Throttle Body Question
Thread Starter
Instructor
Joined: Jan 2004
Posts: 154
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From: Katy TX
Throttle Body Question
I have a '94 auto coupe and I am looking to replace my original 48mm Throttle body with a 52mm Edelbrock. I have never replaced one before, is this a difficult job, do I have to reprogram the ECM? anything I should know? OR is it just a simple bolt on. I have done a ton of other stuff to it, like upraded to c5 brakes, changed all U-joints, replaced heater core<----religious experience, so if it is easier than these things, I can handle it.
Race Director
Joined: Jan 2004
Posts: 18,726
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From: Bergen County, NJ
From what I've read, the 52mm throttle body will not do much more than the 48mm, on a stock engine.
I'm sure some more forum members can correct me if I'm wrong.
I'm going to take mine off for a cleaning, I'm just worried about the throttle position sensor. I have to find out more about that.
I might change the Idle Air control Valve while I have it off.
I'm sure some more forum members can correct me if I'm wrong.
I'm going to take mine off for a cleaning, I'm just worried about the throttle position sensor. I have to find out more about that.
I might change the Idle Air control Valve while I have it off.
Last edited by Wayne88; Jul 13, 2004 at 08:48 PM.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
If the Edelbrock and BBK are the same unit avoid them like the plague; the fitment of the air tube will be terrible. I made that mistake and have spent hours machining the front of that damn BBK to fit the intake tube. Instead get the AS&M TB. It is a quality piece.
You will need to remove the IAC from under the stock TB and transfer it to the new TB. Use care in removing the tiny screws holding it as they tend to break easily, but some PB Blaster should loosen them. You will also need to transfer the TPS onto the new TB but that is not an issue. The method to setup the IAC and the TPS are on my site.
You will need to remove the IAC from under the stock TB and transfer it to the new TB. Use care in removing the tiny screws holding it as they tend to break easily, but some PB Blaster should loosen them. You will also need to transfer the TPS onto the new TB but that is not an issue. The method to setup the IAC and the TPS are on my site.
Melting Slicks
Joined: Dec 2000
Posts: 2,719
Likes: 60
From: Fremont Oh
aside from the fitment issues above , really it is quite straight forward, anyone with a reasonable level of mechanical competance can change it out, I agreee, you probably will not see any significant gains...
as mentioned above, reallt a matter of transfering the IAC and the Throttle positioner... No ecm preogramming anything is necessary the ecm will adjust... basically the 4 screws on the front of the intake... pop loose the throttle cable, I'm not sure if the 94 has a TV cablee for the trans I think it is the same as my 96...
Make sure the throttle plates are tight, when I had a BBK on mine, the throttle plates were loose and the throttle kept sticking... luckly it didnt ingest a screw... it's also a good time to do the coolant bypass if you are planning that... it makes popping the throttle body off easier
Good luck Mo
as mentioned above, reallt a matter of transfering the IAC and the Throttle positioner... No ecm preogramming anything is necessary the ecm will adjust... basically the 4 screws on the front of the intake... pop loose the throttle cable, I'm not sure if the 94 has a TV cablee for the trans I think it is the same as my 96...
Make sure the throttle plates are tight, when I had a BBK on mine, the throttle plates were loose and the throttle kept sticking... luckly it didnt ingest a screw... it's also a good time to do the coolant bypass if you are planning that... it makes popping the throttle body off easier
Good luck Mo
Team Owner
Joined: Sep 2001
Posts: 62,155
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
If you can do the heater core, you can fix just about anything.
Its basically straightforward, just label the lines that hook to the TB so you dont get mixed up.
I doubt the 52 is going to really help you though.
Its basically straightforward, just label the lines that hook to the TB so you dont get mixed up.
I doubt the 52 is going to really help you though.
Burning Brakes
Joined: Jul 2002
Posts: 871
Likes: 0
From: Costa Mesa CA
There's a guy on EBay that sells remachined TB's. He machines the inlets bigger and installs big throttle plates. He does a nice job and everything fits as before.
How much you'll have change the setting of your engine depends on how badly you engine needed more air. On a stock motor it won't do anything good because the 48mm supplies all the air the engine needs. As the engine mods get added and the requirement for more air/fuel goes up, the more the larger TB will help you. If your engine needs and gets more air, it's going to need more fuel as well. You'll at least have to run more fuel pressure and maybe larger injectors.
BIG JIM
How much you'll have change the setting of your engine depends on how badly you engine needed more air. On a stock motor it won't do anything good because the 48mm supplies all the air the engine needs. As the engine mods get added and the requirement for more air/fuel goes up, the more the larger TB will help you. If your engine needs and gets more air, it's going to need more fuel as well. You'll at least have to run more fuel pressure and maybe larger injectors.
