Considering a Z31: kindly advise

[rcky]

Hello guys, just popping by to ask a few general questions. I thank you in advance for all the forthcoming advice and opinions.

Recently, I came across a Z31 on sale in Penang. It looks immaculate and well taken care of, and I am having serious thoughts about it ATM. I was wondering about a few long term issues, namely:

1. the stock engine in there is a twin turbo 3L. Would it be wise of me to swap it with a lower spec but more efficient unit like the SR or RB20DET? If it's possible, would it cause any legal complications if I downgrade the engine?

2. if I were to have any issues with sourcing parts, where would be the best place to get parts or at least fabricate them? I was told that the 1st gen S30 could accept parts from the Cefiro by a junkyard manager once, so I was wondering is that true and if it's even possible. This is the most important issue for me as I want to take care of it the best I can, with the sort of budget I have in mind.

3. what are the common issues that may arise from owning the Z31? I won't include fuel consumption as one of them, because I'm aware that as a sports car and it's not supposed to have FC as brilliant as a daily driver. What I'm worried of are chassis problems and the likes of it, as I want the car to be as safe as possible.

Many thanks in advance for everyone's time. I hope everyone can answer my questions as frankly as possible, no matter how bad the news is. Cheers and have a good day ahead.

 

[khoyos]

i am using a z31. any questions, u can just ask me or we can meet up to talk about the car hehe.

1. there is a model of z31 that comes with RB20DET and i have seen a few halfcut shop selling these z31 rb20 halfcuts. it'll be a simple straightforward conversion. if u decide to install RB20 from skyline halfcut, u need to convert the skyline front sump to original z31 rear sump. i installed rb25det from skyline, and after that i transplanted to 2jz-gte engine and have been using it till today.

2. parts are very very hard to find but try to make friends with halfcut runners. through these friends, i managed to find the necessary parts to put my car back on the road after an accident. i have some spare parts that i keep at home, including 2x rear axles, 1xhalfcut, 2x front zenki bodyparts n others so that i wont face parts problems when something bad happens. best to use back original z31 parts, rather than mix n match. some parts can mix n match but some vital parts must use back OEM.

3. i used the v6 engine for less than 200km, driving the car back home from previous owner's house and driving from home to workshop for engine transplant so i dont know about any engine-related issues. typical problems are excessive camber issues at the back but that only happens when u lower the car, and i noticed some rusts under the chassis of my car. other than that, i think its a nice car to drive, relatively trouble free...

 

[rcky]

@khoyos

Hi khoyos, thanks so much for the inaugural reply. I really appreciate your valuable advice, and I'll be sure to ask you again if I need anything else.

From the sounds of it, I think I was a little too optimistic in thinking that the Z31 can be easily fixed. But given the age of this car, I shouldn't be too surprised. With that in mind, I also have some counter-questions to some of the points you've given:

1. you mentioned earlier that some parts must be replaced via OEM. I presume that the axle is one of them, but is there anything else that you recommend be replaced using original parts? What about the gearbox, can I take it from the more modern Nissan cars?

2. before you converted your engine, did you have any problems with JPJ? I heard that as long as you don't increase the CC of the car, you can swap it with other smaller engines. And if I change the engine, do I also have to change the gearbox as well?

3. with the 2JZ in it, how much FC can you obtain under normal driving? This is just out of curiosity, but my intention is to stick with Nissan engines for now. I don't intend to put in an engine that's too powerful as I intend to use it as a cruiser. As long as it's around 200-250bhp and handles well, that's all I need.

4. I heard that at one stage, you can register the Z31 or S30 as a classic car, and that entitles you for a tax discount. Is that true?

Cheers bro, and thanks once again. You've been most helpful.

 

[khoyos]

1. yup axle better install back original. but if u want to mod, yes u can mod silvia s14's rear axle to fit ur z31. about the gearbox, i'm not so sure but u can browse z31 forums in the states. there are lots of z31 users there, and i managed to source some parts from over there too, including some brand new OEM nissan genuine spare parts. they have strong parts support there. anything u want that cannot be sourced here, u can purchase online from there.

2. no problems with jpj whatsoever. yeah at first u say u dont need powerful engines. but remember z31 is not a lightweight car, so not only u need horsepower, u also need torque to haul the heavy body.

