arghx7

Remember that this is the first production pushrod engine [generaton] on planet Earth with direct injection. It's not like the GM 3.6 for example, or the Ford Ecoboost 3.5, which are using DOHC direct injection architectures that have been done in similar fashion since the 90s.

OnPoint

You guys should consider bringing on board a solid in-house counsel. And if you already have one, you should fire him first thing tomorrow morn.

Just a thought.

Good luck.

irun4cops

dont be silly... its a big piece of cake...

except this powerlabs guy made a really good point on my other thread...

POWERLABS ASKS: ..........

I only have one question for ECS and other shops looking at tuning the C7:

What are you planning to do for fueling???

The reason I am asking is because I've had to do some custom fuel injector design work for my job, and modifying GDI injectors is a real challenge. I don't know of any shop that offers oversize GDI injectors, and the traditional solution of increasing pump pressure will only take you so far. Here is what I think will happen, based on other GDI engine builds and what I know about the injectors:

-Mild builds will be easily accommodated by increasing injector duration and/or commanded fuel pressure.

-Low boost applications will most likely outrun the fuel pump ability to maintain pressure and will require a redesigned high pressure fuel pump (no trivial undertaking seeing as this is a 3000psi pump that is driven by a cam lobe).

-Medium boost applications will run out of fuel pump and injector room.

I was going to guess that people will be adding an extra set of port injectors to meet fueling needs, but now you have to figure out a way to control them, since the factory ECU only has eight injector drivers. a Dual ECU solution is non trivial. Resized injectors are non existent, and even if you designed a high pressure fuel pump that could feed tons of fuel at high pressure, the injectors can only be held open for so long before you run into some real problems (start injecting too early and cylinder wall impingement will dilute your engine oil and cause cylinder wear. Continue injecting after ignition and the cylinder pressure will prevent much flow from going in).

I am very interested in this. I've contemplated talking to my boss into letting me work on aftermarket LT1 high pressure injectors but I want to see what the aftermarket has in mind first.

Injector info: http://delphi.com/shared/pdf/ppd/pwr...-injectors.pdf

irun4cops

and then all the people who were 110% positive this was a piece of cake, and are already advertising 1000hp packages who are requesting peoples cars and money to come get power adders put on in their shops for the piece of cake upgrade time... got really silent.

lt4obsesses

I bet, that's a heck of a question!

The unknowns about the intricate details of the LT1 seem to outweigh the knowns. For instance the max rate lbs/hr of the injectors. There is talk of a supercharges LT1 based engine coming. Will it use the same injector, pump? If so, then it is a tuning issue I would guess.

Perhaps the guys at Calloway, Hennesy, Lingenfelter, that have ties with GM, already have these little details, but I doubt that. But, worry not, in the aftermarket...where there is a demand backed by a dollar, there will be a product...the only question is when.

irun4cops

The only shop i have seen, who had the intelligence to notice they were in way over their head with this new engine, and admit its going to be a bear in a public article... was lingenfelter.

Meanwhile all these other shops are posting up kit prices when they dont even know if they are going to have to put a bigger fuel pump in the car and what kind of labor that will entail, or where they are even going to get a better fuel pump.

And for that, i respect lingenfelter tremendously for their honestly.

All shops make mistakes, i know they made a few in the past that i know about...

but im amazed at how few shops are being realistic, and how many shops already have "kits" and "pricing" of things that frankly... arent even going to work, and they havent even tuned yet...

let alone know how much its going to cost to subcontract the super hacker required to understand and reprogram this engine when boost is thrown its way.

irun4cops

The purpose of this thread is to help everyone get their priorities in line of what we need to collectively try to solve.

And since, step 2, of tuning a car with boost has already been done behind closed doors in the big shops secret dyno rooms with no cameras present...

Lets get in our time machines and go back and re live what it was like to solve step 1...

Step 1, more fuel so our engines don't run lean and blow up while we are trying to tune them for boost.

OD3G

high hp builds (pending stock fuel system limitations) could possibly do away with the direct injection all-together.

Z_Rocks

You've already come to that realization about Lingenfelter. If I were you and wanted peace of mind and support, stay with Lingenfelter. When they say, they're ready, then you go for it.
I have a tuner friend who does many imports, including AMG, BMW, American cars and etc. And he said, to this date, he has not been able to offer a true and reliable tune for any DI cars. He has tried many but he can't release it to customers because he doesn't feel he has everything covered. So, when Lingenfelter said, it's not easy, I believe them.
Good luck...

0MikePeters@Hennessey

Ever notice how test mules have black covers on them? Same rule applies to sharing information online. Just because shops aren't being transparently open on Corvette Forums about what is up their sleeve doesn't mean they don't have it figured out, or aren't making headway overcoming obstacles.

Once Stingrays are in customer hands, shops will start rolling out our vehicles, and be much more open sharing what they've learned. Just because all the high-profile shops aren't sharing their secrets on Corvette Forums and Facebook, doesn't mean they aren't hard at work behind the scenes, and don't already possibly have it dialed in.

