Onesick finally starts building his GNX

You're making great progress, the trans crossmember looks great!

Ok so story time. So get a beverage and grab a seat as this is a big update, with unfortunately minimal photos. 

So we left off at making the trans cross-member and having a gaping hole in the trans tunnel. So time for some CAD.

Cut, bend and tack. This time with shielding gas and solid wire thankfully.

And welded in.

Paint, shifter and boots.. yay no more hole.

At this point things got interesting as I was working on the fuel system, all new brakes, and trying to get the clutch pedal/hydraulics sorted...

I started by installing new front brakes. The calipers are 2.75" big bores. Which fyi may be the cheapest bolt-in front brake upgrade ever! So for $130 you get both calipers, pads, every single piece of hardware, banjo bolts and bleeders. I think it was actually cheaper then the stock parts thru rockauto.

Next up rear brakes....... God do I hate GMs' retainers for the wheel cylinders.

At this point I had a buddy help me change the power steering pulley as the stock hit the steering gear. I was genuinely shocked we where able to get this pulley off and then new one on as it was extremely crusty and the internal threads where nearly gone.

Put the sender In the tank.... It was an efi sender but the only line without a flair was of course the 3/8" feed line... Berk.. flared the line and installed the sender and tank. 

Brake booster installed as well as the clutch master.... So the plunger rod for the clutch master was 6" to long and in the way of everything so disassemble the clutch master, cut the plunger, weld a 1/4-24 bolt on and use a heim joint... Unfortunately this was an extremely aggravating and high obscenity job of which I have no photos.. side note I'm 6'5" and weigh about 340lbs so climbing in under the "dash" area is instant misery for me.

Next up brake and fuel lines. So the fuel lines where run with very minimal drama. However, this was my first experience with Ni-cop lines for the brakes. I literally had to remake every single front brake line at least once. All while bathing in brake fluid... Also seen here is the first attempt at a intake and the accessory bracket/accessories mounted. As well as the clutch res and adjustable brake biased valve.

At this point it was time to mount the cooling system, make changes to the intake, and start down the path of wiring purgatory...

This brings us to last week I have the engine harness all finished up minus the signal wires for gauges and a keyed 12v source. I attempted my first start up yesterday however no luck as my injectors where completely plugged with the thickest most putrid varnish I've ever seen or smelled in my life... So new injector time... Yay.

Today I played around and got the cooling system buttoned up, mounted a ps cooler, got the front sway bar in, mounted the air dam, and made a template for the gauge cluster.

Injectors are ordered and should be here Thursday so look for a first fire up video next weekend. This week, I'll be working on the body electrical, so I can start the car from inside it, yay. This car had every available option so this will get complicated.. I also hope to get the driveshaft ordered this week.

Awesome progress. You're kicking my butt! Have you seen that Fabbot has a short shifter on the market? All billet for $189. 

Honestly I wouldn't be progressing this quickly if it could have been avoided, also Scotty or anyone else who intends to "thin" a factory harness, I highly suggest that you thin it and then lay the harness out over the engine before it is in a vehicle as that would have made life way easier. Anyways, I have seen their short throw although I think the factory throw is fairly short to begin with especially for a truck. Speaking of though I really need to mount my dash and bench seat to make sure I have room for the shifter, I think I should be good though.

Update time! So budget first.

Previous total $8956

Add (8) injectors $175 the cheapest new injectors rockauto sells. I hope they work.

Misc electrical connectors, tape, etc. $20

New total $9156... Wow way more than I intended to get to this point but.. here we are.

Anyways this is unfortunately a picture free update as most everything that I've worked on is sorting body electrical and tidying up some of the engine harness.

So I left you at the failed first start up which was a smorgasbord of laughable fails. So the evening started with me "finishing" engine grounds at which point I could not get the fuel pump to come on the keyed 12v. Checked power at the pump, nothing. Ran a dedicated ground from the battery... Nothing. Switched the ground to a hot, well at least the fuel pump works. Ok. Go eat dinner and have a smoke.. Oh do you think connecting the PCM grounds might help... Finally fuel to the rails... And all over the intake.. the quick connect failed and in doing so got fuel all over the outside of the "high pressure fuel line" that disolved in my hand. Wtf who sells high pressure coolant line... Ok go to flap and get a foot of high pressure fuel line and a new quick connect end. And installed. Hey the fuel lines hold pressure. Go to turn over motor on starter to build oil pressure.(brand new Remy starter mind you).. touch the starter lead. Click. Try again. Click.. are you kidding me. Luckily my buddy that was coming over has a couple of spare ls motors laying around.  So he brings me a original 4.8 200k starter over and it turn over well. Ok moment of truth.... Yeah good spark, good injector pulse, zero fuel flow... The top of the injectors where caked in thick nasty varnish.. I'm done for the night.