3. the fuel consumption of stock 2jz with 5 speed manual gearbox on my car, is somewhat slightly worse than my myvi (daily car). thats all. very economical bro. in fact all JZ family engines have economical fuel consumption due to the torque. plus 1jz/2jz have rear sump which is compatible with Z31. most skyline r32/33 or silvia are front sump which makes engine conversion a tad more difficult n requires custom oil sump or cutting ur crossmember if u cant get interchangeable oil sump... i regretted not having transplanted 2jz in the first place. during rb25 conversion, i did not have access to z31 rb20 rear sump, and my mech a bit crazy, so he cut my crossmember, modified it, and managed to move back the whole front subframe to make some space for the rb25's original front sump. result: handling off, could never get the alignment & camber to be set nicely, car became "nervous" etc etc.

4. can register as classic car status. but the requirement is to have the car in 100% factory conditions. nothing can be changed. not even the steering wheel. everything must be original, down to the stock muffler, stock rims, etc etc etc. for sure my car cant qualify but the penang z31 i think can qualify hehehe.

---------- Post added at 12:35 PM ---------- 6 hour anti-bump limit - Previous post was at 12:33 PM ----------

but why worry? the penang z31 is in good condition, just buy and drive la bro. no need to repair anything.

p/s penang z31 owner: must give me some commission, i'm promoting ur car!!! hehehe

 

[rcky]

Hey bro, thanks again for your prompt reply. I'm learning a lot more now than I could before, ha ha!

1. yup axle better install back original. but if u want to mod, yes u can mod silvia s14's rear axle to fit ur z31. about the gearbox, i'm not so sure but u can browse z31 forums in the states. there are lots of z31 users there, and i managed to source some parts from over there too, including some brand new OEM nissan genuine spare parts. they have strong parts support there. anything u want that cannot be sourced here, u can purchase online from there.

Now, this is what I call extremely good info. If I can source externally, I think that's a good enough lead for me, even if it's overseas. I was just worried that all parts are already out of production.

2. no problems with jpj whatsoever. yeah at first u say u dont need powerful engines. but remember z31 is not a lightweight car, so not only u need horsepower, u also need torque to haul the heavy body.

OK, I will keep this in mind. I had no idea the Z is that heavy, so it looks like the SR or RB20 really is not enough after all. May need to convert to 2JZ or even the 1JZ if needed.

3. the fuel consumption of stock 2jz with 5 speed manual gearbox on my car, is somewhat slightly worse than my myvi (daily car). thats all. very economical bro. in fact all JZ family engines have economical fuel consumption due to the torque. plus 1jz/2jz have rear sump which is compatible with Z31. most skyline r32/33 or silvia are front sump which makes engine conversion a tad more difficult n requires custom oil sump or cutting ur crossmember if u cant get interchangeable oil sump... i regretted not having transplanted 2jz in the first place. during rb25 conversion, i did not have access to z31 rb20 rear sump, and my mech a bit crazy, so he cut my crossmember, modified it, and managed to move back the whole front subframe to make some space for the rb25's original front sump. result: handling off, could never get the alignment & camber to be set nicely, car became "nervous" etc etc.

I had no idea the JZ series was THAT good. I always thought using a diff engine make would screw up the car. If the JZ can really offer nearly as good FC like the MyVi, that really is a big surprise for me, as I always assumed turbo cars will have bad FC. I initially thought that the RB25 would be a straight fit to the car as well, but looks like I was wrong. I still need to learn more about this.

And I sure do not want to go through your experience of cutting and refitting parts like your mechanic did, ha ha! I want it to be as simple as possible. But that mechanic must be very talented to be able to do smthng this extreme. By any chance, I can assume that you're using the stock gearbox, and it can handle the 2JZ's power, right?

4. can register as classic car status. but the requirement is to have the car in 100% factory conditions. nothing can be changed. not even the steering wheel. everything must be original, down to the stock muffler, stock rims, etc etc etc. for sure my car cant qualify but the penang z31 i think can qualify hehehe.

Oh, now this is very good info as well. So I can't do ANYTHING at all to it. Need to be careful about this one. And yes, I think the Z31 I saw looks totally stock, even the wheels are the same as the original design and had no body kits installed.

but why worry? the penang z31 is in good condition, just buy and drive la bro. no need to repair anything.

p/s penang z31 owner: must give me some commission, i'm promoting ur car!!! hehehe

Well, I admit I was very tempted from the fact that the car LOOKS to be in good condition, and I sure would love to get one ASAP, ha ha. But I'm also a realistic person, and that's why I need to be very sure that it will not be a big financial burden before I take on this responsibility. It has always been my dream to own a classic car, so I need as much info (and money of course) to ensure I can take care of it as best as I can. I'm very worried about parts the most, but I'm glad to know that from your experience, it can still survive up till today.

Cheers bro, and hope you can advise me further on what else I may have missed or some important need-to-knows. Thanks again.