Throttle Body Size
12-16-2007, 12:05 AM
#14
You match the TB to the intake you are running. It's that simple.
For example, if you are running a stock intake, leave the stock TB on there.
If you are running an intake with a 70mm opening, then you run a 70mm TB and spacer.
There is no such thing as running too large a TB. This has been TESTED by many guys, one of who is Jay Allen, who ran a 90mm on Red Death.
The "myth" about TB size is a carry-over from the days of carburetors, where, if you ran too large a carb, the air velocity wouldn't be adequate enough to keep the fuel suspended and it would puddle in the intake. This used to cause all kinds of drivability issues and often caused the cars to be slower. Guy would stick on a smaller carb like a 650, the car would go faster and thus the other carb was "too big".
EFI is a dry intake system. The only thing you are controlling is air flow. You want as much of that airflow as possible. Making the throttle body an obvious restriction is a BAD idea.
I run a 75mm on my TFS-R and it works beautifully.
For example, if you are running a stock intake, leave the stock TB on there.
If you are running an intake with a 70mm opening, then you run a 70mm TB and spacer.
There is no such thing as running too large a TB. This has been TESTED by many guys, one of who is Jay Allen, who ran a 90mm on Red Death.
The "myth" about TB size is a carry-over from the days of carburetors, where, if you ran too large a carb, the air velocity wouldn't be adequate enough to keep the fuel suspended and it would puddle in the intake. This used to cause all kinds of drivability issues and often caused the cars to be slower. Guy would stick on a smaller carb like a 650, the car would go faster and thus the other carb was "too big".
EFI is a dry intake system. The only thing you are controlling is air flow. You want as much of that airflow as possible. Making the throttle body an obvious restriction is a BAD idea.
I run a 75mm on my TFS-R and it works beautifully.
12-16-2007, 03:58 AM
#15
You match the TB to the intake you are running. It's that simple.
For example, if you are running a stock intake, leave the stock TB on there.
If you are running an intake with a 70mm opening, then you run a 70mm TB and spacer.
There is no such thing as running too large a TB. This has been TESTED by many guys, one of who is Jay Allen, who ran a 90mm on Red Death.
The "myth" about TB size is a carry-over from the days of carburetors, where, if you ran too large a carb, the air velocity wouldn't be adequate enough to keep the fuel suspended and it would puddle in the intake. This used to cause all kinds of drivability issues and often caused the cars to be slower. Guy would stick on a smaller carb like a 650, the car would go faster and thus the other carb was "too big".
EFI is a dry intake system. The only thing you are controlling is air flow. You want as much of that airflow as possible. Making the throttle body an obvious restriction is a BAD idea.
I run a 75mm on my TFS-R and it works beautifully.
For example, if you are running a stock intake, leave the stock TB on there.
If you are running an intake with a 70mm opening, then you run a 70mm TB and spacer.
There is no such thing as running too large a TB. This has been TESTED by many guys, one of who is Jay Allen, who ran a 90mm on Red Death.
The "myth" about TB size is a carry-over from the days of carburetors, where, if you ran too large a carb, the air velocity wouldn't be adequate enough to keep the fuel suspended and it would puddle in the intake. This used to cause all kinds of drivability issues and often caused the cars to be slower. Guy would stick on a smaller carb like a 650, the car would go faster and thus the other carb was "too big".
EFI is a dry intake system. The only thing you are controlling is air flow. You want as much of that airflow as possible. Making the throttle body an obvious restriction is a BAD idea.
I run a 75mm on my TFS-R and it works beautifully.
12-16-2007, 08:45 AM
#16
You match the TB to the intake you are running. It's that simple.
For example, if you are running a stock intake, leave the stock TB on there.
If you are running an intake with a 70mm opening, then you run a 70mm TB and spacer.
There is no such thing as running too large a TB. This has been TESTED by many guys, one of who is Jay Allen, who ran a 90mm on Red Death.
The "myth" about TB size is a carry-over from the days of carburetors, where, if you ran too large a carb, the air velocity wouldn't be adequate enough to keep the fuel suspended and it would puddle in the intake. This used to cause all kinds of drivability issues and often caused the cars to be slower. Guy would stick on a smaller carb like a 650, the car would go faster and thus the other carb was "too big".
EFI is a dry intake system. The only thing you are controlling is air flow. You want as much of that airflow as possible. Making the throttle body an obvious restriction is a BAD idea.
I run a 75mm on my TFS-R and it works beautifully.
For example, if you are running a stock intake, leave the stock TB on there.
If you are running an intake with a 70mm opening, then you run a 70mm TB and spacer.
There is no such thing as running too large a TB. This has been TESTED by many guys, one of who is Jay Allen, who ran a 90mm on Red Death.
The "myth" about TB size is a carry-over from the days of carburetors, where, if you ran too large a carb, the air velocity wouldn't be adequate enough to keep the fuel suspended and it would puddle in the intake. This used to cause all kinds of drivability issues and often caused the cars to be slower. Guy would stick on a smaller carb like a 650, the car would go faster and thus the other carb was "too big".
EFI is a dry intake system. The only thing you are controlling is air flow. You want as much of that airflow as possible. Making the throttle body an obvious restriction is a BAD idea.
I run a 75mm on my TFS-R and it works beautifully.
It's not a myth at all, it's a fact, an oversized TB will hurt power-I have seen it and done tests myself. So regardless of what Jay Allen did it makes no difference to me and my findings.
You have seen tests on it with different results from the tests I have seen then. Even with a stock intake (with ported inlet), a proper-sized TB can help power and a TB which is oversize will hurt power.
