Does octane boost help the 6.1 Hemi?

[djwhog]

Thanks everyone! Just wanted some feedback. Here in WY since we are above 5000 ft we get 85, 87, 89, & 91 grades. Thin air gets by with less.

But I used to live in SoCal and had a super charged GS Regal. I worked for GM for 15 years even though I have drive a Dodge since I was 15, well owner my 1st Dodge at 13 but could not legally drive. (Dont old that aginst me, they broke more so I had a lot of work)

Anyway on the GS I re-programed the EE PROM and installed an adjustable sensor to modify the waste gate pressure. Stock it ran 8-10lbs boost on 93 oct full load of course and once it heard any rattle the boost and the timing get kicked back along with fuel curve modifications. I experiamented with 100 OCT UniCal Nascar fuel at that time and with the mods it would run between 13-15.5 lbs boost depending on driving conditions, weather etc. Even at steady speeds of 70 on the freeway I would get about 1.5 better fuel MPG, but it did not offset the price. But did run about .5 sec faster i nthe 1/4 with the fuel and the mods.

Just thought that maybe the 6.1 would maybe advance the ignition & fuel curve with better fuel?

That said you guys are correct, without enough compression higher OCT can actually make less power if lack of compresssion combustion design etc do not exist.

Anyway this is a new engine for me and never owner one, so I know little about how they behave.

thanks again everyone!

[PPP-Tim]

On your stock 6.1, even withs heads, cams, headers and all bolt ons. It will run best with normal premium (91-93) We have tried race fuel, 100, 106/108,111,116 octane and see no hp gain in the race fuels on a stock compression engine. If you buy a forged engine with higher compression or run a turbo/supercharger, then you can tune the car for more boost and create more power. The only reason to run above 93 is to avoid detonation commonly caused by forced induction.

So please always run the recommended fuel from the factory. If it says premium, run premium. Yes the car will still run on 87, but the computer will be pulling power and you will loose efficiency- probaly resulting in less MPG

[Go Goody]

Oh yeah! Tim is the man in the know! Thanks.

I also try not to get any fuel with ethanol. I think it hurts performance.

Any thoughts Tim?

[djwhog]

thanks Tim for the explanation details!

[Dodgeram44]

Don't put that crap in your car, save your money and use quality 93 from a branded station .

[SRT-6]

I've used 93 in my SRT-6, didn't notice any difference from 92/91, but CAM 2 was a different story , you put that in and it's pretty noticeable, but ridiculously expensive.

[PPP-Tim]

Ethanol has its advantages and disadvantages. This debate can go on for pages, but a super quick break down.

Negatives:
It has less stored energy then gasoline. Diesel fuel has even more then gas. What that means is that you will get less MPG and produce less HP with ethanol. -- Its a fact.

Ethanol also absorbs water easily and is more corrosive to non-flex fuel vehicles. Flex fuel cars have different fuel systems then the regular model.

Positives:
It cost less

We then send money to American farmers rather then countries that may not like us too much.

It has a much high octane then gas. This is only benificial if you have a forced induction engine or a very high compression ratio. So even though it makes less power per given volume, you can Crank up the boost and, in the end actually make as much or more power then regular gas. Example: You want to run 20psi on your engine. Probably not going to happen on pump gas. You could, (in theory) run E85 at those boost levels and make a ton of power.


Summary: I wouldnt worry about running a blended fuel like 99% of gas stations in the US have. But depending on what state you live in, if you pick a fuel that has less ethonal, your car may make more power. --- You just may not be able to actually feel it.

Also there are websites out there that show you where different companies buy their crude. I often try to pick BP because they buy less from middle eastern countries and more form other parts of the world. ---- No offence to our Middle Eastern friends. We Power Ported Performance, ship Thousands of dollars of parts to our Arab re-sellers monthly and they are very cool guys who love Dodges, Chryslers and the HEMI.

[Go Goody]

Tim,

The Arabs are the ones with inexpensive fuel and no emmissions testing....I would do tons of marheting there!

Thanks for confirming my thoughts on the ethanol issue.....I know my Charger didn't like it. Come to think of it, my last STS caddy didn't like it either!

[Paladin06]

Racing gas supplement (TORCO) will but it is pricey..

[bwbike]

Higher octane actually slows the burn but does not give you more power. It allows you to use a higher compression without detonation (ping). That's why high performance engines usually use high test gasoline.

In most street engines, you should run the LOWEST octane you can and still not ping. If you can not tell if the engine is pinging, then use what the manufacturer recomends.