I don't post here often but I'd like to give you a bit of help.
 

Sometimes thinking outside of the box is useful.

For all of you who are struggling with FI due to fueling, I have a suggestion to make.

Add port fueling...

There is going to be a lot of conjecture and theories, but from experience with adding port fuel on top of a stock DI vehicle, it works, and works just fine.

Just make sure that you are hitting the back of the valves with your injector. How to do this?

I'd suggest looking into an LY7 Lower intake manifold, it'll likely bolt right up. It'll already have the correct bosses in there, and if the fuel rail doesn't fit with the LLT upper, run the LY7 upper.

This could be interesting. :popcorn:

I'm confused. Arent' they port fueled anyway? You talking about spraying along with FI?

No, the LLT is a DI motor. I'm talking about adding port fueling on top of this. This is the best solution. The LLT already has a 4 lobe cam for the pump (so we can't add another lobe with a custom cam)(im almost 100% positive).

People need to be logging rail pressure though. If you guys are really running out of fuel due to the mechanical limits of the pump a couple of things will happen.

#1 Fuel pressure will drop off.
#2 As RPMs climb the amount of fuel that the pump will support will also climb.

If neither is the case, you're likely running out of pressure or volume in the tank pump, or you're running out of injector (which I don't think is the case)

Ok. I get that but most of them would measure rail pressure. And upgrading the fuel pumping system.

So you mean instead of BAP, duel pump, bigger pump etc ....... ???

Are you doing it now?


I had to change my post. I didnt realize you were talking about the LLT. LMAO

Forced Induction - V6 V6 Supercharger, turbo, nitrous discussions

It is one of the things we are looking at. However, if we can keep it all DI then we can maintain the cooling benefits that comes with it.

You still retain all of the cooling effects of the DI even though you are adding port fuel, and you can stage the system if you wish as well.

What is your response on my comment about measuring rail pressure? What have you found?

There are many cars that use both today, including the Lexus IS-F.

Save yourself the trouble, and add port fuel on top of it, you'll be just fine. Direct injection works more like port fueling at high RPM's anyways due to the volume and injection duration. It doesn't atomize quite the same as low rpm. You'll notice a lot of DI cars running 14.5 A/F usually up to around 5000 rpm, after that A/F ratio will drop significantly to around normal port fuel levels.

Seriously. Go on ebaymotors, pick up a LY7 Lower intake manifold, Upper intake manifold, and fuel rail. Heck you could even use stock injectors if you want to start - you'll get them for a song. The issue will be in mating up a simple stand-alone for the fuel trigger and injector control. Problems solved.

We've seen two things happen with the rail pressure. The first is just like all the others that the tuner has seen...at middle RPMs the fuel pressure drops too low. The second scenario happens when he tries to compenstate for that...we see the overall flow drop to low at the higher RPMs.

:rolleyes: I know, I know. I was browsing the 'New Post' page and didn't look at what section it was in.

Ok well that settles it then. You're running out of volume on the high pressure pump. They can be modified, check out what the 2.0FSI guys were doing with them.

However I think it's better to run the port fuel on top of it for many many reasons, namely improved upgrade path, and reliability. Even if it complicates things a bit.

:popcorn:subscribed

It's okay. You learned something new about the LLT and now that you are thinking about it something may come to you.

Port fueling sound interesting. maybe you should bring this up to tracy and see what his response is gretch. does anyone know how adkin did with their turbo build? I wonder how they got around the fueling issue even if they got around it:iono::iono:

I understand they were kicked off the site so either they stopped the whole project altogether or they have continued on and are not going to share with the ppl here who were calling them out on their rudeness. I thinkk a few among us have his phone number maybe we should text him.

It was the very thing we talked about as an alternative. He's still considering it, but would like to keep it total DI if he can. We are both (and I'm thinking many others) convinced the next generation of V8s are going to be DI, so it is better to figure out the right way to fuel a beast now than to take a short cut (no offense to anyone). That doesn't mean we won't go that route if the other ideas don't pan out, but for now he and IPS are working a couple of ideas that will keep it completely DI.

