Fyi...

unplugged default of the cam is RETARDED
which helps power above 4700...

(big text = important.)


Paul, there's not a lot of data on the 01 intake cam. If you tell me how to measure it, I will. I have a spare 01 head, a dial indicator, and a protractor.

 

Ohhhhhhh so i want to, in basic terms, run 12v to solenoid and full advance below 4700 and above 4700 take out the 12v and run full retard.

 

I have no idea. I don't know the first thing about what makes a cam better or worse. I am first curious if the intake cam in a VVT is the same cam as the 99/00 as in same lift, duration, and orientation. Then someone can go from there in cam theory on why one is better than another.

 

Wow i just found the thread by Y8's that i guess paul was referring to before. Has all the info that i need to get this working. Now im just wondering if I should use the ebc map and have the tps settings included in the vvt control or if i should go with just a WI output and have just an on/off rpm and then have to run a manual boost control or buy a standalone ebc.

http://forum.miata.net/vb/showthread.php?t=276072

 

I'm a tool who should think before posting.

 

Why?

 

tps doesn't matter, why add it?

really, you only see changes over RPM. not boost, not tps, not the size of your shoe. just RPM.

Here's a good example. The GREEN line. I advanced til the car made 3 psi and then went full retard. Look at the power drop like a rock. The other lines are the same as the original graph posted earlier. Leaving it advanced until the cross-over RPM point makes more power regardless of boost.

 

I would go with the ebc option because you can choose a couple of cells and make the rpm value change by 50rpm per cell and then scale the duty resulting in an nice smooth tranistion over 200 rpm or so. I expect the on/off option would work but it just seems so crude, like you flick a switch and the camshaft goes clunk. Probably just me being ----.

Edit. Ok I'm game for this, anyone have a VVT head to sell me? Pref with an intake manifold (am I right in thinking that the 94 intake manifold will not bolt up to the 01+ head beacuse of the runner angles?)

 

Tim do you know how to measure a cam?

 

Isky cams does it for about $25. That's where I sent the BP5A MSM intake cam. The peak numbers for the VVT intake are on Randy's site already.

 

My curiosity isn't worth 25 bucks. and mostly I want to know the duration compared to the other stockers. If only to answer the question of "nobody's proven the cam is better than the 99".

maybe if someone had a 2876R on a 99 motor at 10 psi I could answer better.

 

I personally don't but we do have a few different types of camdoctors here. I can learn and do it at lunch if I wanted.

Yeah same here, I want to try this.

 

lift
.370 VVT
.326 99 IN
.349 99-00 JDM/MSM IN "BP5A"
.349 99-00 EX for "exhintake" conversion

The VVT is the shortest duration (slightly) of all these but being able to control IVC sorta makes up for that as you have found.

 

i saw 010 duration on randy's site, but it didn't have a lift value.

duration at 010:
94-97: 218
99-00: 257
01-05: 241

exhaust cams look to be the same.

in any case, turbo cars like modest duration and high lift. there might be off-boost or low rpm gains from using the 99 profile but it hardly seems worth the effort or cost to do that over a custom cam grind.

emilio: in your esteemed opinion would the 99 cam as-is have a wider or taller power band than the 01 VVT cam fully optimized? assume same compression and turbo running, say, 15 psi.

 

new post for different info.

checking the hydra wiring diagram and 01 service manual led me to to this:
2001 ECU Pin 4D is constant +12V
2001 ECU Pin 4R is PWM to gnd. I guess floating or 12V means "full retard".

The top wire in the connector (yellow) is the +12V supply.

so yeah, supply one wire (TBD) with +12V and the other (TBD) with a switched ground that pulls to ground at whatever magic RPM you want. two dyno pulls will tell you.

 

One more question that seems pertinant. Where does the oil feed for the cam actuator come from? Up through the head in a gallery or from an external line?

 

I'm not the best guy to ask but it seems the question is more: "Does the ability to vary IVC and the extra .044 lift outweigh the benefit of 16° or so base duration?" In my non-expert opinion.. yup.

I strongly believe that there is no combination of OE cams and a BP4W head will make more power than an optimized BP6D head. You know, Maruha offers stage 1-3 VVT cams right? Something like that take a lot of time and money to develop. They know VVT is where the power is at on the BP series motors.

 

01+ VVT heads may see a price increase if more people start toying with them and perfecting activation and such. I for one am very excited to see what my new setup will be able to do.

*Important question: Does the 94-97 block have all the proper oil ports to supply the VVT head with oil including the vvt solenoid?

 

nope. there's a banjo at the back of the 01 head.

 

Ok so what your saying is that if i bolt an 01+ VVT head on an early 1.8L block it will work just wont send oil to the VVT, seeing as there is an external oil supply going to the VVT solenoid? So now we have our next problem which can be solved easily. I believe the 1.8L i have lined up is an early one with the oil supply tap on the exhaust side of the block. If so then i'll run that to my turbo and then run a "T" off my oil pressure sensor like the later 1.8L have to and send that oil via an SS line to the VVT solenoid. Does this sound like it could work? Without a service manual for the 94 and 01 im just speculating.