I'm not trying to hurt anyone's online feelings, but just take a couple steps back and think about it for a bit. You've got some of the top people in the industry choosing to interact with your community, and questions are great, but you have to understand that most of us that are in the big shops, aren't really going to divulge our secrets. Just like the test mules have covers, the OEM's aren't interested in sharing all of their secrets, and neither are some of the shops when new platforms roll out.

99C5JA1

As some of the shops have indicated the current trucks are using basically the same powertrain and ECM. So there is indeed a viable platform for testing. I would suspect that the shops advertising estimates on their packages are doing so because they are well on their way to getting there using a truck as a test mule. The truck powertrain is similar enough that it's probably a matter of tweaking the fuel mapping for the C7's displacement and breathing characteristics.

FEAR

im also in jupiter fl, and have had my share of cars too.... i bet i know you. pm me

1BlinkGone

I can tell you this: I personally would want a roots-type supercharger, and not a turbo solution in my C7-for two reasons:
1. more simplicity & less hardware and
2. the ability to keep the smog ***** appeased here in California. I don't think the aftermarket turbo solution would pass muster here....oh one more thing, I don't want the muted exhaust note of a turbo. Just my request and opinion.

Supermassive

Most DI boost builds ignore the DI and use larger port injectors to add the required fuel. The Di is left to do it's own thing and the PI is used to fill the gaps in essence...this is not rocket science. DI is not a cost effective route to add fuel to the cylinder as the parts are expensive and not as readily available as the Bosch style port injectors that you can get in any capacity you want.

As for the guy talking about not being able to control both the port injectors and DI because of the 8 injector channels in the ECU...most DI cars have a standalone injector controller which actually controls the individual injectors while the ECU just transmits the fuel map. I'm sure someone with a bit more experience can chime in, but as I understand it the Injector controller determines the duty cycles required by each injector. I may be misinformed but putting a turbo kit on my DI four banger and seeing a bit of the wizardry that goes into tuning it, it all seemed very practical and not overly difficult.

Of course the real difficulty is cracking the ECU and having access to fuel tables and the ability to edit them without some sort of piggyback.

Don't want a muted exhaust note...go with open wastegates...of course in Cali that would be a red flag. Here in AZ I run open gates on my FR-S and we also only have an OBD2 read for smog certification...so my catless, open wastegate, straight pipes, turbo FR-S is still smog compliant because I don't throw ECM codes

1BlinkGone

Lol well that works for you...but not here in Cali (the dreaded CARB and all that), oh and one other thing, I want the snappiness of a supercharged engine. I just don't want the hassles (including the CARB), the clutter, (and the lag) of a turbocharged aftermarket solution.

irun4cops

cool vid i found of the insulation nasa and chevy use in the torque tube tunnel on the new c7

Racer X

What makes you think that this is the first direct injection pushrod motor made?

I have a turbocharged direct injection pushrod V8 in my vehicle in my garage. It is a 2001 model Excursion. It has glow plugs instead of spark plugs and 17.5 to one compression.

It is only different in the details, the principle is the same. I have increased the power by over 40% without changing the injectors.

irun4cops

comp's ceramic, oil less turbos... how do they compare performance to garrett and precisions? Anyone have any apple to apples comparisons?

Shurshot

I agree

With all of the differences behind the thought and design involved with hi-performance lifters that are still known to fail in hi-stress situations, I would never go or do anything outside of a factory warranty on a motor with variable displacement technology.

IMO if you want a boosted C7 wait for GM to bring it out.

Maybe years down the road and after others have ruined their motors and/or its all around ability because they volunteered their cars to be guinea pigs for the aftermarket industry the risk might subside some.

Until then russian roulette has better odds

Supermassive

Variable displacement tech, is easily disabled in the ECU, hell they flat out disable it through the mode control selections in the dash. The worry worts will always say it isn't practical to do anything to modern engines while the rest of the modding community will undoubtedly find the limits of the drivetrain and make beefier parts where it's needed.

Some people like myself enjoy being at the forefront of the modding community and taking risks with our toys because it's fun. If everyone who bought a new car left it alone in fear of breaking things, the car enthusiast community would be boring as hell.

I'm currently part of a community based around the GT-86/FR-S/BRZ platform, this is a car that everyone thought would break with boost. People were worried that at 240 WHP the engine would pretty much grenade due to the 12.5:1 compression ratio, and the open deck flat four layout. What happened was the car reliably puts down 450-500WHP with stock internals under 20-22lbs of boost. Sure this is only the first year but there are daily drivers out there with more HP to the wheels than the Z06 has at the crank...coming from a 2.0L 4 banger with stock internals.

Basically you don't know what is safe or possible until you try...if we all waited around for GM to get off their *** and produce a SC solution we'll be waiting years, and have to spend in the vicinity of $120K+ for a ZR-1. No thanks. I'll risk a Base Stingray LT-1 with a SC as it's more cost effective and even if I did pop an engine I guarantee it will be cheaper to fix than GM's SC specific engine...

All this said, I will be waiting about a year before supercharging my C7, this will allow time for people to get their hands on the individual kits and real reviews from real world people will make it easier for me to base my decision on a setup. I'm not waiting because I'm scared of breaking stuff...I'm waiting because the domestic aftermarket for Corvettes is wholly unfamiliar territory for me, since this is my first domestic make car since the POS pontiac Sunbird I had back in 1998...