Firebird Trans Am Rebuild...

After the TA's gearbox stuck in top(!) on a 200km run, I decided it needed a rebuild. The build got a bit bigger than planned and ended up including a lot of the car. Then I just, err, carried on changing things! Scan on down to the end if you want to see the whole process from the beginning.

New engine:

Texas Speed LS3 block based 6.2 Litre LS376 V8, with TSP 233/239 .595” lift cam, 11:1 compression, Texas Speed Aftermarket PRC heads with 62cc chamber, 225cc inlet volume + Texas Speed valves/springs, Competition Cams 1:8-1 roller rocker set & TSP chromoly pushrods, Powerbond 10% underdrive front pulley, Professional Products 94mm Throttle body, Fast 92mm intake manifold, Bosch 36lb injectors, and an LS7 card MAF. Modified SLP full airbox air filter system + “honeycomb” air correction. Hooker Headers 1.75” Competition Pro long headers, Fox custom made 4” stainless Y-pipe and rear exhaust system, with oval pipe ends, Oil cooler, No throttle body heating. 160 degree thermostat. Disabled rear 02 sensors, Air injection system removed/disabled, Custom tuned ECU. Racetronics 255l/hr fuel pump. BeCool double thickness all alloy radiator. Elite Engineering oil recovery system.

New transmission:

Tick Performance TR-6060 Magnum 6-speed manual, modified for TA installation with Bronze shift pads, shortened 31 spline mainshaft etc, ratios 2.66 1.78 1.30 1.00 0.80 0.63. Strange Engineering 1350 front and rear propshaft yokes. FX Racing Stage 2 clutch and 15lb lightweight chromoly flywheel. Strange Engineering 12 bolt Chevy rear axle with 4:11 ratio, US Gear clutchpack LSD, heavy duty 33 spline halfshafts. B&M Ripper Shifter, Skip shift gearbox feature removed. BMR adjustable torque arm. Precision Shaft Technologies 3.5” aluminium propshaft.

Brakes/Suspension/Steering:

Strano 1.5” lowered springs + Strano customised bilstein shocks , Braided brake hoses, Energy suspension antirollbar bushes. Jeep rear bumpstops. Corvette Z06 355mm front brake rotors plus CTS-V four piston Brembo front calipers. BMR tubular upper and adjustable lower front suspension arms. BMR tubular adjustable rear trailing arms. BMR adjustable panhard rod. Corvette ZR1 Wheels 18 x 9.5" 285/35 rear and 265/35 front. Summit Racing drilled/slotted rear disk rotors. Hella UP28 supplementary electric brake vacuum pump with pressure switch. Ex Toyota MR2 electric power steering pump replacing belt driven one.

The rest:

Recovered interior seats (same as original). JVC K-V20BT Bluetooth/LCD touch stereo head unit. Replacement interior door panels, uncracked. Sunshades deleted. ‘Angel Eye’ front foglamps. AD244 alternator. LED bulbs in all exterior lamps except headlights. Smoked marker lamps. Brass headlamp lift gears. Aftermarket oil pressure, water temperature, wideband air/fuel ratio gauges on drivers A-pillar. Tick Performance adjustable clutch master cylinder. All stereo speakers replaced with a Kee Audio package with Bazooka 6.5” DVC woofers and CDT 6.5” mids + tweeters and CDT small mids/tweeters.

Ongoing Work:

08/06/23

Not updated lately as car is not in use, due to be shipped back to UK when I go.. However, I have completed the electric PS pump mods and the vac pump, and all seems to operate "as expected".

29/11/20

Finally took a picture of the installed vac and PS pumps, unfortunately the engine bay is covered in dust as well as the unfinished wiring! The PS pump is a little left of dead centre, with piping unconnected so far. The vac pump is at lower RH by the coil of green wire. The control relays and fuses are by the yellow loop of pipe at the RH side, which goes to the pressure switch for the vac pump, behind the relay box. Still waiting for a new 550K6 belt as it's a lot shorter without the pump, plus a new ribbed idler pulley, since the belt routes differently of course.

27/11/20

Manufactured a bracket to mount the MR2 PS pump on the front of the RH head of the engine, roughly where the belt driven pump was. I had to chop all 3 of the existing cast pump brackets off to make room. The bracket bolts to the head via 3x 10mm studs in the holes that already exist there. Required me to also modify the 4x bolts that hold the cover for the electronics on the pump on, I enlarged them to 6mm as I'll hang the pump off them.

