Home » Public Forums » GMCnet » [GMCnet] FiTech is the real deal
| [GMCnet] FiTech is the real deal [message #295002] |
Wed, 03 February 2016 17:41  |
glwgmc
Messages: 1014
Registered: June 2004
Karma: 10
|
Senior Member |
|
|
1000 mile report.
This EFI really transforms the way the coach runs and drives. As others have reported re other brands of self learning EFI, the coach starts instantly hot or cold, idles smoothly, seems impervious to altitude changes, is more responsive, seems immune to vapor lock, and in most all ways now drives like a new car. There seems to be little, if any, change in fuel consumption or power (the 455 S&J engine is quite powerful in its own right regardless of induction) which is what I expected.
So far on this trip we are averaging 8.3 mpg at the speeds encountered through California on the I5 and US 99 (fairly high just to flow with traffic) and in that average is climbing Siskiyou Pass (highest point on the I5) and Tahachipee Pass (alternate to the Grapevine) to get into the southern CA desert. Gearing is 3.67, spark is via an HEI Dick Patterson curved for this EfI and we do not tow but are loaded with everything for a two to three month trip.
Vacuum is more responsive to throttle given the four simultaneous opening butterfly valves in the throttle body vs the two primaries in the Qjet right up to the point that the secondaries would open on the Qjet. In the last couple of tanks it seems to me that vacuum is up a bit during cruise, which could be due either to the system still learning or simply to perhaps driving at a somewhat slower average speed.
From what I have learned from others, and have observed myself over the years of driving these two different GMCs, mileage will change about 0.5 mpg for every 5 mph change in average speed. Want to get 1 mpg more than you get now? Then slow down 10 mph.
Is this FiTech system worth the investment? Emphatically, yes. The cost is right at $1000 for the EFI plus another $400 for the fuel management system (surge tank, voltage controlled submerged high pressure pump, fill valve that mimics the float valve in the Qjet so you can use any mechanical or electric low pressure pump without a return line, and gauges to show high and low fuel pressures). I blocked off the mechanical fuel pump and use a Carter p4070 rotary vane fuel pump drawing only from the rear (main) tank for a safe fuel capacity of about 40 gallons. The magnetic pusher pump is still installed on the aux tank if I ever need it. When I get home I will likely add the two check valves, an oil pressure shut off switch and a second Carter pump to have a running spare and the ability to draw from both tanks but I don't think that is really necessary.
More as I learn more. All gain and no pain so far.
Jerry Work
The Dovetail Joint
Fine furniture designed & hand crafted
in the 1907 former Masonic Temple building
in historic Kerby, OR
http://jerrywork.com
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Jerry & Sharon Work
78 Royale
Kerby, OR
|
|
|
|
| Re: [GMCnet] FiTech is the real deal [message #295031 is a reply to message #295002] |
Thu, 04 February 2016 09:30  |
xplorid
Messages: 213
Registered: February 2012
Location: Boise
Karma: 0
|
Senior Member |
|
|
Jerry - Thanks for the notes and update, many are following this potential upgrade. FWIW there is now the Fitech 30003 rated up to 400hp, presumably that means smaller injectors, and without spark control. It is not shown on the Fitech website for some reason, but is for sale at Summit, Jeg's, etc. for $795. Getting close to break-even with a decent carb, and what I am thinking for the 403 if I end up installing that instead of selling, and for my Firebird's 400 which started vapor locking last summer for the 1st time in 35 years.
Jeff
1974/94 GMCII by Explorer
Manny 6.5 TD Al radiator
1 ton front 4 bags back
|
|
|
|
|
|
|
|
|
|
| Re: [GMCnet] FiTech is the real deal [message #295081 is a reply to message #295073] |
Thu, 04 February 2016 20:50 |
xplorid
Messages: 213
Registered: February 2012
Location: Boise
Karma: 0
|
Senior Member |
|
|
from the Jeg's online description "Includes a built-in fuel pressure regulator, along with a hand-held controller that features a touch screen for easy set-up." Not sure what else the touch screen does or can do, again nothing on the Fitech website.
Regards
1974/94 GMCII by Explorer
Manny 6.5 TD Al radiator
1 ton front 4 bags back
|
|
|
|
|
|
|
|
| Re: [GMCnet] FiTech is the real deal [message #295089 is a reply to message #295087] |
Thu, 04 February 2016 21:44 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
|
Senior Member |
|
|
Espen, fully instrumented (egt sensors on each exhaust port on both 455 and
403 Olds engines) tend to show some incredibly high temps at low throttle
openings on lean cruise. It defies common logic, I know, but, I have seen
too many burned exhaust seats and valves to try to squeeze a bit more
mileage out. Gasoline is way cheaper in the long run. But, it's your
engine, run it as lean as you like.
Jim Hupy
Salem, Or
78 GMC ROYALE 403 (120,000 RICH MILES AND STILL COUNTING.)
On Feb 4, 2016 7:34 PM, "Espen Heitmann" wrote:
> 0.2 or 0.3 leaner A/F would hardly hurt on cruise.
