Guest Locutus Posted February 23, 2000 Share Posted February 23, 2000 I have a 700R4 tranny sitting at home, it needs to be rebuilt, what should I do to it if I want to use it in a daily driver thats gonna have about 400 HP, and is a weekend racer. another option is my friend has a brand new (from the factory) 700R4 he offered it to me for 800 (he apprantly has a hard time selling it). Which option is better, a new one or rebuilt. Do I need to build a racing version of the 700R4 like is popular with the Turbo 350(I also have access to one of those) Quote Link to comment Share on other sites More sharing options...
Mikelly Posted February 23, 2000 Share Posted February 23, 2000 I'd plan on using the 700R4 over the T350 because of the street use you mention. THat overdirve is nice to have on the freeway. As for new or rebuilt, that's a tough call. A couple of guys here can speak to the expense of hopping these trans up, but I think you would be better off maybe keeping your as a backup and buying the new one. Auto Trans guys, what say ye? Mike ------------------ "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted February 23, 2000 Share Posted February 23, 2000 If your engine is in the 400hp range I think it would be best to have the used one rebuilt and upgraded. At 400hp your tourqe has to be around 400ftb so I don't think the stock one will handle that for very long, at least that was what I was told by my tranny guy. Also, put a big *** transmission cooler in it, we have all heard the rumors so it must be true "90% of all transmission failures are the result of high heat". I didn't plan on driving my car very hard but I still had it upgraded, corvette servo, shift kit (not a hard shift but firm, very nice feel) and HD front pump and better clutchs. Some other little things here and there but I can't remeber. Also, you need to make a choice now (I just found this out after talking to B&M) do you want to run a lockup or non-lockup converter? To run a non-lockup requires a little modification to the transmission, and a non-lockup converter (about $75 cheaper) but you don't need a lockup control unit. Downside is reduced fuel economy and higher operating temp. To run a lockup converter you need a lockup control of some kind, or else...... well ask Myron Hope this helps a little Opps, allmost forgot, you know that 1st gear in the 700R4 is low... REAL LOW like 3.06! Forget about giving any more than 1/2 throttle of the line (unless you like big smoke clouds) I don't know if its possiable to change out the gears and put something taller in like a 2.74 but on the street you might be happier. ------------------ Dan, 78 280Z, 383FI, 700R4 allmost ready! http://members.home.net/dporter1/ [This message has been edited by Dan Porter (edited February 23, 2000).] Quote Link to comment Share on other sites More sharing options...
MYRON Posted February 23, 2000 Share Posted February 23, 2000 Yeah, have the transmission blues right now. I cant afford right now to have my already hi-po tranny rebuilt. Improper set up of a 700r4 WILL fry it even if it is a hopped up unit. I did get a deal on a th350 with a fresh rebuild on it with a 2500 rpm stall converter that came out of a 604 hp camaro that has 31" slicks. the car would carry the left front wheel. He went to a powerglide and i got the th350 for 300 bucks. I will let you all know how i like it in a couple of weeks... Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted February 24, 2000 Share Posted February 24, 2000 The tranny guy I have just found said he would make my 700r do a hydralic lockup for 75.00,and a corvette servo for 35.00 more, and I am gonna run it just like that at first, but here is the scarry part,, I bought a book , and an extra tranny and I am gonna attempt to build me a good 700r,, ever see thet commercial where that stupid lookin dude says "I always wanted to work on a transmission " well wish me luck Tony (the tranny guy) ------------------ 74 260, early 350,K.B.pistons,edelbrock manifold,carb,and cam,202 cast iron heads.Let the transformation begin. Quote Link to comment Share on other sites More sharing options...