18/11/20

Quite a lot done, the vac pump is more or less installed, tested and works, with a pressure switch to control it. I have to find the best place to pickup a switched ignition feed for it as well, that’s all. The PS pump wiring is done, but I’m still looking at how I can mount the actual pump. Probably I will have to chop off one or all of it’s cast-in mount brackets because they are too big and in the way, see the picture below;

Ex-Toyota power steering pump.

15/11/20

Some new things! Decided to add an electric vacuum pump to the braking system, because I suspect it doesn’t have the ’suck’ to really work well all the time. PLUS while I was at it I thought that perhaps I could get rid of the belt driven power steering pump, which I hate, because they always seep a bit and generally are a pain. Bought a s/h Toyota MR2 PS pump which is standalone, having it’s own microcontroller to manage pressure demand etc., and a Hella UP28 vac pump off an Opel (I think..). Now have to sort out relays, fuses, wiring, they both take significant amounts of power.

09/5/20

Replaced the long tube headers with standard manifolds and custom built link pipes in order to get the car past its yearly test (very annoying). Has reduced the ground clearance slightly which is also annoying. Changed the AC compressor. Replaced battery which died unexpectedly one day.

21/1/19

Replaced water pump which had started to drip water. Also replaced the air/fuel meter as it started displaying random digits sometimes. New version (of same device) better, software seems to have been improved etc. Rearranged some minor underbonnet pipework and while there, removed the failed AC compressor and blanked off the pipes etc. Cleaned up the throttle body since I had to remove it to change the water pump.

16/1/19

One full throttle blast and rear silencer box shifted again. Ripped it right off, ground the very short clamp slots longer, cleaned off unnecessary and slippery silicone sealant, tweaked the mounts and re-installed. Went for some full-throttle runs and so far it hasn’t moved...

11/1/19

Oil and filter change and I see that the damn water pump has started dripping… I replaced it 4 years ago, I suppose that’s not so bad, sigh, time for a new one. Silencer rear box AGAIN has shifted, adjusted hangers again and modified the clamp a bit, I hope its enough. Changed the air filter/intake from the 100% open K&N to the more ducted SLP airbox that I have, with a flat filter, but modified to allow a lot more air (hopefully cooler) through from underneath. Initial test runs with HPT say that its better than the K&N, I believe due to the better “air path” through it.
Tried to ID the source of annoying oil leak near the oil filter, I’m 90% sure it’s the oil cooler takeoff somehow.

4/1/19

Replaced drivers side o2 sensor as it had failed. Drivers side axle no longer leaks.

23/11/18

New silencer box shifted and nearly fell off! -Reclamped it and adjusted the hangers and seems ok. Changed drivers side rear axle inner seal to hopefully stop it seeping axle oil on that side.

10/11/18

New single outlet rear silencer box has taken the noise down by about 10dB, and now it passed it’s yearly test. Adjusted the clutch pushrod to give a bit more clearance, gearchanges now much nicer. Replaced rear tyres with 285/35’s. Swapped the driver side header gasket to match the passenger one, seems this side was leaking a bit as well. Puzzlingly, the new exhaust has made the car more economical AND more powerful… can’t quite see why.

2/10/18

Adjusted the rear ABS sensor and now it seems to be operating ok. However the car failed yearly test for exhaust noise, so Fox Exhausts are building a new, quieter stainless rear box for it. Topped up oil and water levels.

2/9/18

Rebuilt the A/C <again> after it failed after a year… why I don’t know. Anyway replaced compressor, condenser, accumulator, orifice tube and all seals, plus I installed an aftermarket filter just for luck. Also blew out the old oil from evaporator and any re-used parts (only a couple of pipes). Hope its ok now… Also swapped out the MLS passenger side exhaust manifold gasket for a Felpro one, I couldn’t stop the MLS one leaking slightly.
Also swapped out the failed rear axle ABS sensor for a new one, but no time to adjust it, that must be done later. Replacement of the drivers side rear axle oil seal also has to wait, however I changed the axle oil at least.

12/6/18

Replaced the high level stoplamps with LEDs (I had left those as wasn’t sure LEDs would be bright enough, but they are).

15/5/18

Replaced the steering wheel button cluster with new one, now the stereo is back to normal. Ordered some 4” alloy pipe bends as the existing air cleaner isn’t big enough, I hope to be able to work out somewhere else to put it, such as where the battery now is. Considering ordering 18 x 10.5 rims to replace my 18 x 9.5’s, there’s too much wheelspin! Also I need to change the passenger side exhaust manifold gasket, it has a blow.

