Caldina's plenum mods

[Wolf_Tm250]

I found that Caldina's side-feed intake plenum makes the 3rd cyl. to get less air than the others:

is there anyone that already modified it ?

Bye.

[TWSTD]

interresting - how did you test this? I would be interrested to know of anyone running a custom intake manifold on the gen4 engine also - particularly one with shorter runners!

[Wolf_Tm250]

interresting - how did you test this? I would be interrested to know of anyone running a custom intake manifold on the gen4 engine also - particularly one with shorter runners!

Ehmmm.....

have I really to tell you ???

I didn't use the correct flow-bench tool for now, i'll use it after the mods.

I attached 20 cm of a straight OD 70mm pipe to the throttle body, and I supplied compressed air with a gun:
you can move the gun in every directions in the pipe, but you'll always feel that almost no air is coming out from the 3rd cyl runner.

[TWSTD]

fair enough - but thats not really simulating the intake manifold conditions when running boost is it - as you have no valves closing to cause pressure to build up in the manifold. If you have a constant pressure in the intake manifold it will act differently to the bench test that you did as i suspect feed air more evenly into each cylinder.

[Wolf_Tm250]

fair enough - but thats not really simulating the intake manifold conditions when running boost is it - as you have no valves closing to cause pressure to build up in the manifold. If you have a constant pressure in the intake manifold it will act differently to the bench test that you did as i suspect feed air more evenly into each cylinder.

Yes, TWSTD,

I know this is not reproducing correctly the real behaviour when engine is running...

btw it shows something we should already have learned from books:
in a side feed plenum, the runners near the TB get less flow.

Bye

[CozmoNz]

um dude... boost is basically forcing the air into this chamber, where it BUILDS UP, and holds its Psi....

when a valve opens, this due to the lower pressure inside the cylinder, and a higher pressure OUTSIDE it (in the manifold), it forces its way into the cylinder.

there will be equal pressure forcing onto each set of valves in the manifold... or you wouldnt reach and hold X boost pressure.

your assuming here buddie, that a turbo blows as much as as a compressed air gun... which is probbaly true... on a bloody cappacino or something, and another thing, unless all 4 outlets, and 1 inlet to the manifold are ALL plugged, then its an untrue test.

cap all the inlets / outlets, jap the compressed air gun in (with an extreamly tight seal around the outlet of the gun), then force in X psi, tap a guage off or something, then jab a hole in number 3 cylinder outlet.... i bet you all the air will rush directly out, OMGOGOGOG GADGET DOG, just like boost pressure >.>

remember, manifold on vac turns 4 inlets, into one inlet... and on boost, one inlet becomes 4 outlets...

all for one and one for all. ^_^.

[Wolf_Tm250]

Hello CozmoNZ,

I perfectly know what you mean, believe me...

but if your and TWSTD arguments were 100 % correct,
could someone explain me why ST205 top feed plenum makes the 2nd and 3rd cylinder to be leaner ?

Even flow has its importance in filling a cylinder when its intake valves are opening, and this causes different boost pressure in each cylinder.

And that was flowed and proven...

[CozmoNz]

Very very odd.

in which case you could have a plenium, that was 4 mitres long, and as long as there is *4psi* in that plenium, the turbocharger SUPPLYING enough air, to sustane 4psi. then the entire plenium, SHOULD be pressureized to 4psi...

not 5 at one end and 2 at the other, 4... pressure retains equal unless the manifold is like at sea level on number 1 cylinder and 4k stright up at number 4 lol.

very odd indeed. but ah well, just get something made with a *middle* feed i guess.

guess the 6cyl boys had it figured out from the start .

[Wolf_Tm250]

Motec's injection maps for 3SGTE 3rd gen ( center top feed int.man ) are 3,5% richer for #2 and 2% richer for #3 cylinders....

why ?

[vvega]

because they run hotter.........
#1 and #4 only have one side exposed to another cylander wall wereas #3 and #2 have heat producing cylanders on both sides
the cylanders are not seperated by water......

even in jetting a motorbike with indipendant carbs and also in the case of 20v's you will find the centre 2 cylanders with bigger mainjets


this is very simple stuff and is covered in the first year of uni under the topic of thermodynamics


your flowbench results are a waste of time...........
remeber the engine is a suction pump and it sucks the air though the runners in it's n/a cycle so blowing air though a t/b has no relevance
presure in a vessal also remove the exsistance of lamina flow.......this is what your testing for i believe.......

listen to what peole say and you might lern


if you really have that much of a concern run quads and a big plenum and get on with it

[Wolf_Tm250]

because they run hotter.........
#1 and #4 only have one side exposed to another cylander wall wereas #3 and #2 have heat producing cylanders on both sides
the cylanders are not seperated by water......

