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View Full Version : Boost v Temp v Timing v Power



s4mmie
20-10-2012, 06:39 PM
Whats the relation?

I've started thinking about this with the onset of summer.. the poor little stock SMIC is feeling the summer heat.

I'm aware that the ECU can pull timing to stop detonation. Hotter intake charge temps would increase the chance of detonation, so the ECU would pull more timing on hotter days. Less timing = less power even with the same boost. So from what I gather, it's the combination of increased boost with more timing that equals better power.

Fitting a larger intercooler will reduce the intake charge temps considerably. I guess what I've been wondering is if I will see a considerable power gain by fitting the SEAT cooler? I'm running the stock SMIC at the moment and the intake temps are horrendous... if I'm correct, it has to be pulling a fair amount of timing. Fitting the SEAT cooler should lower the temps and give me my timing back.. more timing with the same boost should equal more power right?


Additionally, is a larger intercooler enough? I have been taking a hard look at water+meth injection to further cool the charge.

clicht
20-10-2012, 08:54 PM
I have been taking a hard look at water+meth injection to further cool the charge.

Do IT :banana:

h100vw
21-10-2012, 11:18 AM
Whats the relation?

I've started thinking about this with the onset of summer.. the poor little stock SMIC is feeling the summer heat.

I'm aware that the ECU can pull timing to stop detonation. Hotter intake charge temps would increase the chance of detonation, so the ECU would pull more timing on hotter days. Less timing = less power even with the same boost. So from what I gather, it's the combination of increased boost with more timing that equals better power.

Fitting a larger intercooler will reduce the intake charge temps considerably. I guess what I've been wondering is if I will see a considerable power gain by fitting the SEAT cooler? I'm running the stock SMIC at the moment and the intake temps are horrendous... if I'm correct, it has to be pulling a fair amount of timing. Fitting the SEAT cooler should lower the temps and give me my timing back.. more timing with the same boost should equal more power right?


Additionally, is a larger intercooler enough? I have been taking a hard look at water+meth injection to further cool the charge.


You would need to log the temps and pull to be sure whats going on.

Since I fitted my FMIC I have been watching the temp using Torque on my phone and a bluetooth OBD thing. Generally on the highway the intake temp is less than 10 degrees higher than the dash outside temp reading. On boost this drops to less than 5 degrees.

I am seeing the same boost on my gauge but I would have to check pre and post FMIC pressure to be sure that the turbo isn't working harder to maintain boost in the inlet, that could be dropped across the FMIC.

With a stage 1 tune, I would doubt that you will see much timing pulled, unless you get massive heat soak or put 95 in on the 98 program.

It would be true to say that performance won't drop off if you can maintain lower inlet temps.

WMI has been mentioned before and also that it is illegal. A proper kit would be up to $1000, Aquamist does one that I would consider myself. I'd run water alone to be half legal.... I'd use it to supplement intercooling, over mapping to take into account the "octane improvement" from meth. Gains would be less but it's safer if you run out.

Limited improvement for the cash involved is my thoughts.

Gavin

noone
21-10-2012, 01:38 PM
As far as my Polo experience goes, the FMIC is not going to give you much over the stock FMIC in winter. In summer, you wont get back to winter power (as the hotter air is less dense), but atleast you keep much more power in summer.

Cant say much about w/meth

s4mmie
21-10-2012, 03:12 PM
Hmm I have an eBay OBDII reader, I'll see if I can get some logs with that to better see what's going on.


I wasn't aware that water injection was illegal.. methanol is understandable.
In terms of Mr Plod, I would say they'd be less likely to pick up on a w/m setup than nicking you for an open pod filter..

USRT (Usually Sideways Rally Team) make a few kits and a nice throttle body spacer to run a nozzle post-TB. I have to look into it further but I think I would run a nozzle post intercooler and post-TB with a progressive controller.
I am thinking of running a large tank in the spare wheel well and keeping a bottle or two of distilled water in the boot in case of emergency.
I'll have to have a look at the Aquamist gear as well.
I agree, water injection is icing on the cake.


I guess I'll see what effect high temps and heatsoak have at Lakeside next weekend!

h100vw
21-10-2012, 03:18 PM
Hmm I have an eBay OBDII reader, I'll see if I can get some logs with that to better see what's going on.


