Wesley's Dream & The Journey of a '72 240Z

[rturbo 930]

2 hours ago, notWes said:

I've gotten to drive (for like 15 minutes) a 911, one of those new chargers SRT 392 I think, and I've sat in the new 4L C63 AMG. Not pushing limits at all whatsoever. As for Japanese turbo cars I've really only been in a 450whp~ r32 GTR and it was a hoot. I absolutely agree with you, I don't need that amount of power... But I really want it. I'll be sitting at 250whp~ for about 2 years anyways so I'll see how I like it! I'm planning for the future so I only have to buy parts once, would you say I'm waaaaay over doing it or just over doing it?

waaaaay over doing it

500whp would be probably 600 at the crank. At 2500lbs or so (with necessary driveline upgrades) you'd be looking at a power to weight ratio of a little over 4. Think about that for a second. 10lbs/hp is a decent sports car. 8lbs/hp is pretty quick. And you'd be at 4.

You would also need some decent chassis reinforcement - definitely more than just subframe connectors and strut bars. Add in driveline upgrades, you'd have to do just about the entire thing front to back. Stub axles, CVs, diff output shafts. All of that won't be in any way cheap. And of course your trans will need to be up to the task. I don't know if the stock driveshaft will be an issue.

Now consider that you will need brakes to stop the car, and an appropriate amount of tire to put the power down. This could mean cutting the fenders for flares, but 275s can be stuffed under stock fenders with some effort. With all that in mind, consider that a major strength of the Z is its light weight, and that you would be adding a lot of weight to the car, between rear end upgrades, larger wheels and tires, a larger trans, the heavier RB with turbo, and intercooler, piping, etc.

IMO the Z is not worth turning into a high HP monster. There is so much that needs upgrading, and I think there is a risk of ruining what makes the car great. It should go without saying, that if you still want to go this route, you are free to do so, but you might find the finished product to be more enjoyable if you instead concentrate on maintaining the Z's low weight, while also giving it a much more manageable power level (lets say 300hp). Much less focus will be needed on tire and driveline/chassis upgrades, which will keep weight down (allowing that 300hp to be more effective in propelling the car) and also saving money.

If you want something with serious power, I think there are better platforms to start with. Cars that have strong drivelines from the factory, and a chassis that can handle the power without significant reinforcement, if any. Of course, these cars will mostly be newer.

[Mark Maras]

Throw that amount of horsepower into a Z and you'll be chasing the weakest link in the drive train. When you correct that weak link, you'll find the next one, and the next one, etc.

[Patcon]

37 minutes ago, Mark Maras said:

Throw that amount of horsepower into a Z and you'll be chasing the weakest link in the drive train. When you correct that weak link, you'll find the next one, and the next one, etc.

Mark made my point very eloquently. You will basically have to reengineer the car to get a dependable car with those HP levels. Also keep in mind you can't just source a fuel pump that will work for 500+ Hp that is good for your current level of 250HP (or what ever). It needs to move more fuel than that. You can't run overly large injectors for a similar reason, you lose resolution and accuracy when large injectors are asked to deliver low volumes of fuel. That means you have to buy multiple injectors and fuel pump and misc odds and ends as you upgrade the car. As you do this you have to retune and retune...

I speak from experience that this kind of project can be really frustrating and very costly. 50/50 odds on whether you ever actually get a dependable 500Hp Z to where you want it to be even after pouring piles of cash into...

11 hours ago, rturbo 930 said:

IMO the Z is not worth turning into a high HP monster. There is so much that needs upgrading, and I think there is a risk of ruining what makes the car great. It should go without saying, that if you still want to go this route, you are free to do so, but you might find the finished product to be more enjoyable if you instead concentrate on maintaining the Z's low weight, while also giving it a much more manageable power level (lets say 300hp). Much less focus will be needed on tire and driveline/chassis upgrades, which will keep weight down (allowing that 300hp to be more effective in propelling the car) and also saving money.

This is very good advise! Doable but still not cheap, and even at 300Hp you are gonna break stuff finding the weak links...

[notWes]

On 12/19/2017 at 10:43 PM, rturbo 930 said:

waaaaay over doing it

500whp would be probably 600 at the crank. At 2500lbs or so (with necessary driveline upgrades) you'd be looking at a power to weight ratio of a little over 4. Think about that for a second. 10lbs/hp is a decent sports car. 8lbs/hp is pretty quick. And you'd be at 4.

You would also need some decent chassis reinforcement - definitely more than just subframe connectors and strut bars. Add in driveline upgrades, you'd have to do just about the entire thing front to back. Stub axles, CVs, diff output shafts. All of that won't be in any way cheap. And of course your trans will need to be up to the task. I don't know if the stock driveshaft will be an issue.

