TTA MATs

[bruce]

Yesterday, I got to spend some time, working on the calibration for a TTA.

Now, we're talking MAT, as in moving what GM calls a MAT, which is in fact a IAT, to the dog house on the intake to actually measure the air temp., in the plenum.

On a hot soak, the MATs would reach 160dF, and then take about forever to drop to 130dF, with his stock intercooler. So on a restart on a hot day, his Coolant Temp., was 190dF, and a MAT of 160dF. While with driving the MAT would drop to 130dF, any real amount of boost, or time in a low boost condition would immediately generate high MATs.

By comparison, my GN even without an Intercooler, would run MATs that were about 10dF less then those. Just as a FWIW, with my Cotton's F/M, my MATs are typically 20dF above ambient, once the car is moving. So while the TTA was running 130dF MATs, my GN is running just slightly over 100dF.

Maybe everyone already knew this, but I found it interesting, I just wouldn't have thought the engine bay was that much warmer in a TTA.

Looks like just a further endorsement, for using Alky Injection......

 

[Razor]

Bruce,
The engine bay on the TTA is more cramp than the GN, and the air scoop for the IC is not the best either. Let alone the air box area could be better.

Agreed.. the response to alky is a given

 

[mark b]

Which brings up my comment from years ago that those vents in the hood don't do squat for cooling.... or if they are doing something, think how hot it would be under there without them.

 

[83ttypecooled]

Hi,
If you take a close look at those hood vents on our cars, they're fake. They could be easily modified though....

 

[j13smiley]

in this pic you can see where the vents line up with everything under the hood...

 

[Jan Larsson]

Cool !

 

[mark b]

Hi,
If you take a close look at those hood vents on our cars, they're fake. They could be easily modified though....

Actually John Pearcey ripped me a new one when I said they were fake and told me they were functional.

 

[bruce]

in this pic you can see where the vents line up with everything under the hood...

I would be interesting to put some wool tuffs in place and see if they actually do any good. With the way they line up, it looks like they help kill the low pressure area behind the radiator (assuming there really is any air flow when at speed). Without real testing, aero stuff ain't always what it appears. If nothing else, at low speeds, they'd allow some air to *chimmey* from the engine compartment.

 

[3.8TransAM]

MAn

Busting on my TTA and I missed it Bruce

Actually we were in disgusting weather.

Temps were puching 90ish and humidity to match ,we were pouring sweat just reviewing log files.

I have walked away from the car for a couple weeks. Im de-angerfying myself(look that up in your crack pipe and smoke it). Have to go back a step at a time and find out what is going on.

Might have a leaking head gasket still or a cracked head(not sure which), used a littel bit of coolant again and had some knock.

Temps at stops would sky rocket, once moving they would drop fairly fast.

As far as the hood vents go, one looka the underneath of the hood and you know they dont work. They look pretty and appear to be well positioned to work if they were opened up. The smaller side ports and main vents towards the leading edge are more or less sealed up. U can see some light thru them, but not like any significant amount. My TTA and GTA are the same.

Opening them I would bet seriously help air venting issues under the hood. On my Formula I removed the block out plate on the bulge and installed a screen and you can watch the heat raidate out at lites.

later
Jeremy