BIG JIM
Safety Car
Joined: Sep 2000
Posts: 3,524
Likes: 4
From: Hinckley Ohio
Originally Posted by 65Z01
.
You will also need to transfer the TPS onto the new TB but that is not an issue. The method to setup the IAC and the TPS are on my site.
You will also need to transfer the TPS onto the new TB but that is not an issue. The method to setup the IAC and the TPS are on my site.
If it is a new Edelbrock 3809, it is shipped with a new tps installed & calibrated.
http://www.edelbrock.com/automotive/index.html
Bench Racer
Joined: Feb 2003
Posts: 4,201
Likes: 15
From: Palm Beach Gardens FL
St. Jude '03 thru 14,'25
Originally Posted by BillSF49
I have a '94 auto coupe and I am looking to replace my original 48mm Throttle body with a 52mm Edelbrock..
Prices for the work are as follow:
$185 52mm bore, sealed roller throttle shafts
$56 optional installed and match bored Hypertech air foil
$75 optional show quality exterior polish, adds a couple weeks to the delivery for the polisher
$25 optional GM gasket kit
$17 shipping and prepaid return label for your old body
$8.75 return shipping if you choose to send me your body
$00 install and match bore a customer supplied air foil
Last edited by tobijohn; Jul 14, 2004 at 01:52 PM. Reason: typo
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Racer
Joined: Jan 2002
Posts: 419
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From: Tampa FL
My only experience has been switching from a 48mm to a 58mm after going to a Stroker Motor. That being said I saw significant gains on the dyno just from the TB. It would be really interesting if you could do a before and after dyno? My personal opinion is more air is good, also you are all set up for the future mods. I have the 58mm Holley unit and it is a perfect replacement.
Max
Max
Race Director
Joined: Oct 2000
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From: Enter Post Count Here
The Throttle Position Sensor is cake to reset. It's a variable resistor, you can either measure the output voltage 0.65-5.00 volts or measure the resistence through the input and output. I don't recall the resistence off the top of my head, but it's in the service manual, someone would be able to find it.
Anyways, you'll probably gain more by adjusting the TPS than changing the TB. From the factory you get anything from 0.52-0.58 volts, which is too low, not enough gas, and sometimes they won't go over a certain voltage the way it's bolted on, I think 4 volts is the magic number. Which is important because the motor doesn't go to WOT setting until it exceeds 80% throttle or something like that.
Anyways, by checking these numbers, you may regain some lost power.
Anyways, you'll probably gain more by adjusting the TPS than changing the TB. From the factory you get anything from 0.52-0.58 volts, which is too low, not enough gas, and sometimes they won't go over a certain voltage the way it's bolted on, I think 4 volts is the magic number. Which is important because the motor doesn't go to WOT setting until it exceeds 80% throttle or something like that.
Anyways, by checking these numbers, you may regain some lost power.
USMC (retired)
Joined: Aug 2004
Posts: 3,268
Likes: 7
From: Wimauma FL
I have already replaced my throttle body with a BBK throttle body and cannot get the air tube to fit. Any suggestions on aftermarket piece or is the answer like what 65Z01 said....machine the TB to fit the air tube? I do not know if a rip on the air tube would generate a MAF code.
Drifting
Joined: Nov 2002
Posts: 1,593
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From: Mobile AL
St. Jude Donor '05
Originally Posted by snakeiz919
I have already replaced my throttle body with a BBK throttle body and cannot get the air tube to fit. Any suggestions on aftermarket piece or is the answer like what 65Z01 said....machine the TB to fit the air tube? I do not know if a rip on the air tube would generate a MAF code.
Drifting
Joined: Aug 2004
Posts: 1,830
Likes: 1
From: atlanta Georgia
BBk 52mm
I bought a used 52 mm BBk throttle body
when i put this on along with a k and n airfilter and cutting the lid i felt a difference in power. its not a significant increase but it helps each mod you put on.
boring our your stock one its about $150 cheaper and does the same thing and you dont have to worry about changing all the gaskets and IAC ****. Because when i changed mine a small gasket broke and I had to order one it was a pain. but its a very easy install!!
bect of luck.
Sean
when i put this on along with a k and n airfilter and cutting the lid i felt a difference in power. its not a significant increase but it helps each mod you put on.
boring our your stock one its about $150 cheaper and does the same thing and you dont have to worry about changing all the gaskets and IAC ****. Because when i changed mine a small gasket broke and I had to order one it was a pain. but its a very easy install!!
bect of luck.
Sean
