How much will a bigger throttle body help?
- Thread starter Medbull
- Start date
turbo nasty
Turbo Dojo / MNTR
- Joined
- Jul 19, 2001
Anyone?
A 62 MM would be a good upgrade for you and a helmco upper this will even out the air to the cylinders so you can run 1-2 psi more without knock. you will pick up some top end.
I have a setup like this for sale $225.00 shipped
let me know if I can help
I have a setup like this for sale $225.00 shipped
let me know if I can help
really though,
has anyone tested this?
Seems to me a tons of people are really fast with the stock TB.
has anyone done back to back testing?
I run a stock TB and would be willing to do some back to back testing if anyone wants to donate a bigger TB.
GN1s
212/212 flat tappet
PTE-54
AC 3500NL
RJC power plate.
CAS V2
Accufab plenum
83#
F.A.S.T.
......stock throttle body and headers.
trying for 10s with straight pump gas (no alky)
has anyone tested this?
Seems to me a tons of people are really fast with the stock TB.
has anyone done back to back testing?
I run a stock TB and would be willing to do some back to back testing if anyone wants to donate a bigger TB.
GN1s
212/212 flat tappet
PTE-54
AC 3500NL
RJC power plate.
CAS V2
Accufab plenum
83#
F.A.S.T.
......stock throttle body and headers.
trying for 10s with straight pump gas (no alky)
A Hemco plenum doesnt allow you to run more boost without KR.Sorry.Any plenum with a powerplate will though.
Dr voodoo on the other board is looking for a Hemco though.
Id think a bigger tb certainily wouldnt hurt anything.No way in hell are you going to be able to run 10's on pump gas with your combo.Good luck though!!
you don't think so?
I have already run 7.2s in the 1/8th with 96 mph on 18 psi
in 90 degree temps.
no weight reduction (unless you count the heads)
and no suspension mods (not even an airbag.)
I do have all the HR suspension stuff on order though.
wait untill the temp drops and I pick up a couple mph.......
but I'll remeber you said that
In one afternoon, I tried switching all the plumbing from the turbo to the plenum.
Stock TB
62
and 70
Also since I was running a I/C delete, I was also able to run different sized up pipes. 2", 2.25", 2.5", and 3.
While some folks are just worried about WOT, I'm of the sort that likes having as much as I can while retaining pretty good manners. So my worry was about drivibility. But I can tell you that for my 206/206, 3.8L, 55 PPH, 60 turbo, stock convertered, car.
The smaller TB and piping allowed for faster initial spooling. And progressive throttling up to including WOT.
As I increased the TB size, spooling slowed, but initial throttle response was *faster*. But it wound up taking tinkering with the Accleration Enrichment, and VE table to get it correct.
Trouble was that at say over 3/4 throttle with the big throttle body there was very little actual throttle modulation available.
For me, and my car the 62, and 2.5" setup is what works for me.
If you're going to try to do accurate back to back TB testing then you also need to figure in the differences in % TPS, and spend a bunch of time getting the AE, and PE stuff optimized.
So you might go a lil faster, but it's doubtful it'll really slow you down, if the tune is optimized for the big TB. But, you'll lose the ability to modulation near WOT openings.
And on a related note, the rate of change of the TB and HP is relayed to the tranny via TV cable. So if your tranny isn't up to it, you might shorten it's life.
Again, just what I've found, YMMV.
sixgun86gn
six offender
- Joined
- Feb 10, 2002
The TV cable remark is irrelevant.The rate of TV cable movement is the same ratio with the larger throttle body.The TV cable just holds the shift longer or shorter based on throttle position and not airflow or horsepewer.Very much like a kickdown rod on a carb.Does going to a bigger carb kill trannies? I think not.I don't see mustang guys hollering about burnt up trannies from changing to 75MM TBs from 65MM.
If the enrichment and everything is tuned for the bigger tb then it will have the right A/F at all positions.Make more power from better airflow...yes,but only at WOT.
If the enrichment and everything is tuned for the bigger tb then it will have the right A/F at all positions.Make more power from better airflow...yes,but only at WOT.
1KWIK6
UNDER PRESSURE!!!
- Joined
- Mar 18, 2003
You may want to rethink your statement. A larger throttle body will flow more air than a stock unit at the same throttle position. However, the TV cable is still being pulled the same amount. Therefore, it is entirely possible to be under a higher load with less line pressure.
OneLethal87GN
R.I.P. Lethal GN
- Joined
- May 26, 2001
Try doing a search on this topic as it has come up alot. I've only seen two magazine articles where back to back testing was done. One was the "Double the Power" series by Popular Hot Rodding magazine. In that test they were using all Kenne-Bell parts and the engine gained horsepower with their 70mm throttle body. The other article was in the all turbo Buick issue of GMHTP. I think the article was called "12's for $1200". In that test the car lost 13 rwhp from switching to a 65mm t.b. from stock. I'll probably just end up doing what most people do and that is to just bell-mouth the stocker.
sixgun86gn
six offender
- Joined
- Feb 10, 2002
You are not going to pick up that much more power or increase the load that much at part throttle.Increasing airflow does not increase load.Cars do not make all their power at part throttle.You in fact would probably be lucky to make 50 HP at the throttle positions you normally drive around at.I don't have to rethink my statements...as I was an ASE certified trans tech once upon a time.BTW My tranny is just fine with a 70MM tb after 3 years...do you have one?
Anyways at full throttle the turbo doesn't care how big the TB is.
