Okay, here goes. The previous owner (xowner FYI) used 92 octane from Chevron, swore on it. I'm not one for paying 2.35 for premium where I live. Plus, I thought that since my compression isn't very high and I'm not using any sort of forced induction, I dropped the gas level to plain jane regular. I got knock. I'm gonna up the octane. Just wondered what everyone else ran and why.

 

Maybe he advanced the timing which is why he swore by the premium, and the reason that you are getting knock with the regular. Check the timing and adjust it back to stock and you should be able to run regular.

 

I use a prem. gas as my engine has a 10:1 ratio but if you have a stock engine you should be able to get away with regular. Check the owners manual and see what it has listed. The only stock bird that required prem was the CFI to my knowledge(prob not the only one but that is the engine I have and is the reason I know that)

 

If you adavance your base timing away from stock than you will need premium. I could run 86 until I bumped the timing up to 4* advanced and now it knocks with anything less than 89.

 

Eek, sounds like a nice little chore... I'll switch to premium and when I get the time, tools and talent to do it, I'll figure out how to check timing... Just another good excuse to get some more tools. Remember, a guy can NEVER EVER have enough tools.

 

Run the lowest octane you can get away with...

Timing is easy to check, all you need is a timing light and a distributor wrench. Running higher octane than the engine needs will actually decrease power since it burns slower (not a whole lot of power, but it does go down). I always laugh at the guys that fill up with 92 and put in octane booster before they head to the track...

 

Yeah - that's why I switched it back to regular - maybe I should've weaned it off of it slowly, instead of the abrupt switch I did. I already knew that premium burned slower than regular, and I didn't see the point, until now. It IS funny watching a guy buy a whole butt-load of octane boost, this dude bought the NOS brand of booster, a few of them and I watched him pour all of them straight into his tank.

Oh, and DO NOT put both octane boost and fuel injector cleaner into the tank at the same time...

 

i run the cheapest stuff i can find.....

but then again, i have a l03....



to see the timing (short version)

1. get timing light. disrib wrench is optional but reccomended if you change the timing....
2. put the black metal clip on the - term of the battery..put the red clip on the + term of the batt... put the pickup clip over the spark plug wire that goes to the front drivers side plug
3 find the single brown wire connector on the pass side wheel well... unplug it.
4 making sure all wires are clear of spinning parts, start the car
5 point the light at the timing mark, and look straight down at the mark... pull the trigger...

what you will see is the line appears to stay in one place on the dampener.... where that line is compared to that tab is your timing... if you look closely at the tab, you'll see it has numbers on it..... the inner point of the large V on the tab is zero. stock setting is that line on zero.

 

You can benefit from setting the timing 4-8 degrees advanced rather than the stock 0 degrees. It kind of depends on what your engine likes. Mine liked 8, others may only like 4-6, it depends really. BTW, this is on a stock motor. On a modified motor (large cam, etc.) you need more initial advance than that...

 

stock time is 6* advanced anyways i thought? at least that is what mine was

 

Stock timing is dependant on the Year and Engine, I have seen 0*, 4* and 6* all stock on various, can remember what my stock timing is, but it is set to 8* and if I use less then 94 it pings ... it even pings alittle on 94 If I let me revs fall to low.

FYI 85 Z28 LG4 9.5:1 cr stock except for L69 dual snorkle K&N and MSD upgrades to stock HEI.

 

0* with the wire disconnected is what the book tells me is stock for a 88 GTA (what his thingy said his car was) it didnt list it by engines, thats just under V8.. i assume they didnt bother to break it up since its the same for TPI and TBI.



in anycase, thats your starting point.... set THAT. put cheap gas in it, drive it..... once you have the gas you plan to run in there, THEN move the base timing so that with a scan tool, you dont see any pings..... then you have as much timing as you're going to get without going deeper into everything....



now max timing may not be the best power wise, but hey, thats what most people on here like to think anyway
really, what you would want to do if you were into it would be to burn a prom with a more agressive timing table... and mess with that at a track until you find the best one for your motor...


but thats alot of work for a diff you wont really feel in a street car anyway.

 

I don't have any plans to go to the track anytime soon - although I would gain insight as to the general state of the car, by flogging it down the track, I get a reference point as to where it is. After my little plan of hopping it up is completed, I want to run it a few times, just to see if it's where I want it to be - I dunno, I supose I should get a G-force meter and use that to determine what mods are working, which ones aren't. Right now, I'm at the restoration phase of my plan, ironing out all the neglect and wear-n-tear the thing's got on it now. Thanks for all your input, I'll tuck this away for future use.

 

you can get a older Gtech on ebay for $35 now....