Now consider that you will need brakes to stop the car, and an appropriate amount of tire to put the power down. This could mean cutting the fenders for flares, but 275s can be stuffed under stock fenders with some effort. With all that in mind, consider that a major strength of the Z is its light weight, and that you would be adding a lot of weight to the car, between rear end upgrades, larger wheels and tires, a larger trans, the heavier RB with turbo, and intercooler, piping, etc.

IMO the Z is not worth turning into a high HP monster. There is so much that needs upgrading, and I think there is a risk of ruining what makes the car great. It should go without saying, that if you still want to go this route, you are free to do so, but you might find the finished product to be more enjoyable if you instead concentrate on maintaining the Z's low weight, while also giving it a much more manageable power level (lets say 300hp). Much less focus will be needed on tire and driveline/chassis upgrades, which will keep weight down (allowing that 300hp to be more effective in propelling the car) and also saving money.

If you want something with serious power, I think there are better platforms to start with. Cars that have strong drivelines from the factory, and a chassis that can handle the power without significant reinforcement, if any. Of course, these cars will mostly be newer.

Sadly I have dreams that I'll never stop chasing and this happens to be one of them. I don't necessarily want 500whp but I want to feel the speed I crave. Whether it's spinning wheels or not my brain is infatuated with future-proofing for safety and planning. Seeing as I'm replacing all the major drive train components anyway I just wanted to overkill my HP part ratings in the event my ego takes over and asks for more. I should start considering building to an exact cause. 

I appreciate the advice. Low weight is definitely going to be more enjoyed than spinning tires. Speaking of tires, I've been on the fence of cutting the fenders and adding the zg flares or just throwing them on anyway. I'll have to do some test fitting when the time comes. 

 

 

 

 

 

 

 

 

 

[notWes]

On 12/20/2017 at 10:24 AM, Patcon said:

Mark made my point very eloquently. You will basically have to reengineer the car to get a dependable car with those HP levels. Also keep in mind you can't just source a fuel pump that will work for 500+ Hp that is good for your current level of 250HP (or what ever). It needs to move more fuel than that. You can't run overly large injectors for a similar reason, you lose resolution and accuracy when large injectors are asked to deliver low volumes of fuel. That means you have to buy multiple injectors and fuel pump and misc odds and ends as you upgrade the car. As you do this you have to retune and retune...

I speak from experience that this kind of project can be really frustrating and very costly. 50/50 odds on whether you ever actually get a dependable 500Hp Z to where you want it to be even after pouring piles of cash into...

This is very good advise! Doable but still not cheap, and even at 300Hp you are gonna break stuff finding the weak links...

That is a very good point especially when future-proofing. I haven't really gone into the research of injectors, but logically that'd prove a serious problem with how I like to plan. On that same note, retune after retune has not even been calculated into my budget. I've been so caught up in figuring out how to just get this Z running again parts wise...  The only outside help I've really looked into was body and frame repair. 

Welp, I definitely can't begin this build with odds like that. I'm more of a 101% kinda guy when it comes to money. Or ROI's rather, but still money in general. 

I guess I'll see what breaks this summer at the stock 250hp~ and go from there. 

Jeez, the L28 swap i was going to do sounds a hell of a lot more viable now haha.

[notWes]

Thank you for all the advice and input fellas. I'm forever in debt to the forum and I greatly appreciate you all taking your time to understand my unrealistic dreams. Information might be free but teaching is not! 

I would also like to apologize for my absence. Holiday season shenanigans are occupying quite the amount of time. I hope everyone had lovely holidays and happy tummies.

 

I'm off to pick up the RB25 and trans in Montreal the 2nd weekend of January! A very kind member has sourced me one of his own 4.1 diffs and 280z mustache bars so that's on the way too. Hopefully he finds the half shaft mounts too. Then it's time to measure for the driveshaft! I'm dreading the wiring but I think a couple beers, a sharpie, and some tape will keep me busy.

 

ADVICE NEEDED: I am going to replace gaskets and seals throughout while i rebuild the engine, would you (personally) replace the journal bearings for the crank regardless of condition? Also, might you have any recommended brands for gasket maker and assembly lube? I've been using Motul fluids and I was wondering if anyone knows of anything better suited for the RB Z. ALSO ALSO, is it actually safe to pull the engine and trans together with just the 2 bolt points? I feel like it might be a little heavy and I might just drop the trans itself tomorrow anyway. Any input would be wonderful! 

 

Thanks again guys, don't drink and drive and happy New Year!

[notWes]

If anyone is interested in a 3.9 open diff, stock driveshaft, or a 4 speed automatic transmission, let me know! They'll be hanging out in my garage for the time being.