Anyways at full throttle the turbo doesn't care how big the TB is.
It changes the ratio of airflow to hydralic pressure, ie making more HP at lower throttle openings, and at lower tranny pressures. More HP with lower pressures, if the tranny isn't up to it, will allow slippage, and then flaring shifts, then a dead tranny. ie while you might be at 12% TPS in cruise with a stock TB, with the big one you might be as low as 8%. As you crack into the gas with the bigger TB there is less intial pressure with the lower throttle opening. Then at say a Kick down amount of TPS the large TB *might* be making a signifigant amount of more HP.
The bigger TB doesn't guarantee better airflow. Bolt on a TB with a 8" diameter TB if you think bigger is always better. Bigger is only meaningful if your engine can actually use it.
I'll stick to what I said.
sixgun86gn
six offender
- Joined
- Feb 10, 2002
I dont beleive that the bigger TB is going to increase HP at the part throttle position.Even if it did 2-3 hp would be it at the most until WOT,not enough to kill a tranny.This is a myth and it is bunk.A 500hp motor only makes 500 hp at WOT not 1/4,not 1/2,not even 3/4.It don't care how big the TB gets.
Airflow DOES NOT increase load.Vehicle weight,gear ratios,rotational resistance,etc...create load.
I tell you what...how many Monte SS guys have tore up a 200r4 by going to a larger carb just because of the extra airflow at all throttle positions?If they did,I guaruntee you it wasnt the bigger carb and it did not happen at part throttle.Improper TV cable adjustment kills trannies...not throttlebody size.
Airflow DOES NOT increase load.Vehicle weight,gear ratios,rotational resistance,etc...create load.
I tell you what...how many Monte SS guys have tore up a 200r4 by going to a larger carb just because of the extra airflow at all throttle positions?If they did,I guaruntee you it wasnt the bigger carb and it did not happen at part throttle.Improper TV cable adjustment kills trannies...not throttlebody size.
I think those that argue that it is detrimental to the tranny are theoretically correct, HOWEVER.... in the REAL WORLD has there ever been a single case of someone actually toasting a tranny because there TB was too big?????
I Highly doubt it.
What sixgun86 is saying is that most people go pretty much WOT or just cruise around.
and that literally THOUSANDS of mustang have increase there TB size and probably millions have increase carb sizes without this being an issue, I think if this was even a tiny problem this would have turned into an old wives tale by now and every old school gear head would be warning against it much the same way they argue that leaving a battery on the ground will cause it to discharge.
total nonsense.
its like saying that when you make more power with the same TB size you run the risk of burning your tranny up because the TV cable is being pulled the same amount as it used to be, but now its producing more power.
say you get bigger heads and cam and turbo etc etc but keep the TB the same size.... isn't it the same thing? you are making more power at the same TPS angle i.e. the same TV cable pull!!!
I Highly doubt it.
What sixgun86 is saying is that most people go pretty much WOT or just cruise around.
and that literally THOUSANDS of mustang have increase there TB size and probably millions have increase carb sizes without this being an issue, I think if this was even a tiny problem this would have turned into an old wives tale by now and every old school gear head would be warning against it much the same way they argue that leaving a battery on the ground will cause it to discharge.
total nonsense.
its like saying that when you make more power with the same TB size you run the risk of burning your tranny up because the TV cable is being pulled the same amount as it used to be, but now its producing more power.
say you get bigger heads and cam and turbo etc etc but keep the TB the same size.... isn't it the same thing? you are making more power at the same TPS angle i.e. the same TV cable pull!!!
sixgun86gn
six offender
- Joined
- Feb 10, 2002
AMEN!! Thanks Mike for helping me get the point across.Finally someone who understands common sense mechanics.
you all need to look at in terms of how much hp you are making. If you are running slower than 10.50s you are probably not flowing enough air for the stock T.B. to become a restriction therefore the T.B. would not be a big benifit. Although I have not seen any situation where it is detrimental to performance.
Once you reach the 10.50 E.T. range the larger T.B. becomes a benifit. So it kinda depends on your goals.
Once you reach the 10.50 E.T. range the larger T.B. becomes a benifit. So it kinda depends on your goals.
No, at a given % of throttle opening with the biggest of injectors, and turbo, you'r still only going to make so much HP, for a given amount of air, In your TPS angle vs lenght arguement. At WOT when the cable is pulled tight is another matter.
At 30% TPS, you're at about 60% of possible air flow. With a TB that is 30% bigger at that throttle opening you might be making ~30% more HP, with the larger TB. Part throttle downshifts will be much more of a shock on the clutches/band. If they're not up to it, they will quickly fail.
And for those agrueing without remembering the original comment, here ya go.
Please note the wording, I was specific in saying *if*, and *might*.
************
And on a related note, the rate of change of the TB and HP is relayed to the tranny via TV cable. So if your tranny isn't up to it, you might shorten it's life.
************
Take a 100K mile old tranny and seriously crank up the HP with *just* injectors, and a turbo, and the statement still stands.
Let me side with Bruce. With a bigger TB, you will cruise at the same horsepower level, but it will take less opening of the TB to get that level. So, the butterfly will closer to "closed", and the TV cable will not be pulled as much. I don't know how much effect this has on the fluid pressure in the transmission, but it is "common sense mechanics" that the pressure will be lower, and that transmission life MAY be shortened. Probably not by much, but it would depend on how much margin was there in the first place. If the tranny is close to slipping at shifts, then the larger TB might be enough to push it "over the line".
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