18psi

iTrader: (76)

01 clutch chatter is a known problem
as for the vvt, are you talking about when the car is warming up? because that's the vtcs butterflies

Erat

iTrader: (5)

Warming up during acceleration. You're probably right, i totally over looked the vtcs butterflies.

williams805

iTrader: (2)

I ran across this picture kind of randomly and could see why conceivably taking some off the floor of the earlier head might work. Also why that would not work for the later head. I have no real science to back this up, just looks like a straighter shot to the valve opening if you took that last corner off the bottom of the early head. Especially on the exhaust.

miata2fast

iTrader: (2)

Your logic is based on the fact that it is a shorter distance to one side of the valve. What about the other side? Do you see the abrupt angle the air has to turn to enter the earlier head? You make it worse by cutting the floor.

Changing the valve angle and or raising the port is what creates equal pressure all around the edge of the valve as it enters the cylinder.

It's head porting 101.

turbofan

iTrader: (1)

^i certainly will not argue with this guy.

Erat

iTrader: (5)

Well. I posted my dyno numbers, with my **** tune, and the .msq with all my variables.

I don't have any flow bench numbers to put out there. Take it how you will.

sixshooter

iTrader: (12)

Yeah, the only place on the bottom of the runner you would want to port is the short side radius on the earlier head. You would do this to make the short side curve less dramatic and a bit straighter. Notice the later head has a much less pronounced short side turn due to superior port angle. There is much less work to be done there on the newer head.

Erat

iTrader: (5)

My engine builder made it in this Magazines top 16 engine builders of 2013.

The 2013 Performance Engine Builder of the Year Contest Reaches

Second one down. Besnik Engine Design, Center Line, MI.

miata2fast

iTrader: (2)

Pretty hard to argue with that. I think the description of the port job you posted on the intake side is somewhat incomplete.


I have spent some time looking at the port pictures since this was brought back up. My guess is he ported the floor at the edge of the runner closest to the intake manifold, and ramped it up to about the stock level at about the middle of the runner to create a slight curve further upstream.


On the roof, my guess the beginning of the runner was kept close to stock right at the intake manifold, and further downstream the roof was ported in order to match the floor profile, and to have a more gradual bend towards the face of the valve.

turbofan

iTrader: (1)

I mean, I think he's right about the true, best way to do porting.

However... your numbers are STRONG. It's mostly because of your car/your build that I feel good going with an FM2 no electronics kit for my turbo build this year. (at least for now... hehe)

I loved how your exhaust sounded, how the turbo spooled, and just overall the way the car felt, even if I only felt it from the passenger seat.

Note: this post was written like 3 days ago. Still wanted to share all the same because I love how your car felt and sounded and I want to copy it in a clean NB2.

Erat

iTrader: (5)

Diary update.
You don't get very many dry road sunny Sundays in January here in Michigan. So when you do, you have to take advantage of them.


Hooked an old battery up to the NA, put the key in, primed the fuel system, and turned it over. She fired to life immediately first try. Ran on 3 cylinders for about 4 seconds then proceeded to purr away.
Keeping it in a climate control garage i'm sure helped a little.

Couldn't help but take it for a spin. I totally forgot how much of a monster this car is. It is so much different than the NB. To spare you from the boring details, i'll sum it up by saying it's simply more raw.
Not to mention the endless wheelspin and actual power.



Even went ahead and fired up the bike. Like a typical Honda, it did it with no fuss.


I am not going out for a ride, even though, it's sooooo tempting.

Efini~FC3S

iTrader: (4)

Same here in Ohio, not many days in January and February to get out and drive/ride.

I made use of the nice weather and finally got around to finish my roll-bar install.

EO2K

iTrader: (37)

Having owned both, this is exactly how I describe the NA to people who have NBs. I kinda miss it actually.

Fireindc

iTrader: (13)

Nice man. Would you agree with the statement, NB is a better car, NA is a better miata? Or whatever I've always heard people say.

Seems like NB would be the ticket for a DD, but NA for a toy/track car. Just speculation, i only drove a NB once and it was on horrible coils with a cut off exhaust. it felt okay, but my NA with AGX (read:terrible) suspension rode 100x better.

jacob300zx

An NB is a better DD and Track car. The NA is the best "fun" car. I will agree that it feels more raw, very similar to an old British car but reliable.

EO2K

iTrader: (37)

+1. Riding around in my Dad's TR6 for most of my youth convinced me to buy a 2 seat convertible, and convinced me not to buy a british car

redturbomiata

iTrader: (5)

Next time I'm up at my dads when its warm i want to take a ride in the red car. I meant to ask when we were working on mine.

Erat

iTrader: (5)

I can't remember why you didn't go for a ride, it was right out front. lol


Edit* NB clutch chatter is REALLLLYYY getting annoying.
Also, it seems like it's getting a random single missfire, perhaps factory spark unit? Oh well, i'll live with it.
NB key is chipped? Ugh, lame...

redturbomiata

iTrader: (5)

That was the day I slit my arm open pretty good on that damn spring clamp. I got a good scar from that lol

skidude

iTrader: (3)

I remember being annoyed by both of those things when I switched from my '94 to my '02. If you slip the clutch a little extra it will sometimes fix the chatter for a little while. It will come back, though. I switched to megasquirt and an FM clutch, and then completely forgot about the chatter.