:::RHMT::: Real Home Made Turbo

General Category => Engine Management => Topic started by: MTZ on June 03, 2013, 12:03:27 PM

Title: Tuning Direct Injection
Post by: MTZ on June 03, 2013, 12:03:27 PM

Hey folks, im interested in hearing the differences in tuning tuning direct injection.

Title: Re: Tuning Direct Injection
Post by: Minor Threat on June 03, 2013, 02:58:40 PM

You'll blow the welds on your fuel rail.

Title: Re: Tuning Direct Injection
Post by: MTZ on June 06, 2013, 12:38:47 AM

any significant changes ? predictable patterns vs non DI?

Title: Re: Tuning Direct Injection
Post by: Joseph Davis on June 13, 2013, 02:23:23 PM

More thermal efficiency.  Had a 350-ish whp Solstice with built motor, tuned by a place that specializes in them, that ran a flat 13:1 AFR.  Stock Cobalt SS runs stoich at torque peak (280ish ft/lbs) then tapers into the 12s.  Going fat up top is catalyst protection, but OEM injector cars temd to run in the high elevens and low 12s then tapering to flat 10s or high 9s up top for blower obras, in the 9's the entire time for VW 1.8T. 

So, there is a difference, but I haven't fucked with one yet to know.  Or bother looking.

Title: Re: Tuning Direct Injection
Post by: Robb on June 25, 2013, 09:40:32 PM

The ability to spray multiple fuel events during a cycle doesnt suck. Start thinking about Thermal Efficiency and be a solid badass.

Title: Re: Tuning Direct Injection
Post by: Foowee on June 25, 2013, 10:53:54 PM

Quote from: Robb on June 25, 2013, 09:40:32 PM

The ability to spray multiple fuel events during a cycle doesnt suck. Start thinking about Thermal Efficiency and be a solid badass.

Yup.  Adding fuel to the fire to keep it going, instead of having a bunch of mixture around the growing flame front getting compressed n soaking heat with the chance to auto-ignite. 

Quote from: Minor Threat on June 03, 2013, 02:58:40 PM

You'll blow the welds on your fuel rail.

Yes.  The fuel pressure has to be jacked way the fuck up.  The diesel world does it, I don't see why the gas world can't... 

Title: Re: Tuning Direct Injection
Post by: MAJORAHOLE on July 31, 2013, 04:55:37 PM

Quote from: Joseph Davis on June 13, 2013, 02:23:23 PM

More thermal efficiency.  Had a 350-ish whp Solstice with built motor, tuned by a place that specializes in them, that ran a flat 13:1 AFR.  Stock Cobalt SS runs stoich at torque peak (280ish ft/lbs) then tapers into the 12s.  Going fat up top is catalyst protection, but OEM injector cars temd to run in the high elevens and low 12s then tapering to flat 10s or high 9s up top for blower obras, in the 9's the entire time for VW 1.8T. 

So, there is a difference, but I haven't fucked with one yet to know.  Or bother looking.

my vw 2.0t stock ,with upped boost, was hitting 10.44:1, before i changed the maps.
my understanding is that the mixture is enriched more for tubine protection rather than cat, but its 6 to one, half dozen to the other...
apparenlty 13:1 can be done, but i dont like it. i have mine at around 12.05:1 at peak boost and rpm.

injectors are the limiter there, or lack there of aftermarket inj

Title: Re: Tuning Direct Injection
Post by: HiProfile on August 03, 2013, 05:46:49 PM

5th injector time ;DDD

Title: Re: Tuning Direct Injection
Post by: MAJORAHOLE on August 03, 2013, 06:30:43 PM

I'd rather just get some rs4 injectors rather than deal with inj controller and plastic im