1985 Pontiac Trans Am LG4 305 A4
Project: Grey Turd
Purpose: Drag Race
Stock HP: 155
Miles: 105,000
Wieght before project: 3140
Gears: 3.23 stock 9 bolt

Estimated wieght after stripping: 2800
Estimated achieved HP: 275
Estimated Quarter Mile time (calculated): 14.7 @ 8000ft density (that would be 13s at sea level )

Parts removed:
AC system, smog system, headlight motors, front sway bar, wipers and wiper motor, heater core, rear seat and all carpet, exhaust system (minus headers), center console, sterio system, climate control panel, cruise control, front and rear bumpers.

Suspension:
Poly tranny mount and poly torque arm bushing, Edylbrock adjustable torque arm.

Engine:
Hooker 2460 ceramic coated shorty headers running uncapped
Gasket matched Heads, intake, and exhaust
Edylbrock Performer EPS intake manifold
Summit Cam .420 204 Intake / .442 214 Exhaust running 4 degrees advanced
Edylbrock 600 cfm carb
Upgraded HEI Vacuum advance with Malory kit and Blaster 2 coil
Accel plug wires

Heres the catch, if it runs into the 14s. She gets my 406 SBC .


Note the SIR badge lmao

The way the interior used to look



The duo

More stock interior

Head casting number (sorry its upsidedown)

The first piece of progress

 

More progress









Teardown for cam swap

 

UPDATE!

Intake on, having trouble starting her but oh well.










More on the way, just keeping this updated

 

8000' ?!? You didn't even bump up the compression ratio on that it looks like eh?
I woulda went up to 11:1 or so, it'd run just fine at that elevation.

What's up with the screen on the intake? You been reading some of those "secret" tricks to adding horsepower?

 

would that screen actually pull the fuel out of the air?

 

i think he probably just has it on there during the build up to make sure nothing falls down into the intake/heads.?

 

i was thinking that but it isnt fine enough dirt/metal can still fall in there now maybe some nylons... or just regular tape...

but i guess you couldnt run it like that it would make a pretty good vacuum leak

 

If he RTV'd it it'd seal.
Someone made an intake manifold gasket that had a screen at each port. The idea was to help "scatter" the fuel droplets, making it atomize better and make more power.

There's a reason very few people (nobody) uses them though, it's total BS.
Just like the magnet on your fuel line, or the tornado, or the electric supercharger.
But there were probably rumors floating around about how great they are so...

The main problem is when it inevitably goes down the tract into the combustion chamber, and does bad things.

I think there are many things that could have been done to get that 305 faster, the edelbrock carb, the weak cam, the stock heads etc, those could all have been improved and you could get a real solid time out of it. Super high compression can be used at that altitude.
I think the july issue of chevy power, or one of those magazines has a letter from a person at 6000' altitude asking about compression due to his elevation. It was a good read, worth looking at.

 

The screans do work, put one on my old 305. That motor had HORRIBLE compression, would bog realy bad off idle. The screen helped but killed power above 5k.

 

Please kill that SiR badge............. hahaha

 

hate to burst your bubble, but you aint at no 2800 lbs. maybe 3100lbs.

the car needs a 600-650cfm holley double pumper and more intake. that intake you put on there is basically a stock replacement...yep you just waisted your money. i'd have gone with the holley street dominator p/n 300-36. also you'll need more camshaft for your goals. i ran a .442/.465 214*/224* on a 114lsa camshaft with good results. i hope you're planning on putting more gear in it as well. a 3.73 with a mickey thompson drag radial in the 26" height would be a good start.

you also need to put an exhaust system on the car. doesn't have to be anything special, just something to basically lengthen the collector length. the shortie headers will kill exhaust velocity when left open. it really needs a set of hedman longtubes and some torque tubes if you're going to keep it with open headers.

 

I'm betting with the carb spacer and stock hood he's not going to have room for an air cleaner (you can see the "hoodprints" in the before picture). The screen is to stop "big" stuff from being sucked into the engine when it's being run without an air cleaner.