with the mods in my signature am i at the point where i should upgrade to a 70mm throttle body and a bigger maf and some 24 lb injecotors?
throttle body and maf upgrade?
- Thread starter Daniel50
- Start date
Since some of your sig is bold and some not ...............
Does that mean you are now running ALL that stuff
If so IMHO, you are at or close to the limit of those 19's at stock pressure.
You can extend a bit with more pressure.
If I was gonna prioritize ... I'd upgrade the maf/inj before the tb.
Close to a 50 50 call ... either way
and
like Mike said ... Depends on your goals!
Grady
Does that mean you are now running ALL that stuff
If so IMHO, you are at or close to the limit of those 19's at stock pressure.
You can extend a bit with more pressure.
If I was gonna prioritize ... I'd upgrade the maf/inj before the tb.
Close to a 50 50 call ... either way
and
like Mike said ... Depends on your goals!
Grady
Daniel50 said:
No, go for it. You won't have to buy another TB ever. I've had three which is just a waste of money. The opening on the intake is that size anyway.
Black95GTS
Active Member
Daniel50 said:
IF you were gonna keep the power mods as they are then I would do this:
And bear with me
- 24 pound injectors
- KEEP the stock MAF... remember, this same MAF is on Cobra's with 24 lb injectors. Its just a different tune, which brings me tooooo....
- Burn a chip / TwEECer for the new injectors so they gel with the stock MAF. The stockers good till 280rw-ish with tuning.
- 75 MM TB like Mike suggested. My personal philosophy differs from lots on here, but "too big" parts often end up making for faster ETs... what are you gonna get, too much air? Too much fuel? If either of these conditions exist with FI then you can tune them out!
Fuel injection makes it so easy so take advantage, and matching t/b to intake just makes sense!!Adam
Black95GTS - Part throttle "putting around" is touchy, causing more tip-in issues. If you want to make sure you are getting all the air you can and don't worry about the cons of the bigger TB. Get it...
Just realize you don't need that big when a 65 or 70mm TB will flow enough air for you in CFM.
To many go by "size" and not actual true flow in CFM.
Just realize you don't need that big when a 65 or 70mm TB will flow enough air for you in CFM.
To many go by "size" and not actual true flow in CFM.
if you plan on staying n/a see if you can get your hands on a 99-04 MAF. then just get your car tuned to run with the 24lb injectors. A GOOD TUNE IS WORTH THE MONEY!! you could also get a tweecer and do it yourself
Black95GTS
Active Member
5spd GT said:
To put this into context: 70mm = 2.756 inches. 75mm = 2.953 inches
Are you suggesting that the increased cfm from .197 inches in diameter could effect driveability? Furthermore, any after market cold air kit pipe is at least 3 inches in diameter, not to mention that the people at TrickFlow who engineer race parts for a living designed their manifolds for that size for a reason.
I personally wouldn't think twice about slapping a 75mm TB on there. I doubt you could find many HCI owners that complain about too big a TB.
Adam
edit for spelling
Black95GTS said:
Adam...your not thinking clearly.
The diameter on the internal lip has less to do with it, than the design of the TB. Again, and I repeat.
You go by CFM rating, not the measurement of the TB given by the company. Not all 65, 70, 75, 90. 105mm TB's flow the same when compared one of the same "size".
Yes, most cold air kits are about 3 inches in total diameter.
Part throttle is velocity. Velocity is part throttle. That blade is your vantage point. At wide open throttle velocity pretty much becomes a non-issue in most or some cases. Not all.
No, the engineers at Trickflow and other companies put the "size" because most TB's in that given size range will not flow any more than what the "size opening" for the TB will allow. Also another reason is for ease on the customer, not "port matching"...
Believe it or not, velocity is controlled during tip-in by the throttle body, despite people saying it has no effect.
The bigger surface area of the blade will allow more air in at the same degree interval of the gas being stepped on. This creates a touchier gas. This becomes more of a problem in lower gears.
Been there done that, and about to add one to my car, just to make sure I'm getting all the air flow I need...even though I may not need it. It isn't my daily driver, so I'm willing.
I can say I know or understand all these issues
Black95GTS
Active Member
5spd GT said:
I agree to what you're saying to a certain point. What I'm saying though is that the TB is only 1 part of the air intake. You have to consider the size of the whole system as 1 unit. Not only does the TB need to flow X CFM, but there needs to be a smooth and uninterrupted path from the filter to the intake. Mixing and matching inlet diameters will undoubtedly negate some of the positive effects of a larger TB.
