1992 Pontiac Lemans Engine swap

SCOTTWHITTY

MEMBER
1992 PONTIAC LEMANS

Engine Performance problem
1992 Pontiac Lemans 4 cyl Front Wheel Drive Automatic

Ok, well, I wanted to upgrade the 74bhp engine to something around 250-300bhp. I heard that a Sunbird of the same year can be found with a turbo charged engine. Now, granted, if I use the Sunbird computer and wiring harness what other issues might I be running into here? Or perhaps maybe a 99 Sunfire GT (more recent then a sunbird) I guess really what I'm asking is, does anyone know if I can even do this without really going retarded with mods? I don't want to spend 5 grand doing this.

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MERLIN2021

MECHANIC
17,250 POSTS

If you swap the PCM and the exhaust I believe is different, you should be ok.

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Sunday, October 19th, 2008 AT 8:36 AM

SCOTTWHITTY

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So will a stock turbo charged sunfire engine fit this vehicle? What engine is faster and more reliable in your opinion?

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Sunday, October 19th, 2008 AT 10:01 AM

MERLIN2021

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If the turbo engine has been maintained, it is a better motor, Should fit.

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Sunday, October 19th, 2008 AT 10:08 AM

SCOTTWHITTY

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Ok, sorry for the fuss. I want to make sure I'm clear here. What year Sunfire GT Turbo engine will fit my 1992 Lemans? Also it is my understanding that all I will need to change is the PCM and the exhaust, correct? Will my stock tranny take the load? More then happy to donate to you guys again, your help is greatly appreciated.

Sincerely,

Scott

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Sunday, October 19th, 2008 AT 10:14 AM

MMPRINCE4000

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8,549 POSTS

To add to what Merlin said, the Lemans was built for Pontiac by Daewoo, so I don't think you will have any GM engine that will "bolt in".

The Sunfire turbo engine will most likely be hard to find, since they were only built a few years and built in (the engine) Brazil. This is not like putting a 3.1 V6 in a 4 cylinder Grand Am (which was offered in the Grand AM).

You will most likely have to remove the Daewoo engine, fit the Sunfire engine to the compartment, fabricate new mounts, check the fit or the drive axles into the stock knucles or use the entire transaxle from the Sunfire, check the length of the axles compared to the old ones, see if stock linkage works or fabricate new linkage mounts.

You will also have to use the Sunfire engine harness and marry that to the Lemans harness, use the Sunfire ECM.

Point is that while you may get all the hard parts within your budget, there will be a lot of labor and time involved and I would hate to tell you that it will work, only to find out that you may need to get new axles made because the originals are too short/long.

Some swaps are easier than others, unless you can find someone who has done it, you would be the first and would have to use the trial and error process to see if it will work.