North American Turbocoupe Organization



fabbed lower intake
Scott Mabe Offline
Member
#1
So far my post have been about trouble shooting. I'm going a different route with this one.
Before I get started this post is about throwing around ideas and getting some tech info.
My idea is fabricating a lower intake manifold with 2 injectors per runner. The intake itself would be made to flow better than stock. The main purpose is the 2 injectors per runner.
I've thought about this for a while, even for other engines. The benefit is better fuel atomization, which leads to better fuel economy and more power. Some of the major manufacturers have used 2 injectors/ runner and also Nelson Racing Engines use it to make HUDGE HP numbers in twin turbo v-8's.

So some of the questions.
Would the stock ecu handle having a extra set of injectors wired in parallel with the first set.
Also how does the stock ecu fire the injectors? Sequential? Batch? Simultaneously?
How is the stock fuel pressure Regulator set up? Preset pressure? Vaccum/boost sensing?
1987 Turbo Coupe
1988 Thunderbird parts car/ possibly street/strip car
1990 F-250HD 460ci
2001 Pontiac Montana (wife's ride)

-PLEASE FORGIVE TYPOS, I USE SWYPE ON MY PHONE-
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boosted chicken Offline
Senior Member
#2
Not sure about wiring a second set of injectors in parallel.
The ECU is a batch fire setup and the regulator is vacuum/boost sensing.
88 TC#1 Boport stg 3 alum dport head, PT6466, Boport header, CP pistons, Crower rods, MS2xtra
88 TC#2 drag car project(someday)
88 TC#3 parts car (just needed the header panel...bought the whole car, lol)
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Scott Mabe Offline
Member
#3
With it batch firing the injectors I would think it could handle the extra set of injectors.
My thought is I can go to 2 injectors/runner that equal or come within 1-2lbs of the stock injectors. Aftermarket fuel pressure Regulator to fine tune fuel pressure to compensate the slight change in injector flow. All too keep the ecu happy, and get a slight increase in horsepower and economy. Also being ready for further upgraded down the road.
1987 Turbo Coupe
1988 Thunderbird parts car/ possibly street/strip car
1990 F-250HD 460ci
2001 Pontiac Montana (wife's ride)

-PLEASE FORGIVE TYPOS, I USE SWYPE ON MY PHONE-
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natmac3 Offline
Administrator
#4
the issue with wiring them together is resistance, and triggering.

to possibly have a shot at making it work properly with a stock computer, stick with low-z injectors and wire them in series.

i think the factory injectors are betwen 2.2-2.5 ohms, so the closer you end up to that, the happier everything will be electrically.

i'd recommend running heavier/dedicated signal wires to supply 12v to the injectors to maintain a more stable signal.

sounds like fun! keep us posted. Smile
1987tc
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Scott Mabe Offline
Member
#5
The problem with wiring in series is the 2-2.5 ohms resistance turns into 4-5 ohms, where in parallel the 2-2.5 would become 1-1.25 ohms because the current has multiple paths for the current. Think of a congested single Lane road opening up to two lanes. It is easier for current to flow. therfore you could add a 1 ohm resister to each injector to keep very close to the 2-2.5 ohms of a single injector.
1987 Turbo Coupe
1988 Thunderbird parts car/ possibly street/strip car
1990 F-250HD 460ci
2001 Pontiac Montana (wife's ride)

-PLEASE FORGIVE TYPOS, I USE SWYPE ON MY PHONE-
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Joe F Offline
Posting Freak
#6
By using 2-2.5 ohm injectors and wiring a one ohm resistor in series, you're throwing away approximately 1/3 of the energy in that circuit leg. Not a good thing because that leaves less energy to open the injector and hold it open. The injector's response time would almost certainly be longer.
JR's Place - My '87 Turbocoupe
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natmac3 Offline
Administrator
#7
if you could find 1.2ohm injctors and run those in series, you'd be in the ballpark.

doesnt bosch make something in the range?

1987tc
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86XR7auto Offline
Moderator
#8
Interesting idea...

With today technology and price on really big injectors...not sure it would be worth the effort. Also you could use an alternative fuel source. I.e. methanol injection. ..which gives you cooling and additional fuel.

Travis
86XR7 in pieces...old time [email protected] http://www.youtube.com/watch?v=kGsz7PdEqTI 88TC stock Red RHSC [email protected], 01 Z71=Nice winter ride, 01 CVLX w/HPP wifes ride!
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Scott Mabe Offline
Member
#9
Joe F Wrote:By using 2-2.5 ohm injectors and wiring a one ohm resistor in series, you're throwing away approximately 1/3 of the energy in that circuit leg. Not a good thing because that leaves less energy to open the injector and hold it open. The injector's response time would almost certainly be longer.

Alittle more insight into how they are originally setup and load tolerances for the injector circuit may shed some light on the best setup for the wiring
natmac3 Wrote:if you could find 1.2ohm injctors and run those in series, you'd be in the ballpark.

doesnt bosch make something in the range?


If so that could simplify the setup as long as there are injectors in the right size.
86XR7auto Wrote:Interesting idea...

With today technology and price on really big injectors...not sure it would be worth the effort. Also you could use an alternative fuel source. I.e. methanol injection. ..which gives you cooling and additional fuel.

Travis

the whole idea behind using two smaller injectors instead of one large injector is better fuel atomization. Better fuel atomization would lead to a increase in mpg& hp.
I've never dealt with methanol injection, I guess you could add another injector and have port injected methanol!?
1987 Turbo Coupe
1988 Thunderbird parts car/ possibly street/strip car
1990 F-250HD 460ci
2001 Pontiac Montana (wife's ride)

-PLEASE FORGIVE TYPOS, I USE SWYPE ON MY PHONE-
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Dan S Offline
Administrator
#10
Pose the second injector per/runner question to Stinger. Also look at the FAQ's on;
http://stinger-performance.proboards.com/

Somewhere in my mind this question has been fielded in regards to PiMP (stand alone ECM) capability. The second injector, placed a greater distance from the intake port, adding fuel at higher RPM's, takes advantage of the increased airflow (PSI) to create higher HP & torque figures.
Dan S
Custom 88 TC, Mandarin Copper Pearl Metallic
http://natomessageboard.com/ubbthreads.p...5#comments
1972 Ford F-100 SWB Styleside
2015 Lincoln MKC 2.3 EcoBoost AWD
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