GolfGTIforum.co.uk
Model specific boards => Golf mk3 => Topic started by: axewielder on 17 September 2009, 16:40
-
Was going to bypass the Throttle bodys supply of coolant to reduce intake temps, just get rid of one pipe+ connect the other up straight from expansion tank to the front bit. Hope you understand my ramblings, any opinions welcome, just seemed simple+easy.
-
Shouldn't be a problem...I've done loads of VR6s with no problems.
-
Hmmm, interesting. It sounds promising in theory; colder intake charge = denser intake charge = bigger bangs = more power. One word of warning though, I have come across a slight practical problem when applying this to my Mini. Now admittedly the Min' does still use a stone age S.U. carb that doesn't even know what day it is compared to the Golf's management system but we're still basically talking fuel and air here. Originally the Mini was fitted with an inlet manifold which was cast in unit with the exhaust, thus giving rather good heating. Mine now has a tubular exhaust manifold and separate inlet, the latter having provision for water heating to replace the lost exhaust heat. Now I, thinking along the same lines as you, eshewed such things and even pushed on further by arranging a cold air feed from the grille. Result, good power but lousy low speed throttle response. Everything was just too cold and the fuel was falling out of suspension in the airstream. Connected some water heating and lovely snappy Mini throttle response came back. Not saying the Golf will do this but just bear it in mind.
S.M.
-
I shall be keeping a VERY close eye on this. Very interesting mod, and if I see dyno plots proving it works or if it gets a large amount of good reviews then I shall do it myself.
-
The cold air feed is before the throttle body / injectors where cold air is more dense and needs more fuel and hence more power, the throttle body / manifold is after the fuel air has been mixed and as already mentioned helps vaporise the fuel / air mixture. removing the heat from the inlet manifold will reduce not increase power. sorry. :sad:
-
The cold air feed is before the throttle body / injectors where cold air is more dense and needs more fuel and hence more power, the throttle body / manifold is after the fuel air has been mixed and as already mentioned helps vaporise the fuel / air mixture. removing the heat from the inlet manifold will reduce not increase power. sorry. :sad:
Correct.
No power gain at all...but less heat in your inlet tract is always a good thing.
No side effects on a Golf, that I've ever found....but no miracle BHP increase either.
-
still if you get it done and see any difference please inform us of your findings. please
-
The cold air feed is before the throttle body / injectors where cold air is more dense and needs more fuel and hence more power, the throttle body / manifold is after the fuel air has been mixed and as already mentioned helps vaporise the fuel / air mixture. removing the heat from the inlet manifold will reduce not increase power. sorry. :sad:
Doesn't make sense....Where the fuel mixes with the air is AFTER the throttle body, keeping the air as cool as possible all the way down the manifold and into the chamber will be a bonus, maybe not miracle HP as said already, but improved response, fuel economy, and smoother throttle will be gained.
-
Been reading on this.
http://www.geocities.com/MotorCity/Track/9558/tbbypass.html (http://www.geocities.com/MotorCity/Track/9558/tbbypass.html)
and a Dyno plot that proves it.
http://www.geocities.com/MotorCity/Track/9558/dyno.html (http://www.geocities.com/MotorCity/Track/9558/dyno.html)
Only one problem thought. Read up that below a temp of 10 C it will idle crap for a while until engine is nicely warmed up. If temp of 10 C causes problems then how would the UK winter temps of 0 C or less cope?
Also, where can I get the caps to block off the TB ends, or what can I use to block them off?
(http://timney.cz28.com/tb10.jpg)
-
The injectors are right at the end of the inlet manifold so fuel dont get introduced until then!
-
if you change the temperature of the air after the air temp sensor, surely the mixture is going to be wrong and cause unpredictable running.
-
Anyway cooling it with water from the cars cooling system you cannot use a feed from the expansion tank as that is hot!
You would have to come off from the bottom hose out of the radiator.
