Monster Rebuild Questions.

[brando132]

***Before I get some hate, I should let you know that I've been researching this off and on for the past few months with many sleepless nights spent researching***


Hi all, I have a 1990 RHD twin turbo 300ZX 85,000 original km's. Had a lot of fun with it but Ive recently gotten a great paying job so money isn't really a problem at the moment and would like to beef it up a lot. It's going to be quite a read but bear with me, I have a few questions:

I'll start with my goal: 500+ WHP, while being reliable for years, mostly as a weekend driver. With the occasional drag and track day.

1. I've got a veteran race engine builder(almost entirely deals with drag engines all they way up to 6 second cars) 250 kms away who's agreed to bore and hone my block .020 over, balance and clearance the rotating assembly, clean the long block as well as some port work for a good price, and some other assorted engine work. So far, after a bunch of research, I've settled on these internal parts:

Z1 ultimate engine rebuild kit including:
Wiseco forged pistons with new rings 87.5mm
Complete Nissan Engine Gasket Kit
Full 60K Kit Timing Kit (Timing Belt Idler Pulleys Optional)
New Nissan oil pump
New Nissan Rod and Main Bearings (you are responsible for providing grades)
12 New OEM Rod Bolts
12 New Nissan Freeze Plug
Cometic head gasket
ARP head and main bolts
Kevlar timing belt and 60K timing kit

So the question is, is there anything else I should be getting to increase reliability? I've read a lot about people saying to get aluminum rods, for high power but my builder has advised against aluminum rods, and I should keep my stock forged rods, this seems to go against most of what I've read.

Also, is it worth it to go for ACL bearings?

Any thoughts?

2. For the other mods I've decided on:
Nismo 740cc injectors
MSP manifolds
GT2860RS Turbos 60mm 60 trim .60a/r
greedy professional boost controller
2.5 inch intercooler piping
3 inch downpipes to 3 inch test pipes, 2.5 inch from there
Nistune
Z1 B.A SMICs
AMS underdrive/OD water pump pulleys
Z1 light weight flywheel and street performance clutch with 6 puck disc

I guess what I'm asking is how will my spool up be?
I've read good things about this turbo, good high end flow with decent spool up, but does anyone have experience with these turbos and mods and what affect they have on spool up time?

3.I will be adding more to the car over time so this isn't everything I have planned for it but this is what I have planned to get it back on the road for now. Any thoughts or comments/answers are appreciated!

Keep in mind and I would like this up and running by June for a break in before a big car meet in the province in September. So trying to keep it under 8 thousand for now, I can always add more next winter but I would like opinions on anything I should get now while everything's going to be apart instead of me ripping it out again next winter.

Thanks!

[The Silent Genius]

I don't see any reason why you cannot accomplish your power goals without rebuilding the engine. The turbo upgrade with supporting mods should do the trick just fine. I however, am in a similar, if not the same boat as you, and am looking for the same information.

Good luck with your build, and I hope to be able to follow along.

[brando132]

At this point an engine rebuild is necessary. I've already got the donor engine block. I want to upgrade the internals so I can push 600+WHP, possibly 700+ at the drag strip without too much fear of blowing my engine.

[DCaff300ZX]

A couple of quick things to note for your build.

First off, the OEM pistons/rods/crank/cams are good to the 600HP range. Any upgrades there will really only gain you reliability if using the car hard (racing a lot) and not really do much for what you describe- that being casual performance usage. Therefore any internal components you change will be just fine if you purchase known OEM-or-better replacement parts from our better vendors, and not spend the extra money for more in this area.

You mention MSP manifolds- just as an FYI, they are great and I would use them myself except for two things- they are EXPENSIVE. The true problem- that being that the exhaust has to flow through an opening at the back of the manifold and into the turbo through an opening that is barely larger than a single exhaust port opening from the head, and is poorly set up- can be fixed by a knowledgeable Z mechanic. The MSP manifolds have been improved to help spool-up, but you can easily do the same with stock exhaust manifolds if you back-fill the area around the turbo opening, and carefully port that opening out for smoother transition and better/more flow. It cost me $150 to have my Z guy do both, same basic result (and you CAN feel it!) for WELL under the $700 a pair cost of MSP's and missing only the inconel metal MSP's are made from.
The 530 bb turbos are a VERY good choice for guys looking at the 500HP range, as they provide a lot of bottom and mid range response and torque, which really gets the car moving quickly. If you want more, the new 700's are apparently very popular if expensive, and will go to higher power levels but will need a lot more work to install correctly and all- the 530's were as close to bolt-in replacement as possible however and why I recommend them for sure, as well as my Z guy who was VERY impressed with them.

Regarding the clutch setup, I also recommend NOT going with the 6-puck and such that you listed, but stay with an upgrade organic disk such as Southbend and just add a slightly stiffer pressure plate for more clamping force. The 6-pucks can be chatter-y and can halve the life of your pressure plate in some cases, my mechanic refused to use a 6-puck and I personally am ecstatic with my setup- which is the Z1 mild upgrade pressure plate minus the ceramic 6-puck and using a upgraded organic disk plus new upgrade fork and pivot...feels stock but stronger, and has a LOT more feel to it as well as PLENTY of grab when launching. Best of all this is far less in cost to buying the other setups but nets the same results or better.
Same with the exhaust- buying the fancy pre-made exhaust setups is insanity, especially with the price. Your 2 1/2# exhaust is fine up to 600HP again, so as you plan simply improving the DP transfer and staying OEM to the back and adding better SS mufflers and larger SS exits will get you everything you need- more/better power and style. Hi-flow cats/resonators would finish the bill at around $500 if wanted.

BTW, take a look at my "refresh" details at the end of my build thread- I have gone the same basic route as you with not cracking into the block, but refreshing EVERYTHING else including clutch and clutch internals (important!) and upgrading the turbos to JWT bb530's and upgrading the smics to Z1 upgrades. My HP/TQ ratings are dead even at 8psi boost and the car is COMPLETELY different with a little exhaust manifold porting and a fuel controller setup with 850cc injectors, LOTS of room left for more power if I decide to get crazy which probably won't happen.

Have fun!

[brando132]

A couple of quick things to note for your build.

First off, the OEM pistons/rods/crank/cams are good to the 600HP range. Any upgrades there will really only gain you reliability if using the car hard

That's basically what I've been reading and I think I'm going to tone back the internal upgrades a bit.

The MSP manifolds have been improved to help spool-up, but you can easily do the same with stock exhaust manifolds if you back-fill the area around the turbo opening, and carefully port that opening out for smoother transition and better/more flow.

That I didn't know! I'm sure the guy I'm getting build the engine will be able to do that, he's a family friend so he's giving me a good price. I have read a lot about how the MSP's are amazing and even better than ported stock and like I said money isn't an issue but if I can save a bunch that would be great. I'll see how much I save from my original estimate before I decide to spring for them.


The 530 bb turbos are a VERY good choice for guys looking at the 500HP range, as they provide a lot of bottom and mid range response and torque, which really gets the car moving quickly.

These were my original choice of turbos, but after reading how good the disco is I seriously considered a similar turbo, I'm still on the fence about which turbo to get. I really like the appeal of the 530 but some where down the road I'd like to get the car into the 10's at the track and don't really want to swap them again. The price difference is pretty much nothing. So more reading and deliberation for me!

Regarding the clutch setup, I also recommend NOT going with the 6-puck and such that you listed, but stay with an upgrade organic disk such as Southbend and just add a slightly stiffer pressure plate for more clamping force.

I've already got the Z1 street performance pressure plate and lightweight flywheel with the upgraded fork and chromoly pivot. I was considering the ceramic, but again on the fence about it. I want something that I can drive daily even if Im not going to so I think I'll stick with organic.

Same with the exhaust- buying the fancy pre-made exhaust setups is insanity, especially with the price. Your 2 1/2# exhaust is fine up to 600HP again, so as you plan simply improving the DP transfer and staying OEM to the back and adding better SS mufflers and larger SS exits will get you everything you need- more/better power and style. Hi-flow cats/resonators would finish the bill at around $500 if wanted

I actually just bought a turbo back exhaust system from a guy who was parting out his 92, I was considering buying the whole car for parts because he had a lot of work done to it and all that was wrong was a blown turbo, such a shame. But the body was pretty bad, so I got a 2.5 inch test pipe with high flow cats, then a join to 3.5 inch single pipe into a hsk silent high power muffler. All for 200$. I also got a 98+ spec transmission because my synchros were going for 150. He must not have known howuch they were worth so I got a steal. Plus a brand new in box AEM UEGO which I plan to use for logging with nistune for 200$.

Is it necessary to run one for each side? Or is there one side that runs leaner than the other so I can be safe.

Thanks for the replies! Its good to hear from knowledgeable Z owners.