944Hybrids: 924/944/968 and 928 V8 Conversions
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Mon Jul 08, 2013 3:56 pm by Admin

For the benefit of 944Hybrids users there are two search functions available for you to use.
The purpose of this sticky is to explain the "Advanced Search" function because it is much more powerful and is the best choice when researching information.

When you log on to the site a list of options is shown in a line at the top of the page. One option is labelled "Search", use this option (NOT the search box lower down on the right).

After you click on the upper search option, a drop down box appears. At the bottom of this box is a radio button marked "Advanced …

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Post  ykalinin on Tue Oct 06, 2009 4:12 pm


Long time lurker, recent member and since I'm starting to actually work on getting the parts I need for the swap, I thought I'd throw this out there since I haven't found a lot of information regarding ym specific question. I want to use an LT1 because they seem to be significantly more plentiful and less expensive than any of the LS blocks. That said, is there a specific version of the LS1 that lends itself to the conversion. Should I go w/ an earlier block and pcm that uses OD1 or the newer OD2? Can I get an OD1 block and use an OD2 pcm and wiring harness? I'm mainly concerned about the wiring issue, the project will be a joint undertaking w/ my brother and I and this is the biggest challenge that I foresee.

Hopefully once I get the manual I bought from Greg I will be a LOT more knowledgable but any help and insight now would be greatly appreciated.


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Post  944v8inDFW on Tue Oct 06, 2009 6:12 pm

The late Lt1's are my preference, namely the 96 and 97 from an Fbody for their vented opti and a good portion of them had 4 bolt mains. They are OBDII engines. Prior to that OBDI. To keep it simple most people including myself convert to OBDI for easy of tuning. The Fbody engine has desirable accessory locations as well.
ODBI conversion is not really needed just my personal preference. Simple computer swap. Keeping the ODBII affords you use of the crank position sensor for fine tuning and diagnostics.

Wiring on a lt1 or even ls1 for that matter is very straight forward and very well documented on this board. Done right you can even keep factory cruise.

The only thing I would do to any LTx that is out of the car is upgrade the timing set to the GM extreme duty, around $250 from summit and Jegs.
A really nice cam selection for a other wise stock motor is the Comp Cams cc305, it will make the motor feel about like the Porsche engine as far as power band and so forth. Little lumpy idle but not terrible.


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Post  944v8inDFW on Tue Oct 06, 2009 6:19 pm

I would avoid the Impala LT1's as they have steel heads and a funky monkey water pump, as far as heater hose outlets go.

Impala are B body chassis

Steel heads add weight.


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Post  gt1scca on Tue Oct 06, 2009 6:35 pm

On the OBDI engines, the e-prom is replaceable...i.e. "chip". OBDII is not. Also with the OBDII, the LT4 knock sensors allow more extreme A/F ratios...less sensitive than the stock LT1 KS.

The LTX wiring info in the manual is OBDII, but the OBDI used basically the same circuits. The OBDII added the crank position sensor.

The first LT1 was available in the 1992 Corvette. In 1993 the LT1 was introduced in the Camaro and Firebird. The 1992-1993 LT1 PCM had a removable MEMCAL that housed the EPROM (chip) that stored calibration information. The PCMs have 4 square plugs, and the PCM case is black in color.

The 94-95 PCMs are identified by service number 16188051. All 1994 and up LT1 PCMs are aluminum in color with 4 rectangle plugs. 1994-95 PCMs can be flashed through the diagnostic port using rather inexpensive hardware and software. In 1995 the 4L60E changed slightly, and an additional solenoid was added to the valve body. This required an extra wire to be added for 1995 models. You can determine 1994-95 harnesses by looking for Pin U on the transmission connector. Also, the 1994 4L60E transmission will not work properly with 1996-97 PCMs.

1996-1997 PCMs (numbered 16214399 and 16242921) may be "flashed" with a .bin file, using software such as TunerCats, Moates Flash & Burn, TTS Datamaster, etc.

You can mix 1996-97 PCMs with 1994-95 harnesses, or vice versa. In some applications, you will need to add a wire or two to the harness to make it work.


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Post  944v8inDFW on Tue Oct 06, 2009 6:42 pm

The LT4 Knock Mudule (corvette) and LT4 knock sensor can be added to the LT1 OBDI computer (94-95)

The 93 is ODB0 (non flashable from diagnostic port)


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Post  Admin on Tue Oct 06, 2009 8:27 pm

I have an 94' Camaro/Corvette motor in my car. It has the OBD1 computer and is great for me as I can reprogram it as need myself with Tuner Cats. Depending on where you live you may have to take into consideration the emission / safety inspection aspect of this too. I have to have mine emission tested and they quizzed me about what , where, and how of the motor.


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Post  ffmedic on Thu Oct 08, 2009 2:25 pm

My computer has the number 16139391 anyone have any info on it?


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Post  944-LT1 on Thu Oct 08, 2009 5:48 pm

My computer has the number 16139391 anyone have any info on it?

Cant find anything with that number. Ive found 16163993 and others that are close, but not the above.

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Post  948 on Thu Oct 08, 2009 10:09 pm

944v8inDFW wrote:The LT4 Knock Mudule (corvette) and LT4 knock sensor can be added to the LT1 OBDI computer (94-95)

Guy's, the LT4 knock module is a wise choice if one is going to use RR's and headers....However, I must point out that changing the sensor will have a negative effect. I originally used a 96 sensor, on my OBD1, and was having issues with wacky knock all over the place and a 43 code. It turned out that the 96 sensor had a completely different resistance than my original 94-95 sensor.....The sensor is matched to the PCM, not the module.

From Shbox.com
"The LT4 module can be used on 1994-1997 engines (OBD-I and II) and no change of the knock sensor is needed (even though the sensors changed in 1996). There is no specific LT4 knock sensor. However, there are differences in the impedance of the sensors between OBD-I and II as listed in the testing section below. You must use the sensor that is matched to your OBD type (or have a wiring modification as frequently done in an OBD type swap situation)."

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