Tell me about 350 Turbo auto-trans

[TheNeedForZ]

Hi fellas,

 

I just bought my V8 240Z yesterday and it is pending shipping. The owner flew in from Toronto to Vancouver on official business so we had a chance to sit down and chat(and exchange payment/ownership too)

 

I knew the car is automatic(which I prefer, for now at least), but he never said in email what kind is it. When we met f2f, he said he remember the transmission is "350Turbo" (he's the 2nd owner since the conversion, so he doesn't know everything about the parts)

 

So I am here to find out what you gents think about "350 turbo", how many "speeds" and are the gear ratios on the high side or on the low side?

 

BTW, the motor is 383ci sbc stroker, rear diff is from a 85 300ZX, which is 3.7? IIRC

 

Thanks in advance

[Mike kZ]

The turbo 350 is a 3 speed auto, no overdrive! With your 3:70 gears don't go on the highway too often

[Chaparral2f]

Yeah, what Mike said. One other thing, they are a good strong tranny and with just a little work they will shift REAL positive. here is a handy link for you to figure the speed and ratios.

 

Joe

 

http://www.dalesplace.com/htm/information/rpm_calculator.htm

[Guest 240zt]

I Had a turbo 350 in a 79 GMC and OMG that thing was unbreakble. Ramed that sonova bitch threw snow drifts long long long 1 wheel burn outs N to D launches never even winced

[TheNeedForZ]

Thanks for the input

 

Wow, a whopping 3 speed, despite the fact that it is tough, do I need to change it? (i.e. if it's on your street car, would you change it?)

 

Planned use of the car is occasional fun driving in good weather. I usually don't go faster than 70kph(44mph) on the streets, but on the highway I usually do 130kph(81mph)

 

Using the calculator above, with default 255/50/17 tire (I'm a noob, what do those numbers mean ), and 3.75 rear diff.

 

44mph or 70kph = 3117rpm (2nd gear)

87mph or 130kph = 3776rpm (3rd gear)

 

At those cruise speeds, rpms seem ok, then again I have not driven the car yet. If there's a need to change the trans, which AUTOMATIC trans will be a good candidate?

 

Thanks in advance

[Chaparral2f]

I have a th350 in my z31 with a 350 (if I ever get it done) I plan to use it to put tire tracks over the idiots who think a large chrome muffler dangling under their Honda makes it faster than a retty old 300ZX. I'm using it because I had it laying around and I'm on a budget. If I were to swap it out, I think the best choices would be either the 200R4 or 700R4. These are both pretty common GM tranys that should bolt onto a chevy, and give you a fourth gear. The 200 has a taller fourth gear (0.67)and will drop your rpms lower than the 700 (0.70) ther is only about 300 rpm difference at 85mph which IHMO isn't Jack. Either one should be fine. If your car was heavier I would suggest the 700R4 but as light as a Z is, and with your power, I don't see much difference. If you decide on a 200, i would suggest getting one from a Buick. I think they are stronger though I am not sure about that. Good luck.

 

Joe

[Brad-ManQ45]

Basically, the TH350 and 700R4/4L60/4L60E share the same 1st 3 gear ratios, with the later having overdrive and sharing the same clutch packs for 1st and 2nd gear...

 

The TH400 and 4L80E share the same gears with the later having an overdrive. Separate clutch pack for each gear, which is why it stands up to torque longer.

[Mike kZ]

I would use a 200r4, it's the same size as a turbo 350

[Sumo]

I would use a 200r4, it's the same size as a turbo 350

 

Ditto! 200R4 is basically a 350 with an overdrive and you probably won't have to change the drive shaft. 8)

[Brad-ManQ45]

200R4 has the advantage of lower numerically speaking 1st gear that the TH400 and 4L80e have - when you/ve got a lot of torque and a light car, it helps...

[TheNeedForZ]

Thanks for the input, fellas

 

Once I got the car and drove it, if the gears and rpm feels alright, then I might look into getting a R200, which is close to the original TH350 ratio and appears to help both launching and high speed cruising.

 

Now where can I find an R200? Probably pick and pull special, I mean what kind of car/truck should I be looking for?

 

Thanks

[80LS1T]

I think you guys messed up the wording..... you mean a 200R4 not a R200.........right? A R200 is a differental and a 200R4 is a tranny? I assume your looking for the tranny and not the diff?

 

Most junk yards would have a 200R4 or you could go on ebay?

 

 

Guy

[spdsk8r]

You might check your local tranny shops, also. We have a local shop that has a catch of 200R4's. They will build one up, for your application for $1200 including converter.