MysteryMachine
Active Member
a50sn95 said:
I agree i have never understood that either. I have a 75mm and my car runs awsome. So much better then when it was stock. But i have no tweecer or anything i just threw it on and it ran great
Intake and T/B Installed
- Thread starter Guero
- Start date
I agree i have never understood that either. I have a 75mm and my car runs awsome. So much better then when it was stock. But i have no tweecer or anything i just threw it on and it ran great
blksn955.o
Founding Member
I gained more in the 1/4 from going to 14* than with my 3.73's...14* gave me .3-.4 while the gears gave me like .2-.3.
BUMP YOUR TIMING
BUMP YOUR TIMING
Here is one thing to remember about most kinds of mods for more power. They all work together!
Lets just stick to tb's as it seems like its drawing quite a bit of intrest as this thread shows.
Two extremes of a tb mod .......................
1) One of the last mods to my sig combo
2) A first mod on a stocker
Which example between 1 & 2 do you think a tb will give the most gain?
Grady
Lets just stick to tb's as it seems like its drawing quite a bit of intrest as this thread shows.
Two extremes of a tb mod .......................
1) One of the last mods to my sig combo
2) A first mod on a stocker
Which example between 1 & 2 do you think a tb will give the most gain?
Grady
a50sn95
Founding Member
I see it as a restriction. It's not like a carb, which is trying to atomize fuel, or a slowdown in velocity will let the fuel drop out. (Think 351c-4v.....).
To me, other than WOT, a TB is a TB. If it's bigger than stock you end up not opening the throttle as far as the stock one to let the same amount of air in.
Which just leaves WOT as the only place I can see that it CAN cause an issue. (Which I still don't get.) Now, you're letting in MORE air (Like a McDonalds Straw versus a Carl's Jr. straw). The engine does not have to work as hard to get the same amount of air, so it can actually get MORE air. Yes, I think even with a stock intake. It may be marginal, but more air is more power, as long as the MAF isn't out of range, or the injectors are big enough. (These are not an issue on a stock motor, in my mind...).
The only other thing I can THINK of is the transition from Part throttle to WOT, which is a function of the computer. (Intake manifold volume, I think) It's possible it COULD need a bigger shot of fuel when the blade opens, which means you have to have a method to tune the computer....
Other than that, I don't see how it CAN be too big.....
To me, other than WOT, a TB is a TB. If it's bigger than stock you end up not opening the throttle as far as the stock one to let the same amount of air in.
Which just leaves WOT as the only place I can see that it CAN cause an issue. (Which I still don't get.) Now, you're letting in MORE air (Like a McDonalds Straw versus a Carl's Jr. straw). The engine does not have to work as hard to get the same amount of air, so it can actually get MORE air. Yes, I think even with a stock intake. It may be marginal, but more air is more power, as long as the MAF isn't out of range, or the injectors are big enough. (These are not an issue on a stock motor, in my mind...).
The only other thing I can THINK of is the transition from Part throttle to WOT, which is a function of the computer. (Intake manifold volume, I think) It's possible it COULD need a bigger shot of fuel when the blade opens, which means you have to have a method to tune the computer....
Other than that, I don't see how it CAN be too big.....
CManT1914
New Member
5spd GT said:Cman - What was the time period between your 95mph run and your 99mph run?
I have gained 3mph with no actual changes
1 month. Same weather IIRC.
Zero Signal
Active Member
A throttle body that's too big can have a few effects. You need to remember the dynamics of moving air.
First, if the TB is larger than the intake opening, you create a really bad restriction there by killing any laminar flow. Think of it this way . . . suppose your engine could run without any intake tube or ANYTHING attached to the intake plenum. How well do you think it will flow with nothing attached to that open hole? It will flow terribly without something to controll the direction of the airflow and keep it close to laminar.
Second, if you overdo the TB size, you loose a lot of air velocity coming through there and the flow gets killed by turbulence again.
Anyay, as for the original post, give the computer some time. Once it adjusts, you will feel a difference.
First, if the TB is larger than the intake opening, you create a really bad restriction there by killing any laminar flow. Think of it this way . . . suppose your engine could run without any intake tube or ANYTHING attached to the intake plenum. How well do you think it will flow with nothing attached to that open hole? It will flow terribly without something to controll the direction of the airflow and keep it close to laminar.
