Idea for better FMIC plumbing

[Sydneykid]

One of the things I've been told is that if you want to go E85 then you need rock solid temps.

Exactly the opposite, being alcohol E85 is many times more knock resistant than petrol, so it isn't anywhere near as sensitive to combustion temperatures. We try and run around 85 degrees water temp as that gives the most horsepower. But in traffic on a 40 degree day we can see temps over 100 and obviously we have engine temp correction mapping to compensate for that. Tuning wise we throw more E85 in it as it acts as a combustion temp coolant. But there's not much ignition timing correction as retarding it actually increases the combustion temperature.

In comparison petrol doesn't act anywhere near as well as a combustion temp coolant, so we really have to pump a lot more petrol in to make much difference. That's commonly not enough in the above example, so we have no choice but to retard the ignition to prevent the knock, which in turn increases the temperature, so we throw even more petrol at it. That circle of pain really kills the horsepower and eventually the engine, too much petrol washes the oil of the bores and we have ever increasing blow by and eventually ring sealing failure.

Swapping the same engine from pump 98 to E85 lowers the engine coolant temp by 10 degrees and the oil temp by 5 degrees. As a result there's more capacity in the cooling systems before they over heat to start off with.


Cheers
Gary

[simon k]

In the drag car systems the pump takes water from the bottom of the reservoir (ice/water) tank and pumps it directly into the I/C so it always has water in it. From the I/C it then goes to the bottom of the heat exchanger, forcing any air in it out of the top, through the return hose and back into the tank. The cycle continues, the air rises to the top of the tank, the pump picks up water etc. Much like a dry sump oiling system.

If the I/C is,say, the highest point then you could put an air bleed tap there, at say the hose return to the tank. It can be anywhere in the system that is the highest.

so in it's simplest setup, we could have the IC in the same position as the standard SMIC, the heat exchanger in front of the radiator and the reservoir sitting somewhere convenient like under a mudguard (or even repurpose the windscreen washer reservoir), yeah?

a for a club level circuit car (say 15 minute sessions), what is a practical minimum volume of the system you'd shoot for?

[Sydneykid]

so in it's simplest setup, we could have the IC in the same position as the standard SMIC, the heat exchanger in front of the radiator and the reservoir sitting somewhere convenient like under a mudguard (or even repurpose the windscreen washer reservoir), yeah?

Yep, I have seen a windscreen washer bottle used as a reservoir for an air to water I/C. Depending on capacity it could be a bit light on volume though. More commonly the windscreen washer bottle is used for the I/C water spray. I have also seen a 10 litre fuel can strapped in the boot used as removable reservoir, plumb it in for the event then remove it for road use.

a for a club level circuit car (say 15 minute sessions), what is a practical minimum volume of the system you'd shoot for?

Around 8 to 10 litres should do it, about 50/50 ice and water, that should give a reasonable number of laps at below ambient I/C temps. Obviously there are many variables, where the compressor sits in its efficiency curve, the ambient temperature, heat exchange efficiency etc. Of course when the ice runs out it still works as an I/C, just that you won't get below ambient temperatures.


Cheers
Gary

[simon k]

where the compressor sits in its efficiency curve

hey!!! what compressor? the turbo?

edit: 8-10 litres is more than I expected, putting it in the boot sounds like a good idea

[Redliner]

Have you seen the Frozenboost website. I am looking at doing a air to water intercooler setup on my S3. Frozenboost cores seem to have a reasonable reputation for the price.
Air/Water IC

Take a look at this link:
Big Turbo 20vt's Public Group | Facebook

Another interesting link based on a drag car but the calculations could come in handy:
Intercooler Design

[sambb]

ok thanks Gary. I'd read long ago of people having dramas when they couldn't properly bleed the systems, lots of the systems have pressure caps on them and also due to the possibility that the fluid temp could get up, so assumed that they had to be pressurised.
So what you are saying re E85 is that because you can run so much advance that combustion temps and EGT's run that much lower than petrol at a same relative (for the fuel) state of tune that you can see 10 degree cooler water temps. wow. E85 sounds like the way.

Thanks Redliner I'll check out those links. I reckon it's be pretty straightforward to run a water to air core where the stock one is Simon as you'd still have a shorter inlet tract than any other air to air setup and can save on $/effort designing pipework as its all there for you. For me If I do do it I'd really like to give it a shot using a passenger side feed inlet manifold for the shortest possible inlet tract. Just from a maintenance/servicability point of view having it all right there and accessible with the DV plumbing, sensor wiring right in front of you and the weight as far back as you can get it (not sure how low I can get it though) is attractive.

[sambb]

The second pic looks like it has the S3 passenger side feed inlet manifold. I can see one problem being that the compressor exit has to get over the top of the TIP. The TIP including a MAF is kind of locked into its position and forces the core forward. It could be that these cores are much bigger than I'd need since they are on a big turbo group and I doubt i'll ever run >300hp, so maybe I'd have a bit more room at my disposal. The other option might be to run a flat core like this one below. Obviously different engine layout but a flat core standing vertically above the gearbox might leave enough room for airbox/pod and keep a bit of the weight low too.


Now that I think about it the most compact system (not for inlet tract length though) would be to run a W2A core where the stock side mount is and the exchanger would sit at the same height as the core across the span of the lower grille = short fluid hose runs and then plenty of room for extra capacity in an engine bay header tank (for me at least) where the battery/airbox used to be.

[Sydneykid]

This is the style of air to water I/C system that I'd choose under the bonnet. Well thought out and nicely executed. Makes full use of the A2W I/C advantages, short inlet system, can be pressurised if necessary, has the header/filler high up close by the I/C, the blow off valve is located close by the throttle body, etc. What does the rest of the system look like? Is it a sealed system or does it have an ice box? What's the heat exchanger like? I take it that they remove the LHS headlight for competition use for air inlet purposes?



Cheers
Gary

[sambb]

Its bit of an exercise to remove a headlight - whole front apron has to come off. I'd probably partition my pod and run an air feed to it from below the headlight where you can get a cold air feed from. Don't have pics of the heat exchanger location. I imagine you'd want to site it in front of the main radiator fan if possible yeah?
I'll have the inlet manifold that is in the other pic that unfortunately puts the throttle body at an angle so think my pipe runs would have to be more like his.

[Sydneykid]

Zeus fasteners on the headlight

I'd probably stick the heat exchanger between the fan and the radiator, that would avoid the fan having to suck air through the heat exchange and then blow it through the radiator. Much of muchness I'd say.

I wouldn't (fixing Trumpism) worry too much about the angle, 150 degrees versus 120 degrees, not really an issue. You could mill the throttle body plate offset to reduce the angle or cut it off and reweld it on at a more friendly angle.

Cheers
Gary

[simon k]

I would worry too much about the angle, 150 degrees versus 120 degrees, not really an issue.

you aren't related to Donald Trump are you?

[sambb]

You know what, I wonder if you were to re-locate the coolant reservoir to the opposite side of the engine bay, and ran a flat W2A core up against the firewall between the compressor outlet and the drivers side strut top, I think there is enough height above the cam cover to do it. The inlet pipe could then run down where the DV pipe and coolant reservoir were in this pic and you could retain the stock mani.

here's some another passenger side example:

[rgvlee]

here's some another passenger side example:
[ATTACH=CONFIG]34426[/ATTACH]

Man that checker plate manifold is INDUSTRIAL

[Sydneykid]

you aren't related to Donald Trump are you?

It is easy to do

Cheers
Gary

[Redliner]

This may help as well Sam: