65mm-70mm tb

[5spd GT]

You're right to an extent. I would use the 70mm as a base size, since that's the size of the opening; start at 70mm and work from there.You left yourself open on this one...

So how do you determine which size throttle body the combination needs? What is the determining factor? Say if I'm using TFS heads, a Performer intake manifold, and a Crower 15512 cam, what size TB?

It is my personal preference to have the lower manifold as the "most" restricting part of the combination, albeit slightly. Since the lower manifold is nothing more than an extension of the intake port on the cylinder heads, the slightest bottleneck in the lower manifold will promote velocity behind the intake valve. When the intake valve is cracked, there is going to be TONS of air getting into those cylinders. That's cylinder fill, and that's the name of the game in these short stroke motors.

Joe

I determine personally by the approximate hp the car will be pushing and what is the primary goal of the car...I do not jump in and say 75mm all the way...I look at what is being run...(street/track/coupe/vert/possible power/etc...)...

Oh and I would say on that combo you listed a 65 or 70mm would be fine...

A 75mm TB or possibly bigger would be great on a blown car because of the FI used to push air into the engine...

You typed: "It is my personal preference"...that is really all it comes down to...but for some on here it is 75mm or the highway... ...which is simply wrong to have a one size fits all TB...

I guess I'm going to go put on a full 3 inch exhaust...because it will allow me room to grow...

 

[nmcgrawj]

The fact that you have no experience with TB's makes me question who is misleading...

Did I say a 75mm is BEST?...nope...I put "A 75mm would be more ideal for a stroked or blown car..."

YOU PUT: "If YOU dont think he needs a 75mm, then say that."...

Well my answer to that is...I did say that...


What makes your facts better than my facts? Any experience...or just what you get from emails/forums/...hmm...sounds familiar...

Show me a dyno run with a TB swap...

Telling me that I'm misleading...

Well...i already said i was a noob to performance. Thats nothing new. Im telling you what Professionals tell me and what people who have done these swaps tell me. Would it be better if i went to these people in person and had them tell me?

I said to JUST say that you dont think he needs a 75mm TB and not that its ideal for stroked or blown applications. How is it NOT ideal for Willie's application? Or for Mikes application? Or for the countless numbers of other people's combo's who run them? How is it not ideal for the n/a h/c/i 302 combos that Ed Curtis puts together?

What facts have you stated? You have said your opinion. Thats it. Show me where your car gained time on the track or driveability from downgrading the size of TB from a 75mm. Or anyones car for that matter. I showed you a car that GAINED with an UPGGRADE to a 80mm TB...what else do you want?

Who cares about dynosheets? Dynos can differ from the person who runs it to the day. I dont care. The only thing they are half good for is tuning. You want a performance meter? Take it to the track. You want a driveability meter? Drive the car everyday. Willie did both and we gave you his results and you st ill dont accept them.

Its misleading to say that a 75mm is IDEAL for blown or stroked applications. That shows noobies that come here that they shouldnt run it on their n/a 302.

 

[nmcgrawj]

You typed: "It is my personal preference"...that is really all it comes down to...but for some on here it is 75mm or the highway... ...which is simply wrong to have a one size fits all TB...

I guess I'm going to go put on a full 3 inch exhaust...because it will allow me room to grow...

I agree with you...its not a 75mm or the highway. It could be a 80mm TOO! But seriously, a 65mm or 70mm TB will get the job done...but can a 75mm do it better without sacrificing power or driveability? I guess its up to you which facts you accept and which you dont. But i will take whatever chance i can to get the best performance out of my combo.

 

[NoSloCoupes]

This is why i at every single tb thread that comes up. No matter what, they ALWAYS turn this way.

 

[wytstang]

This is why i at every single tb thread that comes up. No matter what, they ALWAYS turn this way.

True

 

[Joes95GT]

I determine personally by the approximate hp the car will be pushing and what is the primary goal of the car...I do not jump in and say 75mm all the way...I look at what is being run...(street/track/coupe/vert/possible power/etc...)...

LOL.

I'm done.....

Joe

 

[BlackVert]

why won't someone answer my question about why a 75mm would be too big for a 5.0, but not too big for a 4.6?

there were many dyno comparisons on 4.6s between stock maf/tb and 80mm maf/75mm tb about 1 year ago, all of which showed improvement.

i realize they are different engines, but the fact is that the bigger the engine, the more air it can suck in.

 

[nmcgrawj]

why won't someone answer my question about why a 75mm would be too big for a 5.0, but not too big for a 4.6?

there were many dyno comparisons on 4.6s between stock maf/tb and 80mm maf/75mm tb about 1 year ago, all of which showed improvement.

i realize they are different engines, but the fact is that the bigger the engine, the more air it can suck in.

