aznboysrfr

iTrader: (10)

^^ did you loop the hoses on the TB for the bypass? .. or did you just leave open holes where the coolant used to go?

Blahman240

which is why there is R&D

tinman

Yeah.... your car sounded really bad as you described it. Even I would not have thought that the TB bypass would have such a DRAMATIC effect on the engine, especially since you had been running like this for a while.

Go figure. But we DID narrow it down to the TB.

Blahman240

ohh thats true... I think in this topic they are saying ITB stand for intake throttle body... when it should just be TB

S2000man01

iTrader: (1)

your own website proved you wrong on your own claim. you should practice what you preach and read through things. since you missed this entire paragraph at the bottom i'm wondering how much you have really researched this mod.

well whaddaya know. sounds like the people i have been talking to about this have been right all along.

2K1Civic17"Gabe

iTrader: (9)

I cant wait to put mine back together. I hope this is the deal with my idle. Ever since I was boosted, Ive had idle probs. I did the coolant bypass at the same time. My car runs nice, but the idle sucks big time. I cant turn on my a/c without idle dropping hella low even. Ill be looking for my old coolant line tonight, and hopefully fixing this.

Thanks for the update!!!! much appreciated!

Peace

2K1Civic17"Gabe

iTrader: (9)

and there is nothing wrong with my vac lines. Idle should be perfect right now, but isnt. This is about the only thing left to check.

gearbox

iTrader: (95)

Don't forget to reset the ecu after putting it back and do the idle relearn (10 mins at idle with no accessories or gas once the car is warm). I actually just went out a got a new hose to connect from the auto store. Oh and the way I did the mod was using a pipe connector and putting vacuum caps on the tb holes.

CuRiOuSfIsH

iTrader: (13)

fINALLY! A lot of senior members on here have been telling a lot of noobs to do this b/c they believe it's 1 of the best mods! If this is 100% true, can ego not get in the way and tell ppl the truth? And list this as a silly mod?

S2000man01

iTrader: (1)

i have thoroughly read through each one, as well as talked to an engineer who has his degree in thermodynamics, and was an ASE master tech. i have also asked 2 other s2ki "gurus" regarding this and pointed them to these websites. Let me convey the points they have said to me.

Notice the last dyno you post where the guy gains 5whp. Yet read his statement here:
Notice that while he only measures air intake temp, he does not measure the temp after the ITB. Therefore his results are skewed.

There is not enough thermal transfer going on to support the kind of gains he is claiming. Using the LS1 as an example let's do an experiement. Do you realize how much temperature would have to change to gain 5.6whp? If you calculate the volumetric efficiency of an engine, using mass air flow readings, you can convert mass air flow to volume flow if you know the temperature of the air. Use this equation here:

Where:

t1 = Temperature of air for a known density (32 °F @ 0.0808 lb/ft3)
t2 = Temperature of the intake air measured by the intake air temperature sensor (°R)
d1 = Density of air for a known temperature (0.0808 lb/ft3 @ 32 °F)
d2 = Density of the intake air (lb/ft3)

If the air is 72 degrees, it's density is .0747 lb/ft3. Using that to determine it's effect on horsepower using VE, the equation determines AVF(actual volume flow) is 459.44. On the same engine TVF(theoretical volume flow) is 599.99. This means that the car has 76.57% volumetric efficiency.

Now let's raise the temperature from 72 to 82. A 10 degree change in temperature. This air's density goes from .0747 to .0720. This changes the car's AVF from 459.44 to 452. The car is now only making 75.45% VE. This means about a 1.12% change, which essentially would mean a 1.12% change in horsepower. This particular example was an LS1 that made 275whp. This means that with a 10 degree temp increase, he'd lose 3 wheel horsepower.

In the last example his throttle body went from 102 to 82 degrees surface temp. If the ambient intake air temp was 82, and the throttle body was 82, then there would be no change. With the surface area of the throttle body, if the temp was 82 and the throttle body was 102, the air may increase 1 or 2 degrees at the most. And even that's a stretch.

If you think that your ITB is heating up your air 10 degrees as it passes through, then you are sorely mistaken. Considering that even though coolant is usualy about 180 degrees or so, the actual surface temp of the ITB remains near 100-110. The ITB could still heat up more from the intake manifold and heat conduction from the head, than from the coolant flowing through it.

