: Northstar swap into a Buick Reatta



F14CRAZy
10-12-05, 10:47 AM
Howdy. This may be my first post, but won't be my last. Not new to message boards or cars...

My name is Philip. I'm in mid-Michigan. I'm 18.

My dad and I share our hobby of Buick Reattas. Based on the E body platform and built from 1988-1991 here in Lansing. The only power plant was the first 3800, though 1991 got the Tuned Port Injection (TPI with my buddy Mario) 3800.

Reattas are great cars. I have an '89 coupe, my dad has a '90 convertible, and we also have another '90 vert which we're selling. I've got over 1000 posts at the Reatta.net board. The bad thing about Reattas is that they're not as fast as they should be. The 3800 puts out a mere 165 horsepower, which isn't much for a 3500+ pound personal luxury car.

We want to use a '90-91 (which have a more conventional dash/computer system and NOT the ECC touchscreen/CRT system) and a 90s Northstar-powered Cadillac and put the North in the Reatta.

I understand that I would need to swap the entire motor, transmission, computer systems, and wiring. I don't think it will be too challanging because I figured that because the Allante was on the same platform and had the North in '93, there's enough room in the Reatta's engine compartment. The best way I think to do it would be to buy a salvage (rear ended, rolled over, etc) Caddy for like $1k. I would know how everything is situated and would certainly be cheaper than getting it all from a salvage yard.

The only significant problem I can think of is the instrument panel. The Reatta uses a vacuum flourescent (digital) panel. I can assume that there's no compatibility between them. Does the Northstar use an ECM and a separate BCM? Reattas do, and the only reason I cna think of having to keep the existing BCM would be for climate control. I'd keep ODB/2 of the North. I'd probably get some error codes because of the climate control not really being present but from what I understand, it can be reprogrammed to ignore them.

I might be better off to use the Caddy instrument panel instead of the Reatta panel.

I don't know. What do you guys think? They've been put in Fieros before. Think of a Reatta is just a bigger, luxury Fiero:) I thank you much.

STS 310
10-12-05, 12:10 PM
Anything is possible, however you would probably have less problems with engine management if you used obd I.

F14CRAZy
10-12-05, 05:34 PM
I see. I was under the assumption that all Northstars were OBD2. Which one's we're OBD1?

mcowden
10-12-05, 06:45 PM
All 1996 and newer cars are OBD-II, Cadillacs, Toyotas, Daewoos, Volvos, all of them. Prior to that was OBD-I.

F14CRAZy
10-12-05, 07:52 PM
Thanks

chevelle
10-12-05, 08:30 PM
Neat idea. Lot's of potential problems. Getting the dash to work will be very questionable. Make sure and get the VATS module from the donor as it will have to be wired into the system to make the Northstar PCM play. You will find that the Northstar wiring is integrated into the car and chassis wiring harness so it is not a simple PCM harness that is standalone so separating out all the wiring is going to be difficult.

As another, possibly easier idea, why not put in one of the supercharged 3800 engines into the Reatta. That would keep it all Buick, be much simpler and with a few engine mods,open exhaust and smaller pulley on the blower could make almost as much power as a stock Northstar. Something to think about.

F14CRAZy
10-12-05, 09:26 PM
Chevelle: thanks for the info too. Please ellaborate by "body wiring." What's it connect to? Stuff like auto suspension?

I have thought of the VATS. Would probably end up using a bypass kit like for an aftermarket alarm.

I'd pick up a complete FSM for the Cadillac. Already have them for the Reatta (free in PDF format from Reatta.net).

The series II supercharged 3800 (L67) has been done in a Toronado Trofeo before. Would be decent and maybe easier. I'll give it some more thought cuz it's true that the GTP, GS, Riviera, or wherever it came from is a lot simpler car than a Cadillac.

F14CRAZy
10-12-05, 09:28 PM
Then again, the Northstar engine/tranny is built to move a big, heavy boat. It would probably hold up better to daily WOT than the L67 drivetrain lol

davesdeville
10-13-05, 04:11 AM
I've considered building a Fiero with either an L67 or a N*. If you want a smooth engine that you can squeeze maybe 420hp out of with nitrous and a good exhaust system, N* is the way to go. Anything over that power level (or if you don't want to run nitrous) and you'll want an L67.

dkozloski
10-13-05, 09:35 AM
F14CRAZy, I highly reccommend that you go with the North* project. If you proceed with the right attitude it will be a tremendous learning tool. As you encounter problems and research to solve them you will be well on your way to a useful education. There aren't enough young people around doing this kind of project. There is no doubt that with enough work and research you can do it. If I were your age again you couldn't old me back.

chevelle
10-13-05, 03:20 PM
There is no doubt that with enough work and research you can do it.


Not necessarily true..... I would agree that things like this are an excellent learning experience but some things are impossible. Like getting the electronics of the Reatta dash to talk to the Northstar PCM. Doing the mechanical part of the swap is fairly straightforward and relatively simple as far as engine swaps go. Getting the electronics to play will be virtually impossible. Those cars use two totally different electronic communications methods with the dash and the PCM's and the software in each is completely different and incompatible. You can cross wires the rest of your life and it will not work. You can make the car run but the dash will not play with the engine and you will destroy the intrinsic value of the car that way.


