pparaska Posted July 5, 2000 Share Posted July 5, 2000 1:1 top gear (T350) 24" tire: 3226 rpm at 65mph 25" tire: 3097 rpm at 65mph 26" tire: 2978 rpm at 65mph .68:1 top gear (Tremec 5spd - don't know the 700R4 overdrive ratio, but it's close) 24" tire: 2194 rpm at 65mph 25" tire: 2106 rpm at 65mph 26" tire: 2025 rpm at 65mph As you can see, its a huge difference. Just take the T350 (1:1) rpm at 65 for the tire size you have and multiply by the overdrive ratio of the 700R4 to get the correct rpm at 65 for that trans and tire size. I'd say yeah, the overdrive is important for cruising. ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net - Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted July 6, 2000 Share Posted July 6, 2000 I believe the 700R4 has a final gear of .70. The T350 will be way to high for street driving unless you never get on a hiway or over 50mph. Thats why I am going with the T-56, with a .50 final gear I am looking at some wonderful time cruising Texas's many hiways. Mike Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 6, 2000 Share Posted July 6, 2000 Doing the install finally. Have got loads of info from these forums. Any of you guys run this combo? 350sbc out of a 94 camaro, t 350 trans, with stock 3.54 r200? Dont want to blow my budget on an 800 dollar rebuilt 700r overdrive. Is this bearable? Does it lock up as it is supposed to at high rpm and let the engine loose some rpm. I have heard the lock up acts similar to an overdrive. I am not a gearhead. I only know mostly what I read on the net. Thanks in advance. Would rather spend the 800 dollars on the suspension. btw The car will be a daily driver. I know the answer is a 700r but will the t350 be good enough? Quote Link to comment Share on other sites More sharing options...
Andrew Bayley Posted July 6, 2000 Share Posted July 6, 2000 Highpsiguysz, Good luck on the final install. As for your transmission selection, I ran a TH-350 for about three years behind my 350 V8 in a ’77 280Z. At 60mph I was turning about 3000rpm. I was using a 215/60/R14 which was supposed to be a 24 inch tire, but the narrow rim shortened it to about 23 inches. Cruising around town (below 60mph) this combo worked fine. However, freeway driving left a lot to be desired. Back in 1997, I drove this setup from Detroit to the Z convention in York PA (about 500 miles). Crawling along at a measly 65mph, I must have blown at least 4 quarts of oil out the breathers (from an engine with 5000 miles) and the temp gauge never got below 200ºF. Gas consumption was also rather horrendous. Coming home from that same trip, a piece of overpass decided to implant itself in the TH-350 and permanently retire it. I saw this as an omen to step up to a 700R4. As for a lockup converter, I know of a few 3 speed non-overdrive transmissions that have lockup converters... but I was (am) not aware of any TH-350 that have this option. I feel it is my duty to warn people about the crappy torque converters that were used in the 80’s. To meet CAFÉ (corporate average fuel economy) standards, the big three would install very tight converters that would allow cars to move at very low engine speeds. This does a little bit for economy (remember, in the 80’s American automobiles were playing catch up and they needed anything they could get), but absolutely sucks from a performance standpoint. After removing my TH-350 with a 2200 stall converter and swapping in a 700R4 with the OEM converter, my 0-60 times INCREASED by half a second! Ouch!!! It was all off the line and it was waaay noticeable. Stall speed decreased to about 1500 rpm. Eventually I pulled the OEM converter and replaced it with a 3000 rpm stall lockup unit. My hole shot returned to what it was with the TH-350 and the numbers actually showed a better 0-60 than the old three speed. Do your Z and yourself a favor... invest in a converter! As for spending $800 on a 700R4, I’d shop around a bit. I had my 700R4 pulled out of an 87 Z28 for a mere $250 from a local bone yard. With a $20 shift kit and a 3000rpm converter, I’ve never had any problems (and I drive the pi$$ out of it!!!) The only thing that kind of sucks about the 700R4 is the price of converters. My 3000rpm set me back over 3 bills while the 2200rpm for the 3-speed was only around $100. I can totally relate to low dollar build ups, but an overdrive was something I could not live without. IMHO, overdrive is what made my Z streetable. However, the TH-350 is a great CHEAP alternative. ...just don’t plan on setting land-speed records with a 3-speed (I’d hit the 6000rpm rev limiter at 110 mph, with the 3.54 R200) Good luck -Andy Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 7, 2000 Share Posted July 7, 2000 Well I have listened to everyones opinion and took your advice. I am not using the T350 that I have. I dont want to have a car almost unstreetable. I want performance, comfort and gas mileage. With premium pushing a 1.75 a gallon here in Ga., it would be silly to even consider the t350. Went to the trans shop today. The guys has been in biz 15 years and races almost every weekend. I mentioned the 3000 rpm stall and the shift kits. He told me unless I am racing leave it alone. The 700r will do just great stock. And on top of that will not be pushing my trans to the limit.He said that I would still be very dangerous at any red light $800 bucks and I get rebuilt trans, new oem converter and a 90 day warranty. The bad part is I was gonna put that 800 dollars into the suspension. O well first things first. P.s looking for good used aftermarket springs 78 280z thanks z guys will keep you posted. Quote Link to comment Share on other sites More sharing options...
Andrew Bayley Posted July 7, 2000 Share Posted July 7, 2000 A buck – 75 for premium... ha! I wish! It hasn’t been under $2.00 a gallon around here (Detroit) for at least two months. Don’t know what ‘cha got until it’s gone. -Andy P.S. I still think you would be MUCH happier with a high(er) stall converter over stock. Also, a mild shift kit will actually increase life of the cluth bands... and will only set you back $20 or so. [This message has been edited by Andrew Bayley (edited July 07, 2000).] Quote Link to comment Share on other sites More sharing options...
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