Cobra4B

iTrader: (9)

My FIL actually does very well for himself and his family. He's director of sales for a large sensor and component manufacturer and a musician with a successful band; quite the atypical engineer.

I never asked what color your skin was... simply curious if you weren't American or originally from an English speaking country. You're spelling and grammar are poor and it comes off as someone who wasn't raised with English as their first language.

So I guess this means you're going to ignore my original set of questions? I'm beginning to lose faith that you are really a GM employee. I don't think they'd have someone on a forum representing them in such a manner. Normally they are far more controlled about how information is distributed to the public.... i.e. perspective customers.

You come off as a douche.

Trolls? You're the noob around here. Why do you go straight to race/skin color? Is that the popular thing to do these days? Did I ever ask anything about if you were white or not? I asked what your nationality was... very different. Or did you fail geography and history as well?

You have no idea who you're talking to our what someone's background/skillset is.

If you are truly a GM employee then a marketing manger would have a heart attack from reading this post and how you carry yourself on here.

Get fucked.

Sincerely,

A prospective C7 customer

Bigg_Gunz

Good Morning Sir

He didn't offend me...he offended himself. I don't engage those type of people.

I was made in the Great state of Nebraska. We didn't speak good on a corn farm as a child. There wasn't a need to...however father rest his soul, who needed to calculate tons of corn per acres taught me at a early age how to add and etc. Not how to write a book.... That set the stage for me to love math. English was never my strong point and if that guy intentions was noble...he wouldn't have brought it up a innuendo fashion. And it was very suggestive towards ethnicity/nationality other than domestically.

English is my second language, Advanced Mathematics is my first and I make no point in hiding that.

Bigg Gunz.

J-Rod

So, going back to my questions.

I think many enthusiasts will be happy if the ECM can self tune as it just removes the variabilty of a getting tuning done by a "Good tuner" vs a "bad tuner". The only issue is how good is "good enough" in the ECM.

So, going back to fuel delivery. Justin from GMHTP posted a thread in this forum on the 6.2. I am going to quote from that thread which has some of the press release information.

So, if we assume 125.7 lbs/hr @ 1450 psi then scaling that to 2175 should be ~154 lbs/hr.


So, if we assume that BSFC is ~.5 (for anyone else reading this - This means that the engine will use .50 lbs. of fuel per hour for each horsepower it produces.)

Then:
125.7 lbs/hr / .5 lbs/hr per hp of fuel * 8 cylinders = 2011 HP @ 1450 psi
154 lbs/hr / .5 lbs/hr per hp of fuel * 8 cylinders = 2464 HP @ 2175 psi

So, if that is the case, then I would agree with you that injector swaps are probably not necessary, but I'd like to see if you can comment on that.

So, the big area of concern obviously becomes fuel delivery. My guess is although the fuel injectors can move that ammount of fuel, what about the limitations of the fuel system itself. Electric fuel pump upgrades are pretty commonplace, so I don't see that as a deal breaker.

My area of concern is around the mechanical pump since it is somehting "new". So, you addressed the issue of cam twist as being a non issue with the tri-lobe design from your testing.

But, if I am reading correctly, the mechnaical pump is 1.48 cc/rev geometric displacement fuel pump.

So, assuming my math is right at 7000 rpm that is 7000rpm * 1.48cc/rev = 10360 cc/min = 986.7 lbs/hr

986.7 lbs/hr / .5 BSFC = 1973.4 HP @ 7000 RPM (theoretically capcity of the fuel pump).

So, I just wanted to see if those capcity numbers are really accurate.


Now, going back to the cylinder heads. So, I totally get raising the runners to 12º and 12.5º from 15º. This makes the airflow path a lot straighter and give you a better shot into the cylinder, keeps the air from peeling off the short turn, etc... That Hot Rod 101.

What I still don't understand is the comment you made about moving the ports
So, here is the photo of the head from GMHTP


So, in looking at the head gasket I don't see anything special on cooling passages. I can't see the deck on the head, so I can't make any judgments there. But, in looking at the heads I'm just trying to understand how it is shorter.
As an example, here is an LS3 head.
https://ls1tech.com/forums/attachmen...e-dsc03993.jpg

I wondered if had to do with what you alluded to with your airflow work and what is alluded to in the press blurbs as maximum "mixture motion". What is intersting is the press info it does refer to the Gen 5 LT1 cylinder heads feature large straight rectangular ports that incorporate a slight twist for the most efficient air tumble and maximum "mixture motion,". I know you said that swirl rather than tumble was what drove this design. And I was wondering if the swirl design also drove port layout.