Velocity is largely a function of exhaust.
http://www.popularhotrodding.com/enginemasters/articles/hardcore/0505em_exh/index.html
And I understand that more air will flow at part throttle... its a bigger tb after all. If you didn't want the car to go faster then don't mod it. If you found a 50mm TB that flowed more CFM then a 75mm TB, I would still go with the 75mm TB in this application. With FI, if the thing is too touchy at part throttle, then pull timing at those RPMs. Any competent tuner can do this. I consider myself only marginally competent and I have done it on my grocery getter. My tune is pretty harmless until 2500 RPMs then it hits like a nitrous shot.
IMO, with fuel injection, flow rates aren't as important as they were with carbs. While its very easy to over-carb a motor, its much harder to over-TB an FI one.
Adam
Black95GTS said:
Yes, the TB is only one part of the equation in air flow to the cylinders; never-the-less, air enters the engine from the throttle body opening.
So let's say that "50mm" TB flowed more than the 75mm TB...why in the heck would you get the 75mm TB...lol. For the "look"
Some people do not have the means or tools to pull timing at lower rpms...it isn't applicable to everyone. Just like the 75mm TB. It isn't applicable for everyone.
Also, just because someone likes to modify it doesn't mean they need to sacrifice daily driver quirks. So since I like to go a bit quicker than most I know, should I delete the a/c and powersteering. Nope, because it isn't for me. Not everyone wants to do it. Not everyone needs it. Just like not everyone wants a goosy throttle when trying to cruise around. Not everyone wants it.
Cruise control also is more "stop and go"...and that sucks...when your on a road trip. Been there, done that.
It is cfm, not size that gives you the air flow you might need.
Why get a 75mm TB when a 65mm TB might flow enough, while having a "goosy" throttle...a throttle isn't "goosy" when you punch it, it just goes. It is part throttle tip-in...
Go to www.slowgt.com and see how much cfm your engine is capable of taking in, and make the judgement for yourself...
Black95GTS
Active Member
5spd GT said:Yes, the TB is only one part of the equation in air flow to the cylinders; never-the-less, air enters the engine from the throttle body opening.
So let's say that "50mm" TB flowed more than the 75mm TB...why in the heck would you get the 75mm TB...lol. For the "look"
Some people do not have the means or tools to pull timing at lower rpms...it isn't applicable to everyone. Just like the 75mm TB. It isn't applicable for everyone.
Also, just because someone likes to modify it doesn't mean they need to sacrifice daily driver quirks. So since I like to go a bit quicker than most I know, should I delete the a/c and powersteering. Nope, because it isn't for me. Not everyone wants to do it. Not everyone needs it. Just like not everyone wants a goosy throttle when trying to cruise around. Not everyone wants it.
Cruise control also is more "stop and go"...and that sucks...when your on a road trip. Been there, done that.
It is cfm, not size that gives you the air flow you might need.
Why get a 75mm TB when a 65mm TB might flow enough, while having a "goosy" throttle...a throttle isn't "goosy" when you punch it, it just goes. It is part throttle tip-in...
Go to www.slowgt.com and see how much cfm your engine is capable of taking in, and make the judgement for yourself...
If flow benches raced, you would be dead right.
But they don't.
I'm saying that all the CFM in the world doesn't mean squat if the combo is not well matched. How many 302 combos are there that are faster than they should be? Tons. It's all about matching the components to create an efficient power plant. Flow rates are very important, but if they don't jive with the rest of the combo they are useless. If the poster replaced his GT-40Ps with a set of worked Victor Gliddens it wouldn't matter, even though the VG's flow a ton more.
My point is that matching the components is an overlooked and undervalued strategy.
Adam
Black95GTS said:
Lol.
I never said that a mis-matched combo was part of it.
A matched combo is getting all the parts to have the same flowing capacity to get the desired powerband and power. If you have a TB that flows 1100cfm but your heads/cam/intake flow a potential of 700cfm, why in the heck do you have a TB that flows that much when you do not need it.
Matching the cfm flow is crucial, instead of just saying "bigger is better".
A car can always get faster. There isn't one car to live up to the dream of making it "that fast".
You can always get faster by removing the a/c, powersteering, afw, larger cam and heads, etc...
These all have cons to them.
For example, one guy might get a gt40 combo with an 'e' cam...and he traps 104mph with a/c, powersteering, and he loves the way it is. Can he get faster? Sure...does he need to? No, not if he is happy. Just because someone doesn't match your want to go at this certain goal or speed...why are they looked at as "stupid" or scared of "to much airflow". That is ridiculous, save that for those who deserve it.
My car is by far not the fastest for a 302, but it is where I want it to be for now. I guess I'm going to "up" the cam, but nope, I'll get characteristics I don't want for a real daily driver. I should remove the a/c like so many do, but I like the coolness in the summer...and it is worth losing the power for being cool. Sorry, just my taste...
So what my original point is, is that "size" doesn't matter as matching cfm flow from the parts. Don't go by "size"...
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