'91 Firebird 305

Rear control arms are boxed and fresh bushings installed. A little nervous about limiting articulation but 'everyone' says to do it... I used rubber bushings instead of poly, I KNOW that would be an issue.

Got it out on the strip today (finally). Times were inconsistent, but managed a 15.2 @88mph. A couple more were 15.4 at 90 and 91mph. Not sure how I managed that but timeslips don't lie right?

Well the weather could be responsible for the trap speed change. Traction could be responsible for the ET change. I missed the part, although I am sure it's in there somewhere, where you said what you did with the torque arm.

Well thrashing for the Challenge left me way behind on my posting, so here's how the year rounded out. Final Detroit region autocross showed too much wheelspin in the corners, so I tore the rear diff apart and packed in more shims. Glad I did, had good traction at the Challenge. The motor was shined up when I did the cam swap, so I used some left over paint from last year to do the inner fenders and some brackets. Sprayed the top of the core support too. Turned out better than I had expected, now I wish I had put more prep work into it! Scrubbed and cleaned everything the best I could. Every try to detail the back of an A/C compressor? Even pulled out the battery to give it a proper bath. Head lights got re-adjusted so the doors close better. Open element air cleaner gives a better sound when you stand on it, don't know how much better it is for performance though. More air flow, but it's hot air. Got a good used set of upper strut mounts and added extra tabs so the slots could be made longer. Got an extra degree of camber! Side effect was the strut body rubbing on the inner fender. There was a 1/4" lip that stuck out the side of the strut where the lower section was pressed over the tube itself. A quick session with the grinder fixed that. and finally some nice stickers for the rear window. Who needs a line up of the family? Home from the Challenge and ready for a winters snooze. Competition for the year ends up with a 10th place at the Challenge(10th in Autocross and a personal best of 15.13 in the drags) and a 3rd overall for Detroit Region SCCA autocross running in CAM. I think they should tighten the rules for that a bit. SN197-Coyote Mustangs and C5/C6 Corvettes just don't seem to fit the theme....(I feel I'm pushing the envelope with my car.) What will next year bring? Will I go for the $2015 Challenge? Stay tuned...

So its time to knock off the cob-webs and get rolling for spring. Of course I've been at it for a month now and not posted anything.

When the cam swap was done before the Challenge last year, I managed to mangle the valve seals when replacing them while I swapped out the springs. Car would roll blue coal at start up and a mighty huff when you cracked the throttle after idling for a minute. I saw plenty of crude built up on the back side of the valves when looking down the intake ports too. Time and budget didn't allow me to pull the heads for a proper valve job, those are no longer factors.

Ran the first autocross of the season in late April, then quickly tore down the car. Three weeks later freshly rebuilt heads were in place and the embarrassing exhaust smoke has been banished. Also added a torque arm re-location crossmember. A good CL find.

The budget is shot, so no 2015 Challenge for me. Now I can build 'til my wallet screams for mercy! (that won't take long) I will continue the Challenge "theme" with the car, trying to get the best bang for my buck. E-bay, CL, etc.

Picked up a '98 SLP exhaust for a Camaro SS that will be adapted to fit and brackets for the later aluminum rear brake calipers (which bring along larger rotors to boot.)

Progress continues, maybe even with pictures next time...

Repairs and upgrades continue, now with pictures!

Replaced the pinion bearings, so it no longer whines and whooops its way down the road. While it was out, I did the LT1 brake upgrade. Rear rotors are now 1 inch bigger with aluminum calipers.

The '98 Camaro SS exhaust is on, but it seems too quiet. We'll see how that goes. The big single outlet is different than anything ever offered on these cars. Opinions?

Scored a torqure arm re-location crossmember off CL and installed that too. I can feel the difference in the rear suspension, seems to follow the road a bit better and plant firmer off the corners. Off to another autocross!

I dig the exhaust.

Sleeperish too, I like it.

In prep for its first track day, I added a set of Hawk blues to the car to got along with my cheapo brake duct plan.

