DTB for 7MGTE

4th

New Member
Jun 24, 2008
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Cracov
I've an idea

dtbtx5.jpg


What do you think?
I need to do a intake manifold, so it is no problem to make it like this.
2 throttle body's = better flow, better throttle response ?

I think it will work preety similar to ITB.
 

4th

New Member
Jun 24, 2008
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Cracov
cruisnhard;1157881 said:
Why not just get a bigger one?
S=Pi*r^2

S for supra tb, diameter is 60mm, so radius is 30
S=Pi*30*30= 2826mm^2

Bigger one, lets try 70mm
S=Pi*35*35= 3847mm^2

No lets try DTB, one stock supra 60mm (S1), and one from prelude 55mm (S2)
S1= 2826mm^2
S2= 1589mm^2
S=S1+S2= 4415mm^2

Now You can see why. Same results with itb, but there you have 6 smaller tb's.

figgie said:
in turbo car, itb gain you nothing save for more tuning headaches
Hmm, nothing? I can't agree with it. I will get better throttle response, and some additional horses.
More air&fuel almost always means more torque.
Second thing, I need new manifold and I have second throttle body, so it will be chaep for me.

adampecush said:
good luck finding the space to run two TBs as well.
It is not a problem, leave it to me.
 

cruisnhard

SM Member
Sep 27, 2007
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I say do it then. Sounds like you have some math worked out. Try it and see. The dyno doesnt lie.

I would like to see some pictures as I think out of the ordinary looks great.
 

figgie

Supramania Contributor
Mar 30, 2005
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4th;1157954 said:
S=Pi*r^2

S for supra tb, diameter is 60mm, so radius is 30
S=Pi*30*30= 2826mm^2

Bigger one, lets try 70mm
S=Pi*35*35= 3847mm^2

No lets try DTB, one stock supra 60mm (S1), and one from prelude 55mm (S2)
S1= 2826mm^2
S2= 1589mm^2
S=S1+S2= 4415mm^2

Now You can see why. Same results with itb, but there you have 6 smaller tb's.


Hmm, nothing? I can't agree with it. I will get better throttle response, and some additional horses.
More air&fuel almost always means more torque.
Second thing, I need new manifold and I have second throttle body, so it will be chaep for me.


It is not a problem, leave it to me.

Disagree all you want. You nor anyone else is going to defy fluid mechanics. Additional horses on a smaller diameter tb, not if the flow is already approaching sonic flow. ;)

better throttle response based on what fact? throttle response along with where in the rpm range the power is deilivered is a combination of the ENTIRE intake system and not just isolated to the tb. You must account for diameters of the intake ports, intake runners, intake plenum etc.


again dtb/itb by themselves do not give hp, as a matter of fact without addressing the entire intake system, the gains will be negligible at best.
 

bloodasp90

JZwhore of JAPAN
Nov 9, 2007
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now have you figured out on what kinda runners your going to be using along with the diamatur of those too? plus the shape of the runner too?
 

adampecush

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May 11, 2006
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4th;1157954 said:
It is not a problem, leave it to me.

Ok, so what are you going to do about the more than doubled throttling losses, especially when off boost?

there is a reason automakers are starting to produce throttle-less intake systems...(throttle controlled by valve timing)
 

4th

New Member
Jun 24, 2008
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Cracov
figgie;1158251 said:
Disagree all you want. You nor anyone else is going to defy fluid mechanics. Additional horses on a smaller diameter tb, not if the flow is already approaching sonic flow. ;)

better throttle response based on what fact? throttle response along with where in the rpm range the power is deilivered is a combination of the ENTIRE intake system and not just isolated to the tb. You must account for diameters of the intake ports, intake runners, intake plenum etc.


again dtb/itb by themselves do not give hp, as a matter of fact without addressing the entire intake system, the gains will be negligible at best.

Lets take 1" and 5" butterfly, and open them for about 20%, I think the bigger one will have lower flow resistance, and in result better throttle response (I think, I'm not a master of science. just poor student :p ).
BTW: Head will be prepared, intake plenum will be bigger, custom made and whole intake system will have bigger diameter. I think the ecu will need some custom modyfications.


bloodasp90 said:
now have you figured out on what kinda runners your going to be using along with the diamatur of those too? plus the shape of the runner too?
Stock, ported maybe plus custom plenum.

adampecush said:
Ok, so what are you going to do about the more than doubled throttling losses, especially when off boost?
Smart question, I don't know yet :/ Any ideas?
 

figgie

Supramania Contributor
Mar 30, 2005
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4th;1158800 said:
Lets take 1" and 5" butterfly, and open them for about 20%, I think the bigger one will have lower flow resistance, and in result better throttle response (I think, I'm not a master of science. just poor student :p ).
BTW: Head will be prepared, intake plenum will be bigger, custom made and whole intake system will have bigger diameter. I think the ecu will need some custom modyfications.



Stock, ported maybe plus custom plenum.


Smart question, I don't know yet :/ Any ideas?

so lets say you do this, are you prepared to lose power on the lower RPM because of the "bigger" mentality you are taking?

Custom modification of the toyota tccs, umm how exactly are you going to do that?

A bigger tb whether by a single or multiple tb's, will actually give poor low theottle response, specifically what the car needs when cruising or running around town.

Seems like you need to research a heck of a lot more to understand what you are even asking.
 
Last edited:

Clip

The Magnificent Seven
Oct 16, 2005
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4th;1158800 said:
Smart question, I don't know yet :/ Any ideas?

you could leave it the way toyota designed it? not trying to crush your dreams but it's going to be awful hard to outdo the stock setup unless you've got some mighty fancy equipment, money and time.
 

4th

New Member
Jun 24, 2008
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Cracov
figgie said:
so lets say you do this, are you prepared to lose power on the lower RPM because of the "bigger" mentality you are taking?
It would be a track day car, maybe with misfireing system. We will see in the future.

Custom modification of the toyota tccs, umm how exactly are you going to do that?
Piggyback or stand alone.

Clip;1158843 said:
you could leave it the way toyota designed it? not trying to crush your dreams but it's going to be awful hard to outdo the stock setup unless you've got some mighty fancy equipment, money and time.
Maybe You're both right, I need to do research and think twice before I will start doing this.

Better to spend some more money on common mods, then do the experiments.

Anyway THANKS FOR HELP :icon_bigg
 

JDMMA70

Active Member
Dec 4, 2006
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Correct me if im wrong but doesn't the RB26 use a system similar to this, I was reading the R32 GT-R workshop manual and noticed it had a throttle body for each intake port. But what makes it harder to tune? I know HKS custom fabbed a RB26 intake to work on a 1JZ.


Sounds like a cool idea.