Adjustable cam gears

[RYU]

He really did a great job. It is by far the best retrofit kit i've ever used in any car - that's a huge kudos and compliment to @Johan@SjoebergDP. Still have a couple minor bugs but we should be able to sort thru them soon. It is sooooooooo much easier to read and the response is much faster i've noticed. You do lose the smoothness of the sweep dials as a tradeoff but it depends what you value more. So far so good.

 

[elijahcole92]

Not in my opinion. Think about it this way - you'd be spending about $1500 extra (the gears plus time spent adjusting them) for an ~30WHP gain in a narrow part of the rev band.

Also, if you don't do it yourself, then you REALLY need to trust the engine builder not to screw them up. To properly get the most out of them, you need to degree the cams, verify valve-valve and piston-valve clearances, and then adjust them to verify gains on a dyno. It's time-consuming to adjust while on a dyno since the valve covers have to come off, or you need to modify your OEM magnesium covers (i.e. more money).

You shouldn't be decking the block or heads that much where you change the geometry of the front-rear bank appreciably. We're talking about thousandths of an inch difference on a ~4 inch diameter cam gear arc that translates into what - 0.1 degrees? You'll get more variance when you go to torque the adjustable cam gears.

The block and heads should only be polished to the surface roughness your MLS gasket maker requires for a good seal. It shouldn't remove much material at all. Just pay attention to how much is removed and make up that difference with a custom HG if you really need to. Unfortunately, a bad initial machinist touched my block and took off more than I wanted. In order to maintain the correct squish and P2V clearance, I went with a custom Cometic HG. I measured everything.

To get additional power throughout the entire rev band), you need variable cam timing like the new cars have. Unfortunately, I know of only a handful of people who have modified such systems onto older engines like ours.

My engine makes the most torque of any other FI'd NSX from ~2000 to ~3900 RPM. I taper it off after that to still achieve ~500 WHP. That was done with a fancy turbo setup though and not aftermarket cams or cam gears that can be a PITA to setup.

My $.02.

Dave

most tq of any Fi'd nsx? link or info?

 

[scammy]

My car has a noticeable whine under acceleration, but it's not loud. Not bothersome at all. My LSD is fully WPC treated - all the plates and gears, as well as the final gear ring and shaft. Input shaft, all transmission gears, synchros and bearings are WPC treated too but that shouldn't make much of a difference in this case. Using OSG gear oil. I've been told using the OSG gear oil is key.

Similar to mine, my whole gearbox has been WPC treated the OSG was assembled based on my HP and the use I described my car was for. And I use the redline oil as that was what was recommended for how it was assembled so i went with that but man it was whining and while it sounds cool at first "because racecar" you get over it quickly I have the 4.4 and it was built within a week of Jims so am keen to see what comes out of his diagnosis

 

[Mac Attack]

most tq of any Fi'd nsx? link or info?

It mimics the OEM c-series torque curve from 2500 RPM to redline. At 2250 RPM I have 350 ft-lb at the wheels and it varies between that and ~425 ft-lbs until redline. Still working on the turbos and sizes so the numbers always vary, but my main concern is seamlessness and driveability on the street.

Big power from 4500 RPMs and up is fun on the track, but drivability is too compromised on the street. Someday I will get it the way I like, but it takes a lot of time when you are only self-tuning on the street, and even then, trying to get the semi-sequential semi-compounded turbos working together correctly. I have about $25k in turbo components and countless fabrication and tuning hours of my own invested, but the engineer in me thinks this is "fun."