they came with 1986/1987 Buick Grand National's and they put out 300BHP stock!

I'm curious why this engine isn't used in swaps ( I think I can recall only one). please tell me why?!

seems like a nice alternative for the 3800 SC....

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http://homepage.mac.com/rewq/html/fiero.html

IN PROGRESS: CUSTOM HOOD/MUSTANG SCOOP/HONDA EURO TAILLIGHTS/ DTM UNDERSPOILER/CUSTOM FRONT+many new details!

1987 Pontiac Fiero GT &
1969 Chevy Suburban

Well, I'm not GN expert by any means, but through a quick search, I found them to be listed at 235hp with turbo and intercooler. Might be a reason. Plus, the L67 is vastly available, lots of low mileage examples are available without requiring a rebuild.

Now, if you want to talk about the GNX engine, I'm all ears. But, as I recall, there were only about 500 made, and most all are owned by collectors. Good luck finding one of those BADBOY engines for a Fiero.

[This message has been edited by fiero56 (edited 10-16-2002).]

I did a search before my post, yes there are 235HP versions but also 245 and 300HP versions(I thought the "GNX"). I also guess the ECM is more basic.....no passkey issues for example. I was just wondering why you never see them.....

Im no buick expert but....

The grand Nationals had a 3.8 (not called a 3800) v6 245hp??

The GNX was rated at 285hp. It's more than just a chip that makes the GNX diferent.

If you can even find a GNX motor you would'nt want to swap it into a Fiero. Basically because it's so rare.

There were only a handful of GNX's built , less than 150 I believe. They still fetch huge prices.

As for the swap?.. yes a grand national 3.8 Turbo has been put in a Fiero.. I have seen a few.

JM

The Grand Nationals engines (LC2) Use the BOP bolt pattern. Afaik, no one makes the adaptor plate to go from BOP to the FWD pattern.
The best option is to take a 3800 Series 2 supercharged, sell the SC, then purchace a turbo. Then you you would have the equivelant of the old LC2 but with modern technologies, and a much stronger block anyway.
Also, to mount a LC2 Fiero style you would have to totally re-do the plumbing for the turbo because it would stit where the strut tower is. Its a hard swap to do, far harder then putting in a 350.

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Matt D
1984 Indy Fiero 4sp.
1985 2m4 now equipt with a 1996 3.4 DOHC.

If anybody wants to know about Buick Grandnationals ask away. I restore GNs and T types as a hobby. I am also doing a Fiero with GN motor. Only thing holding me back is the trans issue.If you tell the V8 guys that I looking to put about 500+lbs trq they probably think that I am full of BS.These 3.8 turbo buick motors are very easily made scary fast, My GN in my signature ran 10.70@124mph 3800lbs car w/o driver dynoed 505hp and around 614lbs tq.Bottom half of the motor is completely stock, all boltons except for the cam. As for the GNX there are total 547 made and the price range is about $45,000-$100,000.The GN and the GNX share the same motor except; the GNX has better computer chip,ceramic turbo (better flow)heads are worked a little bit,intercooler has extra cores/fins,trans worked little bit with better shiftkit and a external cooler, better valve body, the rear end has a much better suspension setup for traction and a true dual exhaust.interior is the same as a GN except the dash GNX has a great guage cluster.Exterior the color is the same but the GNX has louvers on the fenders and fender flayers all the way around.The stock GNs run around 12.5lbs boost. GM underated rated the HP for some reason. In 1986 the sticker said 235hp and in 87 245hp yet they are the same setup. Actually in 1986 they ran 13.5lbs of boost stock had problems with leaning out in the winter time they turned it down to 12.5 in 1987.In 1986 the Corvette had 225hp so Buick said the GN has 235hp 10 more than the Vet,in 1987 chevy bumped the Vets HP to 235 so the GN got bumped to 245hp it all BS games that GM plays.The car makes way more HP than what GM stated.We took a bone stock GN put it on the dyno, turned the boost up 18psi from 12.5psi and bumped up the fuel pressure 10psi to 40psi at idle. The car made 333hp and 440 lbs of tq.You can get a GN into 12's easily, all you need is good set of tires, slicks if possible these cars are torque MONSTERS, good chip Thrasher for $25.00, some race gas($20.00), a good fuel pump like Walboro 340 ($95.00), adjustable waste gate (homemade $5.00) , k&N air filter(50.00) and a test pipe (50.00).You must have a tunning tool like the Scan master ($250.00) After you tune your car it will run in the mid 12's all day around 102-105mph.You do the math.When I am done with the Fiero and if the trans holds up watch out, that is all I have to say.

Prasad

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87SE 2.8 w/5speed(waiting for a 3.8 Buick GN setup trasplant)
85SE 2.5 w/5speed
1987 Buick GN(10.70@124MPH)
1987 Turbo T
1992 GMC Typhoon
Other cars; JaguarXJ6, AMG 500SEL,Astro & Legacy

[This message has been edited by WikedV6 (edited 10-16-2002).]

3.8L V6's were grossly under-rated from the factory. Intercooled 3.8L were easily 300 HP engines out of the box. My buddy's GN has an engine that's never been apart. An oversized turbo, bigger injectors, and some altered fuel mapping, and he manages 11.2's all day with a 3.90 gear and 28 inch slicks. He can yank the tires on every launch. It's simply amazing. If someone ever applied this thing in a Fiero, it would make the V8 guys weep. 3800 shouldn't even be mentioned in the same breath as a 3.8 V6. Back in the mid eighties, Buick engineers used to run around the proving grounds in Milford with bumper stickers that said 'I brake for Corvettes'. I wish I'd have bought one those when I had the opporunity.