So stopping the coolant does very little. While it may bring the temperature of the ITB down, you are still forgetting the biggest thing of all. The throttle body simply does NOT have the surface area or heat transfer to change the intake temp air 5 degrees much less 10. Again, notice how much surface area a front mount intercooler has vs what a throttle body has. The ITB has maybe 5% of the surface area of an FMIC if that. And with air moving through at 160-260 cubic feet per minute, it has no effect on your power while you're driving. At even 160CFM do you realize how fast air is moving through the throttle body? It has no time to heat up. Especially since the throttle body is between 100-110 and the air is already say 70-90 degrees.

Oh, and just one other thing. NONE of those examples you gave, actually dyno'd or did their experiements correctly. While only 1 monitored air intake and coolant temps, they did not monitor temps AFTER the ITB. Also, they did not dyno properly. In doing an experiment like this, you have to get 4 good solid runs back to back. why? because you'll get 4 different readings. Horsepower can vary as much as 2-3% just due to dyno error. I could dyno my car at 202whp, install a spoiler, and then dyno again at 206whp. Well look at that! My spoiler added 4whp!!!


The defense rests.

S2000man01

iTrader: (1)

He was reffering to the people who were trying to cool the throttle body by pushing cold water through it.

S2000man01

iTrader: (1)

yup. cognitive dissonance.

aznboysrfr

iTrader: (10)

well, there is something not right here.

before the bypass, I could barely touch my intake pipe (the bend right very close to the tb) because it was so hot after a drive home from work. also note that my intake pipe wasn't even touching my tb either.

I bypassed and now after a normal drive from work it is just like touching any other metal ... after hard driving, it is mildly warm.

I really don't care much about this whole argument ... but my own test is evidence enough for me. if people don't wanna do it, let them be.

R1Style

iTrader: (20)

This part made me laugh!

S2000man01

iTrader: (1)

No one is stopping you. I'm simply trying to educate people as to why it's not making a difference, and in some cases affects their idle.

7thGenerasianCivic

iTrader: (13)

Would anyone want me to test anything out since I have a laser temp tester? I have stock intake with bypass as of now...

I want to help but please don't make me take my stock intake out, it's just too much work for me. hahaha

Perhaps I can use another car without the bypass...

S2000man01

iTrader: (1)

unfortunately the laser temp tester won't do us any good, since the true measurement needs to be taken with some kind of thermometer to measure air temp immediately after the throttle body.

but, as i had already said, it'd be a waste of time anyways. there is simply not enough heat transfer going on to support any increase in horsepower by reducing air temp.

CuRiOuSfIsH

iTrader: (13)

well, your own test is what has been the purpose of the whole bypass thing, to lower AIT.... that is already known... lets hope you will continue to have no idle problem.

tony_buttons

iTrader: (3)

What I'm wondering is why the idle problems only affect some people. I'm pretty sure my idle is fine, but you guys are making me nervous. I felt my throttle body after initially doing the mod and it was much cooler. So I was thinking, I might not be gaining much, but what harm could it do? How long did it take for your idle problems to present themselves?

Logan3024

iTrader: (8)

Well the fact remains, they were ALL happy with this mod.

Quit listening to your so called "gurus". I would invite anyone of them to prove to me HOW the coolant bypass effects the idle. I have provided facts (pictures) showing how the coolant passage is not in anyway connected via to the IAC valve for the d17 TB, now it may work diffent in the s2000s but not on the D17 TB.

You claim "coolant is usually about 180 degrees" well your making general sumptions again. While SOME cars may run at that temp, The "D17" runs at 212 degrees at its optimal temp. Its gonne be higher if you live where the summer temps reach high tepms like in the desert. You may know more about the s2000, but i assure you, i know this engine (d17) top to bottom .

Logan3024

iTrader: (8)

Ive had mine on for 3 years now. Never had 1 idling problem.

S2000man01

iTrader: (1)

Your own sources even said it affects the idle. If you can't see that, then it's not my problem.

The coolant temp is a moot point. 180 is considered operating temp (where vtec will then work and the cold rev limiter is removed on DOHC vtec cars) but yes, the coolant can reach 212 degrees give or take during operating. But again, this doesn't matter.

Now let me point out another fallacy in your argument.