So you alluded to how strong the block is. So, you are using a stronger grade of Al in the block (319-T7 in this case), and I believe larger fastners on things like the cylinder heads.

What I am curious about are the cylinder liners. In the press photos the liner

"Cylinder head sealing has been improved through the use of an all aluminum deck surface (cast over liners) and the inclusion of M12 cylinder head bolts."


Can you comment on the thickeness of the factory liner is so we can work out how much you can bore the block (if any) ? What we've seen up till now is the factory gray iron liners are about 50,000 psi and are pretty brittle and the aftermarket sleeves are ductile iron and go 110,000 psi.

Cobra4B

iTrader: (9)

Interesting that the rocker arm pedestals are now part of the head. The intake ports are so large that they remove the space for the old-style rocker pedestal. Also they pedestals are angled an slightly offset from each other. I guess no more offset rocker arms like the LS3/7?

J-Rod

Bigg_Gunz,

One other question. You keep mentioning E-85. Now, as I understand it with the DI and combustion chamber efficencies you've raised static compression to 11.5:1.

So, at a high level the pro's are that E-85 EGT's run slightly cooler, its a little more knock resistant than pump gas, and coolant temps usually run a bit cooler on E-85.

Cons are it take 30% more fuel as E-85 just doesn't have the BTU's that gas does, its corrosive, its agroscopic, etc....

So, most folks racing on E-85 are going up on compression, adding boost, etc... and take advantage of the higher octance.

But, can you allude to why you recommend E-85 and what you see as its benefits in the LTx?

Bigg_Gunz

The fuel system is up to the task of extreme 4 digit horsepower numbers. I can tell you with 99.9999% confidence the fuel system exceeds the horsepower capability of this block. You will not find the limitations of the fuel system with this block. Equations point towards 500 cu in + to exceed it under 135% VE conditions.

You will NOT have to touch the fuel injectors or pump high pressure pump no matter what level of power you are trying to reach. The high pressure solenoid is on the pump is in control of the pressure & volume from 500psi - 2175 psi. It is extremely complex and extremely fast as I've explain earlier in this thread which required the ECM.

I am allowed to say that your math is sound enough that you are with a target range of 90% accuracy. I'm impressed actually!

The mechanical fuel pump is sound. It has to be..... if it fails the car goes up in flames, possible taking someone's life or home. That is not acceptable... just completely unacceptable. The mechanical pump will not fail. This is why we cannot allow access to the fuel tables or access to the high pressure fuel solenoid table for the pump. Let me put it another way..... if we wasn't 100% sure the aftermarket could not access the fuel tables or high pressure solenoid tables within the ECM.

Our directors and GM executives would have no problem sticking a H.O LS7 in the C7.
And a lot goes on that people do NOT know. We are talking about thousands and thousands of engineers working on the development of the C7 and then its power train would had careers, shattered reputations ruined. A brand tarnished. Any risk was too much....we works in ISO standards, 0000001% risk would have resulted in a H.O LS7 in the C7 #Fact

Look again at the heads J-Rod something fishy should jump out at you. Red Tape....now the shorter exhaust port length... in millimeters you can tell Red tape.

Yes the VORTEX/TORNADO in the combustion produced by the heads is what drove the design. Can't believe they said "mixing motion" in the press that upsets me.... that under values our work. To achieve that Vortex in Low Pressure conditions has never been done before and they watered it down to "mixing motion." (-_-) The true intentions of the engine is what drove the development of the heads. Which drove the re-engineering of the entire engine block.

Red Tape on deck thickness RED TAPE on cylinder thickness. The hiding liners ...RED TAPE...Reason...Red Tape.

Let me go ask....what I am allowed to tell you about stroke and other possibilities with the block give me 30mins...or so....


Bigg Gunz...

Bigg_Gunz

Let me say in this way.... I've seen it in action on the platform which is in debate/discussion. And I've seen it in action on what is too come.

