Throttle body compatibility question
Thread Starter
|
Outstanding HDF Member
Joined: Dec 2012
Posts: 2,557
Likes: 235
From: Texas
Throttle body compatibility question
2003 SE big bore build:
I am running a 95 build with CNC heads, 10.5:1 pistons and SE 257 cams and Rinehart True-Duals on the stock 88 throttle body and injectors, and a Master Tune. I am learning how to map with the Master Tune TTS and the combination runs strong and pulls hard, but I really feel like the stock intake and injector combo could be better for this build. In my research, I see several aftermarket choices but I really want to keep it all MoCo.
The question I am trying to answer is whether or not the SE Pro 50 mm EFI throttle body, p/n 27623-05 will work for my setup. I see it is advertised for '06 and later but these are SE performance heads and not modified stock, and the combination tunes and runs good on the current stock 2003 (46mm?) throttle body and injectors.
Are there larger stock intakes from later year models that will work? Will I see any benefit from different injectors?
I do not feel that it is necessary to change anything, just that I am not realizing what this engine can really do with this stock throttle body and injector combination
I am running a 95 build with CNC heads, 10.5:1 pistons and SE 257 cams and Rinehart True-Duals on the stock 88 throttle body and injectors, and a Master Tune. I am learning how to map with the Master Tune TTS and the combination runs strong and pulls hard, but I really feel like the stock intake and injector combo could be better for this build. In my research, I see several aftermarket choices but I really want to keep it all MoCo.
The question I am trying to answer is whether or not the SE Pro 50 mm EFI throttle body, p/n 27623-05 will work for my setup. I see it is advertised for '06 and later but these are SE performance heads and not modified stock, and the combination tunes and runs good on the current stock 2003 (46mm?) throttle body and injectors.
Are there larger stock intakes from later year models that will work? Will I see any benefit from different injectors?
I do not feel that it is necessary to change anything, just that I am not realizing what this engine can really do with this stock throttle body and injector combination
Last edited by skinman13; May 3, 2019 at 09:45 AM.
Road Warrior
Joined: Mar 2013
Posts: 1,923
Likes: 587
From: Alorton, Illinois
A throttle body is more matched to the sensors and electrical plugs than year of heads. Really any TB will fit any head if flanges are changed out.
If the injectors can supply enough volume of fuel and be below a certain duty cycle. Adding a larger injector will not yield any more power.
With the TB you want to use. I believe the biggest hold up will be the IAT sensor.
If the injectors can supply enough volume of fuel and be below a certain duty cycle. Adding a larger injector will not yield any more power.
With the TB you want to use. I believe the biggest hold up will be the IAT sensor.
Grand HDF Member
Joined: May 2014
Posts: 3,843
Likes: 1,174
From: florida
in order to know what you get to, it would help if we had some numbers on where you are currently at, do you have any dyno graphs? i have a similar build on my 04 and i am over 100 hp and tq with the stock throttle body and injectors.
what year heads did you use on your build? if you used 06 and later heads, the SE 50mm will bolt up, with the 06 later flanges, need to re-wire the IAC, IIRC a couple of pins need to be in different positions in the connector, the TPS connector is different, but pigtails are avaialble, so just re-wire the piggy and thats done.
There has always been the situation about volume vs velocity, combine that with having true duals, if you up the t/b size, you might trade low end torque in order to gain top end horsepower, seeing what kind of numbers and curve that you are currently laying down would help to give better direction.
back in the day when i was at the dealer, we built the combo you describe with the various SE heads of the time, and almost all of them were good runners.....it's kind of a what are you looking to get thing.
m
what year heads did you use on your build? if you used 06 and later heads, the SE 50mm will bolt up, with the 06 later flanges, need to re-wire the IAC, IIRC a couple of pins need to be in different positions in the connector, the TPS connector is different, but pigtails are avaialble, so just re-wire the piggy and thats done.
There has always been the situation about volume vs velocity, combine that with having true duals, if you up the t/b size, you might trade low end torque in order to gain top end horsepower, seeing what kind of numbers and curve that you are currently laying down would help to give better direction.
back in the day when i was at the dealer, we built the combo you describe with the various SE heads of the time, and almost all of them were good runners.....it's kind of a what are you looking to get thing.
m
Regarding fitment - the 06 and later TB will not retrofit to the pre-06 heads with the non-symmetrical flanges because of the non-symmetrical flanges required. When using those flanges, the mounting bolts hit the t-body/runner area.