So Tuesday night after much fiddling I determined body fuse block power ins, 12v keyed in the engine bay, starter relay wire, and got all the lights except the turn signals to work. The brake lights work intermittently so probably try to clean up the brake light switch although I ordered a replacement thru Amazon just in case.. 

Tonight I got all of my signal wires for gauges run but not connected and changed the flasher and now have turn signals. Heck yeah. I'm glad body electrical is going smoothly so far..

Tomorrow I want to get the fuel rails cleaned as best I can, then reinstall them and the injectors, and finish tidying up engine bay electrical. So looks like Saturday is the likely first start up day as I'd like to see oil pressure before starting it for the first time.... Again. So hopefully, lord willing Saturday night or Sunday I'll have a video for y'all.

Friday was the first official fire up. Surprise, surprise first fire up didn't go quite as expected.. however, it did fire up on the first try, no fuel system leaks, no misfires, just a nice smooth idle however I failed to get a video while checking for these things as well as diagnosing a possible low oil pressure issue.. I only ran the motor for about 30 seconds that first time so everythings good but I pulled the driver's side valve cover to find barely a film of oil laying in the bottom of the head. Cranked the starter for about a good minute and finally had oil to all the rockers... Thank God.. so put the cover back on and fired it up for a minute or two and we did finally have steady oil pressure to all of the passenger rockers. There was also no valve train noises so I called it good.

Saturday, I worked on cleaning up more factory wiring, re-ran the wiring for the fuel sender and the reverse light switch. I also tested the wiper motor which was a no go.. hopefully it's just corrosion in the connector or the switch.

Today, I flushed the cooling system, installed my temp sensor for the gauge and filled the system with coolant. It ran for about 25-30 minutes, no leaks spotted yet, both fan speeds work, and my temp gauge never read past 190 so Im happy. I also took a short video but I have no idea how to post it, so any help on that would be appreciated.

I called the driveshaft shop today and unfortunately the only guy there who does driveshafts is on vacation this week so hopefully next week. There is still a fair bit of wiring left to do, I really need to make my gauge panel and get working on the interior. The biggest hurdles currently are the wiper, no rear markers, license plate light and I need to make a bracket for the parking brake cable.. but getting very close... I really can't wait to take this car for a rip.

So between yesterday and today I did a thing with gauges..

I pulled the gauges back out and painted the panel so hopefully it will be dry tomorrow morning so I can do I final assembly and get the gauges wired. FYI, hole sawing 20ga sheet is awful. Of course I found diamond tiped metal "hole saws" (think cutting Stones) as soon as I finished; both harbor freight and Amazon sell them reasonably cheap.... 

So small update. The gauges are mounted back in the panel, I ordered the driveshaft, and started wiring the gauges..

4 hours later and everything but the signals are ready for connector ends.

hopefully Thursday I can get the panel side finished and start on the body side connectors.

Did i miss where these $130 caliper sets came from?? I've re-read this thread 2x... PLEASE SHARE :)

In reply to g00b86 :

Sorry, Speedway has them in standard size, 2.625 and 2.75 bores. Just search metric calipers.

In reply to g00b86 :

I also approve of the big bore calipers. Ran them the whole first year tracking my cutlass with some BP-10 pads and they were great. Really good option for Street/Auto X/ light track duty on a car without big power and lots of tire.

So Sunday update. Happy Halloween.

Budget 

Previous total $9156

Custom 3" driveshaft $375

Jegs 2.5" A-body header back system minus mufflers $186

New total $ 9717

So unfortunately Jegs has an intergalactic backorder till Jan 2022 for gbody exhaust systems and I couldn't find a local shop willing to make a system so I will be making my entire exhaust myself...

In other news the I finished the gauge wiring. And all gauge wiring connects thru weather pack connectors.

Also seats, dash, and gauges are installed.

Also all exterior lights, the horn, and the wipers now work. So with the a few exceptions the wiring is complete. Hopefully this week will see the install of the driveshaft, finishing out wiring and begining of building the exhaust.