-
Anyway cooling it with water from the cars cooling system you cannot use a feed from the expansion tank as that is hot!
You would have to come off from the bottom hose out of the radiator.
what are you implying?
-
Also, where can I get the caps to block off the TB ends, or what can I use to block them off?
Why do you need to plug anything?
and yes i agree that the temp sensor is as the airbox so it wont be perfect
-
Anyway cooling it with water from the cars cooling system you cannot use a feed from the expansion tank as that is hot!
You would have to come off from the bottom hose out of the radiator.
what are you implying?
Well I thought this idea was about COOLING! Well you cant do that with HOT water! :rolleyes:
-
Plus the TB is at the back of the engine and you will be fighting against the hottest part ie the exhaust manifold.
-
there is already coolant pipes running to the TB to warm it, i have removed them + by passed the coolant straight to the expansion tank from the front of the block, maybe there is a different setup on other engines.
BTW took about 3.5 mins with just a leatherman so not a difficult mod
-
Only air/vacuum hoses on my TB!
-
so thats why you didnt understand, i just thought it was your blue lights :wink:
-
axewielder, did you notice any difference?
-
havent driven it really yet, the exhaust has fallen off so the hours drive to work gets a bit deafening, have to drive my mk4 1.6 :angry:+ smoothed out the inside of tb this week which has given better throttle responce
-
I see. Well I'll try and bypass TB before JKM RR day, should be interesting.
TB porting and polishing is also on the to do list, but wont be able to do it before the RR.
Btw have accepted you on fb :wink:
-
Which engine are we speaking about here?
I'm confused.
-
Any engine management system that used an IAT sensor will read the temperature of the air...and that air is passing through the TB at such speed that it's not going to pick up any temperature!
Certainly not when driving on the open road.
The only TB I have 'bypassed' the coolant of the TB is the VR6, and I cann assure all of you you will not get any power out of doing it - 2.8 or 2.9.
You will from modifying the airbox, or modifying the TB...but not by bypassing the coolant.
I've tested it on the dyno.
-
Any engine management system that used an IAT sensor will read the temperature of the air...and that air is passing through the TB at such speed that it's not going to pick up any temperature!
Certainly not when driving on the open road.
The only TB I have 'bypassed' the coolant of the TB is the VR6, and I cann assure all of you you will not get any power out of doing it - 2.8 or 2.9.
You will from modifying the airbox, or modifying the TB...but not by bypassing the coolant.
I've tested it on the dyno.
Seems like you have done pretty much everything :rolleyes:
Got the before and after dyno graphs?
Because in theory, it makes sense bypassing it. The TB stays cold therefore the air does not warm up.
-
if its hot then itll heat the air man even if it is going fast, yes it might not make enough difference to show on dyno but every little helps :wink: mines a 2l 8v ady
-
I was asking Ess about dyno charts but would have been good nevertheless if you had some too.
just doing the little things as and when i get the opertunity
1 little thing might not make much difference, but add 5 little things put together and they all add up :smiley:
-
Seems like you have done pretty much everything :rolleyes:
Well the thing is, I have actually done the testing, whilst modifying cars over the last 20 years...as opposed to thinking about it and achieving Internet Expert status whilst doing nothing.
From stuff I've tested, I know what works, and what doesn't...if I've not tested it, I'll not comment on it.
Simples. Christ knows it need to be for some people.
Got the before and after dyno graphs?
I've got 60+ dyno plots for my Mk3 ABF...
Probably 30 for my S3...
And numerous for mates VR6 Golfs and Corrados I've tweaked for them.
Which, specifically, would you like me to scan?
Because in theory, it makes sense bypassing it. The TB stays cold therefore the air does not warm up.
In theory yes, I agree. But the airspeed it soo high to pick up the heat when driving. It WILL help sitting in traffic though, although you then pick up heat in the TB from conduction from the manifold/head and from radiation off the ex manifold.
The theory of changing an air filter says you should get more power too...but it doesn't prove so on the dyno.
