motor swap

[Guest Brigop]

Hi everyone,

I am looking to add some life to my cherished Red Reatta, and after much reading of tech forums on the 3800, i thought that I would come back here before making any expensive choices. I am looking to upgrade my ride to a series II or III S/C motor but no go as far as adding NOS or Water-methane spray as in a certain Silver Reatta GSX i have seen. Is there anyone out there that has upgraded their rides in this maner that will share any pit falls with me? Hope all is well with the reatta group.

Dan Kelly

South Side of Chi-town

[D-a-n-i-e-l]

Mounts will be uh our biggest challenge. The ecm can be programmed to control the series two not the three unless thou swap out the throttle body. I am hoping to do my swap in the next two weeks or so. If not it will have to wait until I return from Afghanistan. I will be doing a complete write up on it but I am also going to a f40 six speed manual transmission. If you stick with the stock tranny have fun I am on my fourth and that include one of the hd trannys that came attached to the series one.

[ol' yeller]

Daniel, How are you planning to do the pedal swap, adding the clutch? Mine is too original at this point to consider this MAJOR undertaking but in the future??? Did someone figure out how to program the ECM to work with the OBD1 system in the Reatta? Sorry if this has been hashed out already, but I have been away for a while and when I left it was considered extremely difficult to impossible to go to a Series II. I had one in a '98 Regal GS and that thing went like stink!

[D-a-n-i-e-l]

I have a few ideas for the clutch pedal but nothing solid yet. As far as the ecm I mean that the reatta ecm can control the engine with no issues . Just change over a few sensors. I hate seeing people ruin the on board diagnostics etc by just piggy backing or using a completely separate ecm.

[Guest Brigop]

Well here is my plan. I am going to drop in a L67 with a 4T65E. There was a swap similar to this done to an 89 over on the motor swap forum. Excellant write up with pics. There is a GM proformance shop near buy that said he would help. I will do a post with pics once I get started.

[Ronnie]

Well here is my plan. I am going to drop in a L67 with a 4T65E. There was a swap similar to this done to an 89 over on the motor swap forum. Excellant write up with pics. There is a GM proformance shop near buy that said he would help. I will do a post with pics once I get started.

I hope you keep us posted w/photos as you go through each step of the project. If will be interesting.

[padgett]

From a sensor standpoint there are two main issues: change from digital to analog EGR & programming for stock throttle body tops out at 170 gm/sec, far under L67 capability (OTOH if goes max rich for higher values may not be that important). The BIG thing is to replace the advance maps with one from a boosted engine. The N/A maps or even a mix will burn pistons/valves. Also premium fuels at cruise need more advance than 87 PON (if you care about MPG).

We did this on an 88 including a Getrag 5 speed about a decade ago. Does require mods to the programming for the auto trans and TCC signals which are just not there any more else will get all sorts of error codes.

Not trivial but can be done with a stock computer to maintian the digital dash.

[Guest Mc_Reatta]

Well here is my plan. I am going to drop in a L67 with a 4T65E. There was a swap similar to this done to an 89 over on the motor swap forum. Excellant write up with pics.

How about a link to this site?

[D-a-n-i-e-l]

If it is the blue one I have seen and read it many times. He did not use the stock elm. He took the easy way and use the donor elm and destroyed the heart and sole of the 88/89 reatta. AKA the tic and onboard diagnostics.

[Guest Brigop]

As I have a 1990, what differences are there. I know that the original ECM/PCM can control up to a series II. But will it handle it adequately? I would hate to drop in a L67 and hold it back by a inadequate ECM/PCM.

[D-a-n-i-e-l]

As I have a 1990, what differences are there. I know that the original ECM/PCM can control up to a series II. But will it handle it adequately? I would hate to drop in a L67 and hold it back by a inadequate ECM/PCM.

Short and sweet of it, It can control it drivability is fine, but fuel milage will be lower than with a diffrent ECM. Being a 90 I would use a the donor ECM as you will have to use a second ECM/PCM to control the tranny any way. If you are good with wiring and would like to keep your dash functioning and all the sensors working, you could use an ECM out of a 95 SCed car. This will let you use most of the reatta sensors and keep the dash working. It would need to be reprogramed/chipped to run a series two, but IMHO would be the way to go as it would be the best of both worlds.

Next option, and I do not know for sure if the com bus will work on this but it is worth researching, use a PCM (powertrain control module, new ECM controls trannys also) out of a 91 as it in its other uses controlled a SCed engine in the park aves. (best solution if the data stream is the same as 90) I am begining to think it may be the best solution of all, as the only reason I can see for the change in the EC/PCM was the adition of the electronic controlled tranny.

Not having a CRT you have many options, it just depends on how much time you want to invest, or money if you plan on paying for the work.

[Guest Brigop]

Daniel, thanks for the input. My ultimate goal is to keep it as simple and easy as possible. I want to do as much as possible my self. So I am in the process of pulling all of the posts together and sitting down with a local shop that specializes in GM performance to build the plan. I just wish the LN3 was workable with a SCer. But all I have read does not indicate that it holds the power generated by the SC well. I can get a very low mileage LN3 for cheap to use as the donor. And build from there. I want it to be my daily driver with around 250 to the wheels. If someone has build an LN3 that way I could surely use the link.

[Ronnie]

What do you intend to do for a reliable transmission when you get the 250hp SC engine?

[Guest Brigop]

63viking had his tyranny rebuilt near chicago. Based on what I remember of his car and talking to him I would persue the same same rebuild or put in a 4T65E. Again having to deal with the electronic management. Never said my goal was an easy one LOL

[Guest aricrickard]

I am planning a series 3 motor swap into a 1990 Reatta. Am not an expert so will need a lot of help. The supercharger has a boost solenoid with input to the ECM. What do you do with this solenoid input when using the Reatta ECM?

Aric Rickard

[D-a-n-i-e-l]

I am planning a series 3 motor swap into a 1990 Reatta. Am not an expert so will need a lot of help. The supercharger has a boost solenoid with input to the ECM. What do you do with this solenoid input when using the Reatta ECM?

Aric Rickard

You will need a adapter plate to get rid of the electric motor controlled throttle body. You will need a throttle body from a 1998 or older S2 SC engine. a wire harness from a 96-98 engine and quite a few other things. Much of this depends on if you are keeping the Reatta computer or not. I say keep it as it will run the engine. You can skip all of the parts and what not if you are planning on using the 05 ecm. but if you are you will have to get the gas pedel and a few other things from the 05. I would rather do the F40/98 S2 swap than the full 05 swap. I am working on my 05/98 S2/3 hybrid swap right now and it is not too bad for the engine side. You will need to figure out the engine mounts. Mine are going to be different than yours as I am also dropping in the F40 tranny. I will be posting a full wright up once it is complete.