I would really like to know this too...im not sure how its different. Maybe 5spd GT can explain it since he said thats its like apples and oranges...what is so different? Im not saying you are wrong...i just wanna know why you threw BlackVerts argument out the window.

 

[Joes95GT]

why won't someone answer my question about why a 75mm would be too big for a 5.0, but not too big for a 4.6?

there were many dyno comparisons on 4.6s between stock maf/tb and 80mm maf/75mm tb about 1 year ago, all of which showed improvement.

4.6's are a totally different animal. They have 3.543 inches of stroke - .543 more than a 302. This is HUGE. At 3000 RPM in a pushrod motor, the piston is moving 1500 ft/min, in a 4.6 at 3000 RPM, the piston speed is 1765 ft/min. Once you start spinning 6000 RPM, the pushrod motor is moving 3000 ft/min while the modular is going 3530 ft/min. Piston speeds naturally allow you to put a larger throttle body on it. Because the piston speeds are greater, the intake ports are different (I.E. much larger). Although I don't think the 4.6 is "way different," it cannot be compared to a 5.0 when it comes to induction and cylinder fill.

If anyone knew that velocity doesn't need to be created in the intake tract of a 5.0 with a long runner manifold, this discussion wouldn't be needed....

Joe

 

[GTJake]

Joe- I thought you were done...







Jake

 

[Joes95GT]

Joe- I thought you were done...







Jake

Shaddup...

Now I am...

(I'll probably intervene when another thing is said that I disagree with. )

Joe

 

[nmcgrawj]

If anyone knew that velocity doesn't need to be created in the intake tract of a 5.0 with a long runner manifold, this discussion wouldn't be needed....

Joe

Thanks for explaining the 4.6 vs. 5.0 idea. And FINALLY someone comes with a true statement about air velocity and where its started at. But you know Joe, there is no point in continuing...some people just dont want to listen.

Like i said before...too many guys worrying about velocity this and velocity that.

 

[BlackVert]

thanks for the explanation.

by the way, which is better ... 2mm muffler bearings or 3mm muffler bearings? are 3mm bearings too big for my combo?

 

[WHITE94COBRA]

This is a neverending Story!!! I had talked about this a while ago, I had a 75mm to start with on my mostly stock cobra, I also had a 70mm that I bought with my eddy performer, Installed the intake with the 75 mm first then swapped for the 70 mm, my dyno sheet proved I lost some low end torque with the 75mm I did however gain a little hp on the top end, another side effect of the 75 mm was a gain of roughly 50-75 rpm; with the 70 mm on I gained back the torque down low and lost high end hp. I'm talking about 5 hp and about the same in torque. Now when I changed heads and cam this once again changed but a little more drastically, but with the same results. So this is what "I" do: For my everyday driving I have the 70mm on at the track I switch to the 75mm, now let me explain why I dont just keep the same one on all the time, With the cam I chose the everyday driveability with the 75mm makes my car buck, the 70mm doesnt. Now that I have my Ed C cam ready to go in I will be running a 75mm, Because now I will be able to tune the bucking out. So personally I would say go with a 70mm but also remember we all upgrade so think about the future as well, Do you plan on a power adder? do you want to stay N/A is a H/C/I all you are gonna do? There really is no wrong answere to this question, Just what "your" gonna do. So stop arguing damn it lol lol lol. Anyway everyone have a wonderful holiday.

 

[5spd GT]

This is a neverending Story!!! I had talked about this a while ago, I had a 75mm to start with on my mostly stock cobra, I also had a 70mm that I bought with my eddy performer, Installed the intake with the 75 mm first then swapped for the 70 mm, my dyno sheet proved I lost some low end torque with the 75mm I did however gain a little hp on the top end, another side effect of the 75 mm was a gain of roughly 50-75 rpm; with the 70 mm on I gained back the torque down low and lost high end hp. I'm talking about 5 hp and about the same in torque. Now when I changed heads and cam this once again changed but a little more drastically, but with the same results. So this is what "I" do: For my everyday driving I have the 70mm on at the track I switch to the 75mm, now let me explain why I dont just keep the same one on all the time, With the cam I chose the everyday driveability with the 75mm makes my car buck, the 70mm doesnt. Now that I have my Ed C cam ready to go in I will be running a 75mm, Because now I will be able to tune the bucking out. So personally I would say go with a 70mm but also remember we all upgrade so think about the future as well, Do you plan on a power adder? do you want to stay N/A is a H/C/I all you are gonna do? There really is no wrong answere to this question, Just what "your" gonna do. So stop arguing damn it lol lol lol. Anyway everyone have a wonderful holiday.

Hmm...seems to reiterate what I have said...

And Joe why are you done? What was so "special" about what you quoted that made you say "I'm done"...

 

[5spd GT]

Who cares about dynosheets? Dynos can differ from the person who runs it to the day. I dont care. The only thing they are half good for is tuning. You want a performance meter? Take it to the track. You want a driveability meter? Drive the car everyday. Willie did both and we gave you his results and you st ill dont accept them.