I wasn't aware that water injection was illegal.. methanol is understandable.
In terms of Mr Plod, I would say they'd be less likely to pick up on a w/m setup than nicking you for an open pod filter..

USRT (Usually Sideways Rally Team) make a few kits and a nice throttle body spacer to run a nozzle post-TB. I have to look into it further but I think I would run a nozzle post intercooler and post-TB with a progressive controller.
I am thinking of running a large tank in the spare wheel well and keeping a bottle or two of distilled water in the boot in case of emergency.
I'll have to have a look at the Aquamist gear as well.
I agree, water injection is icing on the cake.


I guess I'll see what effect high temps and heatsoak have at Lakeside next weekend!

I have 2 VCDS leads and 2 laptops, so you can use one if you like. I plan to log mine too.

Gavin

gavs
22-10-2012, 11:25 AM
Have you considered the cooling of the intercooler itself and insulating the pipe work? I know many many people ceramic coat and wrap exhausts to keep the heat in the pipe, not the engine bay but with heat soak occurring at standstill, wouldn't insulation of the pipe work be beneficial? In regards to cooling the intercooler, you could use a water sprayer or a CO2 spray setup which super chills the intercooler. One of my work colleagues used to pack his top mounted Subaru legacy intercooler in summer with ice when going down to Philip island and even though the ice would melt fairly quickly, he assures me that the gains of chilled charge air remained long after the ice was gone with a tangible decrease in fuel consumption.

s4mmie
22-10-2012, 03:19 PM
Thanks, I might take you up on that for a few runs, it will be good to see what's going on.
At the Polo dyno day I was seeing almost 90 degree IAT's on a fairly cool day :eek:
Don't think I'll be pushing it too hard on the track..

gavs, I have ;) In particular the pipe that comes straight off the turbo over the exhaust manifold. I think that's where the most gains will be from ceramic coating and thermal wrapping. That's what I plan on doing anyway :)

Re the external intercooler cooling, the main issue I have read is the activation point. It would be easy enough to get a fairly crude setup going but it chews through the water big time. I found this a good read --
Browser Warning (http://autospeed.com/cms/title_Intelligent-Intercooler-Water-Spray-Part-1/A_0527/article.html)

I also like the C02 sprayers but you have to make sure the air intake doesn't get a gutfull.
I was looking at these options inc water injection and so far the water injection seems to be the best.

gavs
22-10-2012, 03:52 PM
The CO2 sprayers are fitted to the outside of the cooler on the front (or top), like below....

http://www.vwwatercooled.com.au/forums/images/imported/2012/10/d_1078-1.jpg

Your biggest issue with the CO2 sprayers however is where do you put the CO2 bottle..... Also not exactly legal unless you have your vehicle placarded!

s4mmie
22-10-2012, 04:05 PM
Sorry, should have written clearer -- I meant the air intake getting a gut-full of C02 'overspray' :)

Lito
22-10-2012, 04:18 PM
What a coincidence, I just stumbled apon this thread after completing this...
http://www.vwwatercooled.com.au/forums/images/imported/2012/10/20121022_150315-1.jpg
Everytime i turned my engine off, i couldn't touch that pipe because it gets soo hot, hopefully this will net some lower temps. I do reccommend taking the pipe off to wrap it though and probably wait until the engine cools down, I did neither of the above and have a nice blister on my left hand along with a few cuts and scrapes.

seangti
22-10-2012, 04:43 PM
At the Polo dyno day I was seeing almost 90 degree IAT's on a fairly cool day :eek:
Don't think I'll be pushing it too hard on the track..


To reiterate the performance drop between hot and cold weather, the frosty trackday at QR was around 5-7degrees when on track compared to recently being mid 20's. I was consistently at least 5km/h slower on my top speed, being 188km/h Vs 183km/h, cornering speed and braking g-force was much the same/marginal across the varying temps, though obviously deteriorated after successive laps which is normal. It was much more evident that after a cool down lap, my following lap achieved higher top speeds.

Probably no surprise in what I've said above, but good to have firm data to back up the feel. The speeds were measured by an incar 10hz GPS logger, that's 10 recordings per second.

dood9n3
22-10-2012, 08:50 PM
As said, the intercooler wont be adding power but rather holding onto the power thats already there

I have a wmi kit which I plan to fit some time soon but being revo tuned, means I will be able to drop settings via sps when I want to run without it on