Cold weather = Less intake cooling needed?

[Coyotemutt]

I was playing with this https://rbracing-rsr.com/intercoolers.htm today, typing in my typical winter temperatures. I recall Clonebug telling me that you really need to keep intake temps below 130 and I see that without any cooling at all the formula doesnt hit 130 until about 12psi at my air temps.

Does this mean it would probably be safe and beneficial to make my water injection pop in later (currently on at 5psi)? Or perhaps leave it but add a couple degrees timing?

I suppose I could just try it and listen real close but I'd rather run it by the folks with real experience first.

[Clonebug]

Technically you could possibly add some timing but then you would need to remember to readjust once the temperature warms back up.
If you are carbed I wouldn't mess with it but if you have FI you could set up timing retard for what your IAT's are.
For example....once it gets to 110 degrees....retard timing a specific amount per 5 degrees or 10 degrees IAT rise.
I should have done that when on my trip to California...since my timing was set with Washington temps I started getting detonation at cruise once I hit the high desert and the higher ambient temps that came with it. I took the easy way out to save my engine by just dropping the timing on the map at the cruise rpm/kpa area that was giving the trouble.

I found with W/I that it's better to have the water come in a little earlier to keep the temps down than to add water later and try to get the temps down.
That is why I have a staged system that gives me 1.0 gph at 4-8 lbs and a second nozzle of 2.0 gph at 9 lbs. for a total of 3.0 gph.
That combined with the small intercooler will keep my temps at ambient or lower most of the time all the way to 24 lbs. boost.

Water Injection is added for a specific hp output. 3.0 gph is what my engine requires at 250 hp. adding 3.0 gph at lower boost...and therefore lower hp just makes the engine blubber with too much water/alcohol......and therefore makes it run too rich.
My map VE at 100 kpa is the same as my VE at 275 kpa due to the alcohol giving the engine fuel....crazy huh......

One thing you need to watch is ambient outside the turbo/ engine vs ambient when the engine is in cruise. My IAT at cruise and/or idle will rise by 10-20 degrees just by going through the turbo without boosting.
That is why when we were cruising through the California desert we were seeing higher temps. The ambient air temps were as high as 106 degrees....add the turbo heating it 10-20 degrees and we could have had cruise temps of 126 degrees without boost and higher if it took a couple lbs of boost to maintain speed at 75 mph and 3500 ft asl in the thin, hot air.

I prefer to err on the side of caution just a bit......riding on the ragged edge is not where I want to be...especially when 1000 miles from home.
It also pays to have a failsafe.....some way to cut boost down to a safe amount that will run on most any tune.

[Coyotemutt]

I think I follow. So if my engine isn't choking out on the added fueling from water-meth, it's better to just leave it on the summer tune rather than risk blowing it up on a warm day.

It especially makes sense with my super low-tech setup.

[madmike]

I'm draw trew so I set mine at 8 or 12 lbs can't remember

[Clonebug]

I think I follow. So if my engine isn't choking out on the added fueling from water-meth, it's better to just leave it on the summer tune rather than risk blowing it up on a warm day.

It especially makes sense with my super low-tech setup.

I just turned up the boost in the spring/winter/fall since the engine would tolerate it due to cooler IAT/s......actually...I just turned it down in the summer and then put it back once it cooled down.......

[madmike]

ditto letting out all our secrets

[buguy]

Interesting. I hadn't thought of what happens when ambient temp changes with W/I.

[buguy]

If you controlled the W/I with MS you could have it work at a certain temp AND boost level. Then you could set it and forget it.

[Clonebug]

If you controlled the W/I with MS you could have it work at a certain temp AND boost level. Then you could set it and forget it.

He doesn't have MS.....blowing thru Kadrons.

I feel it's best to keep everything as simple as possible......Just like the boys at RB Racing say. If you start trying to tune where the W/I comes in you will always risk some detonation while trying to get it right.
The pistons will only take so much.......where is the limit would be the question......get it wrong and you blow your engine to kingdom come.
I've replaced P/C's twice already....just cuz I wanted to be safe...but if you can't hear detonation, you have no idea what the limit is.

Now throw in a purty set of Forged JE pistons......what will they take????? Will they give you warning or do they just shatter after a couple hits of detonation..........

[Coyotemutt]

Yeah, still just blowing through kadrons here. I honestly really like the way its drives. Mostly just lucky it all works together.

Some precise digital ignition would be good though. Just recently I discovered my makeshift boost-retard/vac-advance canister and was getting the Ignitor module stuck against the distributor cap. When it works, I get a really sweet retard curve but I have to just trust its working properly. There's no way to monitor it. I clearanced the cap and the module but it has me feeling uneasy now.

In any case, I went out today and found I can hold 15psi all the way through the end of 3rd gear. W/I comes on at 7psi now. The ignition retards about 1 degree per psi after about 5psi and peaks at 22*. I still started to get a hint of rattle in 4th though. So I cant go flat-out on the freeway for now, even WITH the cold temps.

Anyway, I hope you're all doing well. I really enjoy chatting about aircooled engines with everyone.

[buguy]

I suppose that's true. But don't you run that risk either way trying to get it right?! Otherwise you'd just be dumping it in from the get go. But I've never used it so certainly not the authority. Just seems what is good at 95 degrees out may not be good at 30 degrees. I guess if it still runs good, having a cooler intake charge isn't going to hurt at any temp.
And i will let you know on the pistons! No detonation for me so far, but my intake temps have gotten up there pretty good on the new engine, so time will tell.

[buguy]

We've probably all have had that luck. When i first built mine i couldn't believe it worked! Built it out of scraps i had laying around! The fun factor is how we all got here too. If only the N/A guys knew how much fun we were having!

[Clonebug]

E-85 gives major benefits.......Look at the Swedes and guys in Norway. They are putting out 40 lbs. of boost without detonation with just water to air intercoolers.
you have a large safety factor running yours as is. We don't have that luxury.

As for those pistons.....only you can find their limit.......I'm too cheap to spend that much cash.......

They don't fit into my reality of a driver...I consider them more for a weekend car or race car.

[buguy]

Agreed. I do hope to do something like you for running regular fuel. There is only one place with it here and its kind of out of the way. It's not ideal to run E85 all the time. Last time i just used the laptop to turn the boost controller off but it would be nice to have a way to do it without having to drag the computer out to it.
Mine is definitely more of a toy than yours. I would never even consider driving mine the way you do. No a/c...heat....cruise... Actual working wipers... Etc.... Nope!
Funny that when i first came on here i thought you guys were nuts for spending that money on FI.

[Schweg]

Agreed. I do hope to do something like you for running regular fuel. There is only one place with it here and its kind of out of the way. It's not ideal to run E85 all the time. Last time i just used the laptop to turn the boost controller off but it would be nice to have a way to do it without having to drag the computer out to it.
Mine is definitely more of a toy than yours. I would never even consider driving mine the way you do. No a/c...heat....cruise... Actual working wipers... Etc.... Nope!
Funny that when i first came on here i thought you guys were nuts for spending that money on FI.

An electric boost controller wired to water meth system makes for a very simple low/high boost switching. Or just a switch for an electric boost controller gives you a two boost set up.


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