The only reason the 3800 hasn't posted numbers like that is that the supercharger isnt capable of those levels of boost.

I have no doubt that it could post numbers in excess of 500 with a properly intercooled turbo.

My '87 GN was rated at 245HP. The GNX was rated at 300 (I think). But a simple swap to the Kenne-Belle Hi-Lo Pro Chip upped my boost from 14psi in 1st and 2nd gears to 19psi! That was the only change I made, and the car was crazy fast. Had fun shutting down Vette's and a certain SS396 Chevelle 4-speed that won't try to mess with a GN again.

For all of the effort, I'd take a 3800SC, bolt on the NA intake/plenum and bore it to accept the SC TB and bolt a turbo to it in a wrap-around fashion. Getting a real live GN engine in there (as the one person that did it demonstrated) is a b!tch. Then pray the 4T60EHD holds up.

[This message has been edited by TK (edited 10-16-2002).]

I want to do that swap also, but it requires more than just the intake. You'd also have to swap on N/A cylinder heads. To make room for the supercharger they pushed the injectors out. The injector bosses are in the cylinder heads on the SC engine and the NA intake won't fit the SC heads.

I guess its easier to start with the 3800SC and ADD a Turbo later if you want to go mad!

Yep, it will take some effort. An S1 might be a bit easier.

[This message has been edited by TK (edited 10-17-2002).]

I'd make a plate of metal to cover the SC intake, then drill a hole and some threads and mount the throttle body right onto it. Then go turbo.

I see there are others attempting to do what I will be doing this winter. I already have a GN's stock turbo with ported exhaust housing, an air charge cooler from a SyTy (and an intercooler from a GN on standby if the Sy/Ty idea is no good), a superhcharged 3800 series II shortblock and ported N/A heads and the aluminum camaro intake. I only plan to run 10-15 lbs of boost though. No need in pushing my luck on an otherwise stock engine. With the ported heads and upgraded cam, I see no reason why my car shouldn't run low 12's/ high 11's on pump gas provided the 4T60-E holds up. Of course, I have a trans guy and backup plan if that fails.

As for the stock GN motors not being as good as a V8 as one person eludded to; you are smoking crack. I went to the Buick Nationals earlier this year and watched 455 equipped GS's yanking tires off the ground only to get beat out by the 1/8 mile and thru the 1/4 by GN's running 8 second 1/4 mile's. Oh yea, no to mention a handful of GN's running in the stock class which only allows external bolt-ons and stock location intercoolers running 10's! Stock engines! I personally have 3 friends that own these cars (no GNX's) and have helped work on them also. I can tell you that it costs a fraction of the money to get a turbo buick to go fast as compared to any V8 engine in the same car. My friend's stock 87 GN ran 12.3's in the 1/4 with only a down pipe, adj wastegate, chip, and racegas. The terry houston downpipe was the most expensive mod and I think it costs about $500 or so.

Turbocharging is the ONLY way to go.

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1987 Pontiac Fiero Coupe #18,838
3800 Series II SFI; 4T60-E Trans w/ 3.33 final drive; Terminator exhaust; 4 wheel vented disc conversion; Walbro 307 fuel pump; W-body air box w/ K&N filter; Rear 32mm sway bar; 134a functioning A/C; GM CD player w/ factory location sub; much more and...a stock GN's TURBO on the way!

1987 Pontiac GTA
-5.7L SuperRam MPFI
-4L60-E Trans
-3.73 SRD

http://dtcc.cz28.com

AIM Handle: Darth Fiero

[This message has been edited by SubZero350 (edited 10-17-2002).]

[This message has been edited by SubZero350 (edited 10-17-2002).]

quote Originally posted by SubZero350: Turbocharging is the ONLY way to go.

I whole-heartedly agree. No supercharger can reach the possibilities of a turbo.

BTW: I saw either a GN rebadged as a GNX or, the real thing earlier this year(absolutely perfect!). Not sure which it was, but because of the areas around here, wouldn't be surprised if it were the real thing.

[This message has been edited by fiero56 (edited 10-17-2002).]

If you wanted to do this the easy way find a FWD turbo 3.8 from a FWD t-type LeSabre, not sure of the model of buick. And yes they are out there. This way you get engine and tranny together.

quote Originally posted by fiero56: [b] I whole-heartedly agree. No supercharger can reach the possibilities of a turbo.

True, but maybe the turbo's possibilities exceed what is needed. I'd be quite happy with a M-112 bolted on a 3800 anyday. Sure, I can't crank the boost up to 20 PSI but I'm willing to accept the lowend no-spool-up torque for less HP.

I have an 86 Turbo Regal too and sure, it's more powerful but I think a blown 3800 is just as much fun, if not more (I have two in different cars).

It's ok to say you have enough horsepower and torque! Getting caught up in the "more horsepower" hysteria tends to leave people disappointed with the problems that go with it. The Turbo Buick website(s) are full of people dealing with problems on their TR's. Yep, and there are people with no problem at all. But along with the potential for more horsepower is all of the problems associated with.

Why are people so reluctant to say enough is enough? There are several people here at any one time than can't make their 3.4L swaps run right and we keep on encouraging them to do the swaps.

[This message has been edited by TK (edited 10-17-2002).]