Guest Anonymous Posted January 28, 2001 Share Posted January 28, 2001 IM FINISHED PUTTING MY CONVERSION TOGETHER BUT I HAVE ONE PROBLEM THOUGH MY Z HAS A REAL QUICK TAKE OFF AND PROBABLY CAN BEAT MOST STREET CARS ON THE LINE BUT, MY TORQUE IS TO HIGH CAN I CHANGE MY TORQUE CONVERTER TO MAKE THE SITUATION RIGHT OR IS IT MY CARBURETOR BECAUSE MY TRANSMISSION IS A NEW CHEVY 350 TURBO AUTOMATIC. ANYONE WITH SUGGESTIONS. Quote Link to comment Share on other sites More sharing options...
Guest pauli Posted January 28, 2001 Share Posted January 28, 2001 i'm not quite sure what you mean... do you have more low end torque than you want, or do you just want a tighter torque converter? Quote Link to comment Share on other sites More sharing options...
Guest RON JONES Posted January 29, 2001 Share Posted January 29, 2001 I'm a little confused as well(whats new).I'm almost thinking you have to much stall?Is this what your talking about? Quote Link to comment Share on other sites More sharing options...
Guest pauli Posted January 29, 2001 Share Posted January 29, 2001 if you are, in fact, asking about lower stall converters, then yeah they're out there. lowest i've seen was 2000rpm, but then i've never looked real hard. they make them for rock crawlers, so they should stand up to anything your engine throws at them. plus fuel economy will be better. Quote Link to comment Share on other sites More sharing options...
MYRON Posted January 29, 2001 Share Posted January 29, 2001 most stock converters from passenger cars using th350's are around 12-1300 rpm stall. I took the high performance converter out of my car because it was obnoxious to drive on the street because it would flash @ 4500 rpm. The stock unit in my car now is around 1200rpm and it launches pretty good. best 0-60 time so far was 4.51 sec and 1/4 mile at 117mph. I personally think that with a light weight car like the z and a low stall converter you are much better off as far as traction goes... With your converter locking at a low rpm before the engine torque is strong you get the car moving before all the power hits. On good concrete from a dead stop my care does not spin when you deck it. However it will spin a little when the engine hits 3500 rpm and then when you hit second gear. Myron Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted January 29, 2001 Share Posted January 29, 2001 5 replies now and we're not even clear on the question we must be of the helping nature if you're having a real lunge from idle/too much force to hold it at a stop your idle rpm can be turned down (I like 725-750 out of gear and 650 in gear if your cam allows it, so far I can do that with a .520 lift cam) and you may have a bit much initial timing into it (14 max), initial timing/rpm will give it this 'creep/lunge' In one state of tune on my old 327 I would start it up and when put into gear the rear treads would squeak as I put it into gear with brakes LOCKED as tires bit into the concrete on my cold idle ------------------ Of all the things I've lost, I miss my mind the most. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 30, 2001 Share Posted January 30, 2001 HEY GUY'S THAT WAS ALL GOOD BUT I MAY HAVE FOUND THE PROBLEM. WHEN I WAS STATING THAT MY CAR HAD A UPPER END TORQUE I MEANT THAT THE CAR FROM 0-60 IT WOULD DO THAT IN ABOUT 4.31 BUT AT SIXTY THE CAR'S RPM WOULD BE AT 4500 TO 5500 RPM'S WHAT I FOUND OUT LATER WAS THAT MY TRANSMISSION WHICH IS A TURBO 350 ONLY IS A 3SPEED WHICH HAS A HIGHER RPM RATIO SO WHAT IM GOING TO DO IS GET A 7R400 TRANSMISSION AND TRY THAT, BECAUSE FROM WHAT I WAS TOLD THE POWER AND TORQUE SHOULD STILL BE THERE IN THE BEGINNING AND SHOULD COME DOWN WITH THE RPM'S WHEN IM DOING 75-100 AND SHOULDN'T TEAR MY ENGINE. GIVE ME LUCK Quote Link to comment Share on other sites More sharing options...
Guest pauli Posted January 30, 2001 Share Posted January 30, 2001 ahh, now i see. you just needed an overdrive Quote Link to comment Share on other sites More sharing options...
Guest EPS Posted February 3, 2001 Share Posted February 3, 2001 ahh, now is see what you need, "Sell the car," I'm serious!!! Quote Link to comment Share on other sites More sharing options...
