Sprucing-up the GN

[Fast One]

Well....it's time to spruce-up the GN (again). At ~196,000 miles, it's getting a bit dreary. The Powermaster brake unit is acting-up again, odd electrical issues are cropping-up, it needs a new power antenna, new bumper fillers, new lower window seals, the adjustable fuel regulator is stuck @ 70 PSI, the wipers are really slow, and a few other things. Got Jason Bertram from the MNGTA club coming over on Sunday to check it out.

Here's the rundown on what I've done to it since back in the day.

Major work performed since I've owned the car:

• ~78k: GNX body bushings, frame & trunk braces, Eibach springs, HD shocks, Kirban Performance 145 MPH Speedometer

• ~90k: LT1 valve springs, new turbo & 'turbo-saver' oiling kit, Walbro 340 fuel pump w/adjustable regulator, 3" intake & exhaust
• ~110k: Full suspension & steering rebuild, including a full PST polygraphite suspension & steering kit, plus new wheel bearings
• ~110k: Full brake rebuild - including new rotors, HD ceramic pads, and HD rear shoes
• ~130k: HD double-roller timing chain, new water pump, new GM 200-amp alternator, re-stuffed driver's seat
• ~140k: HD transmission rebuild, new HD torque converter
• ~150k: New LT1 mass airflow sensor*, Translator Plus MAF translator, 4-wire heated O₂ sensor
• ~150k: New high-efficiency 4-core radiator
• ~150k: Forged rear-end rebuild
• ~175k: Remanufactured Powermaster brake unit

Engine: Original. Has not been rebuilt. Still holds good oil pressure. Does not burn oil. I've used only Amsoil & Mobil 1 since I bought the car.

• LT1 valve springs
• Double-roller timing chain

Oiling System:

• HD oil pump
• Precision Turbo Engineering Turbo-saver oiling system kit w/high-capacity, high-flow remote filter

Cooling System:

• High-efficiency/high-flow stock-appearing 4-core radiator
• High-flow 160^o thermostat

Induction:

• Stock intercooler w/Duttweiler neck mod
• 3" mandrel-bent intake & up-pipe
• KN filter
• Precision Turbo Engineering stock-appearing TA-49 turbo w/adjustable wastegate
• 3” LT1 MAF
• Translator Plus MAF translator

Fuel system:

• Walbro 340 pump
• Stock-appearing adjustable regulator
• 42 lb disk-style injectors
• SMC alcohol injection kit

Electrical System:

• Single-point ground upgrade kit
• Fuel pump wiring upgrade kit
• Scanmaster II Computer display
• New 200 amp GM alternator
• 4-wire heated O₂ sensor

Exhaust:

• 3" mandrel-bent downpipe
• 3" fake cat
• Aluminized, mandrel-bent dual 2 ½” cat-back w/stock-appearing low-restriction cross-flow muffler

Transmission: Original, rebuilt with premium HD components by Art Carr at ~140k. Running synthetic transmission fluid.

• HD pump
• Billet servos
• Cryo-hardened input shaft
• Redline clutch packs
• Furnace-brazed 3000 RPM stall converter w/anti-balloon plate & HD lockup clutch

Rear end: Original housing, rebuilt with premium HD components at ~150k. Running synthetic posi lube.

• HD Eaton posi unit w/Redline clutch pack
• HD Moser 30-spline forged axles
• HD Richmond 3.42:1 ring & pinion

Suspension:

• GNX body bushings, frame, & trunk braces installed
• HD shocks & springs, rear air-bags
• Full PST front & rear poly-graphite bushing kit – plus PST upper & lower ball-joints, tie-rod ends, idler-arm, and Pittman-arm
• All wheel bearings replaced

Brakes:

• HD rotors
• HD ceramic pads
• HD rear shoes
• Remanufactured Powermaster electro-hydraulic master cylinder unit w/pump & accumulator

Tires: BFG Radial T/A

• Front - 235/60/15
• Rear - 275/50/15

Interior updates:

• Stock-appearing dual gauge A-pillar& coin tray gauge pod
• Autometer electronic fuel pressure gauge
• VDO boost, water temp & oil pressure gauges
• Kirban Performance stock-appearing 145 MPH calibrated speedometer
• Kenwood Excelon audiophile-grade CD/MP3 player/AM/FM receiver with 24-bit Burr-Brown DACs
• Custom-built curly-bird's eye maple console cover w/built-in cup holders supported by solid rosewood dowels
• Driver's seat freshened-up with new padding & suspension
• Advanced CompuStar remote-entry/alarm system w/long-range 2.4GHz two-way remote

[Z28SSMAN]

Very detailed. I like it!

[Fast One]

Thanks! Well....Jason Bertram came over yesterday. Fortunately, all that's wrong with the "slugmaster" PowerMaster brakes is that the accumulator ball went to hell from sitting too long. Got a new one on order for $300. Had him check out the rest of the car, to see what it needs to get back into "drive across the US" condition. Looks like around $2500 for parts & labor, all-told. Really looking forward to getting it back into cruising shape!

[Fast One]

When it's done, it should be back in "drive across the US & eat Hellkitties for lunch on the way" shape - like it used to be.

[MR.hp]

I can eat hellcats with my Camaro for breakfast, but they sure shit out kind of runny at the end of the race, lol.

