So, Im a pretty big noob when it comes to MS and I have a few questions. Since this will be my first board, I had planned on building a board for mod'd CAS rather than building the 2nd VR and all the extra work.
My real question is, if I dont run the 2nd VR, do I build the board per the DIYAutoTune instructions that come with the kit?
I assume this is the case, but is there anything major I'm missing?

Thanks,
Alex

 

You would build the board set up for VR input and VROUTINV. Configure it for Optical/Coil trigger first so that you can stimulate, then when the board is finished and running move the jumpers over to VR.

Aside from that all you need to do is add the pullup resistors for ignition. If you stick with the GM sensors, you don't need to swap bias resistors or calibrate the sensors.

 

Ok, so in the megamanual's assembly guide Step 52 talks about the VR. Do I build it according to this and use the inverted out:

52. Select the tach input circuit with jumpers:

For the VR sensor:

* Jumper VRIN to TACHSELECT on the bottom side of the PCB (near the DB37, opposite the heat sink.)
* Jumper TSEL to VROUT (Or VROUTINV if you want the VR input to be inverted) on the bottom side of the PCB, near the center.

 

Yes

 

Awesome, thanks.

 

My MS2 kit and stim board are waiting to be shipped

 

will any GM IAT, CLT, MAP sensor work? is there a particular year range I should be looking for?

What about TPS? Can I use my stock s4 one or should I be looking for the better s5 one or a GM TPS?

 

I'm fairly sure that all the GM sensors have been the same for a very long time. I just order them from DIY when I buy the 'Squirts. Or, any auto parts store can get you one if you ask for the sensor from an '89 Camaro. Wear a wife-beater and you'll get better service...

Having a full range TPS like the S5 is better, but you can use the S4 TPS without problems. I try to encourage people to use the same TPS often found on Haltech installations. I think it's a Ford part number.

 

Do you just wire up the full range TPS from the S5 and disregard the short range?

 

Yep.

 

The short range is on the outer? And the fullrange is Closer to the tps?
I was looking at my TB and was wonder that. ALSO, what do the vacuum operated butterflies do? Theres 5 in total, 3 I'm sure I need for the TB to work. Whats the extra 2 for? (S5 TII)

 

You'd have to check the FSM on the TPS issue as I don't remember off hand. If you manipulate the throttle body while observing the TPS, you can see that the 1/4 range will be fully extended at about 1/4 throttle.

There is a second set of vacuum operated throttles that are designed to stay closed when the car is cold. Most of the time, people just remove them with no ill effects.

 

the full-range TPS is the one that is actuated by the cam on the throttle shaft. IIRC its the inner one, but i'm not certain.

 

Thanks again; Just what I wanted to hear.
Also: There's a spacer plate between the TB and UIM. Its for vacuum routing and such. Wondering if an injector plate has been made for AI to fit in there? if not I'll have to make my own.

 

My MS2 v3 kit and v2.2 stim arrived this morning. I managed to get the Stim together in a few hours. It didnt take as long as I had expected to get the hang of soldering. I should start assembling the main board after Christmas.

 

I noticed earlier Aaron Said use VROUTINV for the VR circuit.

That is true for MS1, but for MS2 you can use VROUT or VROUTINV. It doesn't matter because the MS2 software gives you the option of which edge of the square wave to trigger on.

Ken

 

Thanks Ken. Ill write that down so I wont forget when I start assembling the main board.

 

can an S5 TPS be mounted on an s4 TB and work with the full range?

 

I was able to just take the cam wheel from the S5, mount it on the S4 where the short-range would be, and used the S4 plunger and bracket mounted in a different set of threaded holes on the TB and it works great. Thats how i'm running it in my 7.

I don't remember what had been in those holes before though, since the TB had been stripped before I got it, and i've slowly been adding the dashpot and a few other things back on, but I think it had been the equipment for the second set of butterflies

EDIT: I just looked at a spare TB I have and it looks like the TPS was mounted with one bolt in the further hole of the original TPS, and one in the upper hole of the vacuum actuator on the secondary butterflies.

 

yeah my TB is stripped, I just need to find a cam wheel from an s5 TB? besides the TPS itself

 

no, you dont even need the actual TPS plunger or bracket, I used the S4 one. The cam is the only thing you need (altho good luck buying it separate from the TB)