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ANOTHER Datsun Z/LS3/T56 Swap Thread


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I might be in denial, but I am hoping to be able to trim the fenders without completely re-painting them.  I am planning to cut within .5" or so of the desired line, then gradually sand with a flap disc to finish the cut.  If I go slow enough not to overheat things, it might work.  Maybe.  If not, I still have my paint booth and have paint/clear left over.

 

The lowest part is the header collectors.  The ground clearance issue is really my biggest concern with the build.  Speed bumps are pretty much out of the question.

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Got the project started up...

 

I was anticipating any number of hurdles at this point...a wiring snafu I failed to catch....overheating....oiling problems with dry sump system....or simple failure to start for reasons unknown.  But it fired right up, had good oil pressure, reached operating temperature (eventually) and stayed there.

 

I did have a bit of trouble getting the thermostat to open for the first time, but from what I have read that is almost normal for LSX engines.  The problem was that I plumbed the steam pipe from the top of the engine incorrectly (and stupidly) so that it was blocked by the radiator thermostat.  This resulted in a big air pocket in the cooling system before I corrected it.

 

But with that fixed, if fires up more quickly than my daily driver, and seems to hold operating temp, at least during idle with lots of throttle blips and sustained 2500 RPM running for break in.

 

 

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  • 2 weeks later...

Congratulations Ironhead. Huge and accomplished milestone. You should be proud!

Can't wait to see some first road test video.

 

Also, true to statement from years back - I only just got the bottom end of my engine assembled this past weekend. Now waiting on rocker locks and NLA rocker shafts before I can finish assembly of the head and drop that on.  Even then, the chassis isn't ready to accept the engine.

 

I hold that you'll be on iteration 4 of this build by the time I build oil pressure! LOL

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On 3/7/2021 at 2:41 PM, 280Z-LS3 said:

Congrats!

 

Do you have a dB meter, does not seem loud on video.  I think there is a sound meter app for smart phones that is reasonably accurate.

 

19 hours ago, UNHCLL said:

Congratulations Ironhead. Huge and accomplished milestone. You should be proud!

Can't wait to see some first road test video.

 

Also, true to statement from years back - I only just got the bottom end of my engine assembled this past weekend. Now waiting on rocker locks and NLA rocker shafts before I can finish assembly of the head and drop that on.  Even then, the chassis isn't ready to accept the engine.

 

I hold that you'll be on iteration 4 of this build by the time I build oil pressure! LOL

 

On 3/7/2021 at 2:41 PM, 280Z-LS3 said:

Congrats!

 

Do you have a dB meter, does not seem loud on video.  I think there is a sound meter app for smart phones that is reasonably accurate.

 

 

Thanks much Gents!

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21 hours ago, LLave said:

What a huge moment! I am honestly happy for you.... Almost proud of you! hahaha. Great work. 

  

Thanks dude...LOL.

 

I took the car out today just on the road right near my shop...sans front fenders, hood, and many other parts...just to get a feel for it.

 

I honestly got the feeling that I am in a bit over my head.  The car is so damn powerful and fast...even not exceeding 50% throttle or 3500 RPM(breaking in engine), it's like nothing I have driven before.  I have another track car I have been tracking for years, and it is reasonably fast.  But, it is more of a flawless handling momentum type car.  The Z is a completely different animal.  Just driving it on the street seemed....inappropriate/illegal....and I subconsciously kept expecting the cops to show up.

 

Also a bit of an eye opener was the pedal effort required by the brakes.  I know that is part of the deal with racing brake setups...but it definitely takes some getting used to.  I am using Ferodo 2500 pads, which I have always used on my other track car, but I think compounds have improved a lot since they came out and I might order something with a bit more friction/bite to lower pedal pressure slightly....probably DS3.12 compound...which from what I have read sounds too good to be true.  Supposedly good cold bite, consistent friction throughout the temp range, and zero fade.

 

Driving the car also highlighted the amount of work I still have to do.  Something in the drivetrain was rubbing...electric power steering was giving inconsistent boost for some reason...and I will never again drive the car without fenders as the sticky tires pelt the freshly painted bodywork with gravel.  That was pretty stupid, really.  The fronts of the rear over-fenders in particular are so vulnerable, I think I am going to give them a coat of Raptor liner.

Edited by Ironhead
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Intimidating power, YEAH!  LOL.  This IS why you have labored for over the years!!!

