I'm new to this forum, but would like to know the best option for easily improving horsepower of a stock 86 firebird, LG4 V8, carb. considering I'm in upstate NY I was thinking the 180 degree thermostat would be good so I don't have trouble in cold weather, and I have considered a hypertech chip. What type of performance increase would this result in?
Thanks,
-Mike

 

basically i would do a full tune up first,plugs wires ,cap etc. first check your timing(set it at 10 degress btdc)and the hypertech chip imo does very little for the performance of the car(i currently have one in my car and didnt see any big difference)money would be better spent elsewhere,exhaust(headers back)cam, heads,intake. good luck

 

First, welcome aboard.

To see what the LG4 needs to perform better, take a look on the FAQ forum for a thread that talks about the differences between 305's and performance tips.

The PROM and thermostat will do next to nothing. As stated, advancing the timing will do as much, because that's about all a PROM does, anyway. However, I wouldn't go to 10 degrees BTDC, try 6 first. 10 would probably cause pinging problems that you don't want.

Keep a snorkel type air cleaner. You'll want it in the cold weather (and hot, for that matter). Just make it a dual snorkel.

 

Do I need to do anything special for the dual snorkel, like assembling a "stove pipe" for hot air on the passenger side?
Thank you for your help.

 

The way the factory did the dual snorkel was to put a valve on both sides, but only have a stove pipe on the driver's side. The passenger side valve just closed off that snorkel to cool air until the engine warmed up.

 

Thanks. Unfortunately I won't have time to do this stuff for a little while, but I was just a bit confused- is the timing set by the distributor or the computer? Or does the computer just govern the timer with the knock sensor?

Thank you all and have a great new year- Mike
----------
Also, are there instructions posted anywhere on how to adjust timing?
Thanks again, and happy holidays.

 

All three, actually.

The "base" timing is set at the distributor with the ECM disconnected. The computer advances timing based on engine RPM & load, regardless of where the base timing is set. The knock sensor retards the timing if knock is sensed.

If the base timing is set too retarded, the computer won't be able to advance the timing enough, and the knock sensor will (probably) never do anything. If the base timing is set to far advanced, the knock sensor will be active continually, and may not be able to fully control pinging. Either way, the car won't run well.

To set the base timing, disconnect the flat 4-wire connector that goes from the distributor base to the firewall wiring harness. Start the car, set the timing using a timing light in the "traditional" manner. The SES light should come on during the process. 6 degrees BTDC is typically a good starting point (if the EGR is working properly - if not, you'll get pinging). Shut off the engine, reconnect the ECM (flat 4-wire connector), and you're set.