AverageZ31guy

Hi, I've been looking at getting a z31 for years now and have always wondered if it would be cheaper for me to go na or turbo? I like the earlier models more and have heard that the early turbo trannys being a problem point. The big reason is the price of turbos being a bit out of hand right now. With some selling upwards of 25k. I love the car but it's not exactly something I want to spend that much on just to buy it before I mod it. The Na's tend to stay under 10k in my experience which is a lot more appealing. But in the end I don't have the experience and have to come to yall to get some advice is it worth putting a turbo on an na and how do the trannys hold up as well as the internals?

FlyingT

To put a turbo on a NA engine, it is prudent to check the ring gaps. Generating more power generates more heat in the combustion chamber. That means going into the engine, removing the pistons, checking the ring gaps, and maybe filing them wider. A boosted engine runs hotter and the rings will expand more. If they expand too much, they will touch ends and break, destroying the engine.

Also, the VG30E NA compression ratio is 9.0/1 and the VG30ET Turbo is 7.8/1. What are your plans if you do go turbo? Big power or OEM factory power? Any turbo, even factory power on a VG30 NA 9.0/1 engine, will require premium gas. The VG30ET 7.8/1 engine does not require premium with its lower compression ratio.

Big power with larger turbos would require that you fabricate an turbo intercooler system and figure out where to put it and plumb it, not an easy task. You would have to have good fabricating skills to do that, no plug and play anything.

Making big power is one thing, making the engine live a long life is your responsibility. It takes planning.

There are virtually no aftermarket to help you, no kits available to buy. Maybe go with a much simpler nitrous since as it is much cheaper, however, nitrous still has the same ring expansion issue if used in a designed NA engine.

And BTW, I have had my 85T since new, 300K miles on it, and have had no tranny issues on my 5 speed FS5R90A. I would call that pretty reliable.

Here are some very good reading Z31 archive web sites
http://redz31.suomiz.net/
http://zbum.suomiz.net/index.shtml
http://300zx.tombeauchamp.com/
http://www.thumper300zx.com/

Great White Zed

Hello and welcome to the Forum. Perhaps you've answered your own question: the Z31 is generally cheaper to buy than the Z32. In addition there's this from a Nico forum:So the above should translate into there being more parts, more knowledge and more options for purchase. What I think of as a big distinction is what the car offered in terms of body styles. The Z31 could be had as a 2 + 0 seater without a T bar roof. If this style says 'yes' to you then your choice is clear.

AverageZ31guy

My goal in mind has always been around 400hp but that's liable to change when I actually get the car.

Qaanaaq-Liaaq

Read this concerning converting an N.A. model to a turbo: https://z31.com/mods/

Now that the z31 is in its old age with the oldest model year being 40 years old, I’d be more concerned about finding one that’s in excellent condition than what the aspiration type is. Unless it has absolutely has to be an OEM turbo, I’d look for a z31 that’s in excellent condition. And the better preserved ones will be harder to find and are going to command a higher asking price. Rust, accidents, and owner neglect are common problems with all old cars not just z31s.

Auto. transmissions seem to get bum rapped on z31 forums. I’ve never had a problem with the auto transm. I’m an original owner of a 1984 turbo automatic.

dark-divx

just turbo your NA.
many info about it. search for NA2T.