Second, if you overdo the TB size, you loose a lot of air velocity coming through there and the flow gets killed by turbulence again.
Anyay, as for the original post, give the computer some time. Once it adjusts, you will feel a difference.
a50sn95
Founding Member
Zero Signal said:
Yep, you're right. I'd hope that someone installing a bigger TB would check this port mismatch, but I guess since I didn't spell it out, I gotta say you got me on this one.
Zero Signal said:
Diesels Do. They control engine speed with fuel.
It would go full throttle. It'd run fine, just out of control....Zero Signal said:
Okay, even if I agree here, my 75mm TB WILL control the direction of airflow, just like a 60mm will, so I don't see how this is relevant.Zero Signal said:
Zero Signal said:
Hmm. I don't see how. The engine is capable of pulling ALOT of air in. I think of those 8 pistons going down the bore, and then the little opening even a 75mm tb allows, and don't see how it can matter that much.
I think it will let a LITTLE more air in, but it should be able to be compensated for.
Anyway, I run a 75 (Of course I'm boosted) and have no issues with drivability that I blame on the TB. (Maybe the aluminum flywheel and the 2.73's...)
i have to disagree also. when i was first starting to mod the car, i had the gt40 intake with the ported lower, bbk 70mm t/b, cold air kit, pullies, unequal shorties, o/r h-pipe, and flows. i put down 230.2hp and 293.2lb/ft at the wheels. that was with the stock heads, cam, maf, and eec. considering our cars made about 175hp at the wheels in stock form, that is quite an increase in power. im not saying that a 65mm t/b wouldnt be better suited for what i had, but the 70 definitely isnt too big for what he is using it for. by the way, i didnt really feel a SOTP gain either after a couple of my mods. you really need to do a few at once in order to really feel a power increase.94GTLaserRC said:
xkuntrycowboyx
Member
bump ur timing till your car just starts to ping, then step it back a degree.
thats how i've been told.
intake will hold oil (i think i read in the dips around the ports)... make an oil seperator, just read an article myself on here bout that.
oil seperator:
24" + 16" 3/8 fuel line
seperator from walmart
(two fittings for seperator)
1/4 male goes into seperator, and 3/8 goes away for line attachment
then read up on an article or two about it,
also, i believe its been said on here there's a break in period for gears?? am i right guys?
also, since you've been messing around the maf... clean ur air filter, then take out the maf and spray some contact electical cleaner on it and make sure it's clean, but don't touch it. u'll notice a lil throttle response if it was dirty.
if you have a KN filter, DO NOT OVER OIL IT...it blows back onto ur MAF, then you just cleaned it for no reason.
IF you changed ur TB... make sure ur TPS is set right, theres articles about that, but i think it's 0.97 v ...i forget tho
u said you did an intake swap i believe... make sure u torque the bolts properly and in the right order to insure proper seal.
pull a plug and see how it looks, and if nothing else change ur plugs wires, cap n rotor, while ur under there. (don't use crappy wires or plugs or ur wasting ur time)
Lastly for now, i think after an intake swap it's wise to change the oil and over the next few days check for coolant in there.
p.s. while ur under there just go ahead and order a crate engine and make er' a 347, and put a nice little blower on in and swap engines
k, im done! haha
thats how i've been told.
intake will hold oil (i think i read in the dips around the ports)... make an oil seperator, just read an article myself on here bout that.
oil seperator:
24" + 16" 3/8 fuel line
seperator from walmart
(two fittings for seperator)
1/4 male goes into seperator, and 3/8 goes away for line attachment
then read up on an article or two about it,
also, i believe its been said on here there's a break in period for gears?? am i right guys?
also, since you've been messing around the maf... clean ur air filter, then take out the maf and spray some contact electical cleaner on it and make sure it's clean, but don't touch it. u'll notice a lil throttle response if it was dirty.
if you have a KN filter, DO NOT OVER OIL IT...it blows back onto ur MAF, then you just cleaned it for no reason.
