I have my bipipe out should i wrap it in exhaust heat wrap for sh!ts and giggles? - Page 3

Arcteryx::Stock Rods · 10-09-2006, 06:47 PM

Swank4 · 10-09-2006, 08:55 PM

a fully hot engine? Thanks.

Flyboy · 10-10-2006, 04:54 AM

Swank4 · 10-10-2006, 10:37 AM

Flyboy · 10-10-2006, 11:38 AM

the intake manifold, the MAP sensor is before the throttle body, where the two halves of the bipipe join. I don't have a solid answer. Even accounting for some variation in temperature reading between the two gauges, I wouldn't think the air temperature would rise several degrees over the distance of about a foot.

I'm suspicious that the location of the IAT sensor allows it to be affected by the temperature of the intake manifold. Just a guess, but that's the best I can think of.

The chart above shows the affect better. This was data I collected after starting the car in the morning, when all of the sensors were reading about the same temperature. You can see how the IAT seperates from the bipipe reading, even though it's been shown that the temp just after the IC is essentially unchanged before passing through the throttle. Either the air is heating up quite rapidly, which would require a very significant heat source because of the short time available to heat the air, less than a second, or the IAT sensor gets affected by the intake manifold.

Swank4 · 10-11-2006, 11:10 AM

EdyJun · 10-11-2006, 11:46 AM

10-09-2006, 06:47 PM	#21
Arcteryx::Stock Rods AudiWorld Super User Account #: 70072 Join Date: Feb 2004 Posts: 8,200	personally...i would have it PP and CC. __________________ Bored 2.8/9.1CR JE Pistons/034 Rods/RS4 Heads KO4's Port Polished/VAST Meth Injection RS4 Intake Manifold/Throttle Body X-1 Intake/ER IC's ASP Exhaust Heads to Tips Clutchmaster Stage IV with LWFW STaSIS Ohlins 700/800 AWE DTS Alcons 355 6 Piston BBK

10-09-2006, 08:55 PM	#22
Swank4 AudiWorld Super User Account #: 41738 Join Date: Aug 2002 Location: San Francisco Posts: 6,763	Oh, cool! I'm glad someone tried this. Real data = good. I assume you tried on... a fully hot engine? Thanks. __________________ 2001 S4 avant / RS6-K04 turbos / ASP custom tuning / Fast Intentions 3" downpipes / AWE Twin2 exhaust / AWE ICs / Aquamist HFS-5 / SPEC 3+ clutch / Stasis Motorsports (Ohlins) 700F/800R / Stasis Alcon 355 BBK, 298 rears / H-sport rear sway / Stasis 4:1 rear diff / Zeitronix wideband O2 / FATS = 3.35 on 91 octane / Land & Sea dyno = 429 whp.

10-10-2006, 04:54 AM	#23
Flyboy AudiWorld Super User Account #: 4736 Join Date: Apr 2000 Posts: 3,587	Yes. Bipipe is temp just post IC. __________________ MyAudiS4.com

10-10-2006, 10:37 AM	#24
Swank4 AudiWorld Super User Account #: 41738 Join Date: Aug 2002 Location: San Francisco Posts: 6,763	Cool. Why are IATs so much higher than the MAP? I thought the IAT sensor was at the MAP? __________________ 2001 S4 avant / RS6-K04 turbos / ASP custom tuning / Fast Intentions 3" downpipes / AWE Twin2 exhaust / AWE ICs / Aquamist HFS-5 / SPEC 3+ clutch / Stasis Motorsports (Ohlins) 700F/800R / Stasis Alcon 355 BBK, 298 rears / H-sport rear sway / Stasis 4:1 rear diff / Zeitronix wideband O2 / FATS = 3.35 on 91 octane / Land & Sea dyno = 429 whp.

10-10-2006, 11:38 AM	#25
Flyboy AudiWorld Super User Account #: 4736 Join Date: Apr 2000 Posts: 3,587	I think the IAT sensor is inside the intake manifold, the MAP sensor is before the throttle body, where the two halves of the bipipe join. I don't have a solid answer. Even accounting for some variation in temperature reading between the two gauges, I wouldn't think the air temperature would rise several degrees over the distance of about a foot. I'm suspicious that the location of the IAT sensor allows it to be affected by the temperature of the intake manifold. Just a guess, but that's the best I can think of. The chart above shows the affect better. This was data I collected after starting the car in the morning, when all of the sensors were reading about the same temperature. You can see how the IAT seperates from the bipipe reading, even though it's been shown that the temp just after the IC is essentially unchanged before passing through the throttle. Either the air is heating up quite rapidly, which would require a very significant heat source because of the short time available to heat the air, less than a second, or the IAT sensor gets affected by the intake manifold. __________________ MyAudiS4.com

10-11-2006, 11:10 AM	#26
Swank4 AudiWorld Super User Account #: 41738 Join Date: Aug 2002 Location: San Francisco Posts: 6,763	Hmm. Well, maybe all the more reason for phenolic spacers :) __________________ 2001 S4 avant / RS6-K04 turbos / ASP custom tuning / Fast Intentions 3" downpipes / AWE Twin2 exhaust / AWE ICs / Aquamist HFS-5 / SPEC 3+ clutch / Stasis Motorsports (Ohlins) 700F/800R / Stasis Alcon 355 BBK, 298 rears / H-sport rear sway / Stasis 4:1 rear diff / Zeitronix wideband O2 / FATS = 3.35 on 91 octane / Land & Sea dyno = 429 whp.

10-11-2006, 11:46 AM	#27
EdyJun AudiWorld Super User Account #: 48484 Join Date: Dec 2002 Posts: 2,719	The IAT is on the bottom middle of the I.M. and yes on phenolic spacers IMO. __________________ 2000 Audi S4 STG 3 FATS = 3.66 w/ 91 oct AIM: EdyJun 11 September 2001 In their honor. In their memory. <font color="red">---------------------------------------------------------- <u><big> <a href="http://homepage.mac.com/edyjun1/S4/index.htm">EdyJun's S4 Directory (FAQ, DIY, Info, Tips and Help) </a> </big> </u>---------------------------------------------------------- </font>

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