GT3071R ibiza build thread

h17och

the hunt is over. 460bhp
Sep 1, 2005
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im gonna pull #1 plug out 2n. that will soon say if its the cylinder running lean or if the crack has caused the discolouration


HoocH
 

ibizacupra

Jack-RIP my little Friend
Jul 25, 2001
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audiman. i ran 630cc from day one. mapper ditched them and charged mem for new ones (440cc) as he said they were mega over sized. had a big debate over it....what can i do?

afr high 11's egt 800 iirc

they simply cannot be 440's on that power level tho hooch - thats BS from your tuner.
Spark plug colours will be an indication of fuel balance... BUT on FMEA flowmodels of high flows on manifolds I have seen during the SEM development, the port runner #1 often flows less air on high flows, so its not out of the question that one cylinder is not balanced. On stock manifolds and those based on them #3 runner runs leaner than the others also which makes sense when you see the flow paths in the ex manifolds.

You are running stock inlet manifold and t'body still I think on stock smallport head yea?
 
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audiman

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Nov 16, 2003
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in an ideal world you would use 4 for each runner, but one in the collector would be ok. My only fear is that most of the probes that are around wont take that sort of heat and break/melt off. And when they do that they go into the turbine! Sod that! If the probe is in the DP, then its close enough to go on about 100 degs less than in the collector.
 

ibizacupra

Jack-RIP my little Friend
Jul 25, 2001
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ref the flow thing Hooch.
remember these flowbench numbers? note the stock smallport mani's flow on cylinders.
Intake_Manifold_Comparison.jpg


and now superimpose your high airflows into that scenario.
:hide:
 

h17och

the hunt is over. 460bhp
Sep 1, 2005
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is that ibiza small port (pas side TB) or leon cupra (drive side TB) small port? or both?

if #1 is flowing LESS air than others, then surly the AFR will be higher on that cylinder? no?
 

audiman

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agreed, if the amount of air is less then the mixture will be richer.

thats a good flow table tho bill, makes me think about changing from my agu big port manifold. I feel the tig welder coming out! :D

How does that flow rate equate to bhp/torque? any dyno lots of say stock agu and apr?
 

h17och

the hunt is over. 460bhp
Sep 1, 2005
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no didnt get chance. staright to gym then back home for a shower and now im here :(

gonna take a look 2m and inspect turbo exhaust inlet.

rs sent me a report of the mani inc pics. does look quite lean but still has carbon deposites. looks to me it was runnin on the limit across the cylinders but #1 does look lean :(

pics do look different to when i took it off.......probly covered it in talken powder
 

audiman

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oh dear, sounds like it may be all pointing at a mapping issue and possibly a hint of poor design on the manifold. You are stuck between a rock and a hard place. RS will blame the tuner, and the tuner will deny it and blame the manifold.

the fact remains that you are using those stupid small injectors that i just cant beleive can fuel your car enough at the top end.

Its only my opinion, and this is a public forum and you get loads of different opions on here, i think the tuning may well be off. I dont personally know your tuner and have not had any work done by him so dont want to say too much. Maybe a second opinion once its back together by another tuner to confirm that its running within its safe limits?
 

ibizacupra

Jack-RIP my little Friend
Jul 25, 2001
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agreed, if the amount of air is less then the mixture will be richer.

thats a good flow table tho bill, makes me think about changing from my agu big port manifold. I feel the tig welder coming out! :D

How does that flow rate equate to bhp/torque? any dyno lots of say stock agu and apr?

No direct equivalence.. What I can say is on my ibiza, largeport before and after, from a dual plenum to 007 with R32 t'body, I gained a real 32bhp/22lbft on top of 485bhp @ the time.

Cf's across the cylinders were good before and after.. but dual plenum restricted flow.


Good point re flows on bench & #1 lean.... (blonde moment on my part :doh: )
injector flows more likely.

the pictures of the white in the mani is damned hot tho.

440cc injectors??!?!?!

throw your 620's in and validate how accurate your lambda is...
 
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ibizacupra

Jack-RIP my little Friend
Jul 25, 2001
31,333
19
glos.uk
is that ibiza small port (pas side TB) or leon cupra (drive side TB) small port? or both?

if #1 is flowing LESS air than others, then surly the AFR will be higher on that cylinder? no?

#1 cyl is #1 cyl.. I'm pretty sure it was same handed mani as ibiza is as std in those tests.
#4 cyl in that case being closest to throttle body (and #1 for Golfs/Leon Cupras/Octavia's)
 

h17och

the hunt is over. 460bhp
Sep 1, 2005
3,504
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Dunstabubble
lol, i swapped mine for these 440cc. how much? pm me :)

audiman, your opinion equals mine.

bill. do you mean chuck in sum 630cc and make sure it reads really rich? just to check lambda?
 

ibizacupra

Jack-RIP my little Friend
Jul 25, 2001
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glos.uk
630cc is minimum. is this on. 3bar or 4bar reggy you are running
large % change on fuel can be done on unisettings, but I do worry about the base mapping.

not just to chuck them in to check lambda reading to ensure you have sufficient fueling.
OR
to test the lambda is ok, run on a dyno with its own measurement running to confirm fueling.

the manifold pictures you sent me did look like it was lean.
that camera vid you took, did they have lambda logging running maybe?
 
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