Hello i know this is going to be vague and all that but i purchased my 1990 firebird formula 350 from a literal crack addict, the sun gear housing? the big drum thing with square slots cut out of the bottom as well as the front pump thing where the input shaft(?) is was in the back seat when purchased. I am assuming the trans was rebuilt? but other stock 700r4 transmissions do not perform like mine. Its 0-60 is high 4s like around 4.7 sec. and normal ones are pushing low 5s the car also tops out at around 110 mph which is odd to me my 87 GTA 305 5 speed topped out at around 130ish mph no obvious modification to the motor as well (possibly internal mods?). The car is also REALLY sticky in terms of putting power to the ground, yes it will spin off the line if i drove it like a mopar guy, but if my tires (falken ziex 950s) are warmed up it skrts a little bit and chirps 2nd on cold days or when "she feels rowdy some days". I am assuming it still has the stock gears in the diff. it still has machining marks on the teeth of the gears so i have zero idea on A. if they were swapped with 4:10 gears? (sorry i am learning all this technical stuff the hard way, by taking it apart and examining the parts) and B. or if the diff was just rebuilt. the gears also have minimal smoothness where the gears mesh i think is the proper terminology. The car performs wayyyyyyyyy too good for stock but i can`t find any glaringly obvious aftermarket parts and i will NOT be tearing the trans apart until i get another one to throw in cherry (car`s name for sake of context and less typing) then and only then will i buy the necessary books/PDFs on how to rebuild or modify them as well as plenty and i mean like 150 hours of watching ACTUAL pros on youtube for tips and tricks to improve the assembly methods and timing, i would much rather send it off but i am starting a defense business in spite of flockheed shartin and a rare/odd part manufacturing business (mainly for l shaped headlight bucket bracket that mounts it to the body but others as well if asked) so money is tight for context. Any speculations, advice or experience is immensely appreciated, i appreciate all of your information in your brains, i am heavily autistic so my words aint too good please bear with me please. If it helps my father worked on these when they came out at a dealership and he says it pulls way harder than a fresh one off the assembly line.

 

Rear gears are changed many many many more times than transmission ratios. Sounds like rear gears changed. Change out the fluid and count gear teeth.

 

Sounds like maybe the converter and gears have been swapped; and the transmission either has been rebuilt and those parts are left over, or they were planning to, and put new transmission parts in the car butt installed them improperly.

The gear ratio is printed on the side of the ring gear. Usually it'll say something like 41:11, which means 3.73 (41 ÷ 11 = 3.727272727272...). Simple arithmetic.

You can get a hint about the converter by standing on the brake and the gas at the same time with the car stopped. A stock 700 converter will let the engine go to maybe 1650 - 1700 RPM under those circumstances. If the engine RPM goes higher than that, the converter isn't stock. Be sure to verify the accuracy of the "tach" (wavy-pointer trim package thing in the dash) against a piece of actual test equipment first, as the stock "tach" in these cars is notorious for reading WWWWWWWAAAAAAAAYYYYYY high. That's how they always fail. I had one once that read 3 times the actual engine RPM. I don't think I've ever seen one in the wild that was really "accurate".

The way to get one of these cars to hook up, is LCA relocation brackets. Their rear suspension geometry was defective from the factory, and just gets worse as the springs sag from old age, or by lowering. The usual result of the bad geometry is RUTHLESS wheel hop: someone on these boards once posted a pic of their burnout marks on the pavement, and it looks like a dashed line, because of it. They ALL do that to some extent, some worse than others. These brackets weld to the rear axle housing and allow for adjustment of the attachment point of the control arms, thereby correcting the geometry. Usually they have multiple bolt holes in a wide arc, which makes them easy to spot. They look like this.



Better LCAs help also (the stock ones are so flimsy I can bend them with bare hands), as well as the torque arm, its mount, and the transmission mount; but the LCARBs are the single biggest improvement to hookup that I ever made to mine. Overall, these cars' rear suspension leaves ALOT to be desired, butt it's not hard or expensive to DRASTICALLY improve it. Someone may have done some of those things to your car.

 

[/QUOTE] Better LCAs help also (the stock ones are so flimsy I can bend them with bare hands), as well as the torque arm, its mount, and the transmission mount; but the LCARBs are the single biggest improvement to hookup that I ever made to mine. Overall, these cars' rear suspension leaves ALOT to be desired, butt it's not hard or expensive to DRASTICALLY improve it. Someone may have done some of those things to your car.[/QUOTE]

i am terrible with terminology what is a LCA? and the car handles so effing good, i took a turn so hard once i blacked out for a split second and i can take a 80-ish degree turn with maybe 10% banking kinda smooth corner at about 60-65mph it even handles like a dream on an old country back road that has dips, humps, that process where they take asphalt or tar and throw down loose rock to be crushed by driving on it tar and chip i think is what it is called, etc. at about the same speed if i ever record it i will post it but i will continue that on a suspension thread? i think that is the right term i will take pictures of the rear and put them on there but i do remember seeing the TorConv, it was like a robins egg blue, zero wheel hop, both wheels spin and hook hard when the tires are warm, as far as the wavy thing i dunno what that is, im assuming i can data log the info for RPMs and more from the FItech 350 computer i installed ( i usually drive by ear concerning RPMs ) because the stock one was effin atrocious, i just changed the diff fluid like 1500 miles ago but the pinion seal is leaking so i will be in there again when i learn about shimming, the angle of the pinion, gear meshing, blah blah, plus as far as the power braking part am i looking for wheel spin or just before wheel spin?, the trans doesnt leak (yet) the parts that were in the back looked relatively new but gazing at the parts in there now with an endoscope they are definitely new, my car is just odd but i love her if i find anything out i will be sure to post i will definitely know when i get to the easy part, the engine rebuild (crack addict, previous owner drove her hard) i can do that blindfolded and drunk, dad and i worked on LOTS of them growing up (hillbilly mud trucks and such) talk at yall later

also you can`t say r3d n3ck? thats weird just talkin about myself or is that a slur now?

 

Lower Control Arm

Lower Control Arm Relocation Brackets

None of this really has anything to do with "handling"; except that if you go TOO far with the LCARB adjustment, it'll make the car wheel-hop under braking.

Yes the word about a color of one's neck is a slur. More so in some parts of the country than others.

That means the pinion bearings are bad. The seal itself hardly ever fails; butt when the bearings get slop, the seal doesn't stand a chance.

No. You're looking for the max engine RPM that can occur while the rear wheels are held still.

No, not really. It's mass-produced, therefore is the same as all the rest. Just, sounds like somebody has made some beneficial changes to it. Don't read too much into it. Examine it closely, determine what's been changed, so you know what to do next and what you don't still have to do to make it ... superior. Just enjoy it for what it is at this point and don't get all egotistical about it.