[pwr hungry]

Originally Posted by Torgus

Just stfu already. Your comments are useless. Go troll in another thread.

You mad bro?

[Sered]

Originally Posted by scotthureau

What you guys are discussing has been done on 2JZs for quite some time and is part of my SC300 turbo setup. We put two 550cc supplimental fuel injectors in the pipe between the front of the throttle body and the output of the intercooler. An inexpensive Haltech fuel controller adds fuel based on boost level. It is mapped to add x amount of fuel for x psi of boost. We tapped the main fuel line with a T. The system is simple and effective and adds enough fuel for the SC300 to go from around 350whp to 550whp. The system also keeps the throttle body and valvetrain clean, which would be a big bonus for the N54 and its carbon building tendancies. On the N54 with two wideband 02 sensors controlling banks of three, my only concern would be any imbalance in the induction system. Closed loop fueling should be able to keep A/F ratios intact, IMHO.

--Scott Hureau
07 335xi 6MT JB4
92 Lexus SC300 turbo

This guy knows what's he's talking about. I had no idea you were on here. This is Bean from CL, I followed your footsteps and ran a 60-1 on my SC as well. Do you still have yours?

Fwiw klipseracer, I am interested in trying this, but once the vargas fuel pump came out, I jumped on that. We will see how much power the pump can support on e85. If you can keep the costs down, I can see it being a good option since the hpfp upgrade is best done with a new pump causing the price to increase.

[SC300T]

Hey Bean, yeah, still have it but looking to sell. It takes an act of Congress to get that thing out of the hole with any velocity. Ran a 12.7 with 350whp, ran 12.7 with 550whp. The only thing that changed was spinning off the line vs spinning until the 1/8th.

I could put all this stuff on the BMW, but with just a JB4, DCI and E35, don't need any fuel yet... The theory and application is really simple.

Back to topic:

What does adding throttle body fuel injection do to the speed of the combustion process on a DI engine? Does that kill detonation resistance? How much faith do you have in the knock sensors to pick up detonation from the added fuel? Knock is knock, right?

[pwr hungry]

Originally Posted by scotthureau

Hey Bean, yeah, still have it but looking to sell. It takes an act of Congress to get that thing out of the hole with any velocity. Ran a 12.7 with 350whp, ran 12.7 with 550whp. The only thing that changed was spinning off the line vs spinning until the 1/8th.

I could put all this stuff on the BMW, but with just a JB4, DCI and E35, don't need any fuel yet... The theory and application is really simple.

Back to topic:

What does adding throttle body fuel injection do to the speed of the combustion process on a DI engine? Does that kill detonation resistance? How much faith do you have in the knock sensors to pick up detonation from the added fuel? Knock is knock, right?

This is the key reason I am not a fan of this idea. I get that it can work, but working and working safely are two totally different things. I mean, we already have less air getting to cylinders 1 and 6, no? And then we throw more fuel at the motor that will follow the same path as the air and still "starve" 1 and 6. Just seems like the problem would only get worse and potential cause catastrophic results.

[Torgus]

Originally Posted by pwr hungry

This is the key reason I am not a fan of this idea. I get that it can work, but working and working safely are two totally different things. I mean, we already have less air getting to cylinders 1 and 6, no? And then we throw more fuel at the motor that will follow the same path as the air and still "starve" 1 and 6. Just seems like the problem would only get worse and potential cause catastrophic results.

do you think it would get worse as power level increase?

[Joshboody]

Its similar to meth distribution, but with the benefit of same fuel. With meth you can have an imbalance of octane between cyls... TB injection being discussed you don't. The distribution variance is AFR between cyls, but same thing with meth injection also. % of fuel supplement and location injected would matter here as to the degree.

TB injection and more conventional meth setup are similar as far as varying cyl environment. But meth injection can be more upstream and I think the better choice in the end for distribution, IF coupled with a piggyback for control, map switching.

TB injection is fairly simple and a solid solution, just not as good as meth or 6 port injection... or upgraded DI capacity (best option of course).

[pwr hungry]

Originally Posted by Torgus

do you think it would get worse as power level increase?

I don't have any empirical data to show this, but it's part of the same reason I am not interested in using meth injection, eventhough many people run it with what seems to be no issues. I'm just more for solidly engineered solutions, and maybe more so than a lot of other people. My whole outlook on tuning and upgrading stuff is that if it can't perform under the conditions it is run as the stock parts are in stock form, then it's not as well engineered. Design factors are used for a reason. So, it's all just about what you want and how long you want it for.

[Sered]

Originally Posted by scotthureau

Hey Bean, yeah, still have it but looking to sell. It takes an act of Congress to get that thing out of the hole with any velocity. Ran a 12.7 with 350whp, ran 12.7 with 550whp. The only thing that changed was spinning off the line vs spinning until the 1/8th.

I could put all this stuff on the BMW, but with just a JB4, DCI and E35, don't need any fuel yet... The theory and application is really simple.

Back to topic:

What does adding throttle body fuel injection do to the speed of the combustion process on a DI engine? Does that kill detonation resistance? How much faith do you have in the knock sensors to pick up detonation from the added fuel? Knock is knock, right?

Hah. I had a nice setup with my SC300 ready to go (T67 and 4" DP/MP) but then got laid off and moved out here to FL. The car ended up sitting for a bit and I sold it so it wasn't taking up space at my parent's home in AL. And yeah I remember trying to launch my car, was a huge pain. Didn't help that the suspension was old and peg-legged.

I'm sure TBI will speed it up, and yes would hurt det-resistance. Insofar as faith in the knock control system, I have a lot of faith in it. This BMW control system is pretty damn advanced. A helluva lot more advanced to the shit we had to put up with on our 2JZs. And its not so much as knock it senses but pre-knock if you can call it that. It senses the issue before it happens, has ignition advance/retard control and pre-knock sensing on individual cylinders. This, along with the DI is what allows us to run so much damn boost on 10.2:1 CR. I remember running 8psi on 10:1 on my SC300 and being nervous enough to dial back the base ignition timing.

There's definitely going to be some negatives about it. However, if the car is fueled via an E85 mix, I suspect that it wouldn't end up being all that bad. If anything, it will clean up the valves, which would reduce knock issues in and of itself. I'm suspecting this distribution issue won't be as bad as many here suspect since it would only be firing in high boost/airflow situations. I like meth, but it does carry a lot more risk IMO. I've seen too many cars burning because of faulty systems, too many systems not working correctly and spraying air.

[Dave W.]

Bump for updates.
How's it going? It's been over 4 months since this thread was started. Any news?

FWIW the popularity of the new Open Flash Tablet has opened up some of the fueling limits by making adjustments to fuel map and fueling scalar readily available to the masses, so I doubt another injector in the TB will be needed by anyone making less than 600 WHP.

[klipseracer]

Originally Posted by Dave W.

Bump for updates.
How's it going? It's been over 4 months since this thread was started. Any news?

FWIW the popularity of the new Open Flash Tablet has opened up some of the fueling limits by making adjustments to fuel map and fueling scalar readily available to the masses, so I doubt another injector in the TB will be needed by anyone making less than 600 WHP.

There is no progress to report. I haven't found anyone who will come get fitted, although I haven't sought anyone except for this thread and one other. Its not my project anyway, merely my personal desire, so if it doesn't come to fruition right now I"m not worried.