a good around car had.
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#8
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Torque
Quote:
when you say low end torque does that mean the stall cover shifts a lower rmp? Im.still learning soi.apologise if I ask stupid questions? And if low end torque then what is power band range? |
#9
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Quote:
If you are going to enhance the engine with better flowing heads, hyd. roller cam, stroker kit, etc., then a higher stall convertor, like the aforementioned 'tight' 10" convertor would better match the higher power range. We would need to know your intentions for the Formula to make better recommendations. If you have the original vacuum modulator on the PQ trans, and still in original operating condition, it is programmed to shift at 4800 rpm when left in 'drive'. Dennis |
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#10
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With what you described for the use of your car in other posts, You need an overdrive, Bolt in 2004R and a trans cooler. ( can do a 700, but need a controller and adapter).
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"The Future Belongs to those who are STILL Willing to get their Hands Dirty" .. my Grandfather |
#11
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Quote:
Dennis |
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#12
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I thank all the input. My intentions are to restore to stock as close as possible and drive every now and then. Yes I like country roads but freeway is good too.. I like the stock number matching pq not to crazy about the 200r but the over drive is a game changer for freeway speeds. The 307 or 273 will give me better gas milage on freeway but loose acceleration out the gate but Im not racing the car. Racing is to expensive and things break easy. No thanks. Yes 331 is good but Im betting i had 307 from gate since no rear end option was given. Yes still confused on this stuff. With stock parts and a 307 i might be ok not to fast not to slow. but with the 200r i could easily go 331 and no worried but no more number matching ra formula. I got choices. lol I love dads old car. Had it in family since I was 6 and now Im 49. Maybe need more advice or actually drive someone car to see. My 78 ta has 342 posi and grabs, but I has a 72 with auto and smoked the tires from 45 -65 mph with a posi 242 daily driver I built so I know 242 is a good highway gear. it was hooked up to the stock 72 auto and a 1970 t 37 2 barrel 350.
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#13
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Ramairnacho, I believe the Formula equipped with the RAIII (YZ & WS) came standard with the 3.31 rear when A/C equipped (TA too). 3.07's only came on the std. 330 hp YS automatic Formula's (like my first car I bought back in 1974) with or w/o A/C.
Dennis |
#14
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I'm under the impression that everything was an option. The ta did have 331 but posi, mine was an open end unit. I wish there was some data other than the 70 rear end chart to explain options for a 70 auto ra formula. As a boy I counted about 3 turns of drive shaft to 1 right tire rotation. If someone had a correct stamped 331 open with correct date code I'd probably buy it, but it's probably a hard find. I do have the 307 cos in the esprit and it's a sold unit just to get rebuilt and converted to posi along with tranny over haul and I'll be good. If anyone has a simular car to compare that would be great! I found 1 on ebay with the 307 but it was a deal added ram air not factory ordered. I used the supplement chart to determine it and with the help of a few wise men we determined it to be 307 or 331. Will the 307 handle the turbo 400 or is this another concern? Happy Easter everyone.
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#15
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Here is a chart from the Firebird Supplement:
(I added hi-lites for the 12 bolt gears) All 400 cid Birds got the 12 bolt rear end. The TA had saf-t-trac as standard where the Formula it was an option. (extra cost)
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John Wallace - johnta1 Pontiac Power RULES !!! www.wallaceracing.com Winner of Top Class at Pontiac Nationals, 2004 Cordova Winner of Quick 16 At Ames 2004 Pontiac Tripower Nats KRE's MR-1 - 1st 5 second Pontiac block ever! "Every man has a right to his own opinion, but no man has a right to be wrong in his facts." "People demand freedom of speech to make up for the freedom of thought which they avoid." – Socrates |
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#16
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Thank you for chart I did use correct chart and the m40which I think is a pq transmission was only in the 307 on a standard carrier. Happy Easter everyone. I understand the posi and ac found on ta. I'm I reading it right?
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#17
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__________________
John Wallace - johnta1 Pontiac Power RULES !!! www.wallaceracing.com Winner of Top Class at Pontiac Nationals, 2004 Cordova Winner of Quick 16 At Ames 2004 Pontiac Tripower Nats KRE's MR-1 - 1st 5 second Pontiac block ever! "Every man has a right to his own opinion, but no man has a right to be wrong in his facts." "People demand freedom of speech to make up for the freedom of thought which they avoid." – Socrates |
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#18
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thanks i might need to look for a 12 bolt cou. thats going to be hard to find. well the m40 will work with either thanks again
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#19
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I have read of a trans am with a 308 on Facebook. I might have bought the wrong rear end but I guess it will work for now. Hope it doesn't diminish the value of my car. Hapoy Easter everyone again!
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#20
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Thanks Johnta1 for the '70/'71 rear end ratio charts. I tend to believe these more than others I've seen/used, as well as the many cars ('70-'73 Firebirds) we've inspected over the past 50 (!!!) years do confirm their accuracy...not that some anomalies didn't happen from time to time.
Ramairnacho, available new 12-bolt ring & pinion gears now come 3.08, 3.42, 3.73, (3.90?), 4.10, etc. I don't think anyone makes 3.07 & 3.55 any longer...I could be wrong. So that is what you probably saw was a new 3.08 R&P in the car, or just a simple error. I wouldn't sweat finding a correct 3.31 open 12-bolt rear, unless you were building a concours car to go to the TA Nationals, MCACN, or Pebble Beach for 1000 point judging. I would use the 12-bolt you have if it is in good condition as no one will be the wiser since it's very hard to see. If yo find one, great, but it will take a while and be costly...jmho. Dennis |
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