View Full Version : Does this look like Heatsoak
OK - this is my first proper time with VAG-COM & logging
but if y'all could look at these plots & set my mind at rest :)
4th gear pulls, repeated & averaged - waited til inlet temps dropped again before repeating the runs etc
Butt Dyno (http://www.seatcupra.net/m0rk/tuning/Ibiza-Power.pdf)
Inlet Temps & Boost (http://www.seatcupra.net/m0rk/tuning/Inlet%20and%20Boost.pdf)
Cheers
Mark
Oh - and it doesn't look (to me) as if it's flowing enough air.
Mark
low bhp/torque with revo is normal-with vag-com
mass flow should read as normal though??
is that intake temp normal though its bloody high!!! whats it going to be like in the summer! :hide:
is that intake temp normal though its bloody high!!! whats it going to be like in the summer! :hide:
It'll be cooler by summer tho :)
m0rk
what bhp is it running approx mate? or supposed to be
vern
CupraR-Rog
06-02-2005, 10:44
is that intake temp normal though its bloody high!!! whats it going to be like in the summer! :hide:
Hence why fmic's are so worthwhile on these cars ;)
Think Mike used to see 70 - 75 degrees on his before the fmic!
Take it it's the Ibiza? What timing setting? Perhaps a bit too much (big early torque, tails off early, lots of heat)?
Other than that, I wouldn't know what heatsoak "looks" like :hide:
Compare it to graphs from the stealth day perhaps?
MAF does look a bit low, i get about 150g/s.
Ive never logged temp though, didnt realise it got that high.
Think i might just go for the forge SMIC.
It's running HB7, T5 - on UL95
Plots similar on LB7 T5 (which is what we normally run)
I think that there must be some airflow restriction, so I was thinking about pulling the intercooler out & checking all the pipes, but it's wet today.
Goes like shit off a shovel tho, but then I am not a revver in that car.
ibizacupra
06-02-2005, 12:33
OK - this is my first proper time with VAG-COM & logging
but if y'all could look at these plots & set my mind at rest :)
4th gear pulls, repeated & averaged - waited til inlet temps dropped again before repeating the runs etc
Butt Dyno (http://www.seatcupra.net/m0rk/tuning/Ibiza-Power.pdf)
Inlet Temps & Boost (http://www.seatcupra.net/m0rk/tuning/Inlet%20and%20Boost.pdf)
Cheers
Mark
The temp plot is as you would expect.... seeing manifold temps initially, which drop as soon as throttle open and airflow cools it, but then big boost heat affect which overcomes poor little SMIC easily.. Heatsoak for sure on the stock IC.
Airflow less than 150g/s seems low for chipped Ibiza. worth swapping to known working MAF sensor and re-run.. I suspect theres more to come... but heatsoak will continue to be the enemy.
Aquamist and or FMIC type solution to control those temps.
:cheers:
ibizacupra
06-02-2005, 12:34
low bhp/torque with revo is normal-with vag-com
mass flow should read as normal though??
is that intake temp normal though its bloody high!!! whats it going to be like in the summer! :hide:
EVOshield? ;)
ibizacupra
06-02-2005, 12:38
It's running HB7, T5 - on UL95
Plots similar on LB7 T5 (which is what we normally run)
I think that there must be some airflow restriction, so I was thinking about pulling the intercooler out & checking all the pipes, but it's wet today.
Goes like shit off a shovel tho, but then I am not a revver in that car.
My guess is HB and LB on the stock IC'd car will only show differences on extremely cold days.. before ecu pulls back on settings from high induction temps.
95UL used to be timing 4 I thought.
MAF ouput looks a bit low ot me..
must get out in Jans Lupo and log that one.. see what its logging.
Inlet temperature was stone cold to the touch after the runs
the MAF is brand new (last weekend) - the old one was BAD
Pressure Ratio = (Boost + Atmospheric) / (Atmospheric - intake flow restriction)
e.g. 10 psi boost with no intake restriction = 24.7/14.7 = 1.68 PR
10 psi boost with 1 psi intake restriction = 24.7/13.7 = 1.80 PR
The higher the PR, the higher the compressor outlet temperature will be.
(PR to the power of 0.283) x Ambient temp (in degrees Rankine) = Ideal Outlet Temp ('R)
**Degs Rankine = Degs F + 460**
(IOT - Ambient) / Compressor efficiency (at that PR & flow) = Actual Outlet Temp ('R)
Ambient temp / AOT = Density Ratio
DR * PR = Actual PR , Actual PR * engine output in N/A form = FI output (no IC).
If you add an IC, you must correct the PR for the pressure drop across the IC and use the IC outlet temp for the AOT. Run a few examples and you'll soon see how important it is to have minimal pressure drop across the IC, otherwise you'll have to drop a huge amount of temperature across it to get the same Actual PR.
