Gas for Buick Grand National

[John T.]

I just purchased a Buick Grand National This past week and I will pick it up next week once I have the rest of the money. THis is a 1987 Buick Grand National with a 114,000 miles on the engine. I plan on rebuilding the engine in the future and adding some chrome to it. As for now it runs great.

My question is what octane gas should go into this car. Is it Regular(87 Octane),super regular(89 octane) or Premium(91 octane) I'm hoping just regular since gas has skyrocketed here.

Here's the link to see my car:

http://performance-auto-group.com/im...-0031-b001.jpg
Thanks
John

[tman]

excellent! How much did you pay for it?

I'd assume it would run best on 93(premium), simply because 93 is more knock resistant than regular, and with the added boost of the TC, it will be prone to knocking. Premium is about 1.75 or so here, what is it where you're at?

[John T.]

I paid $9200. Gas is pretty expensive over here as of late. Regular gas cost on average $1.89 with Premium going for a wopping $2.09 ouch!!

[tman]

man, I remember when you could get a gallon of premium for 75 cents!

[Hypsi87]

i paid 5,900 for mine but it the motor was toredown.

Anyway soes this car have ADJ. boost controll?? if not i would reccomend runn at lest 92 octane. you can run 89 octane and get away with it (the computer will pull like 4-7 deg. of timing out) but with that many miles on the car i would run 92 or higher

[tman]

Theres been lots of discussion happening here in the regal forum about GN's, I wanted all GN stuff to be in the regal forum, since it's essentially the same car. I am going to request a Grand National/GNX forum.

[Hypsi87]

if it's worth anything you might wanna make it something like a tubo v-6 forum because they put thoes motors in alot of regals. they had everyting from plane jane regal's to the GNX. therer are alot of thoes motors out there and with the exception of the GNX there is no difference between them (GNX had diffrent turbo,chip,intercooler,and suspension stuff )

[tman]

AF doesn't have any forums for any engine in particular, I'm still only going to request a gn forum

[gn1220]

Run the highest octane you can get, regardless of price. The money you spend on gas will be cheap insurance for your head gaskets. I run 91-92 mixed with xylene in mine. Went from 91-92 octane and 13-15 lbs of boost to 18-19 with the xylene. Better yet would be 110-112 race gas.

[tman]

Why don't you just drive to the airport and get some 140 octane gas and watch all 6 pistons go flying through the hood!

[kratefan]

Originally Posted by tman2093

Why don't you just drive to the airport and get some 140 octane gas and watch all 6 pistons go flying through the hood!

I've run 118 race gas in mine. Doesn't knock, but the headgaskets blew out at 120, tho. ;^(
Jeff

[Hypsi87]

Originally Posted by kratefan

I've run 118 race gas in mine. Doesn't knock, but the headgaskets blew out at 120, tho. ;^(
Jeff

blew out at 120??? I don't understand, 120 what??. Anyway that sux man My uncles TTA uses 118 and he run 30 PSI on stock internals and heads. Hes been doing it for about 3 years now. not one thing wrong withit.



tman 140 octane!! That would be cool. Watching the pistons fly out of the block is not cool. Is 140 Jet fuel?? I have a few hours of flying cessnas and the most they have is 110 Low Lead content.



*HyPsI87 goes on a hunt for 140 octane* Must have. Must have!!

[kratefan]

Originally Posted by Hypsi87

blew out at 120??? I don't understand, 120 what??. Anyway that sux man My uncles TTA uses 118 and he run 30 PSI on stock internals and heads. Hes been doing it for about 3 years now. not one thing wrong withit.



tman 140 octane!! That would be cool. Watching the pistons fly out of the block is not cool. Is 140 Jet fuel?? I have a few hours of flying cessnas and the most they have is 110 Low Lead content.



*HyPsI87 goes on a hunt for 140 octane* Must have. Must have!!

120 miles per hour (big end of a 11.10 second quarter). It was a problem with the relationship of the fuel injectors and the fuel pressure. I've got the parts to fix it.
Jeff

[fastrogue]

Aviation gas isn't a good idea, because it has other additives to prevent icing at altitude, and a host of other things you don't need in a car. For this reason, the specific heat available from Aviation gas is less than Automotive gas and you will make less horsepower. You can run big boost and more ignition advance with the 140 octane, but it still isn't a good idea.

[gnfreak]

add alcohol injection (lots of good kits-- i bought a SMC kit) then you can use the lower octane gas (actually burns better than higher octane gas because of the additives added to the higher stuff) I also upped the boost as the alcohol cools the mixture. I have the boost set at around 22 and the alcohol starts to spray at about 10-12 lbs of boost.

keith