3800sc into 2007 impala

[PirateShip]

Hi all, new member here!

 

Here's my story....

 

I have a 1998 regal gs (l67 series 2 supercharged) that's rotted hard. Rear springs poked thru yesterday and now its in pieces in my garage.

 

Today, I made a hasty decision and bought an 2007 impala ex police, ex taxi car with 314, 000 miles. It has serious lifter noise and the trans slips. Needless to say, I got it for a song despite it having zero suspension issues, new brakes all around, and basically zero rust. Everything is good minus engine/transmission. Surprisingly nice quality riding car. 3.9v6

 

Borh cars run/drive (well, the regal did but i began dissasembly)

 

Obviously you get where this is going... l67 swap into impala

 

Now im sure im a pioneer here, and for good reason.. but anyone have any advice for the wiring? Or.. anything helpful to say? It APPEARS the 3.8 ois going to bolt in place, and im going to need to use the gas pedal/cable from the buick, because the imp is drive by wire.

 

The shifter linkage should work as is.. im concerned with the motor wiring.. should I send my cpu out and just have it setup to run just the engine/trans and be done? Ive done swaps inn the past, mechanicallly I'm confident, but not much involving such drastic changes like this.

[Nas Escobar]

This is the first time I've heard this idea before... moreso with a S2 engine. However the Grand Prix and the Lacrosse got the S3 as standard equipment. The GP did get the SC S3 3800.

 

Now I can't guarantee what I'll say will work but I can tell you this.. I can give you an idea of what to do and maybe you look up to see if it can work.

 

So this swap usually gets done on the Gen1 W body cars. Most of them are OBD1 so it requires the OBD2 conversion which means a harness out of a specific car and a specific PCM aka get the stuff out of a 98 or 99 Z34 Monte Carlo because the Monte Carlo is a glorified 1st gen chassis with slight enhancements, and while the Z34 never got S/C, one can find a PCM out of a 97 Grand Prix. My point of saying this is that basically the easiest thing to do is to match as much as you can with donor cars that are very similar to the Impala so you have to fabricate less. The only issue I can't advise on is the BCM on the Impala since the BCM could disable the car if it doesn't see a 3.9 PCM.

 

That out the way, what I would try to do in your shoes is find a 2007 PCM from a Grand Prix. In 2007, only Pontiac got the supercharged engine... well in all honesty only Pontiac had the supercharged engine after 2005. Use the PCM to operate the engine and if the BCM doesn't cooperate, have one of the 2 PCM's reflashed to work with the Impala's BCM while still running an S2 engine. In theory, having the PCM would take care of the programming issue.

 

As far as the wiring goes, you could get the wiring from a 2007 Grand Prix Supercharged as well and plug all wiring to the 3800 but you would have to figure out how to route the wiring with the harness that's around the firewall. This is where the BCM/PCM issue also comes into play except this might affect stuff like the cluster.

 

Dealing with the throttle, you could in theory get the throttle body from an L32 3800 and make it work with the wiring. I'm not sure if the PCM would be too happy with the throttle cable if the PCM controls the throttle. It may throw codes or not operate at all.

[PirateShip]

Thanks for your reply, but i actually have changed directions with my project.

 

I got ahold of a low mileage engine for $300, just a matter of setting her in place.

 

Another question, though, is transmission.

 

Both cars have a 4t65e, ones "hd" meaning it has a different differential, and final drive. Do you think its possible to swap the 1998 trans in place of the 07, assuming I swap the differentials? The 07 isnt torn apart yet so I can't physically view anything other than they appear visually the same and the shifter/big cannon plug looks the same. Is this a viable option? Would be nice to save a few dollars using parts I already own vs finding a replacement. It would be great to not have to pull things apart twice. Ive read there's "electronic change" made in 03 but cannot find any info reguarding anything im asking or what change were made. They also look like they mount similar, but looks can be deceiving

[no1kicker]

Here is what I would do:

 

Use the L67 with the 2007 aluminum oil pan and get a gen V supercharger to reuse the 2007 TB, use stock L32 injectors.

Keep the 2007 wiring harness but add wiring for the boost bypass as if you were doing a "top swap".

Find a 2006(?)-2007 GTP pcm and use hptuners to change the vin to match your 2007 if possible.

Find a 2004-2007 GTP trans and make sure the gear ratio matches in the pcm.

 

It is possible to use your 1998 trans but it won't work without some minor modification. From what I have read: channel plate & valve body must be swapped to 04+, trans cooling lines may need an adapter, the PNP switch is slightly different.

[PirateShip]

You guys make this sound so easy. Lol

 

Right now i still have both cars, the regal reassembled and running again, and the impala engine just sitting in the garage. The manual I got for the 07 sucks and doesn't show jack for wiring schematics. Im going on vacation to texas for a while but im liking the idea of a l67 07imp more than repairing the junk lz8/4t65e. Apparently the transmission in the later cars is junk and i don't want to go through the repairs twice when i have something that in theory with a lot of work, could work and be an upgrade cheaper than fixing the impala. The only downside is the impala is a portly car even compared to the older regal. (Heavier per my sources)

 

When I get back from vacation im going to re-dissasemble the regal and attempt swapping the WHOLE harness, ecm, bcm and every friggen wire into the impala. I know its not the easiest way but I see it being the most "sure fire" way for me to actually complete this. The drive by cable setup looks easy to swap, too. Besides i have a welder if things get hairy. I understand this is probably a "waste of time" to many, but my logic is sound. The 07 is rust free, and slow but handles very well for what it is. (I was extremely impressed actually.. 9c1 police pkg for the win!) But the engine/trans combo sucks.. this way I hope to end up with a good combo of parts and an extremely expandable platform for more power.

 

What scares me into doing it this way, is simply $$ and if I can't physically view a problem (2 cpus killing eachother) then I'll be stumped rather quickly and may end up sending both cars to the scrapper because of two wires I didn't connect right or some other ridiculous reason.

[Cully77]

Good luck!