🔧 BUILD Quest for improved 4th gen Fbody drivability

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I wanted to update this thread (June 2023) with a more detailed summary of the 14-year journey with my 1998 Trans Am. In my day job, I'm an automotive journalist, so I drive a lot of performance cars, and every winter when the TA is under the cover I’m tempted to buy something new after driving the latest and greatest all year, but then every spring I get back behind the wheel and regain enthusiasm to keep at it. My goal over the last couple of years was to give it as much updating as possible to build a well-rounded late-model muscle car that blurs the line between muscle car and sports car, just how the new Camaro and Mustang have evolved over the years. And to get there, I had to correct a lot of self-inflicted mistakes that ruined the car’s drivability without much gain. This is quite the write-up for an only mildly interesting car, but verboseness comes with the territory, so here we go:

I bought the car from my cousin’s husband in 2009 for $4,000 with 100,000 miles. Their priorities shifted and the car was in need a lot of maintenance; it ran poorly, had dry-rotted tires and was in barn storage so it came with a family of mice for no extra charge.

What I bought was a stock 98 Trans Am with 16-inch wheels, sleek beak hood and SLP loudmouth exhaust. I immediately added drag radials, addressed the maintenance items and went to the drag strip, hoping for high 12s, low 13s because that was my expectation after being on LS1Tech for 5 minutes. HA. Well, the fastest F-Bodies run those times in later build years with 3.23/3.42 gears, LS6 intakes and factory production tweaks to the cam/heads. In stock configuration with loudmouth exhaust, my 98 with 2.73 gears, LS1 intake and 853 heads ran anywhere between 13.6 and 14.0 seconds, which was slower than my (at-the-time) daily driver mildly modded Grand Prix GTP.

From there, I added a Yank SS3600 torque converter and rear tubular lower control arms, which knocked 8/10ths of a second off the quarter-mile time to run consistent 12.8s; sub-frame connectors also went on at this time and really helped clean up the rattles and looseness of how the car flexed over bumps.

And then I ruined the car for a few years with poor choices.

I put a lot of trust into a performance shop that picked an inappropriate cam and didn’t put the effort into tuning. The car wouldn’t start when hot, it inconsistently idled and the torque converter tuning would make the car lug and vibrate. It was really a couple of miserable years with a loud, annoying and slow car. The cam was 231/235 .617/.621 113+3 with stock heads and a really mismatched powerband for an auto car with 2.73 gears. The car also had an LS6 intake, 42-pound injectors, 1 3/4 headers, off-road Y-pipe and Magnaflow exhaust. From there, I found a new tuner who fixed all the drivability issues so it drove much nicer, and then added 3.73 gears.

I had it dyno’d a few times in this configuration. The initial shop’s dyno spit out 401 rwhp. On a Dynojet at Dean's Performance with the revised tune, numbers were 370/345 in third gear with the converter unlocked. And then I had it dyno tuned from Speed Inc where it made 380 rwhp and 355 rwtq on their Dynojet. But it I was still disappointed at the track, running a best 12.0 at 113 mph. Looking back, that initial shop’s first dyno was laughable considering the trap speed and how poorly the car drove.

During this time, I also played a lot with the exhaust, finally settling on a Kooks catted Y with true merge, versus the ugly T-merges from previous designs that created that awful hammering sound at part-throttle.

And then I decided to take a big swing at the car. Up to this point, I had been running QA1 shocks at the back with drag radials, while up front was stock shocks/springs and summer tires. I hated how the car drove with a clear imbalance between the front end’s tightness and rear end’s looseness. I also had a drag-oriented short torque arm. So off all that went and in come the final suspension setup: Koni shocks, Strano springs, Strano sway bars, UMI long torque arm, double-adjustable lower control arms, adjustable panhard bar and a few other things. Holy smokes. Besides the converter, it was probably one of the biggest changes to how the car drives. Tight, controlled, responsive. It was like driving a car 20 years newer, instead of a bucket of bolts like how it drove with the old suspension.

Under the hood, I had Pat G from LS1Tech spec out a combo that would give stock-like drivability but with 11-second potential. It consisted of a pair of 799 heads (Z06-equivalent) pulled from a junkyard, which I had cleaned up and checked out, and an EPS cam with the following specs: 222/226 .626”/.626” 115 LSA +3, as well as a refresh of the valve train with trunion upgrade on stock rockers instead of something fancy the other shop installed. With this milder cam and upgraded heads with more compression, the car saw a giant torque increase under the curve, and power was much more usable and better matched to the auto trans. Now, I was making 390/375 to the wheels on Speed Inc’s dyno, but with a lot more power and torque under the curve and stock-like drivability.

That resulted in 11.82 @ 115 mph, and it has trapped as high as 117 mph. I consider this very impressive because it drives like it did when stock and power is accessible all over the place. Since then, I’ve installed a chrs1313 A/C ram air and have a dedicated set of C5 17-inch wheels with Hoosier drag radials to try and hit 11.50s, but my last time to the track with the setup was a bust because (as I discovered afterward) the throttle blade wasn’t going WOT thanks to the throttle cable adjustment being unclipped.

I still enjoy driving the car. I debate what to do with it (sell or keep) because I also feel a sense of stewardship to keep this car on the road looking and driving as good as I can make it. All the kids in the neighborhood turn around and give it a thumbs up when I drive past, and my kids (2 and 5 years old) call it “Dad’s Trans Am.” They pretend work on their cozy coupe (like dad’s car). I know it’s superficial, but I don’t think I’d get that kind of engagement in a CTS-V or newer car. Or maybe I would, because they could actually ride in a car that properly fit child safety seats … the debate continues.

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Turbocharged400sbc

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Laiiid back....with yer mind on yer money and your money under yer behind....

