'91 Firebird 305

looks like a fun car, shouldn't really be running in f stock though

solfly wrote: looks like a fun car, shouldn't really be running in f stock though

yeah, well, them's the rules....

With your new gearing...what mpg are you pulling down?

hrdlydangerous wrote: I am impressed and intrigued by your differential rebuild. Where can I find more info?

This was a repair, not a true 'rebuild'. I didn't change bearings or anything.

Pinion was never touched, and the ring stayed on the carrier so clearances didn't need to be checked/set. Basically removed the carrier, disassembled and removed the friction cones. Machined the end of the cones to gain clearance at the end of the carrier. (about .030). Luckily my cones hadn't worn into the carrier yet. Reinstalled with some shims between the cones and gears to remove slack at the spiders. (Easier than it sounds).

There are some threads on thirdgen.org

Gearheadotaku wrote:

solfly wrote: looks like a fun car, shouldn't really be running in f stock though

yeah, well, them's the rules....

with the springs and whatnot it should be in stx or stu. i think the pax may be better too

The car really isn't well built to any class. A true Formula would be in F-stock and so would a base model car. Actually, you could get a Formula with a TBI motor, but I think it would have a drum rear, not a disc like mine. Even so, a late G92 305 TPI Formula would have 230hp, 300lbs of torque, and 3.42 gears stock vs my 170hp, 255lbs and 3.27 gear.

I've been out of the autocross loop for quite a while and haven't carefully read up on RTR and STU etc.

Xceler8x wrote: With your new gearing...what mpg are you pulling down?

Nearly 26mpg @75 with the A/C blowing! Granted that was a purely highway tank of gas, mountian road hooning and city traffic was about 21.

solfly wrote:

Gearheadotaku wrote:

solfly wrote: looks like a fun car, shouldn't really be running in f stock though

yeah, well, them's the rules....

with the springs and whatnot it should be in stx or stu. i think the pax may be better too

Yeah the PAX in F-Stock sucks. I felt behind the ball even when driving my 04 GTO, granted it had crappy tires, but still felt it was a hard row to hoe.

So whats been happening this past week? Continued to work on my cold air induction system and prepped for subframe connector installation.

Go the car up on the stands and drilled out this little bugger. It's a broken bolt from the trans crossmember. Never took care of it during the swap, done now! Broke 2 drill bits, luckily they didn't wedge them selves in tightly.

Pulled back the carpet and found this:

I know a 2 inch hole is laughable to most people, but it pissed me off. 1st world problem right? Cut a piece for a patch to be welded in later.

Over in the engineering dept, I cut apart a TBI 350 air cleaner to graft its much larger snorkel onto my 305 base. The big hole will be for the hood duct. The taller lid will allow a filter more that double the height of the factory 305. The 305 snorkel had a diameter of 2.5 x1.5 at it's smallest point, now it will have a 4" round hole to breathe from. Hole in the base has been expanded by 1.5" as well.

Sealed up the hood bulge with some galvanized metal, will have to wait until the hood is painted to permanently mount it. Once the hood is on the car, I will know exactly where to cut the hole for the air cleaner.

Got the hood primed and some color on it, will need more work.

This week in the Mullet Madhouse:

Installed subframe Connectors. Feel free to laugh at my super bargain bolt-on goodness.

Patched the hole in the floor and touched up the Firebirds war paint.

The cold air induction is now complete.

So off to the drag strip for a little testing. I've never faced a christmas tree before. Lets just say the times weren't impressive.

Next up, Tightening the loose nut behind the wheel.

Stay tuned!

Well what did you run? 15.5 at 88 MPH? My guess

I had a Camaro with a 305 and TH350, although mine was an 81. I ran 17.40s all day long. Let's hope you fared better.

Yeah, I did better than that. Also the gearing seems "perfect" as I can cross the 1/4 mile mark just before redline in 3rd gear.

Gearheadotaku wrote: Yeah, I did better than that. Also the gearing seems "perfect" as I can cross the 1/4 mile mark just before redline in 3rd gear.

Well what was the time???

I knew it would be slow, but when you add in my non-reaction time, it's just to embarrassing to post.

Gearheadotaku wrote: I knew it would be slow, but when you add in my non-reaction time, it's just to embarrassing to post.

Oh come on, just tell us the ET and mph, forget about the RT. With my super embarrassing 17.40 above, it can't be much worse. My old 350 powered truck did 17.10s in the same fashion as the Camaro.

The Lemons LTD ran an 10.79@64.8 in the 1/8 and the Turbobrick ran 9.46 at the same 1/8th mile, but it was fairly quick. That should make you feel better.

In reply to tuna55:

10.79 in the 1/8th seems impressive to me for an old LTD. I haven't had mine at the track yet, but I doubt it's that fast.

Cotton wrote: In reply to tuna55: 10.79 in the 1/8th seems impressive to me for an old LTD. I haven't had mine at the track yet, but I doubt it's that fast.

Off the trailer it ran 11.50. It had a lot more in it than the 10.79 we laid down. Traction was an issue, but we were mostly tuning for lemons that night, based on which internet calculator you want to believe, we probably gained 30 hp that night on an engine that was probably making all of 230. Tuning is key!

So, not to derail the thread, but honestly, a lot can be gained in an old unknown carb/engine/distributor combo. We are amateurs and we have six runs and we gained 30 hp; don't be embarrassed, I am sure you could find similar gains.

In reply to Gearheadotaku:

In drag racing, the clocks start when you break the beams, so R/T is a non-issue in E/T.

Now spill it! What'd she run?

I thought the time started at the green, R/t was from green to beam break?

r/t varied from .495 to .895

ZZZZZZZZZzzzzzzzzzzzzzzzzzzz

1/4 mile was very consistent over 3 runs, within 3/10'ths

But what was the ET?

Come on.

What the others said, the RT is not taken into the ET, the ET is just broken beam to broken beam.

TELL US

Ok I'll make you feel better. I took a car that should have run 12's and ran low 14's until I figured it out. Eventually running 12.80s with nothing changed but the driver sucking less.

How was your 60ft? Bet you spun pretty bad off the line. The L03 has great torque at low Rpm,makes it tough to launch on street tires. For a reference I've got a buddy with an L03 5speed with open element and cat back he runs low 15s at 85-90mph on street rubber. if he messes up the launch its a low 16.

So with E/T being beam to beam, there's no chance of improvement through better R/T. Ugh. I ran 16.1-16.3 on crappy tires. Don't have the slips handy to see my 60ft times.