#3 is the hotter, followed by #2:
so why #2 is richer than #3 ?

Because #2 is in front of the TB and so it's leaner.

from Hyper Rev, Phase 2 engineer talking about stock ST205 plenum:

this is very simple stuff and is covered in the first year of uni under the topic of thermodynamics

From " Forced induction performance tuning " by Graham Bell, page 228:
PS: on this book they are talking ONLY about forced inducted engines.

your flowbench results are a waste of time...........

I know it, for this reason I asked if someone properly tested and modded a Caldina's plenum.

listen to what peole say and you might lern

Oh yes, I do listen to persons who know what they are saying or writing, especially those that don't think they already learned enough !

Bye.

[vvega]

sorry mate but what i have told you is fact
grame bell is not talking of a caldena manifold he is talking in gereral about badly designed manifolds
"Hyper Rev, Phase 2 engineer talking about stock ST205 plenum:

"
what you want me to listen to you based of a product add too ???



ive read the boook it is quite good but you have to know how to take in information in context

you obviously dont

i gave the reason why all 4 cyl cars run the centre 2 cylanders ritcher this was proven at uni with test theroys and results.....you have no factal accounts of your own to back up your assumptions

but just to make it eazy for you.......

answer this

why do 4cylander engine.... wit ITB's still run the centre cylanders richer....

in fact why with any manifold design do 4 cylander engines run the the 2 centre cylanders richer
....


we tester 20 od different car ecu's and found this to be the result
can you back up your info with that kind of resurch

didnt think so

go and read some more and come back when you have a idea how to understand what your reading not just looking to twist context to argue a stupid point......

so what have were lent

all multi injected 4cyl cars run ritcher in the centre clylanders.... thats a fact..undisputable( to a drgeee

and based on that...... the caldena is no different....
simple really isnt it
must be to much for you

v

[anthonym]

vvega, your aggressive condescending tone is counterproductive and unnecessary, Wolf_Tm250 is actually making a useful contribution and responding to your feedback, unlike 99% of TS.

[vvega]

sorry there nemisis just tring to help him with his questions on fueling and he donsent seem interested in the help

yes there is a problem with cladena's running lean in cylanders at high boost but there has always been this issue with the 3sgte
it is considered to be a fuel rail issue with a presure drop over the centre 2 injectors at high flow rates

unless he is considering going for moonbeam power figure in witch case


first stop will be new ecu
nextintercooling will become a issue
the injectors will be next
the pump next
then looking into a better rail design
at this stage the turbo will have run out of puff...

once you have spent the best part of 15-20,000 getting to here
a look at a new intake plenum to better balance the 5-700 hp you now have of air supply will be required

i answered his question in my first post
a quad throttle setup with a large plenum...airbox will keep the pressures very even across the valves

this would probably cost the best part of 1000 to create and would also require a new ecu

hope that helps a little more than my previous posts
i guess resnoble arguemnt here is a rare thing and to be savoured



v

[Wolf_Tm250]

Vvega,

there is no need for you to teach me that #2 and #3 are hotter... believe me, I already knew !

And I too tell you even that #3 is the hotter than #2, and I'm sure that you already know that !

But it's quite funny that you're taking this discussion off topic, in the wrong directions, only because you would show you've nothing more to learn :
we were not strictly talking about fueling, but about PLENUM UNBALANCED FLOW TO THE RUNNERS.

And I prove to you that is years that Jap engineers found the stock ST205 to be unbalanced ( look one more time at the pic, #2 and #3 red arrows are bigger, and you could even ask someone to translate the Jap text on the pic.... ).