21/4/18

Replaced the idler and tensioner pulleys for the A/C belt, some of the very few parts that came from the original engine. They’d started making odd noises now & again on startup. Oh joy, one of the pulley mount threads was half stripped, had to helicoil it. Noticed that there is still a slight oil seep from the takeoff block for the oil cooler, annoying! Ohhh yes, and the RH side steering wheel stereo buttons died, ordered a new one, I hope the wiring/clockspring is ok...

12/4/18

Oil & filter change, also checked for oil leaks etc. since previous change of clutch front seal etc., all seems ok. Changed spark plugs from TR55’s to NGK Iridium’s.

2/12/17

Greased all the grease points. Checked all pads (ok). Shortened rear trailing arms by 5mm to avoid rear of diff housing touching body sometimes. Checked and tightened intake manifold studs, a couple were slightly loose.

24/10/17

Clutch slave cylinder changed, what a pain, the only good part was that it was easy to refit the gearbox. Also while under the car, changed the front crank seal (weeping), again imho due to the aftermarket underdrive pulley contact surface not being finished well enough, I polished it with 600 and 1200 wet&dry before refitting. Replaced the aftermarket Chinese (sigh...!!) oil pressure sender as well as it was weeping oil when under pressure, fitted a proper VDO one. Changed the engine oil whilst I was there...

21/9/17

Clutch slave cylinder failed a couple of days ago, suddenly. :( I believe on checking that it was a Chinese ‘knockoff’, not OE (it came in the clutch kit…). Bought an OE one, now got to drop gearbox to change the damn thing.

19/9/17

Replaced the stereo speakers, finally getting rid of the mismatched and naff speakers some previous owner had installed. The car has a 500W 8-speaker system as standard already, I just replaced the drivers with newer alternatives! Now it has;

· CDT Audio CL-61CV2 6.5" Midrange & Tweeter component speakers (doors)
· Bazooka 6.5" DVC Subwoofers (sail panels)
· CDT Audio CL-4EX midrange coaxials (hatch area)

1/9/17

A/C now rebuilt and ok. Stripped & rebuilt rear axle and found that one diff carrier bearing was totally shot, (pinion side) don’t really see why, as all the clearances etc. seemed ok (after I changed the 2 carrier bearings). The actual gears seemed fine, so did their contact patterns - anyway shoved it back together and almost no whine now, but I might revisit it.. The backlash was .010” which is the high end of ok (.006 to .010). I also noticed the Strange axle had what I’d say was too much axial play in the taper roller wheel bearings (about .3mm) but no apparent way to adjust it… ?

Still need to change front engine oil seal, its weeping, not bad but annoying. Means pulling the front pulley.

Remains of the Diff bearing…

6/6/17

Installed replacement headers, ceramic coated, identical to the original Hookers but now made by Flowtech. Added a supernumary throttle return spring because the throttle is too light. The A/C pump has seized! Hence purchased a Denso replacement pump plus accumulator, and will have to change it all … :(

Also in process of amassing bits needed to strip and (where needed) rebuild the rear diff, to get rid of the deafening whine. I am hoping it needs only shimming but better safe than sorry!

Running through the tuning cycle again in an attempt to get it closer, so far all ok, but it does drop off a bit above 6000 rpm, perhaps its the steel roller rockers, should have changed them to aluminium during the build!

24/4/17

Installed Tick adjustable clutch master cylinder, which has removed the annoying slight drag and made changes nicer. While doing it, tidied up some badly modifed wiring under the dash by the clutch pedal as well. Ran a bolt check on rear suspension, changed the handbrake cable routing slightly.

22/2/17

The rear bush that I changed seems to be ok now. Replaced the dashboard top panel which was cracked to pieces as they all are in these cars. Changed the front tyres as knackered by the inaccurate tracking earlier. I believe I will need to get an adjustable clutch master cylinder because the standard one only just manages to disengage the clutch sometimes.

22/11/16

Replaced rear bush using Loctite 260 and also oil seal, & topped up the gearbox, it seems to have lost about 3/4L. Readjusted the pinion angle slightly as well, it’s around -2.0 degrees now. Also sealed the diff support bolts which were weeping slightly. Replaced the bolts and spacers on the stamped cross-piece which prevents the exhaust/propshaft falling onto the road if something breaks...

1/11/16

Investigation showed that the rear gearbox housing bush has ‘walked’ (you can see it sticking out in the pic below) and touched the rear seal, causing it to leak. Need a new seal and a new bush, plus Loctite 260 and staking for the replacement bush! It also needed a special tool to get the bush out without pulling the new gearbox to bits...