Well, I'm finally back. So, since the last update there has been little progress. However, I was able to take it for a couple of spins around the block... first thoughts are this thing really really needs an alignment.(I suspect way too much toe in as barely turning the wheel results in a sudden jerk in that direction.) it has both the stiffest and shortest clutch engagement ever!!!(the pin for the master definitely needs to be further up the clutch pedal arm.) Also I'm 100% convinced my 7.5" axle is going to explode in the near/immediate future. Also, an open diff and 225 tires are a laughable traction situation at best.(even slightly abrupt clutch engagement with minimal throttle input results in tire spin)

On the topic of alignment, I think my coil springs need swapped side to side, as it has a serious lean to the drivers side.(grumbles berk gm & moog for using different spring rates side to side...) I also came to the conclusion that a classic plate is worth the lack of frustration for Inspection and emissions purposes. So, my current goals for this summers car season are as follows. Build an exhaust and finish any other work required for inspection. Fix the suspension issues and get an alignment. Build my 8.8 and add rear disc brakes; which will require bigger diameter wheels. So new wheels and tires. Then the rest of the season will be spent ironing out drivablity and maintenance issues.

I ordered my classic plates last week so hopefully I will see them before June but idk. I also am going to pick up wheels/tires tomorrow night out in Youngstown OH. This coming weekend I intend to start working on the exhaust which I built a custom x-pipe for a couple of weeks ago.

The other pressing item on the list is ordering my axles, which I need to take some measurements for. I'm using a foxbody 8.8, want 31 spline axles and intend to run 03+ panther rear disc brakes as the are a fairly large diameter disc and have a drum in hat parking brake. Well that's it for now, hopefully I'll have the exhaust done with an update next weekend.

Sorry if I missed it earlier, but are you planning to turbocharge it?  That and the manual transmission would make for one very neat GNX clone.  Look forward to seeing you progress!  I miss my GNs and want another.

New wheels are home. 08 G8 GT 18x8s wrapped in Firestone firehawks for $350. 

I took a more thorough look at what I'd need to put panther brakes on my foxbody axle and I think it's going to require more work then I currently feel like dealing with. (shortening axle tubes & replacing housing ends most likely) so 9" drums, 31 spline 5 lug fox axles, a new trac lok, and a free set of 3.08 gears are the current plan for the rear end.

Kendall:

I really haven't decided yet. My current goal for it is to make 450 whp NA with some home hand ported factory heads, a tbss intake and a mild cam. However, buying a VS racing 78/75 is very tempting and more than capable of 750+ whp for stupid cheap. I've honestly contemplated buying a 4.8 or 5.3 just to turbo it and squirreling away the 6.0 for something else.

hey happy Bday!!!! at least yours is running......

In reply to 759NRNG :

Thanks. Yeah it is running/drivable and does wicked one wheel peels even from a stab..  

But so many kinks to iron out. The body/suspension lean is really grating on me most, I just don't understand why with all new body/suspension bushings, springs, shocks, etc. It leans so bad, if it where only one corner I could see it being a frame issue, but a whole side.. the more I research it the more I wonder if it's just normal for an 80s GM but I don't ever remember it before. The easy solution would be coil overs but I really don't want to drop that kind of cash in a spend and hope situation. It could be either bushings binding or the coils aren't seated properly/swapping coils side to side but if it isn't either of those the only cheap solution I can figure is either cutting coils or adding spacers. Also I can't cut the rear springs as gbodies use double pigtail rear springs.

I did get a fair bit of the exhaust cut/tacked this weekend, however I ran out of shielding gas so.. that came to an end.

No lie, we had an '85 Cutlass Supreme that my folks bought new and had the car loaded up with four people when we drove over a wooden bridge. One of the rear springs just straight-up broke. It couldn't have been any later than 1987 when it happened because we traded in the car that year -- after getting the spring fixed. Much later (like 2013) we took apart an '85 fox Capri and sure enough one of the springs is already broken. Springs from back then just weren't very good. Bad metallurgy close as I can figure.

Update time.

Budget first

Previous total $9,717

Speedway 2.5" multi bend pipes used to make the x-pipe $53

G8 GT wheels w/wide ovals $350

New total $10,120

So last weekend I was only able to tack everything up to the exit of x-pipe and then promptly ran out shielding gas. So, I called around and managed to get a free upgrade from a 20CF cylinder to a 40CF cylinder and by Saturday afternoon this happened.