John Scott Posted March 9, 2000 Share Posted March 9, 2000 I know this is an older post, but I think there are a few other points to the 700s. As all my research indicated only the later 86 and up 700s were worth having. The z28s and Vettes were the only ones to have the 4th gear that would hold at top end use. The other models, like my old 85 truck 700 would downshift from 4th to third at full throttle. B&M makes a valve for this problem, but still isn't a full throttle deal. Pay close attention to the TV cable mount and settings. This isn't just a downshift cable, but controls fluid pressure, shift feel, and shift points, incorrect setup can ruin a tranny. Find the a template for the correct geometry.The Toy Shop offers a lock up kit for little$$. Hooked to a hot wire it only locks up 4th when you shift into it. The lock up,I was told, and unless modified, is part of the lubrication circut and must be used in 4th. Beware of Vette 700s 'cause they don't have your traditional mounts. I changed tailshaft housings from another and fabricated a pretty cool setup. The 87 vette trans stays in 4th, but you have to go 140+ to prove it! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 10, 2000 Share Posted March 10, 2000 My little budget Z and I are going with the Th-350. It will mostly be a street driver. I don't know why I posted this, actually. Just gettin excited I guess. It won't be long. Quote Link to comment Share on other sites More sharing options...
Administrators SuperDan Posted March 10, 2000 Administrators Share Posted March 10, 2000 I found a nice little webb page with good info on automatic trannys. http://www.thegrid.net/thedrivetrainpage/articles.htm ------------------ Dan, 78 280Z, 383 450hp?, 700R4 allmost there! http://members.home.net/dporter1/ [This message has been edited by SuperDan (edited March 10, 2000).] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 8, 2003 Share Posted April 8, 2003 i have one in my car. that low 1st gear will get you some great launches if you have the tire to back it up. i have a manual lockup. it is the only way to go for racing type conditions. when i want to top it out i lock it up and it helps my top end. if you go with a big cam you will want to be able to disengage the lock up when slowing or stopping. if not the cam lope will jerk the drivetrain back and forth. i can hold mine to the floor and stay in 4th. hope it helped. Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted April 9, 2003 Share Posted April 9, 2003 I have the 700r4 that John used to run and it rocked. Finally started to slip on shifts say 6k shift would go to 7k before shifting. No problem, one of my good friends had his friend completly rebuild it with #9 clutches and shift kit staying with vette servo. Wow, shifts real stiff and real quick. The only problem I see with 700r4 is tire fryer off the line unless you hook it up then plant it hard then katie bar the door like a dog in heat. Mike Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 9, 2003 Share Posted April 9, 2003 Ya, well I want to say a few things about the trans and rearend gear ratios. The trans input shaft sees things opposite to the rearend. The trans ratio in 1st being 3.02:1 means 3.02 turns of the input shaft = 1 turn of the output shaft; actually (in my opinion) this is a pretty good "Low Gear" for a Datsun Z 1st. with 400hp. Now If you couple this output shaft to a 3.02 ring and pinion in the rearend you would effectively have what I call a "Low Geared" rearend (I would call anything from 3.54 thru 2.54 or whatever, a low gearing for the rearend). These are numerically "Low" numbers for any rearend.. As the rearend numbers decrease numerically the numbers in the trans (1st gear for example) must do the opposite and increase numerically likewise, (if you want to maintain the same accelleration you had before). All this stuff is tied directly to the cam and it's peak RPM. If you really want to get the most out of your engine gearing-wise then you have to prematurely set an expected top speed and fit all the gearing into the desired accelleration pattern you want as you go thru the gears, beginning with 1st gear to it's top speed (at the cam's peak RPM), then 2nd. and so on. This is why there are so many different ratio combunations available is standard tranny's..... It's to aid the builder in matching his particular build so as to get the maximum results he needs from the power he has available. An automatic is not as flexible in such choices in my opinion but, you do have the 3-6 speed options + the Powerglide option which is good enough (again, in my opinion). And so, it is not at all as simple as it seems if you get serious about gearing of any kind. Gearing is as critical to performance as any other thing you can do to get the most out of your car and be a contender in your class, whether on the street or strip! 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.