Things I need to know, I can't seem to find... VVT swap in 90.
 

I've been kicking around redoing my car for a little over a year and I think I'm ready to pull the trigger. Thought about going v8, but just too much work and money right now. Any who... VVT here I come.

Been searching for almost an hour, here and m.net, and not having much luck on what I'm getting into. I know Savington has made several good post on what needs to happen, but can't find them.

I'm getting a 04 engine, mounts, and harness. I need to use the original 90 harness and sensors, correct? Run a 94-97 alternator with the 04 water pump and crank pulley? I plan on fixing the VVT stuff after it's in the car and running, just use my MSPNP for the time being. Is that no bueno? What is the trick with the fuel, seems like I remember you need a mish-mash of parts.

What else am I missing?

Mod questions. I'm going to have to redo the exhaust since all I have is turbo parts. Is it better to go with the engine parts or chassis parts, do I want a 04 header or something for 94-97 cars? I have access to a free 00 Raceland header, it's not what I'd buy, but if it's free gimme three... Good idea to snag that or just pull the trigger on a RB? Should I prep for E85 while the car is down, I have a local source close to my house.

Couple of other things...

Plan on using my current COP set-up, that shouldn't be an issue? Need to use the 90 CAS on the 04 motor?

Would you deck the head while the motors on the floor?

You reuse basically everything from the motor that you possibly can and just splice on the new pigtails.

A short list:
99-00 Fuel Rail
90-93 Fuel Damper
Splice the 4 wire CAS into 3 wire crank and 3 wire cam sensor
NB throttle cable
94-97 alternator
94-97 header
Rewire your TPS from 4 wire to 3 wire
Rewire the IAC to the NB style IAC
Splice 2 wires on the MAF to a GM AIT
Run a MAP
Use a 94-97 starter
Use your oil pressure gauge sender

:party:

I am doing a similar swap, non VVT. I am curious as to why the 94-97 starter is needed. also why do you say 94-97 exhaust manifold? strictly because of better flow? Also is the NB throttle cable needed or is it an option instead of using the flyin miata bracket.
I thought i already knew everything i needed to know but your information seems to stray from that of other threads.

94-97 header because it bolts to the 1.8 engine and the NA catback. If you use a 99-05 header you have to fuck around with the cat back to make eveything fit and its not worth it.

I don't know everything about the NA6s, and I was making an assumption that 1.8L starter will work with a 1.8L flywheel, etc. It might not be necessary, but I've never looked at Miata starter part numbers. I know that trying to use the NB starter on an NA chassis is a PITA and that the NA6 cars have a different ignition system (lol 90-93, 94-95, 96-97, 99-00, 01-05).

For the exhaust manifold, you use the header for the chassis, but in your case you want a header for the 1.8L for the right chassis. The routing is all different post header for basically every single year Miata AFAIK. 90-93, 94-95, 96-97, 99-00, 01-05 all have different hanger locations and axle clearances and whatnot. If you want the best bang/buck for a full exhaust, RB Header for a 94-97 car and then a 2.25" header back for 90-93 from like Enthuza.

For the throttle cable, you don't have to swap throttle bodies; however, there's a trade off between paying for a new throttle cable and using the newer IAC versus finding an older TB versus doing the Flyin' Miata rigging, etc. I paid 23.79 for CABLE, ACCEL. (NC10-41-660A) earlier in the year.

e: oh yeah, you need a 5/16" fuel adapter from your FLAPS

Use the starter that matches the transmission if you want to use all of the bolts. The starters and flywheels are all compatable.

The partsgroup has throttle cables for $6.

found this post the other day, actually MidTN found it, and it answered alot of of my questions.

https://www.miataturbo.net/engine-pe...72/#post864873

EDIT: ^ the above post made by savington answered all of my questions. I sure wish i would have found that yesterday before i asked a billion questions.
Thanks Savington for being all knowing. Also thanks JRW for posting the link.

You're right, but we assume anyone doing this swap is going to be running a standalone.

super noob question... :facepalm:

I do not need to run the 90 CAS because I'm using the 04 cam sensor, correct? how do I set base timing, will be using a MSPNP for now.

You set lock the timing on the MS to 10deg and change the timing offset in the MS until your timing light shows 10deg on the pulley.

The actual cat back part of the exhaust on 90-97 are all the same. The hanger positions all line up.

The hangers do line up, but axle clearance is different (yay 2 piece axles that no one has). My 94 has an Enthuza built for a 97, and the slip joint needs to be almost popping out for it to clear the axle... then the muffler hangers are all tweaked a bit.

It fits, but it ain't pretty.

Sounds like an aftermarket problem.

Enthuza catbacks for 94-95 2-piece axles and 96+ 1-piece axles are different.

Sounds like an aftermarket problem to me.

Couple more questions....

Savington says: The injector and coolant temp sensor wiring stays the same.

I know the coolant stuff needs to come off the 90, but can I use the injector harness off the 04 or is that a bad complicated idea? One of the plugs on my 90 is broken, never given me problems in the 3 years it's been turbo'd though.

Been trying to figure out how to use the 04 coil packs instead of running my COP's. I know I need to remove the igniter and get the tach signal out of the MS. I am not a electrical person by any means, but I can follow instructions.

Bad idea. Swap the broken plug for one of the good plugs from your '90. You're cutting wires anyway since you want to convert the '90 to sequential fuel.

'90 wiring will provide power and triggers to the '04 coils (provided you loop the wires correctly at the ignitor). You'll need to ground the coils to the head yourself, since there's no ground wire in the '90 wiring. Not sure on tach signal with an MS, our AEMs provide that and it's already wired into our PnP patch harness.