87 GN LS turbo swap

[Kevin87TurboT]

A few months ago, I found this 87 GN in Alabama. The body was solid, but the paint was faded and the car hadn't been started in a few years. A few weeks later, I figured out why. The original V6 had a rod knock. I sold the car to a friend and we strategized on how to proceed. We decided an LS swap was in order. He just wants a reliable 10 second car with all of the amenities that a Buick should have...cold AC, PS, cruise, etc.
Here's what he started with.

 

[Kevin87TurboT]

He removed the engine and began cleaning the car. With a lot of elbow grease, the original paint actually turned out very nice!
He buffed the original paint, then rebuilt the brakes and did a lot of detail under the car and under the hood. There were a couple of small spots in the floorpan that had to be tended to as well. It's all good now. The new heart is ready to go too.

 

[Kevin87TurboT]

While Heath was at it, he replaced all of the body bushings and installed drilled and slotted rotors on the front.

He found a gently used 5.3L and a 4L80E transmission locally. Then it was game on! He is a very good fabricator. The headers were first on the list.

I ground a mild Comp Cams custom grind cam along with dual springs, and pushrods, on the SBE 5.3L. For now, it will have the ON 3 Performance 76/75 turbo.

Here are the specs at a glance.

FAST XFI 2.0 ECU.
TCI EZ-TCU
FAST 92 mm intake and TB
Walbro/FAST 450 lph fuel pump
FAST 60 lb/hr injectors
Comp Cams custom grind 225/226 .612/.605 114+3 cam
Comp 850-16 Lifters
Comp 26925TS-Kit springs
Comp 7955-16 pushrods
Comp 7106 Timing set
Rebuilt 4L80E transmission
TCI 9.5" Street Fighter torque converter
ON3 Performance 76/75 turbo
CX Racing IC
Custom headers, cold side and hot side
Summit Racing radiator

 

[Kevin87TurboT]

The fabricated mounts put the engine in the perfect spot. The truck AC compressor fits nicely with no notching on the frame. There is plenty of room for the PS pump and the turbo tucks in real nicely. The best part is that there was no cutting done. The original engine and trans is sitting in the corner of the shop and can easily be slide back in place.

 

[Kevin87TurboT]

I stopped by a few nights ago and did a little tuning on the XFI. It fired right up and runs nicely now.
We are just waiting on the ice and snow to melt so we can drive it and start turning up the boost!

 

[larry33kc]

Nice build.

 

[Boostdeznuts]

Very nice

 

[bigmandengo]

Sweet build.

Out of curiosity, where did you plumb your turbo oil drain too?

 

[Kevin87TurboT]

Sweet build.

Out of curiosity, where did you plumb your turbo oil drain too?

It's plumbed to the block above the oil filter.

I did a little more tuning on the hot start tonight. I fires right up and idles great now.

 

[Kevin87TurboT]

 

[tbone87]

Great job!!! Nice nice

 

[mtocrs1]

Wow. Would this Heath guy do another one? How do I contact him?


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[Kevin87TurboT]

Wow. Would this Heath guy do another one? How do I contact him?


Sent from my iPhone using Tapatalk

He has a full time job, so he's really not interested in doing another set of headers. However, you might consider one of the Trick Performance turbo kits for an LS1. They look awesome and are reasonably priced.

We finally got some decent weather today and was able to put some miles on the car. It's very docile and driveable. It is a beast at WOT though! It needs some sticky tires badly. From a 60 mph roll, it just smokes them. The boost comes on quick too...only 1.4 seconds from a 2100rpm cruise at 40 Kpa to 5000rpm and 200+ Kpa. I really expected around 12psi boost max with the current setup and wastegate spring. However, it immediately when to 14 psi and averaged 14.5 psi in high gear. The tires will be here in a few days and we'll go pick on some of the local Mustang guys.

 

[tbone87]

And camaro guys lol!!!

 

[Kevin87TurboT]

And camaro guys lol!!!

You have to watch those turbo Camaro guys T-bone, they will just crank up the boost on you!

 

[AllGoNShow]

Love the build, sub'd for vids and beat down results

 

[Wknight13]

curious. what are the diagnostic displays in post #10? Im trying to decide what systems diagnostics (scanmaster) I want to invest in. thanks

 

[DCVING 6]

The top one is for the FAST ecu and the bottom one is for the trans controller.

 

[toyin]

Bada$$ just like your other builds! He definitely did an amazing job on on the exhaust system! Curious if you might have the part numbers for a couple of the parts in your list(Below). I have an LY6/4L80E i'm putting into my 87 GN but trying to make a parts list so any help or suggestions is very much appreciated! How reliable are the ON3 turbo's? they look like a nice price but i'm curious if it's on of those you get what you pay for type deals? If you got any part numbers on the parts below id appreciate the help.

ON3 Performance 76/75 turbo
CX Racing IC (Did you use a universal cold side piping kit)
Summit Racing radiator

I know ill need to get the LS2 timing set up and cover but ill still need to figure out what i want for the turbo cam. It's going to be a street car mainly so i'm not looking to go to crazy with the cam.

Thanks
Austin

 

[HG88]

Mind me asking where in AL y'all are located? Im looking for a GN or ttype roller in similar condition to what this GN was in.