The bush is surprisingly beaten up, I can’t really see why, unless it was installed badly, since it’s almost new.

22/9/16

Refilled the AC, which was operating very well...until it all leaked back out in about 10 days.. Now got to find the slow leak. Even better, the last time I parked the car, it leaked about half a pint of gearbox oil onto the floor! Whats going on! That gearbox is NEW! It appears that the rear seal has failed, which thankfully is easy to change and cheap, but I can’t see why it would fail. I’ll know more once I get it off.

Also had a full 4 wheel suspension/steering alignment done by a firm with the lasers etc, as I knew it was way off, and it’s not easy to set as DIY... Caster was well off on one side, toe-in off, but camber was close.

5/9/16

Discovered the A/C condenser (dodgy Chinese aftermarket) has a crack in one pipe.. :( Replaced it with an OEM one, which interestingly only weighed half as much as the Chinese one (?). Still got to refill the A/C. The headers sent are correct ones, but uncoated!! Grrrr...won’t fit them yet... Finally got the car through it’s yearly test (it failed emissions twice) by suitable ECU tweaks. Now back in closed loop at idle, it seems to be ok, now I understand the emissions settings (and got the 5-gas analyser working).

1/8/16

Rebuilt the A/C system with all new seals and some new pipework. Nice new A/C drive belt also. Adjusted the tracking which was way out. New Flowtech 1 7/8” long tube headers, ceramic coated, are on the way also (the same as existing design). Car running in open loop (only at idle) now, and it seems easier to setup & control.

19/7/16

All recent work has been on setting up the fueling/ecu, and it is a long and complicated task! However it is getting quite close now, after many many changes. The headers also blew a hole in themselves(!) due apparently to fatigue, so a new set of headers will have to be found and fitted, but I have temporarily welded the hole (badly...) for now. Ordered a few bits (seals etc.) for the A/C so that it can be got back running.

OOPS!

21/6/16

Been “away” so little work, but I did discover how to improve the on-idle HC emissions –a lot, by tweaking the injection start point, so I’ve done that. Now need my “new” gas tester to be working, awaiting some bits for it (principally a 3V battery for the PCB, otherwise it seems all operational, I might even buy it a new 02 sensor, although I’m not that interested in the 02..). Replaced the front antiroll bar bushes & links with HD ones also.

8/5/16

Replaced bent pushrod, readjusted all etc. Fitted MAF honeycomb, it has clearly improved air metering, managed to get the car’s low speed idle behaving much better, though still a way to go, now need lots of testing logs! But on a short road test it already feels better and the logs look more healthy...

2/5/16

Found & fixed odd issue with handbrake, the mechanical lever was out of whack, now it’s ok and adjusts properly. Replaced all the rocker adjusters as ANOTHER one backed off and this time also a pushrod bent, I’m not sure why it bent though? Anyway, a new pushrod to be fitted, hopefully the valve is ok. Fitted shorter drive belt and now that also is OK. Fitted new reverse light bulb as one had blown. Ordered airflow “straightener” to improve MAF behaviour as I think it’s fluctuating and messing up the fueling.

27/3/16

Header-back stainless exhaust now custom built by Fox, and very nice it is. Bought new, drilled rear disks due to the parking brake drums being worn, also new park brake shoes. Found cause of misfire, one intake rocker adjustment nut had backed off, because the nut had failed (fatigue fracture), so a new set of locknuts are en route. That should get rid of misfire/smoking. Got to get a shorter accessory drive belt, it’s slightly too long, now & again it slips...

20/2/16

Temporarily fixed exhaust until I get it remade later. Fitted 2 new front 02 sensors and fitted new Innovate MTX-L wideband 02 gauge plus wideband sensor, and at the same time rewired the other 2 aftermarket gauges it has (oil press/water temp) so that they switch between day and night lighting like they should do, the previous idiot who installed them had stuck them in “night mode” all the time. Bought a leakdown tester as well, so I can check rings at weekend, since the smoking has NOT stopped, although it seems to be less. I suspect the valve seals getting damaged whilst I was cranking the engine and installing pushrods.

20/2/16

Adjusted the damn TPS for about 20th time, now finally it seems to operate reliably and between the right voltages. Installed an Elite Engineering catch tank system as well, and the smoking does seem to have stopped... However I split the silencer box with overrun backfires while out “testing” in the desert, so now that has to be fixed. A more worrying thing is that I have seen that one cylinder has far too many misfires showing in the ECU. It’s plug is wet/oily, and I don’t yet know why. Investigation required... Also ordered a pair of new O2 sensors “just in case” and a reasonable quality O2 gauge plus a pillar mount for it...