IF you changed ur TB... make sure ur TPS is set right, theres articles about that, but i think it's 0.97 v ...i forget tho
u said you did an intake swap i believe... make sure u torque the bolts properly and in the right order to insure proper seal.
pull a plug and see how it looks, and if nothing else change ur plugs wires, cap n rotor, while ur under there. (don't use crappy wires or plugs or ur wasting ur time)
Lastly for now, i think after an intake swap it's wise to change the oil and over the next few days check for coolant in there.
p.s. while ur under there just go ahead and order a crate engine and make er' a 347, and put a nice little blower on in and swap engines
k, im done! haha
a50sn95 said:
Right.
a50sn95 said:
Interesting, I swore a diesel had an intake tube track?
a50sn95 said:
Well you better hope that engine can withstand to be revving to 6,250 bouncing off the limiter. It would not run fine.
a50sn95 said:
A bigger straw has a more dispersed area of incoming (blowing) air. A smaller straw (throttle body) has a more concentrated hit of air. Make sense? Sure it controls it but not as concentrated.
a50sn95 said:
You will lose velocity (concentration) and that is key for overall driveability. A 75mm TB will give you a goosy feeling (especially in the lower gears). Some like it, some don't. I'm sure your AFW makes up for that off idle...
A 75mm TB does have an effect on incoming air. Many more cc's of air come thru
273's wont' effect driveability. It is a set gear ratio that doesn't vary. Your AFW, tune, TB could very well be those effects.
Green 94 5.0 said:
The stock cars dyno a bit higher than 175rwhp. Also you other mods can contribute to that power. Just because a throttle body is "in the mix" doesn't mean it contributed to those "high numbers". I don't think a 70mm TB hurt you though in that particular case.
xkuntrycowboyx
Member
Setting TPS:
http://www.muscularmustangs.com/tps.php
Setting idle:
http://www.muscularmustangs.com/idlereset.php
http://www.muscularmustangs.com/tps.php
Setting idle:
http://www.muscularmustangs.com/idlereset.php
94MustangGT5.0
New Member
Well, my break in period for gears was the time it took the lower the lift, drive onto some good pavement, and run the living dog crap out of my car. Gears are either right or wrong, there should be no break in period. It would be wise of course to make sure you don't have any leaks after a bit of driving. If they grind, they will most likely need adjustment. I have heard a few guys say they made noise for a few hundred miles then it went away, so I guess there are some exceptions.xkuntrycowboyx said:
The only thing I have to add about the TB argument is this: Why not upgrade the TB while you are replacing the intake? Maybe it's not going to yield the highest amount of HP for the $ at the time, but it sure won't hurt anything. I find it asinine to put on an intake with a 70 or 75mm opening (to increase air flow), then re-attach an air limiting 60mm TB. BTW... not trying to put down anyones theory, I just wanted to express my own.
i wasnt trying to say those numbers were because of the throttle body. for all i know, the throttle body may not have added much power at all. the only true way to tell would have been to do a before and after comparison on the dyno. the only dyno comparison i have was n/a (230.2hp 293.2lb/ft) with the mods i listed and with a zex nitrous kit jetted for 75hp (280.8hp 361.7lb/ft) in which both runs were made during the same dyno session. what i was trying to say was that i dont think the size of the throttle body had a negative effect on performance with the mods i had. so it seems we are in agreement there.5spd GT said:
MysteryMachine
Active Member
94MustangGT5.0 said:The only thing I have to add about the TB argument is this: Why not upgrade the TB while you are replacing the intake? Maybe it's not going to yield the highest amount of HP for the $ at the time, but it sure won't hurt anything. I find it asinine to put on an intake with a 70 or 75mm opening (to increase air flow), then re-attach an air limiting 60mm TB. BTW... not trying to put down anyones theory, I just wanted to express my own.
:Teh-Win: Thats the reason i changed mine. I ran my stocker till i got the new one for a while but after i put the new on one i think the car runs a lot better. I even went as far as buying a used TFS elbow adapter so i'd have a 75mm one and not the 70 edelbrock one i had at first. I don't see the point in buying a bigger tb then down the road do a mod and need to upgrade again just buy the big one and get it over with. not trying to put anybody down but all these people say its hurts performance but have any of you's actually done it? I have a 75mm tb on mine with the mods in my sig and it runs awsome. I could never get it to break loose while already moving now it will break loose and fish tail after the tb install
YEAHLOH95
Founding Member
my only ? why put a 75mm throttle body on a intake with only 65mm? opening? if you anything about flow you would understand why this is bad, it may not hurt power output that much but a 65 would make the same power .its called an sudden contraction and it hurts air flow ...