Now let me say it another way... There is a "supercar" in sweden that is bi turbo. And under normal gasoline its rated at 8XX hp. And when it runs E-85 its rated at 1XXXhp. Simply running E-85 vs Gasoline. So I say this.... to give you an visual picture of what happens just by switching the fuel type.

This is going to sound cheesy. But this is necessary just in case my "ALIAS" is ever compromised.

(Disclaimer: The platforms discuss by "Bigg Gunz" on this Swedish company are provided for information purposes and only informational purposes no award compensation was not awarded for any breach of the act.)


Bigg Gunz

Bigg_Gunz

Ok J-Rod..... No GO on the releasing stroke possibilities ...more red tape.

But any other questions feel free....

I'll keep you and other posted on what is to come looks like their about to make a major release on information MONDAY.


Sincerely

Bigg Gunz.

wssix99

iTrader: (5)

The internet lied to me!

http://www.brighthubengineering.com/...ic-efficiency/

I've always been under the impression that the resonators were needed to properly balance the pressure waves to aid in the efficiency of moving air in to the head. (Synchronized pressure waves helping counteract the loss of air momentum in the runners when the intake valves shut.)

Maybe this is more of an issue for smaller engines and not 8+ cylinder models? Or perhaps the effect is insignificant in this when compared to the challenges of getting exhaust gasses out of the head on these engines?


I can't wait. Maybe I won't have to run this product on the new engine?

http://tornadoair.com/tornadoair.php

J-Rod

So, without saying it, I'm assuming you mean a Koenigsegg.

So, the Koenigsegg makes about 960 on pump gas and 1140 on E-85. But, that increase is by virtue of being able to run more boost on E-85, not just the fuel itself. The LTx is in this particular combination N/A.

I mean E-85 is great to a point, but most E-85 is mixed with low grade gasoline and you can actually run out of octane on E-85, E85 is typically assumed to have an Octane rating of 105 (but that is an inference rather than a direct measurement, and again varies on the actual alochol content (down to 70% in the winter), and the gasoline can be the cheapest hydrocarbon that whoever is blendeing it has available

So, if the Koenigsegg can make 1140 on E-85, then chances are you could up the boost a bit more on race gas and make more than 1140. Or even the same on say 104 Octane Racing unleaded.

But, if an engine can't take advatage of more octane then there is no power gain.

When the air/fuel ratios are correct for both fuels, E85 and normal street gasoline will usually make about the same amount of power. Sometimes E85 will have a slight horsepower advantage, but that’s due to E85’s superior cooling effect over gasoline as the fuel evaporates, not its higher octane number. That goes out the window with DI as the fuel isn't cooling the intake charge.

Since this is your area of expertise. The LTx has a small chamber, the plug has been moved to a more central location for better flame propogation, etc...All in the name of increasing power production and combustion chamber efficency.

So, excessive ignition timing is just negative work on the engine. I'm just trying to understand what else E-85 brings to a N/A combination.

Bigg_Gunz

ROFLMAOO!!! That picture my office can't stop laughing!

Bigg_Gunz

The timing isn't excessive it moves -4 degrees or + 4 degrees range when running E-85. This allows for substantive power gains from a more violent combustion and dynamic cylinder pressure = more power. The VVT adds more duration at this time without the increase in EGT = More power on E-85.

And yes... this is speaking relative to the 2014 LT1 N/A form. A range of 40-80hp. Depending on ambient temperature outside.

(Disclaimer: The platforms discuss by "Bigg Gunz" on this Swedish company are provided for information purposes and only informational purposes no award compensation was not awarded for any breach of the act.)


Bigg Gunz

Wnts2Go10O

iTrader: (12)

VVT adds more duration? is this implying that the way VVT w/ a pushrod engine is based more on the position of the cam on a given cycle than simply retarding/advancing the cam like previous versions?

dbs1

I see all kinds of possibilities to hot rod this thing, and it appears to me that BG and his buds have actually plugged that in, and in a couple of ways are doing some things that will lend itself to rodding it without us having to do some of the normal requirements (upgrade fuel supply-tuning). At least I don't see me needing a 2000hp track car in the near future. Might I ask what kind of HP capabilities the block has? I'm getting the feel (hint) part of the design was to accomodate some form of FI to make outrageous #'s. Can we assume the heads flow well enough to support 800-1000HP?

