What's considered best practices when doing EFI dual throttle bodies on a Tunnel Ram?

[kenbaker]

I am wanting to install a Holley HP System on a 440 Chrysler with individual injectors in welded bungs. I want to run dual Dry Throttle Bodies on a Tunnel Ram. Can I use 2 of the Universal 4BBL 1000CFM 4150 Flange Throttle Bodies Part# 112-588? I know there will be two TPS's and IAC's. Could I leave the second TPS in place and put a block off plate on the second Throttle Body's IAC? Are there Throttle Bodies that would be a better choice? Would this cause any tuning issues? What pitfalls am I not seeing? Thank you

[andrewb70]

See my Cougar build thread for another option.

Andrew

[68Cuda440]

I used three throttle bodies on the tunnel ram on my 440...

[chpr1972]

I have dual holly throttle bodies on a tunnelram with individual fuel injectors using a HP EFI. It is a BBC bored .030 and stroked 1/4". The roller cam is .230/.236 and the lift is .510/.520. I run with both throttle bodies in unison. The rear throttle body controls everything and the front one just gives air. I am running a small cap HEI dist that is comp controlled. It is street driven and I am waiting for my son to help me with the fine tuning. The car started right up and drove good with no problems for about 1500 miles. I like the system and am well pleased. My only problem is getting a hold of Holly tech. I have been trying since friday[today is wednesday morning to find out what what wiring harness number I need to hook up a knock sensor and a the speedometer and fuel psi.

[andrewb70]

I have dual holly throttle bodies on a tunnelram with individual fuel injectors using a HP EFI. It is a BBC bored .030 and stroked 1/4". The roller cam is .230/.236 and the lift is .510/.520. I run with both throttle bodies in unison. The rear throttle body controls everything and the front one just gives air. I am running a small cap HEI dist that is comp controlled. It is street driven and I am waiting for my son to help me with the fine tuning. The car started right up and drove good with no problems for about 1500 miles. I like the system and am well pleased. My only problem is getting a hold of Holly tech. I have been trying since friday[today is wednesday morning to find out what what wiring harness number I need to hook up a knock sensor and a the speedometer and fuel psi.

Post your questions on the Holley support forum.

Since a BBC does not have provisions for knock sensors, my first concern would be where do you plan to mount them?

Why do you need to feed a speedometer input to the HP ECU?

What main harness PN are you using? Most main harnesses already have the fuel sender wired and terminated.

Andrew

[Danny Cabral]

...to find out which wire harness part number I need to hook up a knock sensor, the speedometer and fuel psi.

To connect up to 4 Inputs & 4 Outputs to the EFI Main Harness, use I/O Auxiliary Harness 558-400.
Eight Wire I/O Auxiliary Harness Connector Pin-Out (also in the Holley EFI Wiring Manual - LINK):
Pin A...A12...White/Blue (Input #1) F,5,2,T,H,G
Pin B...A3....White/Red (Input #2) F,5,2,T,H,G
Pin C...A13...White/Black (Input #3) F,5,G
Pin D...A4....White/Green (Input #4) F,5,G
Pin E...B12...Gray/Yellow (Output #1) H,P+
Pin F...B11...Gray/Red (Output #2) H,P+
Pin G...B10...Gray/Black (Output #3) G,P−
Pin H...B3....Gray/Green (Output #4) G,P−
http://documents.holley.com/199r10516.pdf (Holley 558-400 I/O Auxiliary Harness Instructions)

The 558-400 I/O Auxiliary Harness is 20 feet long. It's "plug & play" into the main harness, and an easy way to connect common things like an electric cooling fan (LINK). This I/O Auxiliary Harness isn't required for the optional oil & fuel pressure transducers, which are also "plug & play" into the main harness. The oil & fuel pressure transducers are used for Data Monitoring, Data Logging and setup Outputs based on oil & fuel pressure.

