MBC install with PE

[soldthedart]

I am upgrading my 85 to the 86 PE and understand the Boost controller will no longer work.
Ordered a Gillis Manual boost controller and was wondering if I should use an aftermarket Boost and EGT Gauge or can I just use the stock gauge?

[MikeFleming]

Aftermarket gauges can be more accurate - the stock gauge is just a reference (usually very repeatabe, however rarely accurate).

An EGT is an entirely different animal. A useful tuning tool though.

BTW - if this is your first experience with EGT usage on a boosted petrol engine, you will scare yourself.

[soldthedart]

High temps? can I use the line off the stock boost gauge for the aftermarket one?
I was thinking it would be useful to do a pillar gauge set up.
I really don't want to cut any holes in my firewall or dash. The car is really nice and complete.
I plan on keeping anything I remove and I love driving the car.
We are shocked at the mileage it gets, but I know that will change with the upgrades.

[soldthedart]

just bought the ATM-5701 boost gauge and a single Pillar Pod.
The Rest of my parts should be here tomorrow!
Can't wait!

[soldthedart]

Just curious, What is the difference between the Boost Control set up on the 86 and the 84?
I obviously purchased the parts and plan on installing them.
I thought the incompatibility was with the LA3 from the turbo coupe.

[Laredo]

Just curious, What is the difference between the Boost Control set up on the 86 and the 84?
.

The 84-85 uses a separate electronic module (wired between the ECM and the solenoid) to activate the actual boost solenoid. The 86 ECM controls and activates the solenoid directly from the ECM.

[soldthedart]

So the signal could be pinned from the ecm directly to the boost solenoid, or is the wattage rating higher on the boost solenoid on the 85?
Is it the same pin and conductor in the wiring harness?

[MikeFleming]

The 84/85 BCS is about 10 Ohms while the resistance on the 86+ solenoid is between 55 and 70 Ohms. The transistor driver in the PE EEC is rated to 0.8 Amps MAX so it will not drive the earlier solenoid directly.

However it MAY drive the input on the BCM, letting the module drive the solenoid (BCS). I have not tested this though. Pinout/wiring is same. The Boost Output signal from the EEC is still same pin and the signal is a PWM signal completing the ground side of the 12-14VDC circuit.

Boost Output from the EEC is pin 32 on TE, PK, ZBA, & PE; Pin 31 on LA2/3.

[soldthedart]

If it is the same pin on the ecu it would seem that someone has tried it and declared the output incompatible with the BCM on the 84-85. I wounder if the signal is PNP as apposed to NPN?
Not that this would be a common method in an automotive environment. Is it as simple as the connector from the 86 is diffrent from the 84-85 and becuase it will not plug directly in it has been deemed incompatible by others?

[MikeFleming]

In almost all cases the EEC provides the ground path to circuits it controls: Injectors, IAC, EGR solenoid, BCS, ...

[soldthedart]

Im still perplexed as to why the signal will not work if the rating of the output is of sufficient Current rating and similar voltage?
from what I understand now it is even pinned the same. I cant believe it is only a connector that will not plug in causing everyone " Including Myself!" to buy a MBC.
I think this deserves a more in depth look. Even if it turned out you needed a relay.

[MikeFleming]

It just might - but no one has tested and verified this.

Try it using the existing 84/85 BCS & BCM. Run the EEC in KOEO (engine off) output test mode and see if the BCS cycles.

[Raven855]

I think you will find it won't work. I prefer the way the mbc works over the stock system anyway. It makes the car more driveable. I think you will find that the case also.

[soldthedart]

Im not sure I understand the term "More Drivable"?
If my car was a little faster id leave it like it is. The car runs and drives great!
I just want to see if I can squeeze a little more HP out of it without breaking the bank.
Ive always been of the opinion that the car company's spend Millions of dollars researching and testing.
I like to take advantage of their labor and dollars spent as opposed using my own. Im sure using the manual boost controller enables one to twist the boost up enough to end in disaster if one wasn't sure what they were doing. I'm just thinking the use of the signal deserves more investigation.