As far as his grammar-we all might check ours first. I appreciate good grammar and spelling as much as the next guy, but let's be honest, his mistakes are few and far between. If I compared his grammar to my math...I'll take his mad math skills and understanding of his profession as a complete cover for a couple of grammatical errors.

Thanks for the input on my questions!! My engine builder did ask me prior to the build and because of the chance of it being a dd I told him I didn't see the need to build for E85. Now I know why he asked me. And he did say he clearanced it for my RR purposes. Now if I can just get the oil temps down...and I have a better set of headers here waiting to be installed, but now I'm scratching my head if they are leaving more "porkchops" on the table. I sure as heck hate giving any pony boys some of my porkchops!!!! So you're saying that IF you were using headers it would be those built by an AMERICAN company, and would thermal coating be better then wrapping them, even if they're ss??? Hmmmm...

Che70velle

iTrader: (6)

There are far better materials out there to build headers out of than stainless steel. We were experimenting with titanium and inconel headers, long before they were common place in circle track racing. What Mr. Gunz is trying to stress here is that you can never have too high quality of a header. It's gonna be pricey, that's for sure, but I have seen dyno runs with header swaps only, that picked up stupid high numbers, for the very reason mr. Gunz is talking about. But let's be real here. Who's going to pay $2500 to $3000 for this type of quality in an exhaust header?

DrkPhx

iTrader: (15)

Without a doubt this setup has great potential along with great supporting hardware. The adaptive learning on this ECM seems to be light years ahead of the current ECM's which bodes well for hot rodders.

I read on the Corvette forum in a thread where someone leaked some CAD's of different C7 components (including the LT4) and the LT4 will have somewhere around 580-620 hp is supercharged released in 2015 and Big Brother (Stingray or ZR1)will debut in 2016 with 700 plus hp.

ringram

Nice info Mr Gunz,
I like the sounds of the better ECU handling physical changes in the engine.
If it can adjust dynamically then we may not need to crack it afterall.

I was considering a viper, but if the C7 handles mods like you say I might be convinced to change and stay GM

By the look of the heads the exhaust port is skewed to the side of the valve..!?
It does look like a very short port, though he manifold has nice long runners for an OEM.

Looking forward to reading some more details.

Also look forward to seeing this in the 2014 Camaro

out2kayak

BG,

I gave you a solid answer as to why the NV in ECM will be changed. It is apparent that you don't have deep software / computer experience.

Given your responses and who I work with on a day to day basis, I'd put you as a management type.

Nothing against the management types, they are needed too. I'm just glad I'm not one and that my software is able to provide the tech for a better planet and better vehicles.



-- Joe

ringram

Yeah I dont think Mr Gunzz is the calibrator for the project. But the use of RSA encryption in the latest ECUs including the latest Duramax stuff which is already out there and the European Bosch ECU's suggests its not going to be a walk in the park.

So if mods are more easily supported in the base thats well and good, but we all know some will want better throttle control. Or to tweak things like DFCO and lean out fueling more for cruise, or even full throttle. Its not as if GM ever made a perfect calibration first time. Being locked out of the injector tables is one thing. But being locked out of the whole tune is another. What about messing with VVT as at present to advance the cam more at low rpm etc and/or take out/reduce torque management or change rear gear ratio!?.. The hacking will continue

Robert91RS

iTrader: (2)

A couple of questions if I may,

Forged cranks are great, but the PM rods don't appear to be much beefier. Have the PM rods not always been a weak link?


Will the other Gen3/4 engine displacements be carried into the Gen5 power train lineup or will they be resized around the new head design?


Nobody has thought to ask about the 3 valve OHV design that was rumored. Is it completely off the table again? How did it perform?


The LST motor got scrapped before it got off the ground. Can we expect another attempt at a factory hotrod Truck?


I own an iron block Gen4 5.3 which you suggested was begging for a combustions engineers touch with a poor boy budget. Educate me, I'm all ears.


The LY6 still has secrets? Tell me more.


I AM GENUINELY CURIOUS, how did you get selected as our GM rep? Does GM give you a script response or just a general guide to what should be said? Did you request it or was everybody told simultaneously they could stir the pot so long as they didn't cross the line? I find this method of communication with a customer base to be fascinating.