CaryKen

I know absolutely nothing about this subject, so help out a neophyte...

Can you switch back and forth between the two types of fuel to see what happens? Can you put one on top of the other while there is still some left in the tank/engine? Or do you need to do a complete drain to make sure the two liquids ne'er meet?

RocketGuy3

That seems very fishy to me, especially given that the compression ratio is fixed and E85 has a fairly significantly lower energy density than petrol.


I'm 99% sure you can mix. I'm no chemist, but regular "petrol" is generally about 10-15% ethanol, anyways. And E85 (as the name suggests) is only about 85% ethanol. So if you mix you fudge with the ratios a bit, but you're not mixing any chemicals that aren't already being mixed. Nothing is going to explode. You'll just get some performance somewhere in the middle of the spectrum.

Snobike Mike

99SoCalFRC

Alot of the 5.0 boys are using E85, after injector swaps, spark plug and timing changes, most seem to be reporting a 10HP gain.

If you think you are getting 80HP from a fuel change without changing the pistons, milling the heads or adding forced induction, you are crazy.

7LitreC5

Have GM said whether or not the LT1 will be FlexFuel?

JoesC5

There is a patent for an engine design that can mechanically change the compression ratio at will, but the LT1 does not use that patented design. As for as I know, the patented design is not used by any manufacturer.

Paulchristian

Hemi Dave, you may be right...however, at this point, with all this anticipation,clues,rumors,leaked videos,preview videos,gaming downloads, etc, it BETTER make a huge bang or a lot of people are going to feel either let down or

This car needs to make a big bang.

jimmyb

Maybe I missed it but where was said that the LT1 would even BE Flex Fuel capable?

Jimmy

chaase

Saab has it and I thought it went into production at some point. A variable boost engine would be the one most able to handle E85. You could raise the boost on the fly to take advantage of the higher effective octane.

EDIT: nvm, it got shelved and never went into production due to cost.

jimmyb

You're talking about 2 different things. A variable boost turbocharger is NOT the same as variable compression ratio. No one has ever produced a variable compression ratio engine in a passenger car, but many have experimented.

http://en.wikipedia.org/wiki/Variable_compression_ratio

Jimmy

WaxWeekly

Just watch the first minute and a half.

having trouble with embedding the video, but here's the link of the CCX where they talk about getting more hp simply by adjusting the tune and using E85. 806 on US fuel, 850 on EU fuel and 900 on E85.

http://www.youtube.com/watch?v=svxRpqeqFRY

Based on several articles found with a simple google search, the tune is all that's needed to make more power on E85 under certain circumstances, not on just any engine/setup. We won't know until it's actually done, but it sounds like it's entirely possible that the premise is accurate. Since google doesn't mean it's factual, we'll just have to wait and see...

Hemi Dave

Welcome to the future my friends.....2013....

BeaZt

He went into great detail explaining how it would work on LT1 over on the tech site. If it does work I have over 20 E85 stations within a 25 mile radius of my house

hig4s

The calculated compression ratio presumes that the cylinder is sealed at the bottom of the stroke, and that the volume compressed is the actual volume.

However: intake valve closure (sealing the cylinder) always takes place after BDC, which may cause some of the intake charge to be compressed backwards out of the cylinder by the rising piston at very low speeds; only the percentage of the stroke after intake valve closure is compressed. Intake port tuning and scavenging may allow a greater mass of charge (at a higher than atmospheric pressure) to be trapped in the cylinder than the static volume would suggest This "corrected" compression ratio is commonly called the "dynamic compression ratio".


So two identical engines with the same static compression ratio may have completely different dynamic ratios which would mean completely different power characteristics.

R6cowboy

I suppose for those who don't know. Increased power using E85 in leau of 91 or 93 octane is no mystery, nor is it new, even with N/A applications. Many have converted their LS based Corvettes (among other vehicles) to run E85 naturally aspirated and have seen decent power increases. Of course in any current LSx engine, a much bigger fuel pump, larger injectors and re-tuned PCM to run stickly E85 is necessary to take advantage of the fuel. Forced induction applications can see much higher power increases using E85 in leau of 93 octane by being able to increase boost pressure and timing due to the fact E85 has higher octane levels and runs much cooler then gasoline.

I have no idea if the new LT1 C7 will be able to do this on-the-fly (it will have the high pressure fuel system E85 requires), but technology never seizes to amaze us.

91redragtop

Mine will just be one day older on 1/13/13!! I will gladly keep my GS and be very happy with it!!!

Hemi Dave

The C6 will be an oldie but a goodie....no shame in that

SBC_and_a_stick

The way this new ECU adapts and the hardware is there to support it is really neat. It gives me that Back to the Future vibe, throwing banana peals in the tank for fuel and whatnot

No E85 around the house for me, but I do have some 100 octane gas stations.

Boo383

I can't think of any reason this isn't feasible. GM has made flex fuel vehicles for many years now, and even the Corvette racing team has used E85.

Although E85 was originally marketed as a renewable fuel substitute it proved to be uneconomical for us as consumers. It lacks the BTU factor of gasoline and despite costing less it yielded a lower MPG which was not offset by the lower price.

However from a performance standpoint E85 makes lots of sense! 110 octane racing fuel is around $10/gallon, and E85 offers comparable if not better performance for around $3/gallon. Using E85 will of course lower your MPG, but you could see significant power gains. Obvious Win Win situation.

If the GM power train team designed this DI system with these things in mind then we could fill the tank on 93 and get 30+mpg on a long trip, but if we're going to the track we can fill up with E85 for an extra 40hp. Marketing could advertise the new vette runs on biofuel making the environmentalists happy and giving us more power at the same time! Another Win Win!

If this turns out to be legit, then the Corvette team has once again pushed the technological envelope and exceeded expectations in every possible way.

Looking forward to Jan. 13!!

BuddhaZ06

Dynamic compression possibly? That's changed a lot in n/a motors with different cams. And the lt1 will be able to adjust it with valve timing right? I'm not real up to date on this stuff but it would be pretty badass