Switching from 3.4 SFI to 3.4 supercharged/carb

[jwvess00]

Hi there!

You'll likely need a 2-bar MAP sensor to go with the chip change, assuming the code is dialed-in for boost. Talk to the person providing the chip to be sure, but without a 2-bar MAP sensor the ECM can't see any boost -- the stock 1-bar MAP sensor can't measure it.

[cardana24]

Hi there!

You'll likely need a 2-bar MAP sensor to go with the chip change, assuming the code is dialed-in for boost. Talk to the person providing the chip to be sure, but without a 2-bar MAP sensor the ECM can't see any boost -- the stock 1-bar MAP sensor can't measure it.

That's what I was thinking. Do any of the GM vehicles come with a 2 bar map sensor that will work for me, turbo diesels? Or is that something that is aftermarket?

[jwvess00]

Hi there!

Most diesels until recently did not have electronic fuel injection, so that's out.

The GMC Syclone/Typhoon, turbo Sunbird, and probably the late model supercharged 3800 cars would be good candidates. I say "probably" on the 3800SC engines only because I'm not sure what their MAP sensor physically looks like. At one point GM changed both the connector and physical sensor mounting design. Both are easy to overcome but I thought I'd mention it since it may not be a direct replacement. The Sy/Ty MAP sensors are externally physically identical to your 1-bar MAP but read over a 2-bar scale.

Regardless, you will need a chip change to use the 2-bar MAP sensor even if you just want to install the sensor before adding boost. The output will be wrong if you try to use it with existing 1-bar code.

[geoffinbc]

Diesels only have boost there is no vacuum so they probably only have a boost sensor and cannot sense manifold vacuum.

[34blazer]

the turbo regals also have the 2-bar map sensor

[cardana24]

Hi there!

Most diesels until recently did not have electronic fuel injection, so that's out.

The GMC Syclone/Typhoon, turbo Sunbird, and probably the late model supercharged 3800 cars would be good candidates. I say "probably" on the 3800SC engines only because I'm not sure what their MAP sensor physically looks like. At one point GM changed both the connector and physical sensor mounting design. Both are easy to overcome but I thought I'd mention it since it may not be a direct replacement. The Sy/Ty MAP sensors are externally physically identical to your 1-bar MAP but read over a 2-bar scale.

Regardless, you will need a chip change to use the 2-bar MAP sensor even if you just want to install the sensor before adding boost. The output will be wrong if you try to use it with existing 1-bar code.

Sounds easy enough. I just need to find out where to get a chip made. Ideas?

Diesels only have boost there is no vacuum so they probably only have a boost sensor and cannot sense manifold vacuum.

I forgot about that.

the turbo regals also have the 2-bar map sensor

Cool, the T-types. I'll keep that in mind too. It sounds like all of the sensors that would plug into the same connector (assuming only Sy/ty, and T-types would plug right in) are cars that I will never find in the junk yard. I guess I will be calling the dealership on this one.

[cardana24]

I plan to do the wiring for the new ecm in the next few weeks, and I also picked up a set of 1.6 stamped rockers that I am going to drop in too before I attempt to run the supercharger. Thanks for the advice so far. Also I have the link for the pin outs but if anyone has done the 3.4 ecm swap then please let me know if you have any easy to read pinout available. Thanks.

[ForcedFirebird]

I plan to do the wiring for the new ecm in the next few weeks, and I also picked up a set of 1.6 stamped rockers that I am going to drop in too before I attempt to run the supercharger. Thanks for the advice so far. Also I have the link for the pin outs but if anyone has done the 3.4 ecm swap then please let me know if you have any easy to read pinout available. Thanks.

I am an the progress of this swap and have written a spreadsheet for the pinouts...

http://60degreev6.com/forum/f104/the-obd1-5-to-obd1-conversion-thread-t43453/post392074

What transmission are you using? Hope not the '94 electric 4l60e.

betterthanyou, the 93's were in fact OBD1 with the non-e 4l60, but was a flash-only ECM.

[60dgrzbelow0]

No offense intended here ...but... putting a supercharged 207 CID engine in an '85 Jeep is a bit like putting a $50.00 Saddle...on a $2.00 horse...Yes? I'm just curious as to what advantage it might bring to an otherwise four-wheel drive, OTR vehicle. But never mind...I have been known to get things very wrong on one occasion or another...

[jwvess00]

Hi there!

Can I answer for the OP?

Superchargers (esp. roots-type like the Faegol) do a great job of building boost right off-idle, so bottom-end and midrange power is improved; this is perfect for a heavier 4WD vehicle. If the vehicle has larger diameter than stock wheels/tires (i.e. 31x10.5x15), it really benefits from more bottom-end and midrange power.

The 3.4 is a drop-in, making it an obvious choice. It's certainly cheaper to swap in a 3.4 than to do a V8 swap.

Just because it's an '85 doesn't mean it's not worthy of a good engine combination. If age and current market value were the primary reasons to build an engine, nobody would be touching many of the cars on this site

[60dgrzbelow0]

jwvess00

LOL... I can't (in recent memory) ever remember being so deserving of being properly chastised, or being spanked so gently for my 'misbehavior'. Thanks for the explanation ...and the fine straightening out.

[cardana24]

I am an the progress of this swap and have written a spreadsheet for the pinouts...

http://60degreev6.com/forum/f104/the-obd1-5-to-obd1-conversion-thread-t43453/post392074

What transmission are you using? Hope not the '94 electric 4l60e.

betterthanyou, the 93's were in fact OBD1 with the non-e 4l60, but was a flash-only ECM.

I'll check out your thread. I am not running an electric transmission. I have a stock AX5, it was the stock 5 speed that AMC used behind the 2.8 in 1985.

No offense intended here ...but... putting a supercharged 207 CID engine in an '85 Jeep is a bit like putting a $50.00 Saddle...on a $2.00 horse...Yes? I'm just curious as to what advantage it might bring to an otherwise four-wheel drive, OTR vehicle. But never mind...I have been known to get things very wrong on one occasion or another...

I see what you are getting at but these are the things that I enjoy doing. I also drag race my supercharged FWD maxima...some may question that but I have fun doing it.

I see supercharging the jeep as a fun project. It's not my daily driver so why not?

Hi there!

Can I answer for the OP?

Superchargers (esp. roots-type like the Faegol) do a great job of building boost right off-idle, so bottom-end and midrange power is improved; this is perfect for a heavier 4WD vehicle. If the vehicle has larger diameter than stock wheels/tires (i.e. 31x10.5x15), it really benefits from more bottom-end and midrange power.

The 3.4 is a drop-in, making it an obvious choice. It's certainly cheaper to swap in a 3.4 than to do a V8 swap.

Just because it's an '85 doesn't mean it's not worthy of a good engine combination. If age and current market value were the primary reasons to build an engine, nobody would be touching many of the cars on this site

These are good reasons too. My 3.4 does not like turning over my 32x10.50 swampers.

[cardana24]

I am an the progress of this swap and have written a spreadsheet for the pinouts...

http://60degreev6.com/forum/f104/the-obd1-5-to-obd1-conversion-thread-t43453/post392074

What transmission are you using? Hope not the '94 electric 4l60e.

betterthanyou, the 93's were in fact OBD1 with the non-e 4l60, but was a flash-only ECM.

The ecm you are changing to has a different number than the one I am using, are the pins going to be the same? I don't have the ecm in front of me but the one I got is from an early 90 z24 cavy with a 3.1L engine and 5 speed transmission.