By 9pm the over the axle, tail pipes and hangers where finished as well as finally having O2 sensors. Also, I finally have no CEL issues. 

Today I wanted to get the bumpers mounted and do a bolt check. The hood release had other plans however and left the chat. 2hrs of mangling the sheet metal between the core support and the fiberglass header panel; and eventually I was able to remove the hood latch with multiple wobble extensions. The pot metal clip that retains the hood release cable broke off.. So, I did eventually get the bumpers mounted but by that point I was more than ready to call it a day.

So that brings us up to current. Hopefully my title and plate will be here this week.

Hey sweet exhaust porn ......well done!!!!!...sorry about the hood release what a PITA. My latest drama is an electrical drain in my 03 Dmaxx....have been givin' some instructions on how to proceed ,but not the time to address.....carry on

Holy crap it's been over a year. So, brief update I bought HP tuners and a laptop last summer so other than buttoning up the exhaust I spent most of last summer teaching myself how to tune and trying to get it dialed in. A couple of weeks ago I had a fruitful trip to Pittsburgh U-pull & pay. I picked up an 07 grand Marquis 8.8 and a set of 243 heads for a little under $400 bucks. Also a buddy gave me an TBSS intake so this winter/next spring is looking good for a heads, cam and intake swap. I will likely do a write up on my adventure to narrow, truss and rebracket that 8.8 in the near future.

Small update, trying to not let too much time pass between posts. My plans for the car this year are to make a few small steering and handling upgrades, maybe upgrade the front brakes to a C5 setup but most importantly build a solid 8.8 rear with mostly stock suspension geometry. There are kits to swap a foxbody axle under a Gbody.. which was my original plan but after seeing what brake options were available for a foxbody swap and my lack of enthusiasm for the swap kits. All of the swap kits use double adjustable heim joint trailing arms which I don't dislike on there own, but the angles at which the joints live at ride height are far less than ideal sooooo... Why not build brackets and spring seats myself.

So I started by cutting off all but the caliper mounting brackets and grinding them smooth.

Then sanded and painted the majority of the axle since it's currently in a pretty damp garage.

Next I tore the axle the rest of the way down to see what brake components could be saved. Unfortunately it's mostly just the backing plates as the calipers could probably be rebuilt but with as cheap as panther platform brakes are it just doesn't seem worthwhile to do so. Speaking of which the panther discs are 11.250" dia or so and have a large single piston caliper. The rotors also feature a drum in hat parking brake which I'm pretty stoked on. The adjustable proportioning valve is definitely going to get a good test as these probably produce close to the same braking force as my current front setup. 

Lots of measuring later... And measure again.. and again.. 

Next I tore into the foxbody axle I had originally planned to use for more measurements. It has some decent stuff in it. Seems like the diff, ring/pinion gears and and axles had been recently replaced.

Hopefully this will recoup some nice $ into the budget. I paid 150 for it a few years back. I ordered 31 spline fox axles with the 94-04 mustang 5 lug hubs as well as new bearings and a few extra crush sleeves as this will be my first time setting up a gear set. I'm revisiting the idea of building an axle truss since the stock spring seats sit so close to the center section of the axle it seams pointless. I've also decided that sleeving the axle tubes might be a good idea since I intend to cut them near the center instead of drilling the factory welds and pulling the axle tubes to cut them as I don't have the tools/fixturing to make it straight again after. That brings us up to current there are a few more parts to be ordered and more to be made but my hope is to have the axle and new wheels/tires on the car before the fourth of July when family will be in town and a week before the Gbody Classic car show in OH.

Big update!

The axle housing is done!

I started the rest of this project by pulling the stock 7.5 for all of the dimensions needed.

Next I cut 5.125" out of each axle tube.

I used a couple of pieces of 3" channel as a jig to hold the tubes straight while I tacked the tubes together.

Tubes tacked.

Next I final fitted the "battle box" as I'm calling it and cut UCA bushing brackets to fit.

UCA and LCA brackets are tacked.

Test fit for the spring perch/tube braces.

All welded up and in need of cleaning and paint. Christmas does come in July.

Next up is clean up and paint then a test fit. Followed by replacing the diff and setting the ring and pinion. Updates to follow soon hopefully.