I rather be a little pessimistic and not be super disappointed later on. In a way its a sunk cost as you can't revert back to stock without spending a fortune again. Take a look at MotoIQs vq37 build, I believe they made about ~370hp on e85.

https://motoiq.com/building-the-nissan-vq37vhr/

A cam swap on a LS motor is much simpler with it's OHV design and can easily give you 40whp. If you go with a really aggressive cam then valve spring replacement is recommended every 25k.

Only the exhaust side gets changed, the intake side can be manipulated via tuning. The big upside of a variable valve timing is you can keep your idle smooth.

Have you thought about having them replace your galley gasket? That would be a great use of the warranty IMO.

I'm not a fan of replacing the stock clutch if there are no issues with it. Ride it out and wait for the slave to fail. Makes it easier to justify to your wife

 

I think the sweet spot with the transmission mods is the LW flywheel, and since the tranny is down already then the clutch upgrade is fair & reasonable game. As for the slave, personally I'm already on my second OEM slave, and don't trust it. Never have, ever since the original failed.

Let's put this hypothetical another way: knowing what you know about the OP's car, if you were going to throw $2k more or less at a mod, and your two choices were cams or clutch/FW... which would you choose? Assuming one had to be chosen, because he's staying up nights thinking about these things.

 

Rochester- It seems as though the cam decision was made for me since no one at my shop has the tools to do the valve springs. I was up at 3 am due to recently diagnosed sleep apnea- not just the cams. I think you are right about the mod bug though. I might have run out of ideas for now. I have even been trying to talk myself into the oem lip spoiler. If you are thinking of cams I would do those instead of the flywheel first if the costs are similar. A lighter flywheel will allow your engine to rev faster, but it is not going to free up as much torque as cams with a tune.

I would not go with the ultralightweight flywheel if I were you, but one that is a bit lighter for street use. I looked into this when my csc got replaced under warranty when I actually needed a starter. At the time, just the ultralightweight flywheels were available and everyone told me they suck for the street because your transmission sounds like a cement mixer. I will probably go with a bit lighter flywheel when my clutch finally goes to keep the NVH within reason.

Rob- I thought the same thing about labor savings with just doing the exhaust cams, but it literally only saves about 2 bolts per bank because everything else comes apart. Are you referring to the timing chain cover gallery gasket? It looks pretty small like it is just the area near the oil pan at the bottom of the engine. Unfortunately, I need it to leak to replace it under warranty. But I do have almost a year left of this extended warranty. Wow, did that thing pay for itself about 10 times over.

 

If the clutch/FW ever happens, I'd be choosing the most tame of options. I've a friend who went with an aggressive clutch/FW upgrade, and it was way, way too brutal to drive, IMO. And it sounded like a bag of hammers. No wait, it sounded like a bag of wrenches.

If you don't have any clearance issues (like I do with my driveway), absolutely get the OEM front chin. It's a great design. Wish I could get one.

 

Ok, glad to know you are aware of the "NVH" issues with a very light flywheel. That seemed a bit extreme for your car.

The oem chin spoiler is growing on me and clearance issues are not really a problem, but I think it looks a bit weird on white cars since the seams are so obvious. I am also worried that my 7 yr. old paint will have faded so that the paint will not match. It's a mod I have been thinking about, but not one I am terribly excited about.

 

If it ever happens (big if), pretty sure I'd put the OEM transmission mount back in, and ditch the Z1 Poly mount. That makes some sense to me.

 

I wonder if you would notice much difference since you have the motor mounts and rear differential brace. Those two items seemed to really firm up the driveline for me. All the rear subframe bushings did not seem to make that much difference.

 

I just want you guys to know that I have this week off for vacation. You are probably wondering why I am telling you this. It is because when I have a week of vacation it gives me ample time to make excellent car or car part decisions while making my bank account cringe. One time I even bought an extremely low mileage mint condition E46 BMW M3 while on vacation.

So this means that I am definitely reconsidering adding cams to my car. At this point, I am probably more curious as to how the mod affects the car than anything since I don't know anyone who has actually spent the time and money on them. Another reason I am reconsidering the cams is that my lead Nissan tech at work told me that he thinks they will reimburse him for the valve spring compressor that he needs and he is fine with me working alongside him on the project so I can learn exactly how it works too. I am still waiting on the details of the labor costs and if they will reimburse him, but so far things are looking good. I figure if I order the parts this month and pay to install them next month it won't be one huge bill. #carguylogic

 

Wow. Whiplash, LOL. I wish you all the best on this.

Pretty sure you're going to have to have the car re-tuned part & parcel to the install, before driving it again.

 

Jon at Z1 said he could send me a tune to change the cam phasing so it sounds a lot easier than the custom tune I had from him the 1st time. I certainly hope so. I plan to talk to the guys at Z1 again soon.

 

I'd love to see the results. You've probably already read the thread on the 370 board, but I'd guess you'd see some decent gains since you already have the reworked intake manifold, and IIRC, long tubes.

Curious, would this allow the motor to rev beyond 7500?

 

Went from a 23 pound flywheel on an RX7 to a 12 pound ACT ProLight and it was AMAZING. But did increase trans noise and made idle more difficult to tune, especially when the car was cold you had to give a little throttle all the time.

ACT's street flywheel was 18 pounds and was generally well-received in terms of noise, engagement and regular driving. Never had one myself. Both moved most of the weight to the center rather than the OEM which had the weight around the outside, so the aftermarket ones had much decreased inertia.

All that to say - if you don't mind the 3-pedal dance on a daily basis then the very light flywheel might work for you just fine. If you're getting a little too old for that sh$t then pick a street-rated weight - personally I like the ACT stuff from prior usage. Their streetlite is 17 lbs vs oem 25.

 

How so? What was amazing about it? I'm all for hyperbole, but would rather understand what got you there.

 

The way you describe the change in rear gear ratio, basically - maybe slightly less so.

First car I drove the prolite FW on was a 1989 RX7 convertible with turbo drivetrain. Engine was mostly stock, making around 220ish HP. After prolite flywheel it felt more like my street-ported, up-turboed and tuned 90 Turbo RX7 coupe that had +100HP on it and several hundred pounds less weight.

Thinking back, it added perceived torque to lower gears/speeds that made the car feel much more powerful. Revved MUCH faster, especially under boost. Not as noticeable above 3rd gear or at highway speeds. In the convertible, really lowered the perceived boost lag (that car came on boost around 2700 RPM), I assume because the engine revved faster up to that point.

 

I don't believe the new tune would change the redline of the engine, nor would I really want it to since all of the internal parts of the block stay the same.

I talked to Spencer yesterday and he said one thing to be careful of is that depending on the casting from Nissan of the head, there is a relatively good chance that the head will need to be milled/reshaped just to make the cams fit. This could be a much bigger project than I thought. Still waiting to hear back from my mechanic about this process to see just how involved this will be, especially if we need to do work on the heads as well- might be a cost/time tipping point for me.

If I remember right most rotary engines have a lot less NVH than our VQ which is a bit rough. I seem to remember people complaining about all of the additional NVH with a superlight flywheel in our cars. Maybe the rotary engines are not so bad with a really light flywheel?