i posted this over on teamfc3s and a lot of guys were really interested in it. i just figured everyone did stuff like this, but i'll post it over here too, in case you guys haven't done it yet.

here's a generic coolant temp fuel correction map. the hotter the engine gets, the more fuel it dumps, until it gets so rich, it just stalls out.

what brought this post on is i had very limited ground clearance with my old radiator and scratched a hole in the bottom of it. all the coolant drained out and the highest temp i ever saw was 233F. at that point, it ran so incredibly rich, i knew something was up. any hotter and it would have shut itself down on its own.

i've got similar safeguards for air temp, overboost, etc.

 

I guess you don't run from the cops that often.....sometimes that 230F can be justified!

j/k great idea


Justin

 

i did a correction map like that, i think it was air temp, on a stock t2 in traffic on a hot day, it just fouled all the plugs

 

Dude, you're a genius! That's just like the old air-cooled desert racers pulling the chokes on their overheating dirt bikes to prevent meltdown. Very nice! (Why doesn't everyone do this?)

 

The problem with that coolant correction map is that you're bumping up the 200F - 220F range, which is still "normal" temps according to my book.
This is an old trick which I use on all my tunes, and I only touch the last two bars, which are over 240F+.


-Ted

 

Just about every stock car manufacturer does that including Mazda. They would also decrease timing, cut ac, limit boost and raise the idle just to name a few. Some of the newer cars also cut power to certain cylinders.
They also do the same thing when air temps get too high to prevent detonation.

 

I do the same thing.

I bumped up the fuel correction 10% for every bar starting with the 221F bar. I was assuming starting to add a little extra fuel there would help cooling.

..or do you think it is better to bump up JUST the last bars?

 

dood, i whooped that up from the e8 base map to give everyone an idea of the concept. it's not my actual map. 220 may be normal to you, but not to me. anything higher than what i want is too high. if you can't control your temps, get a better cooling system.

 

aside from the hole in the radiator, i've never seen anything higher than 208*, but that was after i parked and it heat soaked. i've never noticed anything higher than 204* when the engine was running. my e-fans are set to come on @ 200*

 

Yeah, my FC is a little under-cooled. It still retains the AC and has a huge FMIC. Pretty much all airflow through the radiator is from the fans. The radiator is all alumimum, but I have still seen 218F with both the factory A/C fan and the the large junkyard fan on if I beat it fairly relentlessly on a 90F day.

Justin

 

you might want to look into better ducting for everything. a front mount, a/c condenser, and oil cooler is quite a bit of blockage.

maybe grab 2 earl's or mocal coolers and stick them in the brake ducts, build a better wind tray and seal up any gaps, etc.. might not cure everything, but certainly would help.

my intercooler lets all sorts of air through to the radiator and the a/c condensor doesn't block flow. i paid attention to all that stuff when i was building the car so i wouldn't have to pay attention to the gauge when i was driving it

 

Just me putting a block of foam between the bottom of the oil cooler and the undertray dropped my oil temps about 7* F .

James

 

stuff like that is always a good idea

 

how much timing to cut in a overheat situation?

when should timing be cut and fuel be added to the air temp map?

thanks.

 

i don't pull any out. extra gas + retarded timing = more heat, and you might actually add to the problem before it gets to the shutoff point.

 

Why do you think it's a personal attack on you?
I was just commenting on the correction map you posted AND THAT'S IT.
You take it was a personal attack?
Grow up and get a life.
(That was a personal attack.)

We've run a 13B-REW motor no turbos up to 250F indicated on the water temps and the oil temps (Autometer mechanical gauges) up at Thunderhill in the middle of summer with ambient temps easily north of 100F.
The motor stayed in one piece.
That's enough proof for me that the engine can handle it.
Now, don't take this (I know you will) that I would recommend it - I don't.
It's just one data point of what the upper limits of what a 13B engine can handle in terms of temps.


-Ted

 

i don't think it's a personal attack, but you always come in with some cocky post after you either don't read fully, or just misunderstand someone else's post. take another second to read and pay attention to what is said, and you won't put your foot in your mouth so much.

and it's funny how i posted this up and all of a sudden you've been doing it for years.

 

How many times was this done? Temps of 250F don't directly destroy any one part. They do cause more motion between dissimilar metals (r-hsg and iron). However, the affects of this motion will probably not show itself until several heatup/cool down cycles. At this point I would speculate the water seals fail.

Justin

 

We've run a 13B-REW motor no turbos up to 250F indicated on the water temps and the oil temps (Autometer mechanical gauges) up at Thunderhill in the middle of summer with ambient temps easily north of 100F.
The motor stayed in one piece.


Who's car would that be???

 

Paul Ko of K2RD.


-Ted

 

I must have missed you, you should have said hello... Is this in the black car?

 

No, this was years ago, when Paul first started to campaign in NASA.
The black FC was an evolution of what we learned off his old yellow FC.
I've been out of NorCal for over 4 years now.


-Ted

 

the yellow car is part of the black car now, well at least the left rear 1/4

 

I also learned this trick a few years back from one of our local tuners, waynespeed (www.waynespeed.com)

We do it a little differently. The last few bars are increased ALL the way to the top so the car actually floods and dies. We start it around 230 degress around there.

It has saved me once already.

Anthony