And I even show you that, as Graham Bell told in his book,

- even side feed plenum are unbalanced ( usually near to the TB runners receive less air)
- and they are unbalanced even if we are talking about a TURBO engine, and even if valves are for the bigger time closed

PS: I'm not saying Caldina's plenum is unbalanced...
oh yes, surprised if it isn't....
but I'm only asking if someone measured its runners flow

first stop will be new ecu
nextintercooling will become a issue
the injectors will be next
the pump next
then looking into a better rail design
at this stage the turbo will have run out of puff...

once you have spent the best part of 15-20,000 getting to here
a look at a new intake plenum to better balance the 5-700 hp you now have of air supply will be required

Vvega,
another attempt to go off-topic with a list of mods to do before balancing the plenum...

... but.... oh what are seeing my eyes, finally we're talking about a plenum balancing !!!

PPS: do you know my engine ? Are you REALLY sure I did not already spend those $$$ ?
FYI a TTE thick block costs 3,942 euros plus VAT

PPPS: Thanks Nemesis

Please, back in topic, did anyone test and mod Caldina's plenum ?

Bye.

[vvega]

if you really have that much of a concern run quads and a big plenum and get on with it

answered it in the first post ....

itb's fix the problem ....
that would be my solution..

Motec's injection maps for 3SGTE 3rd gen ( center top feed int.man ) are 3,5% richer for #2 and 2% richer for #3 cylinders....

why ?

i was just answeriung your question mate .. you asked it i answered it
there would be very little you could do to a stock manifold to effectively balance the lengths...

v

[blitza]

vvega, sorry man, nice head knowledge, but you were being a cock.

fyi, I broke ring lands in #4, bent rods #2&#3.
also fyi, 6 cylinder engines often have problems with #6 geting hot, due the last to see coolant as well as oil pressure.

[fivebob]

This subject is so complicated I’m not even going to attempt to fully explain it

Uneven flow in a manifold tested under steady state conditions is not a good indicator of flow into the cylinders. Your original test with an air gun is next to useless as that relies on the air changing direction of it's own accord, which of course it can't do until it hits a surface an bounces off it, which is nothing like what is going on when the engine is running.

Even if the manifold was tested on a flow bench it still wouldn’t emulate the conditions in the engine. Flow inside the manifold is not steady state and one cylinder is influenced by the others, and also by the exhaust manifold so it may be that in operation the difference in the flow of the runners may be needed to even out the Volumetric Efficiency differences in the cylinders.

Motec's injection maps for 3SGTE 3rd gen ( center top feed int.man ) are 3,5% richer for #2 and 2% richer for #3 cylinders....

why ?

Depends on how the engine was tuned, if it was tuned with individual Lambda & EGT sensors for each cylinder, then it may be correct. If, as I suspect, it was tuned based of flow tests on a 3S-GTE manifold (which may not have even been a Gen III) it could well be causing #1 & #4 to run lean and #2 & #3 to run rich.

Now I’m not saying this is the case ,but I’ve seen a lot of tuners who erroneously try to apply simple principles of steady state flow base on flow bench measurements, without verifying that this is what is actually happening inside the engine. Best case your engine isn’t running to it’s full potential, worst case is you blow the engine

[Wolf_Tm250]

This subject is so complicated I’m not even going to attempt to fully explain it

Uneven flow in a manifold tested under steady state conditions is not a good indicator of flow into the cylinders. Your original test with an air gun is next to useless as that relies on the air changing direction of it's own accord, which of course it can't do until it hits a surface an bounces off it, which is nothing like what is going on when the engine is running.

Hi fivebob,

yes, I had this suspect, that's why I asked if someone made a good test, better than mine

Motec's injection maps for 3SGTE 3rd gen ( center top feed int.man ) are 3,5% richer for #2 and 2% richer for #3 cylinders....

why ?

Depends on how the engine was tuned, if it was tuned with individual Lambda & EGT sensors for each cylinder, then it may be correct.

Yes, this is the case.
My Motec is from Fensport, received it already mapped:
they mapped many ecu on their 3rd gen car, but not bench-testing the plenum, but using the data they received from EGT over each exhaust runner.
That's why I said there is even an unbalanced flow issue, because if they only had to protect the hottest cyl, they'd increase only #3.
On the contrary is the #2 the richer, so they make it because it's in front of the TB.

Thank you, bye.

[vvega]

5% is a awful lot of of fuel....

to give a example a 550cc injector would pump in another 22.5 cc's of fuel per cycle at max output.....

that woudl be the differance between extram lean and extreme rich

is that what your saying...

a estamite says you only need 12 dgrees in chamber tempurature to require 5% more fuel


what did fengsport have to say about this issue ??
v