http://forums.holley.com/showthread....ors-Holley-EFI (Connecting & Tuning Knock Sensors)

http://forums.holley.com/showthread....ith-Holley-EFI (VSS Input)
http://forums.holley.com/showthread....0291#post30291 (Speedometer Information - Dominator ECU Only)
http://forums.holley.com/showthread....p-Digital-Dash (Additional Speedometer Information)

http://documents.holley.com/efi_sele...chart62914.pdf (Holley HP & Dominator EFI Component Selection Guide)

[sccacuda]

I am wanting to install a Holley HP System on a 440 Chrysler with individual injectors in welded bungs. I want to run dual Dry Throttle Bodies on a Tunnel Ram. Can I use 2 of the Universal 4BBL 1000CFM 4150 Flange Throttle Bodies Part# 112-588? I know there will be two TPS's and IAC's. Could I leave the second TPS in place and put a block off plate on the second Throttle Body's IAC? Are there Throttle Bodies that would be a better choice? Would this cause any tuning issues? What pitfalls am I not seeing? Thank you

Your right on track. Did this dual throttle body setup on a Gen2 Hemi for a customer with a Holley Dominator. Blocked of one of the IAC's and just leave the TPS and IAT where they are at.

[dirty rick]

With dual TB's you should be opening both TB's together and you only need one tps. Only one IAC is needed block any others. Get a stable idle tuned before enabling the IAC for idle control or you may wind up chasing your tail. After getting a stable idle you should probably close both TB's completely just shy of sticking, then all idle air is supplied by the IAC. Or set TB's for a base idle less than target speed like 500rpm.

[BBPanel]

... Since a BBC does not have provisions for knock sensors, my first concern would be where do you plan to mount them?...Andrew

Perhaps a topic for another thread but since the orig question seems to have been answered - aren't there many retrofit EFI applications that don't use knock sensors? Since I'm looking to use a Mark IV block and EFI this might be an important question.

[sccacuda]

Perhaps a topic for another thread but since the orig question seems to have been answered - aren't there many retrofit EFI applications that don't use knock sensors? Since I'm looking to use a Mark IV block and EFI this might be an important question.

You don't have to use a knock sensor with any of them. Retrofitting knock sensors is easy to install, but difficult to find the correct placement and to tune. The best sensors are from the Gen 3 Hemi. They are "listening" for a harmonic, so you have to tune the sensitivity for each application, and depending on placement, you may pick up other "noise" that false triggers. If your running a solid roller cam, don't bother, they will never work with the valve train "noise". I don't really see the need in a performance application. OEM's use them to compensate for gasoline quality and carbon build up in the chamber and on the pistons that raise the compression ratio over the life of the engine. Performance engines usually always get good gas and good care and are not subjected to lack of maintenance and poor quality gas that makes the knock sensor necessary in peoples daily drivers.

[68Cuda440]

Your right on track. Did this dual throttle body setup on a Gen2 Hemi for a customer with a Holley Dominator. Blocked of one of the IAC's and just leave the TPS and IAT where they are at.

That is pretty! Mine uses TPS on the center TB and IAC on the front. Mine uses a progressive linkage with the outer two start opening at about 1/2 throttle. System was developed by F&B Performance and they have done a large number of 6bbl EFI conversions. 2bbl, 4bbl, 6bbl, 8bbl, or single throttle blade not sure that EFI really cares. From talking to guys running the systems it seems that the stack EFI individual runner systems are the hardest to tune for drivability.

-Michael

[MonzaRacer]

For the cash I would rather run FITech, especially since they have dual throttlebody set ups also.
Fitechefi.com

[chpr1972]

I went with a TPI system compared to a TBI system because of the fuel distribution problems of carburetored tunnel rams. The difference in price was not too much different. With a single 750 carb and a 4 speed muncie I was getting 8 mpg on a 2 lane highway. I am now getting over 10 mpg with very little tuning and a TKO600 trans with both intown and 2 lane highway. I have not done a lot of tuning yet so I am looking for 15/18 when done on highway. Can anyone tell me witch wires to use for a Ford electronic sensor from a Tremec 5 speed would use?