13/2/16

Fitted an OE TPS sensor, because the chinese copy one seemed crap. Fixed the reverse unlock issue, it seems that the solenoid pins are the other way around in current solenoids, even though everything else is the same. Added a PCV valve to the PCV circuit (supposedly not needed on these newer designs.. but...) because it smokes at idle for a minute or 2 after a run, seems to pull oil into the manifold. I have ordered a proper catch tank system as well, from Elite Engineering. Changed & filter oil (twice) and now on standard, semi-synthetic oil. I’ll go to fully synthetic after it’s run some miles...

26/1/16

Ok, now run 250 illegal (!) miles on the road, it runs well enough to use but needs a proper rolling road and o2 sensor setup. Just has 1st oil change (still on break in oil) and all seems ok. No leaks etc.. :) For some reason the “unlock” for reverse, that blocks it when you’re moving, doesn’t unlock, so you have to give it a huge shove to get it into reverse. Not sure why yet, the solenoid does have it’s DC supply present, but I’m not so sure the actual connector isn’t buggered. Seems unlikely the solenoid driver (which is part of the ECU.... :( ) would have failed, they are very well protected... Oil pressure runs at 5 Bar or more, temp around 80C when moving, so thats all very good. So far I took it to 6000rpm, no issues, except some pinking on heavy throttle, which I mostly tweaked out via the Knock Retard, but it’ll need proper setup.

17/1/16

Much work done:

New BeCool rad fitted, plus propshaft and all other items, exhaust system, etc., & car brought to functional state. Via a copy of HP Tuners software, an initial ECU config has been made and after about 50 iterations(!) it does start, warmup, and run reasonably, although it will need to visit a rolling road for a proper setup...

4/12/15

Engine cranked with no ignition in order to get oil and fuel pressure checked (ok). Intake system fitted, though radiator isn’t here yet. All electrics reconnected. Engine cranked again and fired up first time! Didn’t keep it running due to no rad etc.! PST propshaft assembled but not fitted yet.

...Intake system fitted

21/11/15

Engine bay cleaned and repainted, new knock sensor holes drilled/tapped and sensors fitted, engine refitted to car, with crossmember, gearbox etc. Much of the wiring reconnected. Changed my mind about the propshaft and got a PST 3.5” alloy one instead. Much of front end suspension & brakes also put back on, pipework reconnected etc., the new BMR rear trailing arms and panhard rod are fitted. I think I must get a new radiator as well, probably a BeCool one.

New engine in place...

Old vs. new trailing arms...

New front A-arms...

7/11/15

Quite a lot done: exhaust headers trial fitted and seem ok. Headers HT paint coated. Engine wiring loom refurbished and fitted to engine. Suitable knock sensor positions (that miss everything) established. Decided to replace the propshaft with Strange 3” steel with 1350 UJ’s. Still need to clean up engine bay more.

18/10/15

Engine rebuild ongoing, but not a lot has happened due to holiday! Engine loom is mostly cleaned up now, engine bay a lot cleaner but not enough, still not found anyone to cleanup the headers... :(

11/9/15

Engine rebuild continues, top end, clutch and gearbox fitted, plus the crossmember and water pump, power steering pump, steering rack etc.. All seems good so far. Next steps are to reinstall some minor pipework and the engine harness (after cleaning, refurbishing etc.). The headers are a questionable area, I’d like to get them ceramic coated but I doubt anyone in Dubai can do it.

21/8/15

The TSP long-block engine has arrived! Rebuild begins, the sump is cleaned/refitted, along with related parts, as is the FAST intake, with uprated 36lb injectors. Water pump fitted. Lightweight flywheel installed. Various sensors reinstalled, the uprated engine mounts installed... Waiting for a checking pushrod so that I can be certain about pushrod length. Pic below is before I refitted the water pump and some brackets etc.

26/6/15

The rebuild progresses: The complete engine/gearbox/front crossmember/suspension/steering etc. are out of the car. I have the gearbox and most other parts now, awaiting the engine from TSP. The crossmember has been cleaned and repainted. Rocker covers + coils and mounts also cleaned and repainted. Bellhousing cleaned, threads recoiled, and installed on gearbox. The suspension struts have had new top mounts installed (the rubber/steel isolation mounts). The sump has been cleaned, rebuilt, and had it’s structural bolts (the 10mm’s at the rear) helicoiled.