[Fast One]

I gave the GN a little snack on the way back down here from getting it back from my best bud up north. Filled her up with 130 octane Avgas before I left Warroad. Was driving through Grand Rapids on Hwy 2, when a Hellkitty wanted to stoplight race. I smoked his ass! That was ~2.5 yrs ago & I haven't seriously raced anyone since. Just too nervous about dumping 22-25 lb of boost into it until after I have things gone-over. But that Hellkitty driver sure had a surprised look on his face at the next light! Maybe he thought he was gonna race a Monte Carlo SS.

[Fast One]

Jason came over & fixed the brakes today. Was just a bad accumulator. Put new hood struts in, too. Also found that when my brother's mechanic got rid of the alky injection, he left the fucking boost line to the waste-gate open! No fucking wonder that it pulled 25+ lb of boost when I floored it, even though I had turned the boost down to 17 lb when I sold it to my brother!! Jason won't be able to get it into his shop for the more extensive work until after the Buick GS Nats @ Bowling Green, but at least it's driveable now. He's also gonna pick up a set of gel-coat fiberglass bumper fillers for me while he's there, to save me the shipping.

When it's all done, I want it to be reliable for cross-country driving along with some WOT hotrodding @ 25 lb of boost - like it used to be.

[Fast One]

Bunch more stuff happening with the GN! Got a set of 18" aluminum GN repro wheels from GBody parts coming. I'll be running Z-rated 255/40/18s in the rear & 245/45/18s in the front. Got a full A/C rebuild going, to fix the botched 134 conversion from back in the day. Putting a new Walbro 340 in the tank. New programmable chip. New up-pipe & KN filter (the old ones were shot, due to wear-through issues). New KYB shocks. New NGK plugs. New valve-cover gaskets & diff cover gasket. Transmission service. Replacing the rag joint steering coupler with a U-joint. Got the fiberglass bumper fillers. Full set of silicone hoses to replace every single rubber hose under the hood. Also having the power antenna redone, along with the wiper motor. Getting new inner & outer lower window seals, too.

When it's done, it should be good for running 11s in the quarter & running 165+ MPH top-end like it used to do - and the handling should be even better with the 18s

[Z28SSMAN]

I like it!

[MR.hp]

Ya those GN's were pretty fast in their day for a V6 car. Nice work.

[Fast One]

Ya those GN's were pretty fast in their day for a V6 car. Nice work.

Thanks! But they weren't just fast for a V6. In '87, the GN was the quickest production car you could buy in the US & put a license plate on. Did 0-60 in 5 sec & ran 13s in the 1/4 bone-stock with the factory POS Goodyear 215/65/15s. Just putting decent rubber on the back, changing the chip, and feeding 'em some 100 octane unleaded turned 'em into 12-sec cars. Would be years before Chevy, Ford, or MOPAR came up with a production V8 car that could come close!. And the GNX was a fair bit quicker, stock. It was unquestionably the quickest production car in the world in back in '87!

[Fast One]

Was over at the guy's shop earlier today, checking stuff out. Looks like the engine/trans/rear end are still in good shape, but fuck - there's some oil residue in the intercooler. My TA-49 turbo is seeping a bit of oil. Gonna have to run with it for awhile, as I'm already blowing my "sprucing-up" budget. The wheels & tires are gonna be nearly 3 grand. The fiberglass repro bumper-fillers are nearly another grand. And then there's the cam sensor, Walbro 340, a shitload of bad wiring, all of the hoses & rubber shit under the hood that needs replacing, fuel injectors, computer chip, up-pipe, new KN filter, diff cover gasket, plugs, and a full A/C rebuild w/new compressor because the asshole that did the 134 conversion for me back in the day fucked me over & didn't change the other shit that's supposed to be changed.

[Fast One]

Well...we're making progress on my GN, but it won't be done for the 4th as I had hoped. Got the new Walbro 340 & associated plumbing in the cleaned & repainted tank. Got the new 8 ga FP wiring harness installed. Got the new 2 ga positive batt cable w/8 ga alternator wire installed. Got all of the parts for the correct R134 A/C conversion. Got the up-pipe fixed. Got a new KN cone filter. Got a set of NGK plugs. New diff cover gasket installed. Intercooler has been cleaned inside & out. Got all new silicone hoses under the hood. Shitload of new wiring. Got a new MAF translator for my LT1 MAF, as the circuit board was rusty in mine. Got a new programmable chip. Got the new KYB shocks installed. Got a new 3" downpipe ordered, as mine is rubbing the frame. New 60 lb fuel injectors on the way. Got the aluminum 18x8" GN repro wheels from GBody parts ordered. Gonna order a set of 255/40/18 Bridgestone Potenza Sport AS tires for it. Ran the 16" version of those on my 40th Anniversary GTP & they were great! Also getting the window seals replaced, wiper motor/gearbox freshened-up, and the power antenna fixed.

Looking at $7k+ just for all of that. It won't look any better (aside from the new bumper fillers & wheels), but it should be good for pulling Hellkitties faster than they can go on their own & also challenging quite a few sports-sedans in the corners again.

[Z28SSMAN]

Nice! Does Tom Shea (sp) still run Buicks?

[Fast One]

Nice! Does Tom Shea (sp) still run Buicks?

He's still the club president. I think he still has his Turbo Regal.

Joel

[Z28SSMAN]

I wonder if he knows where JR's TTA ended up? Along with all his shop equipment.