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,928
Likes: 8,032
From: poway
While you can make the later throttle bodies fit the HD HTCC CNC heads mechanically by clearancing the manifold bolts on the short side turn on the manifold, IMO, the connector change is a PITA. IIRC the injectors and fuel manifold are different, and you will need to add adapters or rewire the connectors for the injectors. If the throttle body comes with the fuel manifold, you be set there. Also the IAC stepper motor needs to be rewired. If you want to go SE look for a 02 to 05 SE throttle body. Might find NOS on fleebay. If you do I'd send it out to be cleaned up as they didn't flow very well.. Personally, I'd hunt around for a kuryakyn 57mm throttle body as they flow the as one of the best for an early TB. IIRC the intake ports on the HTCC CNC heads is 1.7 inches. Make sure the throttle body has a 1.7 manifold or have it bored out to match. You'll need to check the port size.
As far as injectors go, look at the peak duty cycle of them in the map. If close to 80-90% go up one size as the motor should flow more with a bigger TB. As far as AC goes, I'd go to a zippers or Woods filter on the SE AC as it will flow more or go to a air cleaner that flows more.
As far as injectors go, look at the peak duty cycle of them in the map. If close to 80-90% go up one size as the motor should flow more with a bigger TB. As far as AC goes, I'd go to a zippers or Woods filter on the SE AC as it will flow more or go to a air cleaner that flows more.
Thread Starter
|
Outstanding HDF Member
Joined: Dec 2012
Posts: 2,557
Likes: 235
From: Texas
What I am understanding here is that the stock tb and injectors with a good map are adequate for this build and retrofitting a later model tb is either not possible or a pita that may not be worth the final outcome...
I am new to EFI. I keep thinking carbs...increased head flow and high lift cams need larger carbs and jets to make power. The same build will not work worth a flip with a stock CV-44 carb. I am learning that is not necessarily true with EFI and how to tweak map tables instead of jets...PFM stuff
I am new to EFI. I keep thinking carbs...increased head flow and high lift cams need larger carbs and jets to make power. The same build will not work worth a flip with a stock CV-44 carb. I am learning that is not necessarily true with EFI and how to tweak map tables instead of jets...PFM stuff
Road Warrior
Joined: Mar 2013
Posts: 1,923
Likes: 587
From: Alorton, Illinois
Originally Posted by Ed Ramberger
Regarding fitment - the 06 and later TB will not retrofit to the pre-06 heads with the non-symmetrical flanges because of the non-symmetrical flanges required. When using those flanges, the mounting bolts hit the t-body/runner area.
Trending Topics
Advanced
Joined: Apr 2019
Posts: 58
Likes: 12
From: Western New York
50mm
The SE 50mm is for 1.75 intake ports. It will bolt up to 06 up heads but the heads may be restrictive. Prior to 06 the intake was different but may have been the same distance, angle. I believe the pre 06 TBI was 44mm where 06 up we're 46mm. I just bolted up a 50 to S&S 89cc because the 46mm bore was too small for them. Anyway, the 46mm with 06 or newer heads is good for up to about 100+ hp. Not sure about the 44mm with older heads. As was pointed out the pre 06 wiring config was different but pretty easy to change. You may want to consider adding the 4.31 or 4.9 g/s injectors.
I just took 06 heads and 46mm 25 degree TBI off. I was going to box them up for some future project or whatever. May be for sale? IDK. I'd probably let them go pretty cheap. Have about 38k on them so basic reconditioning would be advisable. Lot of carbon due to an idiot that wrote over a Dyno tune at local shop after a minor cam change. Now I do my own work just like old times.
Sorry if it seems like I am trying to sell in the discussion area. It didn't start that way and doesn't matter to me if I sell or not.
I just took 06 heads and 46mm 25 degree TBI off. I was going to box them up for some future project or whatever. May be for sale? IDK. I'd probably let them go pretty cheap. Have about 38k on them so basic reconditioning would be advisable. Lot of carbon due to an idiot that wrote over a Dyno tune at local shop after a minor cam change. Now I do my own work just like old times.
Sorry if it seems like I am trying to sell in the discussion area. It didn't start that way and doesn't matter to me if I sell or not.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Intermediate
Joined: Jul 2021
Posts: 49
Likes: 9
From: PA
Thanks!
Thread
Thread Starter
Forum
Replies
Last Post
adm
Ignition/Tuner/ECM/Fuel Injection
23
Dec 21, 2024 12:36 PM
twism_23
Exhaust System Topics
32
Dec 22, 2012 09:31 AM