You are stating that removing the coolant has NO EFFECT on the air that is flowing inside the throttle body via the IAC passages you've shown, right? Yet you want to somehow argue that the coolant DOES affect the air flowing through the throttle body into the intake manifold. The air would be more affected in the IAC passage than anything, since it's a smaller volume of air moving through more surface area of the "hot" throttle body.

So which is it? Because it can't be both. The laws of physics and thermodynamics prove that.

The bottom line again, is this mod will NOT INCREASE HORSEPOWER. It does NOTHING to improve performance.

Jrfish007

iTrader: (3)

S2000man01, what engineer has a degree in thermodynamics? As a Chemical engineer I know far more than most other engineers in this field, and to my knowledge, there is no such thing as a degree in thermodynaics. Don't get me wrong, people can specalize in it (personally I watch the back of my eyelids when people talk about thermo).

Anyway, the basic equation for a heat exchange is going to be to the effect of q=UAdeltaT (McCabe, Smith, and Harriott 6th edition, Unit of operations of Chemical Engineering) where q is the total heat transfer, A is the transfer area, U is the overall thermal conductivity and of course deltaT is the change in temperature. Now all I have to do is look at the throttle body and say that it has surface area in the realm of 12-20 square inches and the volumetric flow is around 459ft3/min (from your earlier example) and converting that to inches we get 793,152 cubic inches per minute. So, with that kind of flow and that kind of surface area with an approach temperature of only 100F (80C air and 180F TB which is very unlikely), I would say the largest delta T can be is 1, maybe 2. So at most the temperature will only rise about 2F, that won’t do crap to your power. You will probably save more power because the water pump isn’t pumping through as much tubing as you will by cooling your intake. This mod has the same effect as pissing on my engine and saying I’ll make more power because it’s cooler after I **** on it.

Jrfish007

iTrader: (3)

Also, IF this gave signifgant power increases, I'm sure Honda would have looked into this, they spent millions on devloping this engine.

S2000man01

iTrader: (1)

His exact words were he's an engineer specializing in thermodynamics. He used to do something involving plane engines and now does car engines. I assumed that meant his degree was in thermodynamics. I'm not an engineer so I have no idea. lol

S2000man01

iTrader: (1)

His results were exactly what yours were. he had said 1-2 degrees maybe. Hence the reason I showed what 10 degrees did to a 275whp car, much less 1 or 2 degrees. If a 10 degree temp change only results in a 3 horsepower loss (-1.12%) then 1-2 degrees will do pretty much nothing. particularly on a lower horsepower car.

And you stole my pissing idea.

S2000man01

iTrader: (1)

exactly. if this made a difference they would have developed a valve that would close once the engine was at operating temp, so the coolant would bypass the throttle body.

Logan3024

iTrader: (8)

There is NO performance increase, what it does is prevent you intake/intake manifold from being heat soaked, everyone knows heat kills hp.

The ONLY reason Honda puts them on vehicles is like i said earlier, to prevent the TB from sticking. Imagine a auto civic driving in 10 degree weather while its snowing. If the TB wasnt heated there would be a VERY good chance of condesation freezing and causing the TB to stick causing it to stay open, so there you are on icy roads with a TB stuck at 3k rpms. Thats VERY dangerous. Whats honda supposed to do put TB heaters on cars ONLY sold on the east coast? Same reason why Honda doenst use 100% H20, you could get away with it in some places but not everywhere. So thats why every car is sold it TB heaters and use Antifreeze with 50/50 mix, that way in either hot or cold situations it will work just fine.

Logan3024

iTrader: (8)

well again you got to point out engineering. Im sure a valve like that would cost them at cost probly about 4$ we all know how expensive sensors are!! Multiply that by the 2 million Hondas sold world wide each year. Its would cost them MILLIONS to produce a valve that isnt even needed.

Jrfish007

iTrader: (3)

Well Dizzle, I know you never said that it increases performance, but many people apparently think it does, those are the ones I was primarly talking to. However, I see no need for this type of mod, infact I agree that it is only needed in cold winters. If you lived in Florida (and your car isn't flooded yet) and you do this mod, you sill see nothing gained or lost in a thermodynamic and performance since. However, you will probably then get transfered to Ohio and face -10F winters and forget about that mods and screw yourself. lol So my point is I don't see a reason to even waste time on this type of mod.