I'm thinking about a VVT swap in my daily
 

I'm bored, this might be fun. My daily is terrible and probably needs an engine, I just picked up another 6-speed and I'm using my spare 3.63 in it.

My questions:
MS3x or MS1/2 w/vvt box? (I've heard the MS3vvt code isn't great)
Should I run off the 1995 harness with the CAS?
The VVT harness looks easy to build, am I missing something?
How much power are we seeing out of NA engines with VVT? Can I get 140whp on a stock engine with a 93 octane tune?
Is this a huge waste of my time?

in for answers.

Go with the MS3x. The VVT code is pretty close to done and is usable. To use VVT I believe you have to use the NB sensors. Those are easily wired into the stock CAS harness.

I don't think it is a waste of time at all. I am actually planning on doing the same thing in my daily driver. Sometime in the fall hopefully.

If you're bored, have the time/money/motivation, and your stocker is on its last legs: why not?
I'd choose the ms3 over the others, and use nb sensors over na. You aint looking to gain much n/a, but its a daily and you already knew that.

Though if it was me I'd install a cheap/simple msm mani/turbo, 5psi un-intercooled and with nb exhaust. you'd be looking at 150-160whp and much more importantly on a daily: just as much torque.

Just a thought.

Right now, I would still prefer the MS2 as it is mature, there are still issues here and there with the MS3. You can always upgrade to the MS3 later on. Btw VVTz for the win.

if ms will have 3d vvt and not 2d, 2d maps are a drop in gas mileage.

What issues are you having with the MS3?

I had been DD my boosted miata for the past 2 months with no large ms3 problems. At least nothing that would stop from hoping in the car and driving to and from work every morning. There are a few things I am still trying to get work perfectly. VSS and EBC just to name a few. Other then that it has worked well. On the other hand I am also not using AC which might change things a bit, but Brain and Y8s AC work decently enough.

I got 30mpg with my MS3x with VVT enabled driving from VA to SC. I was still running a little rich to.

I found out that if you tried to start with a battery that is not in top shape or if it is very cold and the engine doesn't crank very fast (ie cranking RPM less than 160rpm), then there was no spark. VVT would also bounce around and never reach it's target - that was with alpha6 and alpha7. I haven't fiddled with it since then though.

I also don't want to use it on my own car if it isn't open sourced. I have personal mods that I want to apply.

I get that with MSII :vash:

Can you replicate it on the stim? Because I could, but it works fin on the MS2, right down to 50rpm.

Not tried it on the Stim, but this is with 12v triggers for the coils rather than the OEM 5v.

Dunno, maybe extreme cold dropped the voltage enough for them to never trigger.

cranking issues with VVT have been resolved.

I'm making 136whp dynapak with my 99 motor, 93 octane tune, MS1. It was stock freshened, port match, no valve job just a lap. 99 IM just with the VICS stuff removed. I have no doubt I could be +5whp with a square top and a switch to sequential. More for a real valve job or minor porting. The VVT motor has to make a bit more just with the slight CR bump, and it is ostensibly quite a bit stronger on area under the curve with the VVT tuned. I'd call 140 pretty easy for the VVT motor, I've seen claims of 180whp on full build CSP motors running funny fuels, but I'd say even the 165 range is fully attainable.

Not a waste of time at all.

So is the 140whp doable? I'm going to be driving 600 miles round trip 3-times per month and I want the most reliable Miata on Earth to do it in which means I'm probably freshening up an engine for $1200 or buying a VVT engine and MS3x judging by the way this thread is going.

What are everyone's thought on attempting to run this off a CAS in regards to resolution for how VVT works with the crank position?

Might need to tweak a VR trim pot a bit on the scope.

I can sync down to the lower limit of the stim on the bench just fine. And as far as real life testing, we have a customer running 6000CID engines that crank over at 45-50 rpm off MS3X hardware. They sync immediately and fire up. We have some of their boxes running on hall input with pullup, and others working with the vr input and no internal pullup (using LS1 sensors which have a small bit of built in pullup). This is a 0 fault tolerance industrial application, and we've been running for around a year.

Thanks. I'm leaning over the cliff, looking down on my knowledge of electronics. I'm intimidated by things like building harnesses and setting up sequential injection, the VVT stuffs, and possibly converting over to Hall sensors.

My plan is get a really slick drivetrain in this miserable looking car, then when I have more cash I want to buy a nicer roller and swap the drivetrain in.

Depends on the dyno. You get the right egojet, and yeah you might.

I would plan on a little head shave to make it more realistic.

VVT control will require using the NB sensors.

What does this require in addition to running 2 wires from the crank sensor, 2 wires from the cam pulley sensor, and 3-wires to the VVT parts?

I'm really dumb to this stuff, but I can assemble Legos. There's also the thought of educating myself, however that was a somewhat miserable experince when I put MS on the green Miata the first time.

I havent done it on mine because im going to use the ECU for it, but the e-fan sensor as well (on my 1.6, not sure on 1.8)

the vvt ignition coils are different, and use your fuel system from your current engine to be return style with the batch fire (harness) and it should be pretty basic.

if you cant fit the fuel rail, this is the temporary solution i came up with that i made from the original non-return fpr surge thing...
http://i71.photobucket.com/albums/i1...t/2a286a0b.jpg

I was planning on running the rail from my turbo car on the potential VVT engine.