|
07-20-2014, 02:22 PM | #41 |
Junior Member
Join Date: Mar 2013
Posts: 78
Likes: 11
Liked 18 Times in 5 Posts
|
Re: EFI, Alpha-N vs Speed Density fueling Strategies
No worries, but now I understand why we are not on the same page. All of my information relates to VE based speed density only, not fuel flow based speed density (which is not speed density at all). As far as dialing in quickly, I think it is just a matter of what you are familiar with. I can dial in a speed density setup in 4-5 pulls, or 3-4 passes down track!
|
Liked |
07-21-2014, 05:21 PM | #42 | |
VIP Member
Join Date: May 2002
Location: Shelby, NC
Posts: 1,680
Likes: 1,763
Liked 1,767 Times in 430 Posts
|
Re: EFI, Alpha-N vs Speed Density fueling Strategies
Quote:
|
|
07-22-2014, 06:54 AM | #43 | |
VIP Member
Join Date: Nov 2009
Location: Egg Harbor Township, NJ
Posts: 1,420
Likes: 1,269
Liked 3,861 Times in 456 Posts
|
Re: EFI, Alpha-N vs Speed Density fueling Strategies
Quote:
Last edited by Bobby Fazio; 07-22-2014 at 12:09 PM. |
|
07-22-2014, 01:44 PM | #44 | |
Junior Member
Join Date: Mar 2013
Posts: 78
Likes: 11
Liked 18 Times in 5 Posts
|
Re: EFI, Alpha-N vs Speed Density fueling Strategies
Quote:
But whether you are in Alpha-N or Speed Density, the cylls that are not being dropped still need the fuel based on the load and RPM. When you are on the 2 step, the engine load is still controlled by the throttle and measured by manifold vacuum. In other words, as long as you are on the floor, the engine is still under 100% or max load, the RPMs are just being limited by dropping cylls. Now, the problem with being in closed loop while on a rev limiter (or two step) is that the dropping of cylls will cause the O2 sensor to read false lean and if you are in closed loop, this will cause a ton of un-needed fuel to be added as O2 correction. The FAST XFI has internal rev limiters that you can use even if you are using an external ignition box. The benefit of using this feature is that closed loop is automatically turned off when any rev limiter is active, but this only works if you are using the XFI's two step feature. If you are using a different system that does not have this feature, or if you are using the rev limiter in your ignition box, you must set your closed loop activation RPM high enough to be above your two step RPM. Using the XFI's limiter is really nice because you can have closed loop active down low in the cruising around the pits areas and burnout areas. This helps the car run and drive better if you haven't had an opportunity to perfectly tune or "clean up" those driveability areas. |
|
07-22-2014, 07:37 PM | #45 | |
Senior Member
Join Date: Sep 2009
Location: Elkin, NC
Posts: 672
Likes: 168
Liked 44 Times in 13 Posts
|
Re: EFI, Alpha-N vs Speed Density fueling Strategies
Quote:
__________________
Mack Reeves 2377 STOCK & SUPER STOCK |
|
07-23-2014, 10:38 PM | #46 |
Junior Member
Join Date: Mar 2013
Posts: 78
Likes: 11
Liked 18 Times in 5 Posts
|
Re: EFI, Alpha-N vs Speed Density fueling Strategies
Yes Mack, this is a 2.0 feature and it is automatic, you don't have to do anything to turn it on.
|
07-24-2014, 07:28 AM | #47 |
Senior Member
Join Date: Sep 2009
Location: Elkin, NC
Posts: 672
Likes: 168
Liked 44 Times in 13 Posts
|
Re: EFI, Alpha-N vs Speed Density fueling Strategies
That is a feature I had not known about.. Another reason for updating to 2.0. Thanks for the information...
__________________
Mack Reeves 2377 STOCK & SUPER STOCK |
06-14-2019, 01:50 AM | #48 |
Junior Member
Join Date: Jun 2019
Posts: 2
Likes: 0
Liked 0 Times in 0 Posts
|
Re: EFI, Alpha-N vs Speed Density fueling Strategies
Ed I bracket race an 01 ls1 camaro and how and where are you putting the ITS sensor in the intake manifold. Thanks just trying to get better.
|
06-14-2019, 11:22 AM | #49 | |
Veteran Member
Join Date: Mar 2005
Location: Sand Springs, OK
Posts: 8,132
Likes: 896
Liked 389 Times in 168 Posts
|
Re: EFI, Alpha-N vs Speed Density fueling Strategies
Quote:
The older "TPI" cars used a threaded IAT sensor, screwed into the Intake. I just bought an IAT sensor for a '90 Vette. I just remembered this: I originally put my air temp sensor in the tray I had in front of my throttle body (no longer used) And was seeing large temp variations from the water box to third gear. Looked too large to me. Moving that sensor to the rear of my manifold took much of those large changes away. Also made my air/fuel ratio more stable during a pass, and made my car more consistent, easier to dial.
__________________
Ed Wright 4156 SS/JA Last edited by Ed Wright; 06-29-2019 at 06:30 PM. |
|
Liked |
|
|