>
> James Hupy wrote on Fri, 05 February 2016 03:24
>> Sure, lean em up. Valves and seats are cheap. (Grin)
>> Jim Hupy
>> Salem, Or
>> 78 GMC ROYALE 403
>> On Feb 4, 2016 6:22 PM, "Espen Heitmann" wrote:
>>
>>> I am also pretty sure you can lower the air/fuel ratio a bit at
> cruise to
>>> get the mpg up a bit, maybe 14.7 or 14.8
>>> --
>>> 1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green
> Machine,
>>> And just sold my 1973 26'-2 # 581 White Canyon lands under the name
>>> Dobbelt trøbbel
>>> in Norway
>>>
>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> --
> 1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
> And just sold my 1973 26'-2 # 581 White Canyon lands under the name
> Dobbelt trøbbel
> in Norway
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
|
|
|
|
| Re: [GMCnet] FiTech is the real deal [message #295094 is a reply to message #295089] |
Fri, 05 February 2016 02:09 |
Mr ERFisher
Messages: 7117
Registered: August 2005
Karma: 2
|
Senior Member |
|
|
YESSS
8 to 10 MPG DEPENDING ON IF YOU TOW
is still safe, and has worked well for
almost 40 years 😄
On Thursday, February 4, 2016, James Hupy wrote:
> Espen, fully instrumented (egt sensors on each exhaust port on both 455 and
> 403 Olds engines) tend to show some incredibly high temps at low throttle
> openings on lean cruise. It defies common logic, I know, but, I have seen
> too many burned exhaust seats and valves to try to squeeze a bit more
> mileage out. Gasoline is way cheaper in the long run. But, it's your
> engine, run it as lean as you like.
> Jim Hupy
> Salem, Or
> 78 GMC ROYALE 403 (120,000 RICH MILES AND STILL COUNTING.)
> On Feb 4, 2016 7:34 PM, "Espen Heitmann"
> wrote:
>
>> 0.2 or 0.3 leaner A/F would hardly hurt on cruise.
>>
>> James Hupy wrote on Fri, 05 February 2016 03:24
>>> Sure, lean em up. Valves and seats are cheap. (Grin)
>>> Jim Hupy
>>> Salem, Or
>>> 78 GMC ROYALE 403
>>> On Feb 4, 2016 6:22 PM, "Espen Heitmann" wrote:
>>>
>>>> I am also pretty sure you can lower the air/fuel ratio a bit at
>> cruise to
>>>> get the mpg up a bit, maybe 14.7 or 14.8
>>>> --
>>>> 1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green
>> Machine,
>>>> And just sold my 1973 26'-2 # 581 White Canyon lands under the name
>>>> Dobbelt trøbbel
>>>> in Norway
>>>>
>>>>
>>>> _______________________________________________
>>>> GMCnet mailing list
>>>> Unsubscribe or Change List Options:
>>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>>
>> --
>> 1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green
> Machine,
>> And just sold my 1973 26'-2 # 581 White Canyon lands under the name
>> Dobbelt trøbbel
>> in Norway
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
|
|
|
|
| Re: [GMCnet] FiTech is the real deal [message #295125 is a reply to message #295089] |
Fri, 05 February 2016 16:19 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
|
Senior Member |
|
|
The real way to pull milage is to have a real computer controlled timing
unit.
Our Howell unit with the EBL Flash drive does that very well and our
customers are gaining 1-2 mpg better and throttle response.
There are lot of Old Basic Howell unit owners that have no clue to our
Advanced units with EBL Flash drive that is far advanced and delivers
timing and fuel.
On Thu, Feb 4, 2016 at 7:44 PM, James Hupy wrote:
> Espen, fully instrumented (egt sensors on each exhaust port on both 455 and
> 403 Olds engines) tend to show some incredibly high temps at low throttle
> openings on lean cruise. It defies common logic, I know, but, I have seen
> too many burned exhaust seats and valves to try to squeeze a bit more
> mileage out. Gasoline is way cheaper in the long run. But, it's your
> engine, run it as lean as you like.
> Jim Hupy
> Salem, Or
> 78 GMC ROYALE 403 (120,000 RICH MILES AND STILL COUNTING.)
> On Feb 4, 2016 7:34 PM, "Espen Heitmann" wrote:
>
>> 0.2 or 0.3 leaner A/F would hardly hurt on cruise.
>>
>> James Hupy wrote on Fri, 05 February 2016 03:24
>>> Sure, lean em up. Valves and seats are cheap. (Grin)
>>> Jim Hupy
>>> Salem, Or
>>> 78 GMC ROYALE 403
>>> On Feb 4, 2016 6:22 PM, "Espen Heitmann" wrote:
>>>
>>>> I am also pretty sure you can lower the air/fuel ratio a bit at
>> cruise to
>>>> get the mpg up a bit, maybe 14.7 or 14.8
>>>> --
>>>> 1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green
>> Machine,
>>>> And just sold my 1973 26'-2 # 581 White Canyon lands under the name
>>>> Dobbelt trøbbel
>>>> in Norway
>>>>
>>>>
>>>> _______________________________________________
>>>> GMCnet mailing list
>>>> Unsubscribe or Change List Options:
>>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>>
>> --
>> 1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green
> Machine,
>> And just sold my 1973 26'-2 # 581 White Canyon lands under the name
>> Dobbelt trøbbel
>> in Norway
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
|
|
|
|
| Re: [GMCnet] FiTech is the real deal [message #295127 is a reply to message #295002] |
Fri, 05 February 2016 17:11 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
|
Senior Member |
|
|
Well, I do about 9 towing and about ten bobtailed in my 23' with a really scurvy looking Q-jet which I kind of think is the original. Alls I've done is tighten the mounting bolts and the screws that hold the air horn on, thereby stopping the fuel weeping. It looks like it does about 6K miles a year. At $2 gasoline, an increase from 10 to 11 would save me $110 a year. Even the FiTech doesn't pay out, JimK's fancy one doesn't either. At engine build, it might be a thought. Right now, me and the Q-jet will continue to negotiate.
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
|
|
|
|
Goto Forum:
Current Time: Sat Sep 28 14:26:38 CDT 2024
Total time taken to generate the page: 0.00944 seconds
|
GMCforum
Search
Help
Register
Login
Home