 

Once upon a time got the keys to my Dad's 81 Corvette.  Cold, wet roads so traction was non-existent.  Had the high school sweet heart in the passenger seat and came to the stop sign at the local pizza place where all the kids came to hang out.  Wanting to show off nailed the throttle while making a left out of stop sign and the car just started fish tailing.  Guard rail, on coming traffic, guard rail, the OH SHIT kinda stuff.  Learned a lesson but have since not experienced that sort of power exceeding traction/skills.  My build will be similar to yours in power so very excited indeed to get it on the track for some adrenaline pumping action!

 

Curious how pounds of pedal effort you have designed into your system.  Using a brake calculator I plugged in 60 lbs of pedal effort to produce 1g and choose the dual master cylinders accordingly.

 

 

 

 

 

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7 hours ago, 280Z-LS3 said:

Curious how pounds of pedal effort you have designed into your system.  Using a brake calculator I plugged in 60 lbs of pedal effort to produce 1g and choose the dual master cylinders accordingly.

 

 

 

 

 

 

One of the trade-offs, is to design in lower effort by using smaller master cylinders, you kind of have to accept longer pedal travel, because the system still needs to move a certain amount of fluid to operate.  I'm fairly tall, so I positioned the pedals close to the firewall, which limits the amount of pedal travel I can have.  My pedals have an adjustable pivot point on the balance bar, which I moved from low effort/high travel to medium effort/medium travel for this reason.  I wanted full braking well before the pedal was bottoming on the firewall, for obvious reasons....

 

There's really no free lunch....

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On the flip side of the pedal ratio vs master diameter/effort thing, if you don't have a booster then the pedal won't travel as far. If I let you drive my car you'd never come back with a comment about the brakes, either travel or effort. Just feels normal. 

As to your first drive comments, when I drove mine for the first time it was just around the block and I found that I could just step on the gas and roast the tires for basically as long as I held the pedal down. It was intimidating, and immediately brought up that Mark Donohue quote. Anyway once I got it out on the track I realized that it is in fact drivable, and doesn't do anything stupid. Pretty easy to drive for what it is. Hope yours turns out the same, I expect that will be the case.

Congrats!

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Just purchased a brake kit from Essex and now the next step is to talk with Tilton on what they recommend for masters cyl with their dual master pedal.  How close/realistic are theoretical values like pedal effort and effort derived brake calcs?  My first time going through this exercise so don't now what to expect.  Thinking they can give me an idea of pedal travel amount based on caliper specs but have a feeling it's going to be trial and error to find the right compromise between pedal effort and travel.

 

 

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1 hour ago, JMortensen said:

Just tell Tilton what you're doing. They'll give you advice. Take it. Worst case scenario you need to swap a master or both. They're not that expensive. Or make your own thread and state what you have for brakes and people can give their thoughts. 

 

I got the sizing on my master cylinders directly from Tilton.  Their tech support is great...they offer assistance without talking down to you or trying to sell you big $$$$$ items you don't need.

 

Anyway, they took weight (anticipated at the time) of my car, weight distribution, front/rear rotor sizes, caliper piston areas, and other variables to recommend master cylinder size.  I told them I wanted to lean toward relatively light pedal pressure, and I followed the sizing they recommended.  Once it was all working though, because of my pedal position I found I was getting just a bit more pedal travel than I was comfortable with, hence the switch in the pedal pivot/leverage.

 

As I see it, the only thing I can do now to lower pedal effort would be to try a grippier pad compound, which I am doing.  Other than that, I imagine it is just a matter of getting used to the increased pedal pressure.  My other track car has power brakes, which I suspect is why I was a bit surprised at the effort required in the Datsun.

 

The effort required by track pads always decreases as they heat up...so there's that to keep in mind.

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I got the front end of the car pretty much assembled....

 

The only drama I encountered was that with the 6 degrees of caster setting, the front wheels are far enough forward that they now interfere with the headlight buckets.  So I have to sort that out one way or another.  It's always something.

 

Thanks for looking.

 

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27 minutes ago, 280Z-LS3 said:

Are you happy with exhaust note?  Mentioned before my past interest in the inline "resonators" design you used but due to fitment constraints on other projects was never able to give it a try.

 

I would say I am happy with it.  Reasonably quiet at idle, pretty aggressive sounding when you step on it.  Definitely quieter than I expected it to be....which is fine.  I'm not really a fan of loud cars....even track cars.

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