By "body wiring" I mean all the wiring in the car that is not specifically related to the engine....i.e..HVAC system, lights, dash, accessories, etc. Many cars (such as TPI Camaros) have the PCM on a separate , standalone wiring harness. Not the Northstar Cadillacs. The wiring will be co-mingled togehter.

dkozloski
10-13-05, 04:48 PM
chevelle, he was already talking about a dash swap. Maybe he doesn't care that much about the original esthetics. He can always go with brushed aluminum and needle gauges anyway.

chevelle
10-14-05, 01:13 PM
chevelle, he was already talking about a dash swap. Maybe he doesn't care that much about the original esthetics. He can always go with brushed aluminum and needle gauges anyway.

True, but I assume he also wants to keep the HVAC system operating which requires the body computer from the Reatta and input from the engine controller .... which will not work with the Northstar PCM. Just making sure that he knows what he is getting into, here.

dkozloski
10-14-05, 01:46 PM
True hot rodders don't need no stinkin' HVAC. When you mash the foot feed it's got to go. Anything else is BS.

CadillacSTS42005
10-14-05, 02:13 PM
i think youd be alot better off just beefin up your 3800 rather than go though all the trouble of throwin a N* in it. For the amount of money and time your gonna put into it, have your 3800 intake opened up via runners wided and razor edged, have your heads bored out ported and polished and youll have alot more umph.

dkozloski
10-14-05, 03:25 PM
Since the restrictor plate has been adopted by NASCAR for the super speedways the fastest lap time turned by any car has been by a V6 Buick Busch series car at over 193 MPH. In fact Buick withdrew their support when they were denied being able to race the V6 against V8's. Some of the fastest laps ever turned at Indy are by V6 Buick powered cars, faster than any North* powered machine.

davesdeville
10-14-05, 08:51 PM
Do I have to bring up the N* LMP?

chevelle
10-14-05, 11:08 PM
Since the restrictor plate has been adopted by NASCAR for the super speedways the fastest lap time turned by any car has been by a V6 Buick Busch series car at over 193 MPH. In fact Buick withdrew their support when they were denied being able to race the V6 against V8's. Some of the fastest laps ever turned at Indy are by V6 Buick powered cars, faster than any North* powered machine.


True....but....the "Northstar" related engines at the speedway were running normally aspirated and those Buick's were turbocharged, heavily turbocharged. Don't forget, also, that those turbocharged Buick Indy engines were allowed an EXTRA 10 inches of turbo boost compared to the other engines they were racing against. Give me an extra 10 inches of boost on ANY motor and it will turn fastest laps....LOL LOL

Not to take anything away from the Indy Buick effort. Those guys did wondrous things with a fundamentally stock engine (at least stock in spirit...) but the engines were pretty sensitive and failed quite frequently.

There were two basic problems with them, both related to the fact that they were V6's racing against V8s. The V6 has to make much more HP per cylinder than the V8's so keeping the piston temps in check were a real problem. Especially when the engine was running at slow speeds and the driver stood on it...like at the start and after yellow flag laps. Ever notice how often they blew up on the start and after a yellow flag restart...??? Almost always. The engine was relatively cold and the sudden heat input into the piston caused it to expand and scuff before the cylinder bore came up to temp. Almost no way to avoid it. In practice and qualifying the driver could "ease" into it and avoid the problem but in the race it was the achilles heel of the program...having to suddenly stand on the throttle when everyone else did.

The other problem was controlling an overrev situation leaving the pits. EACH cylinder made so much power that the rev limiters were ineffective. If the rear tire went over a tar strip or slight bump under hard acceleration the tire would freewheel for just an instant as it hopped over the bump, the engine would redline and hit the rev limit. The rev limiter in the PCM would kill the fuel to the next cylinder firing but the previous firing cylinder would make so much power it would take the engine past the red line and turn the pushrods into spagetti. That happened a lot, too.

A great deal of time and money and effort went into those motors for many years and it is too bad that they never got a win.

danbuc
10-15-05, 11:37 AM
If your using the N*, I would recommend using an aftermarket ECM. Most of the Fiero guys use them since you can really do any mods to the engine with the stock ECM. Also, it will be alot easier to wire up, and probably more reliable in the long run. I can't remember which one most people use. Holley Commander 950 comes to mind, but I'm not sure if that the one. Sounds like an interesting project. Good Luck.

chevelle
10-15-05, 12:39 PM
If your using the N*, I would recommend using an aftermarket ECM. Most of the Fiero guys use them since you can really do any mods to the engine with the stock ECM. Also, it will be alot easier to wire up, and probably more reliable in the long run. I can't remember which one most people use. Holley Commander 950 comes to mind, but I'm not sure if that the one. Sounds like an interesting project. Good Luck.

How would he run the transmission with an aftermarket PCM..??? I'm afraid the way to go here would be the production PCM. A 1995 or earlier unit would make the task easier as it is pre-OBD2 and a speed density system that would not require a MAF meter.

As far as reliability I have yet to see anything in the aftermarket that is as reliable as the OEM parts.

danbuc
10-15-05, 06:13 PM
Damn, I forgot abotu the trans. The easiest way to find out what is needed is to check out som eof the fiero forums, and speak to a few people that have done such a swap. There is one person here who has done it I think, but he isn't here that much. Try and find someone that has doen it, and see what is needed to make it work properly.