L99 discussion

[Mr. Wyndham]

Originally Posted by Jak

Yeah, I know, we'll have to wait for this afternoon for the real answers, but what do you think about this theory? Possible?

It's possible. The tune for regular would affect power, but not E85-compatibility.
Only 6 more hours, now......


And Shank, when I said "not true", I meant in some cars. Automatics are starting to return the same, if not better mpg than a manual counterpart in some vehicles. But there's too many variables (like gearing, and driving-habits) to say for sure if any one approach definitely gives an improvement. And that's new...it used to be the case where the automatic delivered worse mileage; no argument...

[fastball]

Originally Posted by shank0668

but sticks get better gas mileage thans autos

That is true, in most cases, from the old days when both transmissions were hooked to the same exact engine with the same exact everything.

AFM is not yet developed properly to work well with manual transmissioned cars. GM is going to use AFM as much as they can to increase their CAFE as much as possible. They aren't going to alienate those of us who still want our performance with the manual, but at the same time they are trying as best they can to improve fuel economy wherever possible.

It is quite possible due to this anomily that automatics will get better fuel economy than manuals (thus another dagger into the heart of manuals everywhere).

[Dan]

Originally Posted by jmliptak

It APPEARS the L99 is the L3 with AFM, etc, its a 6.2, but it has been rumored for quite some time that there would be a hp difference between the auto and the stick..I hear what you are saying, we should know a great deal more tommorrow

You know one of the biggest reasons why I don't believe it? If that is true and this isn't a truck engine (better not be), why isn't it an LSx?

[Mr. Wyndham]

Originally Posted by Dan

If that is true and this isn't a truck engine (better not be), why isn't it an LSx?

L76 in the G8 sound familiar?

[jmliptak]

Originally Posted by Jak

Remember awhile back Scott said to forget everything we knew about engines for the Camaro. Could the L99 be geared for regular unleaded and be set up for FlexFuel (Would that explaine the difference in HP?) where the LS3 would run on super unleaded. Yeah, I know, we'll have to wait for this afternoon for the real answers, but what do you think about this theory? Possible?

The HP difference does not appear to be due to E85, it will get lower mileage due to the energy content per liter, but produce MORE horsepower due to an increase in octane rating.

http://www.iowacorn.org/ethanol/ethanol_5a.html

What is the range of a flexible fuel ethanol vehicle?
Ethanol has less energy content than gasoline. However, E85 also has a much higher octane (ranging from 100 to 105) than gasoline. FFVs are not optimized to E85, so they experience a 5% to 15% drop in fuel economy. This will vary based on temperature and driving conditions. For comparison purposes, aggressive driving habits can result in a 20% loss and low tire pressure can reduce mileage by 6%.

Research indicates Ford FFVs experience a 5% horsepower gain on E85.
The range of any particular vehicle is dependent on the size of the fuel tank and driving habits.

One the articles posted talked about a higher geared rear end in the auto as well, so I suspect that you are right, that the auto will be pointed towards gettting the same or perhaps even better mileage with the auto, especially on the highway I suspect with the AFM....

I would love to have flex fuel on both the LS3 and the auto, its a lot cheaper around me right now and would probably offset the lower mileage right now...That would be quite a statement from GM, our LS3 can run on ethanol and produce more horsepower than on gas...

[SilverTurtle]

y'all are going to be so surprised this afternoon... some people in this thread have gotten some stuff right... but there's alot of speculation in here that's wrong... talk to me in 7 hours.

[jmliptak]

Is the broadcast really gonna go that long?????? It would be cool if it did.....

I gotta go to the store and buy the right cable so I can project the webcast on the big screen when its on...

I think you can count on MANY people asking you, it will be fun to look in the rearview mirror and laugh at some of the stuff we dreamed up....

[radz28]

I wonder if GM has reached a power threshold for engines with AFM then. I understand the way the lifters work and that jazz, but is it because anymore lift will result in the lift collapsing or pumping because the cam profile would be too aggressive? I wonder if there is a way for GM to integrate some multi-displacement technology with the L92's VVT (or whatever it's called.)