It can't do any harm...but don't go expecting miracle gains.
But hey, what do I care?
If people want to waste their time and money on crap...so be it.
If however, they want to buy or modify things that actually work and save on buying crap...maybe what I've found could help.
-
if its hot then itll heat the air man even if it is going fast, yes it might not make enough difference to show on dyno but every little helps :wink: mines a 2l 8v ady
I have no experience of the ADY.
Perhaps that will behave differently to every other internal combustion engine, or defy physics...but I doubt it.
Cold air is good, of course.
But the speed the air passes through the TB doesn't allow much latent heat transfer...even if it's very cold air going in...
Then of course, there's the people who feed it hot air from their cone filter in the engine bay!
-
Will this small insignificant tweek make any difference in power of an 8v?
:laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh:
-
Will this small insignificant tweek make any difference in power of an 8v?
:laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh:
yes
:cool:
-
It's probably worth 45 BHP...and remember to compound it with the 12 BHP from the cone filter, 10% for the exhaust, 15% for the de-cat and 15% for the cheap re-chip...so about 90 BHP on the ass-dyno. A VR6 beater indeed.
-
Will this small insignificant tweek make any difference in power of an 8v?
:laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh:
yes
:cool:
Boll0cks!
Be telling me next an 8v produces more torque than a 16v!
-
Will this small insignificant tweek make any difference in power of an 8v?
:laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh:
yes
:cool:
Boll0cks!
Be telling me next an 8v produces more torque than a 16v!
Funny you say that actually....
(http://i254.photobucket.com/albums/hh115/kharekatoh/golf%20mk3/dynochart1-1.jpg)
16v torque? 132ft-lb.
Torque on my standard at the time 8v that hadn't been serviced for over 25k miles? 135 ft-lb :wink:
-
They aint the official figures! :tongue:
-
They aint the official figures! :tongue:
Official figure for 16v is 132 ft-lb. Official for 8v i 125 ft-lb iirc.
-
They aint the official figures! :tongue:
Official figure for 16v is 132 ft-lb. Official for 8v i 125 ft-lb iirc.
So you 8v makes a bit more.
So does my 16v:
(http://i188.photobucket.com/albums/z72/Ess_Three/Dyno%20Plots/4thRun196-141BHP159lb-ft.jpg)
-
Just checked Boney's website and its 122 for an 8v! :tongue:
Consider your eye poked again! :laugh:
-
Just checked Boney's website and its 122 for an 8v! :tongue:
Consider your eye poked again! :laugh:
official or not, realistically 135 ft-lb is 3 ft-lb more than a 16v
-
Have to dig out my RR read outs then! Hmpft!
Bet my 16v is more than 132!
-
Have to dig out my RR read outs then! Hmpft!
Bet my 16v is more than 132!
and waits....
-
Have to dig out my RR read outs then! Hmpft!
Bet my 16v is more than 132!
and waits....
................. and waits!
A very long time!
At home somewhere when I can be arsed to find em! Probably for the 3rd Oct!
-
:grin: :grin:
-
chill out guys :grin: thanks for all the input everyone even the old 16vs8 rearing its ugly head
-
Had a look today under the bonnet and the 2 hoses are in a pretty awkward position, so rather than a straight bit of pipe I shall need an "U" shaped pipe, size is about 7 or 8mm, not sure. For best access gotta remove the cam cover, although it COULD be done with just removing the intake pipe and one of the brackets from the cam cover to the top of the manifold.
-
Had a look today under the bonnet and the 2 hoses are in a pretty awkward position, so rather than a straight bit of pipe I shall need an "U" shaped pipe, size is about 7 or 8mm, not sure. For best access gotta remove the cam cover, although it COULD be done with just removing the intake pipe and one of the brackets from the cam cover to the top of the manifold.
I knocked up a job lot of bypass pipes out of 3/8"OD Stainless Instrument Tubing, machined down by 1mm at the ends, and bent using a pipe bender.