I wish I could tell you more, but I'm not asking IPS to give me details on what they are doing ("none of my business" thing from my perspective and maybe theirs), and Tracy and I just haven't had time to talk in details about where he is with it. I'm sure once he has a good feel for what will work he'll share.

Last I heard, Will stepped away from Adkins. I don't know if he got his car back, but he told me the turbo was still not tuned and it was leaking badly.
The guy who had the manual there got his car back without the turbo. They had the clutch in and it felt bad. They redid it and I think the guy said he was going to drive it back to SanAntonio from CA.

Jonathan was making promises he couldn't keep and had a bad business sense. He said the clutch was done, sold one to me, a month went by with excuse after excuse as to why it hadn't shipped. I asked for a refund and was told it would be granted. Another month goes by and I am losing it. I finally contacted my bank and got my refund finally yesterday.
This is not the first forum to ban them and I don't believe it was just for rules infractions.
I'm now going to get back in touch with Spec and see how they're doing with their clutch project.

Now back to our regularly scheduled program.

WOW!!:confused0068: god must have been with me because at one point I was about to put a nice amount of loan on my card and go for a supercharger build from them, but I changed my mind at the last minute and decided to stay all N/A this time around.

Im glad everything worked out for ya at the end but I can just imagine what you was probably going through.

well, hate to say we told you so..but we told you so. Poor John took some heat from his posts too:facepalm:

Let's just let them disappear, guys. Will sounded good, sounded enthusiastic, but in the end, couldn't fix what was wrong with Adkins from the start. Google them and you'll see Adkins Performance has been banned from different forums and it's always the same story.

there were a few people who called adkins on this from the moment he started looking for cars to do this with. those of you who refused to believe...well obviously you should have...jonathan is simply an idiot who couldnt run a lemonade stand. funny, i was just curious if i was ever proven wrong with this build so i just did a search, and this is what came up. i feel bad for you guys that got taken, including will if this is true....but you all were warned.

Good thing...

...your NA build is more impressive to me anyways than a supercharged application!

Will seemed like a decent guy. Looks like he just made a bad decision in hitching his wagon to the Adkins Business of Fail.

Who among us hasn't made a poor decision or 2 in our lifetime?

Thanks for the insight USA1. Glad you didn't get the shaft in the end.

I'm out of this and movin on.
:burnrubber:

Throwing this out there but has anyone looking into the fuel system for the Cobalt? I know alot of guys that have run 30psi over the stock system so my logic is leading me to believe that the direct injection system from a cobalt should flow enough for a LLT.

I know Cobalt's fuel pump is in tank and the rails can run up to 2800psi. So if it can push 4 cylinders to 30psi then it should be able to push 6 at 5-10psi.

Hopefully this can help solve the puzzle

Actually the Cobalts have a similar setup to ours. The in-tank low-pressure pump and a high-pressure pump connected to the cam shaft. They have exactly the same pump and had to rely on aftermarket manufacturers to build new high-pressure pumps. That's what we are working on now.

Our fuel delivery isnt cutting out though. Its the Cobalt guys with larger turbos that are upgrading the rail and sometimes adding a secondary rail. Its my understanding that you guys are only planning on pushing about 10lbs max right? Could the Cobalt injectors flow at a higher rate? If so, using them could be a cheaper solution.

From what i understand of this, its not the rails thats the problem, they spray fine, its that the high pressure pump cant work fast enough to send the amount of fuel we need. I hope im right? lol. i try to follow these turbo threads but i get lost sometimes.

How did I miss all this!

Any news on this issue. Any updates?

Tracy thinks the pump for the V8 DI Twin Turbo BMWs will work, but hasn't been able to get hold of one.

Jeff at IPS was trying to get the Audi pump but no luck on that either....

Ok thank guys for keeping us updated.