Hey so i previously had a post on the mopar pcm. Its been bought and is currently in the process of being shipped. It has a reccomended octane rating of 92. Best octane they have here in soldotna AK is 90. and I know octane boosters dont work like they claim. I also cant buy racing fuel and im not messing with toluene or anything like that. Would it affect my perf and knock with the pcm installed? I really want to use it but not as much as getting a new motor or rebuilding because of cylinder walls getting destroyed. Thanks again to DF and its members. AND........ I feel like an idiot for not realizing this before I purchased it..damn

 

Octane booster oughta do the trick. But if you get knock, back off on the pedal because sometimes what oughta happen ain't what does happen.

If octane booster doesn't quite do the trick, try Marvel Mystery Oil at four ounces per ten gallons of fuel with the octane booster, or eight ounces per ten gallons without. Sometimes lead substitute will do the trick. If neither does it, well, ya done fuggedup.

 

Well said unreg haha. Ironically i picked up a jug of that marvel stuff at the auto parts store an hour before. I fill up with 90 that has techron in it and its some of the best gas in the area. I used stp once and it did alright. I guess no harm in trying since i bought the darn thing. Could B&G custom tune the perf mopar pcm? to specs for 90 and possibly do better? Its still a computer and being a '95 I believe i dont need a vin #. Thanks for the suggestion though. Just waiting to get it out of the trans rebuild stage. Guy had to order an extra part after waiting in line a month. The grand am im driving just dosent feel right haha oh well its a good build ill have coming up.

 

hey if worst comes to worst i will buy the mopar pcm lol... But i think you will be fine with 90 octane and some octane booster. not sure which one i would recommend i have never really used the stuff. But someone has to cause they make a 5H17 ton of it

 

Whats the standard octane at the pump, 85 or 87?

 

MMO is good stuff, you can also add a TCW3 marine type oil to your gas at a ratio of 1 oz. to every 5 gallons of gas.

It will boost the octane slightly, and also put a good bit of detergent in the gas to keep things clean. Another benefit is most have a gas stabilizer in the additive package and they provide added lubrication in much the same way a lead substitute will, while being a bit more cat friendly. Also, the lubrication makes up a good bit for the lubrication loss you get when running E10 (10% ethanol) fuel.

I like the Pennzoil product myself, and at under $20 per gallon, at a 1 oz. to 5 gallon ratio, it's very economical to use, but basically any marine oil that meets TCW3 specification will work just fine.

I used this product with NO adverse effects and even picked up a modest 1-2 mpg until I did some research and found some non-ethanol gas stations in my area. I felt I didn't really need it anymore once getting off the E10 gas. The 100% pure gas seems to also give me that small gain in fuel economy over the E10 crap. When I'm traveling and can't get the ethanol free stuff, I will see that MPG advantage slip away at about the 2nd or 3rd tank of E10 now...

 

You're overthinking this. 90 should be fine. Many parts of the country have lower octanes than other parts, has a lot to do with elevation. I remeber driving through southern ID and in WY and MT, regular is 85 octane instead of 87 like most places and premium was 89 or 90 I believe.

 

Id hope so. I fill at our local chevron station whcih has 87/ 88.5/ and premium which is 90. They also have techron in their gas pre mixed so its clean and very efficent at burning so Id bet that your right and 90 would be against the reccomended "92". A little pinging and prob some octane booster might help. NOS is the most potent over the counter i believe but with the techron and maybe some marvel mystery in there i bet ill be good. Thanks for the help guys. Ill post a thread to tell how i like my new trans build coming to a completion in combination with my mods and the pcm. Like on the last one Ive got somebody whose already replaced there motor with a perf crate 360 and now is selling there 5-10k use hs non adj. 1.7 rr's. If i dont buy ill sell myself i suppose. He wants 100 so thats a flippin steal. Thanks again DF! OH annnd im prob answering my own question but this is only a temp mod. Summer use only. Come winter which is 7 monthes here, ill put the stock pcm in. This is an okay procedure i assume to do repeatedly over time. Of course ill use 87 on stock.

 

Do you have a tune?
If anyone wants Ive got a link to a site that has a few 5.9 and 5.2 pcm's. Like literally 4-5 unused units around the states at mopar warhouses. Grab em while they're there ya know. i paid 259 plus shipping which wasent bad even for up here lol. They're a good site and did good for me.

 

87 is the base