Pressure Ratio = (Boost + Atmospheric) / (Atmospheric - intake flow restriction)
e.g. 10 psi boost with no intake restriction = 24.7/14.7 = 1.68 PR
10 psi boost with 1 psi intake restriction = 24.7/13.7 = 1.80 PR
The higher the PR, the higher the compressor outlet temperature will be.
(PR to the power of 0.283) x Ambient temp (in degrees Rankine) = Ideal Outlet Temp ('R)
**Degs Rankine = Degs F + 460**
(IOT - Ambient) / Compressor efficiency (at that PR & flow) = Actual Outlet Temp ('R)
Ambient temp / AOT = Density Ratio
DR * PR = Actual PR , Actual PR * engine output in N/A form = FI output (no IC).
If you add an IC, you must correct the PR for the pressure drop across the IC and use the IC outlet temp for the AOT. Run a few examples and you'll soon see how important it is to have minimal pressure drop across the IC, otherwise you'll have to drop a huge amount of temperature across it to get the same Actual PR.
The what what and the what what? :confused:
Bill> What kind of inlet temps did your Ibiza see when the forge smic was on?
ibizacupra
06-02-2005, 14:16
Inlet temperature was stone cold to the touch after the runs
the MAF is brand new (last weekend) - the old one was BAD
Airfilter clean?
ibizacupra
06-02-2005, 14:18
The what what and the what what? :confused:
low pressure loss IC so the turbo does'nt have to blow harder (which makes it hotter) for same airflow output..
or summat like that :p
ibizacupra
06-02-2005, 14:20
Bill> What kind of inlet temps did your Ibiza see when the forge smic was on?
I had forge SMIC when I was IHI'd.
It would hit 70'C+ easily & ecu pulled back a lot.
FMIC has also run to 60'C (previous one)
no figures on new one yet. (running on dyno again next weekend)
Dormouse
06-02-2005, 14:23
Not so much heatsoak as insufficient heatsink.
I think m0rk mentions he let the car cool after every run.
So things arn't getting hot and staying hot (soak). It's simply a case of area of flow cooling in the I/C. In other words the charge doesn't stay in the I/C long enough to get cooled sufficiently.
All part of the theory of what's better for a fixed area? A long thin I/C?
Dor.
Did you have the forge SMIC on before you were IHI'd?
ibizacupra
06-02-2005, 14:25
Inlet temperature was stone cold to the touch after the runs
23+ degrees C on the plot you posted.
when I've datalogged mine previously (FMIC) it was dominated by heatsoak after a switch off and dwell of about 10 mins.. 50+ degrees C shown afterwards and would only drop when throttle opened and cooler air passed air temp sensor. Closed throttle it jumped back to manifold temp 50+'C
On loading it the temps would sit to low to mid 30's on road test, but on the dyno it too would sky rocket to 60'C with poor recovery. Aquamist has stabilised temps I think, and new core does seem to flow more, having less pressure drop across it.
I run EVO shield on mine now so will see how things go... but I have made 3 changes since running on this dyno, so no one thing will be conclusive. Larger FMIC, EVOshield, Aquamist all new additions since previous logging.
ibizacupra
06-02-2005, 14:27
Did you have the forge SMIC on before you were IHI'd?
I cant remember, but I dont think I did. Mine did 325bhp on stock SMIC but owul dheat up very veyr quickly. SMIC is marginal benefit over stock IMHO. Flowed better I think... but not night and day difference.
low pressure loss IC so the turbo doesn't have to blow harder (which makes it hotter) for same airflow output..
or summat like that :p
Pretty much, but also that a restriction on the intake side of the compressor has a much bigger effect than one on the output side.
eg. 10 psi boost with pressure drop of 1 psi across IC = 25.7/14.7 = PR of 1.75
10 psi boost with pressure drop of 1 psi across airfilter/MAF,etc = 24.7/13.7 = PR of 1.80
Think about what happens when you cover the nozzle on a hoover. This is also demonstrated by the TT TIP collapsing.
Something else I found in Corky Bell's book on supercharging is an ideal maximum in-cylinder air temp of 1075'R (323.9'C). He doesn't explain where this number comes from exactly (flashpoint of air/fuel mix?) but says that if you keep below this number, you'll stay out of detonation.
His formula bases around the static compression ratio :
(C/R to the power of 0.283) x charge temp ('R).
So, for a CR of 10:1 with a charge temp of 20'C :
1.92 x 528'R = 1013.06'R = 289.48'C
If you transpose the formula, you can work out the maximum charge temp you can run on a given compression ratio without running into knock.
1075'R / (CR ttp of 0.283) = max ideal charge temp ('R)
10:1 CR = 560.3'R = 37.9'C
9.5:1CR = 568.5'R = 42.5'C
9:1 CR = 577.2'R = 47.4'C
8.5:1CR = 586.7'R = 52.6'C
From that, if you know your IC efficiency at various boost pressures, you can work out how much boost you can run at a given CR. He also gives a rule of thumb that every one full point of CR drop will cost ~4% output.
So VR6 @ 190bhp @ 10:1 CR = 182.4bhp @ 9:1 CR.