Guest RON JONES Posted February 3, 2001 Share Posted February 3, 2001 Why should he sell the car? Quote Link to comment Share on other sites More sharing options...
72zcar Posted June 20, 2001 Share Posted June 20, 2001 hey zrider, I am in the first stages of my 72 350, th350 and i don't want to be turning 5000 rpms at 60 mph... this would be bad. Question: What gear ratio are you running in the rear end? Some of the other guys I was talking to said some of the original r180 rear ends in the zcars have 4:11 gears. This might explain alot. Hey, your car must really fly up to 60 though right! What do you guys think if I put the 3:54 gears in my 350. th350? Would it help and make it drivable on the interstate? If not i must find a cheap 700r4. Quote Link to comment Share on other sites More sharing options...
pparaska Posted June 20, 2001 Share Posted June 20, 2001 The 240Zs had 3.36:1 unless it was an automatic. I don't think a 4.11:1 was ever offered from the dealer, although NISMO has/had them. Quote Link to comment Share on other sites More sharing options...
72zcar Posted June 20, 2001 Share Posted June 20, 2001 thanks scottie for the info. So if i go ahead and put the th350 for now just to get it on the road and look around for a 4 speed auto what should I look for in a good tranny? Model? Wrecked car ro look for it in? And would the tranny mounts and the drive line need to be re-done or should it bolt up to the mounts and drive line I'm installing for the th350? I already have the th350 and its bolted to the motor ready to go in. But if I have to redo all that stuff later I might just dig deeper in my empty pockets and get the right one now. Wife is already wanting food. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 21, 2001 Share Posted June 21, 2001 I've been told to get one from a camaro or firebird. The later series is supposed to be the better of the 2. You will have to change the trans mount though.JTR sells them seperate for the 700R4. Quote Link to comment Share on other sites More sharing options...
Andrew Bayley Posted June 21, 2001 Share Posted June 21, 2001 The 700R4 trans to looks for are those out of 87.5 and newer F-bodies. In the early 80's to 84, the 700's had a 27 spline input shaft. In 84 GM switched to a stronger 30 spline shaft, although the 27 spline can still withstand about 300 ft*lbs of torque. In 87.5, an auxillary valve body was added to improve shift quality. I also think that this auxially valve body allows the trans to be shifted into overdive at WOT. One thing that kind of sucks, is that the driveshaft needs to be shortened an inch or two when swapping from a TH-350. On the plus side, the trans mount for the TH-350 will work fine with the 700R4, however it might need to be repositioned on the floor if the Z (no big deal, just drill two more holes). When looking around at bone yards for transmissions, try looking at (and smelling) the trans fluid out of the dip-stick. It should be red and not smell like burnt pop corn. Good luck in your search -Andy Quote Link to comment Share on other sites More sharing options...
72zcar Posted June 21, 2001 Share Posted June 21, 2001 oh, thats right the rear end that I got out of a parts car a while back was an automatic. When I do the spin test it comes out just over 3.5 to one. So the 240z auto has a 3.54 : 1 ratio... am I right? Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted June 21, 2001 Share Posted June 21, 2001 Here is a quick formula to help determine RPMs when cruising. It requires you to know the diameter of the tire and the final drive. MPH/1000RPM = (tire diam * 2.905) / final drive So 24.5" tire with a 3.54 will yield a tad over 20mph/1000RPM which equates to 3500RPMs at 70mph. That gets old after a couple of miles especially if that is the RPM range for an annoying resonance. Quote Link to comment Share on other sites More sharing options...
Sean 83ZXT Posted June 21, 2001 Share Posted June 21, 2001 Hey Scottie, do you have the formula for determining your ET by the MPH at the end of the run? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 22, 2001 Share Posted June 22, 2001 good luck finding a lesonably priced 700r4 out hear a good one sells for 700+, I got lucky I have one left from my camaro I blew up good luck! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 22, 2001 Share Posted June 22, 2001 Are you sure that the transmission is shifting into high gear or that the converter is not shot? I use the same trans, 3.90 gear and 24.5 inch tires and do not have an OVER REVING problem. Car keep up with trafic on interstate at 3600 rpms. It seems that you have done a good job in getting your car together; but the hardest part is always sorting out the details. Hang in there. There are alot of good guys here who offer excellent advice and sincerely want to help. We all realize that we have problems that seem unsolvable, but are usually something simple that we have ALL overlooked. Good Luck. 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.