Does weather really make this much of a difference in performance?

[EJ257]

Well Excuse me... But IAT do effect how the ECU deals with timing, I believe 126*F or so the ECU starts to retard timing so you loose power... No? As for saying that I got rid of heat-soak, well YES, I DID, even with a TMIC so I do not have to deal with it any more... I guess the bad advice could be linked to the fact that I didn't explain how I did it...

You realize that any modification to the TMIC you make has no impact on the ECU IAT compensation tables, right?

[wrxdrvr]

I'm asking!! Clear the air, please!!

EDIT: Read your profile. A water sprayer? Really? How and where?

I can keep my TMIC within 13*F of ambient when parked for 15 minutes and below ambient when driving in the city, I can also keep the IAT at MAF sensor about 40*F to 50*F colder than normally with stock set up... Bla bla bla... STi Mods pictures by wrxdrvr - Photobucket

[wrxdrvr]

I have some ACTUAL, IAT out of turbo and INTO throttle temps, for those interested in how ambient temperatures effect the TMIC and IAT into throttle, for my '02 WRX stage 2, with stock set up and my stock set up...

-4*F ambient stock set up;
169.9*F into TMIC
39.7*F out of TMIC
13.2*F TMIC core 78% efficient

32*F ambient stock set up;
207.8*F into TMIC
72.5*F out of TMIC
45.3*F TMIC core 77% efficient

77*F ambient stock set up;
223.*F into TMIC
136*F out of TMIC
86*F TMIC core 59% efficient

77*F ambient stock but my set up
226.*F into TMIC
99*F out of TMIC
77*F TMIC core 85% efficient

96*F ambient stock but my set up
253*F into TMIC
118*F out of TMIC
96*F TMIC core 86% efficient

As can be seen the warmer it is the better my set up works...

Parked for 15 minutes 77*F ambient day;

149*F+ TMIC core stock set up
83*F TMIC core stock but my set up...

[mangostick]

K now my ears are perked up.. we know the easy way to relieve heat soak is with heat shielding on the hot parts.. turbo wrap, blankets. etc. We also know that water/alky spray onto the intercooler works really well to super cool the core and keep ineffieincy at bay. Your numbers here show that quite well. What you're numbers also show backs my point that without help, you cannot get a air/air cooler below ambient temp. Or any cooler below the temp of the substrate that flows over it. Be it water/air/nutsweat.. lol.. its only going to get as cool as the environment around it unless assisted by other means. (aka.. water alky mix evaporating off core surface enhancing core efficiency)

But the underlying question to the thread was if weather could affect the car's performance. Simple answer, yep.. it does. And thats normal.

My statement about iat and heatsoak are still accurate. Once you heatsoak a heat exchanger it is very hard to bring it back to a working condition let alone an efficiently working condition. True heat soak condition entails that the cooler can no longer absorb any more heat energy. At that point, it has stopped working and you might has well have a pipe directly from turbo to throttle body.

Personally I think the "heat soak" term is thrown around too loosely because on modern street prepped turbo cars true "heat soak" isn't achieved under normal street driving else we'd never be able to cool the intake charge at all once reaching that point. There's also the point of view from emissions because warm charge atomizes better and creates less emissions, backing off timing also helps to keep combustion cooler reduce nox emissions. It all plays together but we're straying from the original question asked.

What we do certainly have is an increasing inefficiency as the cooler warms AND as ambient temp rises. Its right there in the numbers. That proves weather vs performance.

the fmic vs tmic debate though.... man that's so much more complicated and brings so many more factors into play that we'd seriously derail the thread just breaching the topic.

[wrxdrvr]

I guess what I should have said originally was, yes hotter temps do effect how the car responds, but not on MY car, not any more...

As for the inefficiency increase, 1; I guess I just look at it differently, as my TMIC set up actually INCREASED it's efficiency, the hotter the days got... Because of all the things I did to get rid of heat-soak. As can be seen with totaly stock set up the numbers show lower and lower the TMIC efficiency dropped, the hotter it got, (and it probably would have been down to 50% or less by the time the temps got to 96*F ambient) instead of the 86% efficiency I got with stock TMIC, but set up MY WAY...

As for the inefficiency thing, 2; yes, the output of the engine WOULD drop on a 77*F ambient day, if, it was tuned on a -4*F ambient day... But what really happens is that engine doesn't make more CHP (that it could, if it was tuned for it) on the colder days, if it was tuned on a hot day... That's the way I see it.

[mangostick]

cant argue that. Just by the numbers whatever you've done is working quite well.

[etnpnys]

What about a fan bolted to the bottom of the TMIC? That might just affect performance at really low speeds -- at which point the turbo hasn't even kicked in -- but it may also blow the hot air down and away.

Thoughts?

[SD_GR]

Fans were tried long ago. I've never seen one in the wild.

[etnpnys]

Fans were tried long ago. I've never seen one in the wild.

Well it must be wildly successful then, right? haha

Thanx again everybody!

[rexxx0486]

Fans were tried long ago. I've never seen one in the wild.

Toyota put a fan behind the side mount intercooler on MR2 Turbos with good results. Actually it is a popular mod on those cars to put a bigger fan on it to lower the temps. I don't really see where you would put it on a WRX though.

[wrxdrvr]

Fans were tried long ago. I've never seen one in the wild.

Here' mine, no room under the TMIC... More fans galore, Stg 2 hood mods. Now on a 75*F day ambient I can keep the IC temps below 85*F when car is parked, and at ambient or lower when driving in the city. picture by wrxdrvr - Photobucket