i know theres alot of threads. but its easy to get lost on here. lol. im doing a turbo build. and i dont know when our cars cant supply fuel sufficiantly enough. does anyone know? and can anyone ginve me some advice on where to go when i need better fuel management. i intend to hptune it. but that will only go so far right? so what would be the next step or steps and how much $$$ will it cost per say.

HP Tuners should be able to take care of everything you need. Albeit, not as good as a standalone ECU, but it will get the job done.

Rough estimates (assuming gasoline)

Stock Injectors (24 lb/hr) ~ 180 hp
Stock Fuel pump ~ 350 hp
Stock Fuel Rail ~ 600 hp (IIRC, Fetter was having issues around 500whp)

* Note: HP values are rated at the crank




I have no signiture

Whalesac wrote:Rough estimates (assuming gasoline)

Stock Injectors (24 lb/hr) ~ 180 hp
Stock Fuel pump ~ 350 hp
Stock Fuel Rail ~ 600 hp (IIRC, Fetter was having issues around 500whp)

* Note: HP values are rated at the crank

Yea, from the way it looks around the site, most builds would only need larger injectors and fuel pump.




its an old concept. time for something new to take the reigns. - Z yaaaa

what arfe cheap bigger injectors to get that would work great for a 225+hp build?? any pplug an play?

None. All injectors require a retune.




its an old concept. time for something new to take the reigns. - Z yaaaa

well im getting it tunned anyway. not a big deal. if i dont get bigger injectors... can i just get the portfueler instead with the same power results? if not what injectors should i get?

Wagonwes wrote:HP Tuners should be able to take care of everything you need. Albeit, not as good as a standalone ECU, but it will get the job done.

While this is a potentially true statement in some cases, it's a tad general and does leave out significant detail, As a result, there's room for potential misinterpretation by the OP, as well as others who may read this thread. Mind you, I am not taking you to task...just looking to add some of the detail. My motivation is twofold...to help folks better understand their options, and to also enhance theur understanding of what we sell at Hahn RaceCraft and how it fits into such a discussion.

HPTuners, while a wonderful product (that we use too!), is not a solution for boosted applications in every case. Addtionally, some would argue that in its effective iterations, it is at least as good (if not better!) than a standalone! However, that's also a subjective statement with much nuance, as well as involving aspects of personal preference. It all makes for good discusssion however. Let's dive in!

As the OP did not call out what year or engine he has, let's open up the discussion and add some detail. Matt, for clarity...what are your build details? Year, engine, trans, turbocharger type?



Bill Hahn Jr.
Hahn RaceCraft

World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com

Bill Hahn Jr. wrote:

Wagonwes wrote:HP Tuners should be able to take care of everything you need. Albeit, not as good as a standalone ECU, but it will get the job done.

While this is a potentially true statement in some cases, it's a tad general and does leave out significant detail, As a result, there's room for potential misinterpretation by the OP, as well as others who may read this thread. Mind you, I am not taking you to task...just looking to add some of the detail. My motivation is twofold...to help folks better understand their options, and to also enhance theur understanding of what we sell at Hahn RaceCraft and how it fits into such a discussion.

HPTuners, while a wonderful product (that we use too!), is not a solution for boosted applications in every case. Addtionally, some would argue that in its effective iterations, it is at least as good (if not better!) than a standalone! However, that's also a subjective statement with much nuance, as well as involving aspects of personal preference. It all makes for good discusssion however. Let's dive in!

As the OP did not call out what year or engine he has, let's open up the discussion and add some detail. Matt, for clarity...what are your build details? Year, engine, trans, turbocharger type?

This is true. I was just figuring that if he was new to cars/tuning, it would PROBABLY be the easiest solution for him (versus making a custom harness and/or computer like MS2). I am fully aware that HP Tuners has many limitations and quirks that some may not see as up to the task for their build.

It appears that the OP is only looking for around 225 HP, and HP Tuners will be able to do that without a problem.

Wagonwes wrote:It appears that the OP is only looking for around 225 HP, and HP Tuners will be able to do that without a problem.

Not if he wants actual proportional boosted fuel control, which unless he's also willing and able to convert to a 2-bar system, HPTuners cannot provide. For 225 HP, there are less extensive (and expensive!) options, such as the good old FMU, which actually does provide proportional boosted fuel.

For those who would like to understand better, I'll elaborate. HPTuners can be used to tune a boosted car using its stock 1-bar MAP sensor, but the result is a distinct compromise, for the fueling will only be correct at the point where it is tuned to be safe, typically at full boost. At all other boosted manifold pressure levels, it will be over-rich. Driveability also suffers, for these are also transitional boost pressures that occur at part throttle. "Chugging" and loaded-up spark plugs typically result. Of course, the preferable method is to incorporate a 2-bar MAP sensor and related OS for the PCM to support it, but this is not an option for every car, nor is it inexpensive in every case.

On the other hand, a properly selected FMU and injector combination can provide optimal fueling at all manfold pressure (boost) levels. As the FMU proportionately adds fuel pressure according to boost pressure, it can accomodate all boost points. It helps to think of it as a mechanical '1 to 2 bar' MAP sensor.

There are a number of other configurations one can consider, but let's wait for the OP to chime in.




Edited 1 time(s). Last edited Friday, September 24, 2010 10:07 AM

Bill Hahn Jr.
Hahn RaceCraft

World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com

i have a 2003 ecotec. with a t3/t4 kit. full 2.5in exhaust and other mods but no more power adders. im getting forged internals. and i need to know what i need to accomplish 225 hp at the minimum. i dont understand this 2bar map sensor though? what is it? why do i need it? how far will hptuners get me? whats my best option? whats my cheapest option? thank you

Bill, it almost sounds like you think the car is speed density. We're all ricking alpha-n (unless you can use the ld9 reflash). So fueling is directly related to throttle position not manifold pressure, which make stuning for boost with HPT a pain in the ass. Spark, idle, and decl are the only things that use MAP.


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WPI Class of '12 Mechanical Engineering
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True enough that it's alpha N, and a fact I am well aware of, but thanks for pointing it out nonetheless. What the PCM does is actually a form of MAP or load "modeling" based on a matrix of numerous factors.

And yes...without a switch to a 2-bar GM SC flash, boost tuning is a mess at best.


Bill Hahn Jr.
Hahn RaceCraft

World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com