If anyone is in the Instrument trade, maybe they could knock you one up...or if you need to buy tubing, 3/8" stainless works a treat.
-
really, i did it last night with my leatherman in 5 mins, did remove the left inlet mani braket thing, i just completely got rid of one pipe+ the other goes from front of block to expansion tank. just left the tb with nothing connected. make any sense?
Had a look today under the bonnet and the 2 hoses are in a pretty awkward position, so rather than a straight bit of pipe I shall need an "U" shaped pipe, size is about 7 or 8mm, not sure. For best access gotta remove the cam cover, although it COULD be done with just removing the intake pipe and one of the brackets from the cam cover to the top of the manifold.
I knocked up a job lot of bypass pipes out of 3/8"OD Stainless Instrument Tubing, machined down by 1mm at the ends, and bent using a pipe bender.
If anyone is in the Instrument trade, maybe they could knock you one up...or if you need to buy tubing, 3/8" stainless works a treat.
where does this go??
-
axewielder, any pics?
Ess, 3/8" (10mm) sounds about right. I'll try and get U shaped copper piper or s/s pipe and try it out.
-
http://www.facebook.com/photo.php?pid=437451&l=beb2ec8bbc&id=1641456246
heres where the pipe now goes in green
-
i dont understand where the copper pipe would go??
-
what did you do with the other pipe...I don't quite understand you're method but I guess until I inspect the hoses then I can't say anything.
-
put it in the boot lol, nothing goes to the tb anymore, the coolant goes straight from the front of the block to the exp tank as in the green line
-
Can anyone post some pics?
It's easier to suss out for us non-8v owners if there are some pics.
-
http://www.facebook.com/photo.php?pid=437451&l=beb2ec8bbc&id=1641456246
can you open this link? doesnt work as img?
-
http://www.facebook.com/photo.php?pid=437451&l=beb2ec8bbc&id=1641456246
can you open this link? doesnt work as img?
I can...
But was hoping for one a little closer up to the TB!
There should be a supply and return line...is there a 3rd?
-
you just remove both from the tb + have one going where the green one does on the pic, get it??
-
(http://www.joetlc.com/images/037133064F.jpg) shows the brass thing the pipes used to conncet to on the right, that are now just left with nothing on.
-
Done it you're way axewielder. Works perfectly.
Ess, basically there are 2 pipes going to tb, one from front head flange and the small one from header tank. I unclipped the one from front flange to tb, and connected it so instead of from flange > tb, it now goes flange > header tank. It replaces the header tank small line.
-
Yes but does it give you more torque? :grin: :laugh: :grin:
-
Not driven it yet :tongue:
Will try it out in a bit, curently waiting for a call.
Mind you from reading up, you only notice a difference on hot days, so gotta wait till next summer to try it out :grin:
-
cool man, on mine both pipes were exact the same size.
-
cool man, on mine both pipes were exact the same size.
yup on mine too.
-
Done it you're way axewielder. Works perfectly.
Ess, basically there are 2 pipes going to tb, one from front head flange and the small one from header tank. I unclipped the one from front flange to tb, and connected it so instead of from flange > tb, it now goes flange > header tank. It replaces the header tank small line.
Sounds spot on to me!
-
so what was all that copper+instrument pipe stuff about, i was just lost :laugh:
sorry if my earlier descriptions were abit sh!t, at least were on the same page now
-
basically joining up the 2 pipes that go to tb dude.
Like so.
(http://www.thirdgen.org/tech/coolantbypass.gif)
-
aha makes sense now, but my ways best baltently lol
-
took it for a drive. Didn't really step on it due to circumstances but haven't really noticed much of a difference apart from maybe a little bit more backfiring, so maybe it has affected something and now it's pumping more fuel in or maybe the mix is just purer due to colder air. Not a clue. Let's see how she does on the dyno.
-
Cannot see it make much difference plus will affect how it runs at the end of the day.