I'm assuming you were kidding about the above right?

Have you ever been to your local track? There are way to many factors to consider when trying to apply a gain from a single TB swap...what was the humidity/air temp of both those nights...did the driver shift at the EXACT same rpm...did he shift just as quick...etc...etc...

A dyno shows the real potential of a car...not a track time...

I've seen a 03 zo6 run high 13's...but they dyno 350-360rwhp...and are capable of low 12's at 116-117mph...but I guess since the zo6 I seen run means all the zo6's run high 13's? Because dynos don't matter...the track time does...when referring to power...

I wouldn't mind hearing this "advice" from someone else...your just carrying the torch in an unprofessional way

When did I say I didn't accept these people's gains...I just said show me a dyno...Is that total denial?

White94Cobra summed it up nicely with what I stated (experience)...driveability and torque loss at lower rpms...but remember I don't have any clue what I'm talking about and I just love making up things

 

[nmcgrawj]

I'm assuming you were kidding about the above right?

A dyno shows the real potential of a car...not a track time...

I've seen a 03 zo6 run high 13's...but they dyno 350-360rwhp...and are capable of low 12's at 116-117mph...but I guess since the zo6 I seen run means all the zo6's run high 13's? Because dynos don't matter...the track time does...when referring to power...

White94Cobra summed it up nicely with what I stated (experience)...driveability and torque loss at lower rpms...but remember I don't have any clue what I'm talking about and I just love making up things

White94Cobra was right...but he also hit the nail on the head when he said that with a correct tune and properly designed combo...a 75mm will be FINE with no bucking at all. But it doesn't matter...im so tired of going back and forth.

You seen a 03 zo6 run high 13's huh? What was the MPH on that run? I believe there are two sides to a time slip....ET and MPH. Not just ET. I doubt the MPH was that far off as well.

"A dyno shows the real potential of a car...not a track time..." That is one bad statement. So on a dyno....do they take weight of a car into consideration? Gearing? Suspension? Anything besides the motor just spinning the machine?
If you take a little car that weighs 2500lbs on a dyno and it makes 350rwhp. Put that drivetrain in a car that weighs 3500lbs and it will make that same 350rwhp right? But what changes at the track? Yes the track has its variables but it in no way is inferior to the dyno. The dyno is a good way to measure the power output of a ENGINE. But it can not tell you what the car will do on the track. A dyno is no different than a tool in your tool box. Just like a torque wrench, it measures something with known inaccuracies. Now a dyno is something you can use just like anything else...but its still just a tool. The real test is the track. Only the track can tell you what a car(not a engine) will do...because it takes every single variable into consideration...including a terrible driver.

Now when you build a car up....most experienced people will know what to expect out of it performance wise. If you go to the track and it doens't run it....then use the dyno to see if it is in fact making the power you expected. I just view the dyno as a tool to see the air/fuel ratio and other things to get the best output at the track. And honestly, i would think the best setup would be to get a wideband setup and datalog runs at the track so you can see your track times with you a/f ratio and other datalog numbers. Then make changes and go back out. A dyno can not give you real world numbers. The track is real world. A dyno is not.

Your statement explains everything. You go off of dynos on what a car performs at. Go ahead. Build your dyno queen. I could care less about what you say at this point. Because you can internet race and dynosheet race all you want. What matters is what the car does on the track...not spinning on a machine.

Go tell Jay Allen, Ed Curtis, or another hardcore racer and car builder that what matters is the dyno...and not the track. Im pretty sure they would laugh at you.

 

[wytstang]

This thread has gone waaaayyy of track from the original question it's time to be way to much View attachment 519589 going on here .

 

[nmcgrawj]

Yea this thread should have been a long time ago

 

[5spd GT]

I thought this was a mustang site and we were talking about h/c/i on these mustangs... ...I guess were talking about every car...

Why didn't you mention the weight factor on the track? gears? suspension? etc...? Hmm...looks like there is two sides to that...

AGAIN...where did I say the track doesn't matter? Would you please quit twisting peoples words up...your as bad as snoozer IMO...

Now you realize I just make up stuff right ...oh and I've talked with Ed (look at sig.)...

Your arguments aren't very concrete...in fact it hasn't even been mixed yet ...try again...

Again if your going to post...don't do the childish namecalling (earlier) and don't twist up what I type out...(past, present, and probably the future)...

Very well said white94cobra...very well said..."some people just don't listen"...with personal experience...but I guess everyone has access to a dyno/custom cam right?...um...no...

Again as I stated...the lower torque suffered and the bucking (driveability) problem can occur and has occured...funny how that is exactly what it did on my cousin's 90 Gt...maybe that is where I got my infamous concoction...or maybe it was from others...geee...I don't know