Airflow is down m0rk!!! filter? etc
as a guide standard 210 leon runs 155-170 g/s stock no mods
chipped lcr's 190 +is good over 200g/s is fantanstic
i gather the ibiza is running 210-220 bhp for comparison, new mafs can be bad too :(
vern
wild willy
06-02-2005, 19:31
here's an interesting read on intercoolers for the 1.8T.
http://www.vwfixx.com/forums/index.php?showtopic=32642
surprising results eh.
ibizacupra
07-02-2005, 08:26
here's an interesting read on intercoolers for the 1.8T.
http://www.vwfixx.com/forums/index.php?showtopic=32642
surprising results eh.
thats the same one as is being argued about on vortex....
they do so luv to rant at each other...
Yeah I read it on the vortex - not surprising really, the SMIC they're punting has a fair bit larger volume than the FMIC they tested it against. I suppose it tests the view that "SMIC=bad", but I don't know if anyone really said "SMIC (no matter how big)=bad".
How does the volume of the forge SMIC compare to stock SMIC?
The volume is the same, but it has better flowing end caps & the cores are a lot better (the OE one is pretty abismal for flowing air down)
ibizacupra
07-02-2005, 12:46
Yeah I read it on the vortex - not surprising really, the SMIC they're punting has a fair bit larger volume than the FMIC they tested it against. I suppose it tests the view that "SMIC=bad", but I don't know if anyone really said "SMIC (no matter how big)=bad".
Area to heat exchange..... FMIC rules over SMIC in my mind.. Just how big an SMIc can you get airflow to to cool a core.. Big and flat vs short and deep..
lol - just wondering if I'd rather be big and flat or short and deep. Short and deep sounds more "mysterious".
Anyway, just wanted to point out that the SMIC they are punting (and selling - surprise, surprise) is bigger than the FMIC it was tested against:
Stock 218 Cubic Inches
UG SMIC 355.5 Cubic Inches
FMIC 340.1 Cubic Inches
So where that thread talks about mythbusting, it's not exactly a scientific test. If they compared a SMIC and FMIC of the same volume, then that would've been a little more scientific...
Also, pressure drop means more turbo work which means more heat? So, there must be a point at which "enough is enough" and "big is not necessarily better"?
Logging my intake temps (LCR) and they are around the same as Mat's and Jonah's (fogs out). Must post the graphs...
also how they ar flowed as well could be a rubbish fmic
Exactly, although it would have to be REALLY bad to be worse than the single stock side mount, esp. at 150% of the volume?.
The guy posting the mythbusting information has a vested interest doncha think...
Mind you, it does disprove the belief that an FMIC is always better than a SMIC.
Edit: Sorry m0rk, just call me "Mr Off Topic"
Edit: Sorry m0rk, just call me "Mr Off Topic"
it's OK _ makes interesting reading
almost convinced it's air flow restriction on the Ibiza - an the most likely place is the intercooler. I imagine it'll just be full of crud / oil hence the turbo gets hot as it can't push air thru a small hole - hence low MAF reading
I'll empty it on the weekend & do a few other small mods & see if it can't be improved upon.
I've often wondered "how hot would it get without an intercooler".
Bit of spare pipe lying around while you de-gunk your IC ???
old maserati bi-turbo's ran no intercoolers
were much better for having an intercooler mind
they're not hard to get at on the ibiza - get under the car, unclip one end, lower car, jack one side up & watch the black stuff fall into the cracks in the driveway.
You can work it out using the formulae I gave you, just use 70-75% as compressor efficiency (average for a turbo in the centre of the island).
ibizacupra
07-02-2005, 15:58
I've often wondered "how hot would it get without an intercooler".
Bit of spare pipe lying around while you de-gunk your IC ???
ferking hot..
Lupo CC intake is 80'C + outlet is cool to touch (thank god!)
cuprabaz
07-02-2005, 16:15
they're not hard to get at on the ibiza - get under the car, unclip one end, lower car, jack one side up & watch the black stuff fall into the cracks in the driveway.
Are you taking about stuff coming out of a std SMIC? if so i think it's time i cleaned mine!
Yeah - tis normal to see it - just one of those things
cuprabaz
07-02-2005, 16:45
o well mines will be getting cleaned soon then, we've got a big ultrasonic bath at work so that'll come in handy.
ibizacupra
07-02-2005, 18:54
oil breather / catch tank anyone?
;)
Nice combined with baffled sump :)
cuprabaz
07-02-2005, 18:58
Have you got these for sale bill?
ferking hot..
Lupo CC intake is 80'C + outlet is cool to touch (thank god!)
Not much hotter than m0rk's is now - so prolly IS worth cleaning it out :-o
ibizacupra
07-02-2005, 23:11
Have you got these for sale bill?
its in process now.. but its for hardcore track users so you would need to be prepared to remove some bits to fit one. Baffled sump is also req'd as you need a drain... (or drill ya sump. for fitting)