-
Cannot see it make much difference plus will affect how it runs at the end of the day.
Only the JKM RR day will tell :smiley:
-
IMO this is a pointless mod. consider why it was done as it will have been done for a reason.
at full throttel with the engine pulling some revs the air speed though that TB is going to be quite high it simply wont be there long enough to pick up heat.
but at part throttel you have a reasonable amount of air flowing, and expanding into the manifold as the pressure drops as it flows past the butterfly. gas expands temp drops. chould it be possible that with quite low ambient tempritures and realativly high humidity that the air tempriture drops below the freezing point of water at whatever pressure it's at there and causes ice to build up ? pritty much the same as carb freezing in a way
-
IMO this is a pointless mod. consider why it was done as it will have been done for a reason.
at full throttel with the engine pulling some revs the air speed though that TB is going to be quite high it simply wont be there long enough to pick up heat.
but at part throttel you have a reasonable amount of air flowing, and expanding into the manifold as the pressure drops as it flows past the butterfly. gas expands temp drops. chould it be possible that with quite low ambient tempritures and realativly high humidity that the air tempriture drops below the freezing point of water at whatever pressure it's at there and causes ice to build up ? pritty much the same as carb freezing in a way
Spot on.
-
IMO this is a pointless mod. consider why it was done as it will have been done for a reason.
at full throttel with the engine pulling some revs the air speed though that TB is going to be quite high it simply wont be there long enough to pick up heat.
True.
but at part throttel you have a reasonable amount of air flowing, and expanding into the manifold as the pressure drops as it flows past the butterfly. gas expands temp drops.
Indeed it does, but the JT effect is not noticable at such low Delta-Ps as you get from an inlet tract to inlet manifold on a NA engine.
1000mb dropping to 980mb or something similar...it just doesn't affect it.
chould it be possible that with quite low ambient tempritures and realativly high humidity that the air tempriture drops below the freezing point of water at whatever pressure it's at there and causes ice to build up ? pritty much the same as carb freezing in a way
Of course, that is possible.
All I can say is that on VR6s, from experience, in the UK we nave neither the low ambient temperatures nor the humidity to cause any problems - even through North of Scotland winters.
The situation of Carb icing cannot occur - in a Carb the water freezes, blocking up the jets that need the airflow over them to 'suck' in the fuel, giving fuel starvation and bad running.
On an injected car with a TB, there is nothing for any minute ice particles to form on...the air entering the manifold may be cold - even cold enough to freeze - but the inlet manifold isn't, so no ice forms. There is no venturi capable of giving a high enough JT effect to freeze the ice, unlike a Carb.
The fuel goes in from injectors mounted in a manifold bolted to the head and sitting at around 100 degrees C, so the injectors get warm - so no freezing there either.
Even with one of these so called 'power gaskets' or 'insulating gaskets' that keep the inlet manifold cooler, there are no problems with freezing and fuelling. not on an VR6 anyway.
If what you suggest were true, then cars running ITBs would freeze up in winter. They don't. From experience.
All this being said, it still doesn't add any power!
By all means remove the coolant lines - I tend to, well, just because. But it won't add any BHP.
so you are absolutely correct...it's a pointless mod! :grin:
-
By all means remove the coolant lines - I tend to, well, just because. But it won't add any BHP.
so you are absolutely correct...it's a pointless mod! :grin:
Why do you do it then?
-
By all means remove the coolant lines - I tend to, well, just because. But it won't add any BHP.
so you are absolutely correct...it's a pointless mod! :grin:
Why do you do it then?
Because my mates wanted it doing...
I don't own a VR6...and wouldn't want one of the boat anchors in my engine bay...but mates cars I've tweaked, or tuned, wanted it bypassing...so I made and fitted bypasses!
The ABF TB isn't heated at all by coolant...so that tells you something about if it's needed!
-
http://forums.vwvortex.com/zerothread?&id=3336122
even the yanks are upto it