12-16-2007, 12:09 PM
#17
It's not a myth at all, it's a fact, an oversized TB will hurt power-I have seen it and done tests myself. So regardless of what Jay Allen did it makes no difference to me and my findings.
You have seen tests on it with different results from the tests I have seen then. Even with a stock intake (with ported inlet), a proper-sized TB can help power and a TB which is oversize will hurt power.
You have seen tests on it with different results from the tests I have seen then. Even with a stock intake (with ported inlet), a proper-sized TB can help power and a TB which is oversize will hurt power.
The Explorer engine has a 65mm TB on it stock, but power-wise, were basically identical to our antique "HO" engines. Look at the size of the TB's on the Vortec and LSx engines, HUGE.
Unless you've been faster than Jay with similar parts (I know I haven't) then I'm going to take what he, and his decades of experience with this subject (and others like it) over yours. No offence to you, but he actually gets into the topic of flow dynamics and the like.
But if you are confident in your opinion on this, then lets debate it. Come over to SBFTech and we'll have it setup in the Myths and Rumours section and this can be discussed in a logical, and professional fashion.
Not trying to be a dick at ALL, so don't take it that way. I just feel Jay is right on this topic, his logic makes sense, and since you don't agree, I'd like to see this discussed.
EDIT:
I've gone ahead and asked for this topic to be discussed over there. I think this could be a great little debate, so Ponyryd, do you want me to link you to the thread when it's up or?
Last edited by OVERKILL; 12-16-2007 at 12:37 PM.
12-16-2007, 01:12 PM
#18
No thanks, I don't care THAT much about being right, and as I said, I don't care what Jay Allen says, and don't even know who he is.
And no, I will not follow you around the net debating a topic which you have clearly already made your mind up on.
I don't know why you NEED to be right about things and what Jay Allen knows, etc.... but feel free to update the thread on your findings. I'll stick with a 65mm and if others take my advice, that's fine with me.
BTW, I'm quite sure the Explorer V8 had quite a bit more power than a Mustang 5.0, otherwise why would Ford waste all the money on better induction and heads on it? Maybe you're using the wrong specs? the Mustang in '93 made only 205hp compared to a year before when it made 225, due to different measuring standards.
I too am not trying to be disrespectful-so don't take it that way. But I don't live on the internet and have much better things to do with my time.
And no, I will not follow you around the net debating a topic which you have clearly already made your mind up on.
I don't know why you NEED to be right about things and what Jay Allen knows, etc.... but feel free to update the thread on your findings. I'll stick with a 65mm and if others take my advice, that's fine with me.
BTW, I'm quite sure the Explorer V8 had quite a bit more power than a Mustang 5.0, otherwise why would Ford waste all the money on better induction and heads on it? Maybe you're using the wrong specs? the Mustang in '93 made only 205hp compared to a year before when it made 225, due to different measuring standards.
I too am not trying to be disrespectful-so don't take it that way. But I don't live on the internet and have much better things to do with my time.
12-16-2007, 01:24 PM
#19
No thanks, I don't care THAT much about being right, and as I said, I don't care what Jay Allen says, and don't even know who he is.
And no, I will not follow you around the net debating a topic which you have clearly already made your mind up on.
I don't know why you NEED to be right about things and what Jay Allen knows, etc.... but feel free to update the thread on your findings. I'll stick with a 65mm and if others take my advice, that's fine with me.
BTW, I'm quite sure the Explorer V8 had quite a bit more power than a Mustang 5.0, otherwise why would Ford waste all the money on better induction and heads on it? Maybe you're using the wrong specs? the Mustang in '93 made only 205hp compared to a year before when it made 225, due to different measuring standards.
I too am not trying to be disrespectful-so don't take it that way. But I don't live on the internet and have much better things to do with my time.
And no, I will not follow you around the net debating a topic which you have clearly already made your mind up on.
I don't know why you NEED to be right about things and what Jay Allen knows, etc.... but feel free to update the thread on your findings. I'll stick with a 65mm and if others take my advice, that's fine with me.
BTW, I'm quite sure the Explorer V8 had quite a bit more power than a Mustang 5.0, otherwise why would Ford waste all the money on better induction and heads on it? Maybe you're using the wrong specs? the Mustang in '93 made only 205hp compared to a year before when it made 225, due to different measuring standards.
I too am not trying to be disrespectful-so don't take it that way. But I don't live on the internet and have much better things to do with my time.
FWIW, Jay Allen is a cam grinder from Michigan. He runs seminars that many members of this board, a well as GTAMC have attended. One of his goals has been trying to dispel rumours, myths and half truths that people have learned from the "Internet Experts" as well as at lot of the "old timer" stuff. I honestly think you might learn something if you came over and actually read some stuff.
I don't NEED to be right about everything. Just, on this topic, I feel I am right, and you are wrong. My reasoning has a lot to do with what I have discussed with Jay, his tests, as well as others, and the results of how my car behaves with the 75mm on it.
There are times when I feel I am right. There are times when I feel I am right and discover I'm wrong. And there are times when I re-read what I said and realize I'm wrong to begin with.
I do kinda "live" on the internet, being a Network Engineer...... Computers ARE my business, so being on one all day......... Anyways, no disrespect taken, but if you don't mind learning stuff, I WOULD appreciate you coming over to SBFTech and listening to what Jay has to say. Chad (from Misener Motorsports) knows Jay quite well, so it's not some random dude on the Internet that nobody has ever met
12-16-2007, 03:31 PM
#20
My buddy schlodes ported a stocker to about 63mm for me - it was on my 86 when I went 13.2@102 with a mostly stock 300,000km stang (gears, pullies, ported stock headers, stock h-pipe run open, and 9 year old at the time mt et streets) - and that was with the E6 heads!