I love the corbeau in the tr.... It just takes a couple weeks of driving it before my ass cheeks mold to the seventeen inch width

At the dealership we used to clamp the headrest in the vise and bend the mount bars when customers requested changes.

It was a wrench with the twelve point teeth round out with a diagrinder that we used to gain leverage And not damage the chrome
 
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sktchy

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Honestly the firebird seats are where it's at unless you wanna spend the money for high end. A couple washers underneath on the front mounting studs to lean the bottom part back a touch is all they really need.

You ever sat in one of the leather Camaro seats? They're terrible.
 

Bru

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$40 Goodwill amp arrived. Looks well-taken care of. Retails for $189 new, so ?

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Bru

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I dove into the headlight replacement, first starting to diagnose why the driver’s side headlights weren’t getting power.

IMG_5358.jpeg


For the second time, the 5-pin headlight harness connector was corroded and gunky. I replaced this connector about 7 years ago, and it was serviceable this time, but that wasn’t my only problem. I hacked it together the last time, using poorly sized connectors and wrapping everything in copious amounts of electrical tape. A couple of connections were also corroded and falling out of the splice.

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I haven’t soldered anything before, so thought this was a good opportunity to learn. What a pain in the ass when there’s no slack and very little run from the harness to the end (also my doing, hacking it off too short last time).

IMG_5368.jpeg


Anyway, everything worked after cleaning the connector and soldering the wires so I installed the new replacement LMC Truck headlights with 9006/9005 bulbs instead of sealed beams. Against the garage wall, the new housing (left) is much more focused than the original (right). This was with the engine off.
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After I get these lights in I need to align all the new hardware and then take it for a drive. I also plan to explore LED headlights but have some concerns with depth and the retracting headlights.
 

sktchy

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I looked into LEDs really hard when I was driving my bird and have a couple sets laying around I could send if you want to experiment. The biggest thing is gonna be getting them to fit in the housings without it being janky iirc. Of course it's next to impossible to find a size that will just pop in.
 

Bru

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I looked into LEDs really hard when I was driving my bird and have a couple sets laying around I could send if you want to experiment. The biggest thing is gonna be getting them to fit in the housings without it being janky iirc. Of course it's next to impossible to find a size that will just pop in.
Appreciate the offer. The GTR Lighting Ultra 2.0 appears compact and adjustable and is what I hope will work.

 
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Thirdgen89GTA

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I dove into the headlight replacement, first starting to diagnose why the driver’s side headlights weren’t getting power.

View attachment 165406

For the second time, the 5-pin headlight harness connector was corroded and gunky. I replaced this connector about 7 years ago, and it was serviceable this time, but that wasn’t my only problem. I hacked it together the last time, using poorly sized connectors and wrapping everything in copious amounts of electrical tape. A couple of connections were also corroded and falling out of the splice.

View attachment 165405

I haven’t soldered anything before, so thought this was a good opportunity to learn. What a pain in the ass when there’s no slack and very little run from the harness to the end (also my doing, hacking it off too short last time).

View attachment 165407

Anyway, everything worked after cleaning the connector and soldering the wires so I installed the new replacement LMC Truck headlights with 9006/9005 bulbs instead of sealed beams. Against the garage wall, the new housing (left) is much more focused than the original (right). This was with the engine off.
View attachment 165410View attachment 165408View attachment 165409

After I get these lights in I need to align all the new hardware and then take it for a drive. I also plan to explore LED headlights but have some concerns with depth and the retracting headlights.
Soldering is great, and your job is already done.

But after the squirrels chewed the harness on the GTA and I had to fix nearly 25 PCM wires in a parking lot, dragging the soldering station out there and trying to solder int he engine bay just sounded a pain.

So I picked up these, and I love them. Just need a heat gun and wire stripper. The heat gun melts the metal solder insert so it wicks into the wire, and weather seals the connection at the same time. Strip wires, slide the end on, twist them together, and heat gun. Boom done.
 

Thirdgen89GTA

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Well, I'm gonna bet that your soldered connections are better than these. But, for most connections I'd say they are good enough. I mean, if simply twisting the wires together is good enough, then this is 10x better. And your straight soldered connections are better still.

But the convenience is nice if its a pain to get a soldering iron into a tight spot.
 
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Mr_Roboto

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Theoretically you're not supposed to use solder on car wiring because it can work harden and break off. Done it anyways admittedly, so take it for what it's worth.

That said, you really forgot the last step on the original repair. Those light blue connectors are heat shrink butt splice connectors. They're really nice and not cheap shit like the regular ones. If you had the wire stripped to a good length (not way over stripped like a few of those) and took the bic lighter to them after you probably wouldn't be touching it again.
 

Bru

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Theoretically you're not supposed to use solder on car wiring because it can work harden and break off. Done it anyways admittedly, so take it for what it's worth.

That said, you really forgot the last step on the original repair. Those light blue connectors are heat shrink butt splice connectors. They're really nice and not cheap shit like the regular ones. If you had the wire stripped to a good length (not way over stripped like a few of those) and took the bic lighter to them after you probably wouldn't be touching it again.
You can see the burn marks on the tubing. I tried :rofl:
 
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IDAFC21

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Soldering is great, and your job is already done.

But after the squirrels chewed the harness on the GTA and I had to fix nearly 25 PCM wires in a parking lot, dragging the soldering station out there and trying to solder int he engine bay just sounded a pain.

So I picked up these, and I love them. Just need a heat gun and wire stripper. The heat gun melts the metal solder insert so it wicks into the wire, and weather seals the connection at the same time. Strip wires, slide the end on, twist them together, and heat gun. Boom done.

Well I don't have any immediate need for these, but they are now saved in my amazon shopping list. so that if/when the day comes, I don't need to try and find this thread again :ROFLMAO:
 

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