Well the new brake ducts worked.

(search "lets build brakes ducts on the cheap" in tech tips.)

Did a track day at Waterford Hills without any fade. A faster driver may push the boundry betterthan me though.

Next mod needs to be a radiator upgrade. Needed to go into "cool down" mode a lap or two before the session ended. Then again it was nearly 90 degress today.

 Wow, nearly 4 years without an update.

Still have the car and still enjoy it. 

Won the overall Detroit region CAM championship for 2016.

Didn't do much in 2017, time was spent on my 2017 Challenge S-10.

2018 - new door seals and hinge pins. Made yet another cold air intake that pulls from the inner fender. Finally put in a fast steering box. Went to a HPDE at Mid-Ohio and found a driveline vibration at 100mph.

2019 -There still is some slop in the steering that needs to be tracked down. Hope it just the rag joint. Changing the box last year did not affect it. Need to work on my dual fan system and radiator upgrade if I want to continue with track days. Should think about new tires and maybe a 17" or 18" wheel upgrade so I might be competitive in autocross again. (no 200TW tire in 245/50/16).

Yesssssss... CAM Championship with a 305... yessssssssssssss

Finally caught up on a few things. The front seal of the trans was leaking a bit. Changed that, just need to get some miles on it to make sure its staying dry.

I'd long suspected that the ignition module for the TBI and TPI engines were different.  Finally got some good numbers and found out, yes they are different. The TBI module pulls 4 degrees of timing at 3500 RPM while the TPI module does not. It actually adds 2 more around 4000. The base timing is 0 degrees for TBI and 6 degrees for TPI. I'd been running 2 degrees with my LT1 cam on 89 octane E10 gas. Put in the new TPI module and filled it up with 90 octane Rec fuel ( no ethanol) and what a difference. Car pulls smoothly all the way to 5000rpm vs before with a dip when the timing was pulled and was running out of breath fast at 4250. 

Can't wait to try it at the dragstrip and see what the true improvement is.

( the good module is D1943A) the old OE ones have the number 369 on them. the weak module is marked 048.

Whoa, great info! going to try out that ignition control module on my Firebird as well. 

Did you ever figure out the driveline vibration? 

Thank you for sharing! 

 Took a long Sunday drive, the drive line seems ok.

 Finally installed my dual cooling fans. These are from a 4th gen car, not sure the exact year but I think they are all the same. They are flipped upside down to clear the steering box and cooler lines.  Removed the old fan and shroud, trimmed the shroud a little on the new fan and it slides right in. Cut off a section of the old shroud and it clamps right over the duals. The plugs are the same as the old fan. Plugged one into the existing wiring and used a second harness for a single fan to run the other. There is an empty spot next to the blower motor for the relay. Tapped in the circuit for the original fan for the temp sensor and relay power (the factory '91 dual system is made this way too) while running a new wire to the power point for the main feed.

Fans work great, charged the A/C and called it good.

Motivated, I fixed the horn too. The brass contact ring under the steering wheel shifted on its mount and wasn't touching the spring loaded contact. Pushed it back in place and bent it a bit to keep it clamped in tight. When I re-routed the air intake, I had to remove one of the horns. Modified the bracket a bit and stacked one on top of the other. Dual note horn working again.

Picked up a set of N10 exhaust pipes awhile back, finally got around to installing them. This eliminates the hard "T" that the early y-pipe has. I'm surprised at the difference in exhaust note. Sounds a little more LS than SBC.

Forgot to note this last year. Removed the dual fans and went back to the single one.  Car seems to run cooler this way oddly enough. I think all the shrouding holding the dual fans created an air blockage rather than a air guidance.

Car surged at idle as it warmed up out of closed loop. More ignition advance helped a lot, running about 7 degrees now.

Read back through my whole build thread today, it was a nice trip down memory lane. I learned a lot building this car and enjoyed my time with it.  Its been sold and I hope the new owner has as much fun as I did.

Damn, was hoping for another update. I love me a banshee bird.