I think pretty much all of GM's current high performance engines (except for the LS9 and LSA) will run on sub-premium fuel, but the PCM will retard timing a lot until it stops detecting detonation. I'd run premium regardless, with a splash of unleaded 100. Gas here in CA sucks donkey b@lls, and the best we get is crappy 91 and unless you find a station with individual fuel nozzles, if the person in front of you just finished pumping 87, and you select 91, you're probably going to get a couple gallons of that 87 until you start actually getting the 91 you selected. Stations with separate nozzles are harder to find around here, so those are the places I frequent when I fill up my Camaro.

All this speculation is killing me!!!

[SilverTurtle]

Originally Posted by radz282003

I wonder if GM has reached a power threshold for engines with AFM then. I understand the way the lifters work and that jazz, but is it because anymore lift will result in the lift collapsing or pumping because the cam profile would be too aggressive? I wonder if there is a way for GM to integrate some multi-displacement technology with the L92's VVT (or whatever it's called.)

I think pretty much all of GM's current high performance engines (except for the LS9 and LSA) will run on sub-premium fuel, but the PCM will retard timing a lot until it stops detecting detonation. I'd run premium regardless, with a splash of unleaded 100. Gas here in CA sucks donkey b@lls, and the best we get is crappy 91 and unless you find a station with individual fuel nozzles, if the person in front of you just finished pumping 87, and you select 91, you're probably going to get a couple gallons of that 87 until you start actually getting the 91 you selected. Stations with separate nozzles are harder to find around here, so those are the places I frequent when I fill up my Camaro.

All this speculation is killing me!!!

can't talk about the auto SS engine just yet, but I can tell you that GM's "premium" recommendation is based on 91 octane... and that the premium recommendation is just that, a recommendation... the engine will run on regular unleaded gas, but there is a plain of programming in the computer that is described as "low octane" and the spark is adjusted to match up with that... this low octane spark table is also the default table for when you have a MAF failure.

I really wish Sunoco would make a move into the Texas region... I'd love to be able to pump 94 octane into our high performance V8s and I'd even pump it, on occasion, into our 5.3L Tahoe

[The_Blur]

Wait until this afternoon...We'll have facts very soon.

[AirGoya]

Originally Posted by shank0668

hmmmmmmm my brothers 5 speed g5 gets better mpg than the auto

Thats because the manual has 5 speeds unlike the autos 4 speeds. Now the camaro will have equal 6 speeds on both sides so the auto should get equal, if not better mpg than the manual.

[Grape Ape]

Originally Posted by radz282003

I wonder if GM has reached a power threshold for engines with AFM then. I understand the way the lifters work and that jazz, but is it because anymore lift will result in the lift collapsing or pumping because the cam profile would be too aggressive? I wonder if there is a way for GM to integrate some multi-displacement technology with the L92's VVT (or whatever it's called.)

All this speculation is killing me!!!

The L76’s deact lifters are not able to absorb as much lift as the LS2’s stock cam has. So if you installed a hotter cam the valves still would open slightly when the cam hit max lift and confuse the computer.

I am expecting someone to start offering hot cams rocker packages for these motors soon that would bump the valve lift up to whatever the valve spring and piston clearance allow.

I also expect the power to be the same for stick and autos with the next generation of small blocks since they should be designed for AFM.

[ralniv]

I have to say that I'm rather disappointed with the 6sp auto SS specs. A 400 hp engine sounds great (literally and figuratively), but the nearly 4,000 lb curb weight is pooing on my parade. I'm hopeful that the car is agile for a 4,000 lb fat cat.

I was figuring on an SS that weighed nearer to 3,500 lbs. I better go on a diet so I can recover some of GM's weight overruns!

[boxmonkeyracing]

Originally Posted by ralniv

I have to say that I'm rather disappointed with the 6sp auto SS specs. A 400 hp engine sounds great (literally and figuratively), but the nearly 4,000 lb curb weight is pooing on my parade. I'm hopeful that the car is agile for a 4,000 lb fat cat.

I was figuring on an SS that weighed nearer to 3,500 lbs. I better go on a diet so I can recover some of GM's weight overruns!

have faith, and 3500 lbs is closer to what the 4th gens weighted and this is a bigger car. . .how could it weight that much?