Guys,

I was just wondering if anyone has experience running 87 octane in their blower car. My compression ratio is down to 9.0 to 1 so I believe it should be safe out of boost. I have an Alkycontrol kit that sprays 100% alcohol when its in boost. Now if my calculations are correct with the alkycontrol in use and using 87 octane my theoretical octane should be around 103 when the car is in boost. I have also heard of people seeing better gas mileage using 87 octane due to its flash point.

I was considering testing this to see if I get any knock. Anybody got any insight on if this will work.

 

I would just be worried that if you hit boost and the alky didnt kick in or ran out, your motor would go kaboom

 

The alky kit has a light to show if its reaching full pressure and a low level sensor. It also has a test button so you can test it before you actually go into boost. I have tried the test button a few times just cruising down the highway and it will make the AFR go down to like 10:1 on the wideband. So it seems pretty foolproof. I just hate to give anymore money than I currently do to the ragheads that are driving the price of fuel up. Almost as much as I hate giving my money to Hilton Hotels and lining Paris's pockets. LOL

 

Well, my opinions on the the proper injection fluid are well known here, so just to be clear - I do not advocate using straight methanol. A water/meth mixture is much more effective at suppresing detonation.

But no matter what, you are flirting with disaster if you were to get into boost with 87 octane. It is just plain nuts and as to how you have decided the "theoretical octane should be around 103" I would just say there is no generally accepted methodology for making such an estimate. You are proposing a very risky experiment and I do not recommend it. If you can't afford premium fuel, take the blower off because you sure can't afford a new motor.

Rich

 

Thanks for the reply. You're right I have no idea what the actual octane will be so the 103 octane is purely a guess. But if I had someone watch the scanner to check for knock as I ease into the boost I could quickly come out of the throttle if I picked up knock. Not to mention the computer would pull timing. I would not call it a disaster if I broke a piston or ruined my short block. Heck, I've only got about $1500 in my short block anyway. You're right it is risky though.

 

I ran 87 octane the other day when I removed my blower's belt. Since the car a CR of 9.0:1, I figured it was okay.

 

yeah me too....but still we build these gas guzzling F-bodies. With 15 lbs. of boost, you are just asking for trouble, if you really want to save some gas do what Ultra Dog & I did, pull the belt for a while and run 8x octane "cheapo" gas in it until the prices come down!!

Michael

 

My thoughts exactly... I wouldnt even want to experiment with it.

Cost of engine > cost of premium gas/87 gas differential.

 

Well, It appears that I will either be a pioneer or a dumb@ss if I try this . Surely somebody has tried 87 octane/alky with boost. I'll Pm Julio and see if any of his customers have done it.

 

You have to be on top of your tuneup.

How bout this, 10:1 91 0ctane.. you'll see the rest
http://www.campbellautomotive.com/1000hpv6.wmv

No water...

If your on top of your knock readings, have your timing tables where they need to be.. why not. It is what it is.

HTH









PS.. sorry for stirring trouble with a V6 motor and a hair dryer

 

The laws of physics and chemistry have not been repealed. There is NO WAY to get close to 3.5hp/ci on 91 octane fuel with an OHV 2-V motor. Nope, no sir, no way, no how. Not with current technology, anyway.

Rich

 

Buwahahaha.. so what your saying is that an 88 MM turbo on a fully built 291 CI motor cannot make 1000 HP?

Or do you question the 91 octane? See cuase its methanol being shot in with 91 octane.. you can see the braided lines going to the "nozzles"..

Or will you need to see the motor in the truck its going in "do the number".. then start the questions again when it does the number??




Ok.. back to spraying water into the engine discussion

tee hee

 

Holy crap that V6 motor made over 1000Hp on 91 pump gas and methanol. Well this gives me new hope for my 87 octane and methanol theory. Was that 10:1 compression ratio or Air Fuel Ratio?

 

Yes, the 91 octane is what I question. How much of what the motor was running on was gas and how much was methanol?

Rich

 

Both. Nolan typically runs his big number pump gas/methanol tune-ups at 10:1 for AF and that motor was built at 10:1 so not to have to run as much boost. Thats how 21 PSI makes the number vs the old school way of building them at 8:1 and requiring way more boost to achieve the HP target. Way more boost would require a much larger IC due to heat.

You need to pay attention to what the engine tells you.. 87 is not an issue with injection. If your sloppy on tuning.. put 100 in the tank.