Does your exhaust add power ? Good X- Flow read
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Joined: Oct 2011
Posts: 429
From: Germany
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Tim,
your setup for sure is like you say and I agree with what you are saying - but only for what you are doing. For the rest of us - or most of us - the emap vs map is more like 2-3 : 1. Having a lower backpressure is a good thing for all of us, that's no question. There is a point of diminishing returns though.
Going with a larger volume will bring the exhaust gas temperatures down by itself and this will reduce the kinetic energy. Wrapping the tubing and/or turbo will keep more of the gas energy in the tubes and hence reduces the losses and the only thing the system can react to it is a faster rotating/spooling wheel. That's why I have ceramic coating inside and outside my headers and the hot side of the turbo (see attached pic).
Of course you need a pressure difference to move air/gas, but it is always volume in combination with temperature and fluid speed that moves things.
Having said that, my new exhaust from 911tuning has a 2nd pre-cat O2 sensor style plug for doing ECU independent O2 measurements and also backpressure tests. Pictures will follow soon.
You see: there are some others who care about backpressure
The probe on the pic is for EGT.
Regards,
Andreas
The MoTec engineer I consult states my emap vs map is platinum 1-1 and under. golden is 2-1 emap vs map. Also it is worth noting that the lack of back psi lets the combustion chamber (heads and pistons) and entire engine absorb less heat.
I was told its thermal energy of the exhaust that spools a turbo (Why they heat wrap the header/turbine housing) and not the psi of the exhaust. My case proves that, no matter how hard it is for me to understand. I feel in order to move air/ gasses you need to have a difference in psi.
I was told its thermal energy of the exhaust that spools a turbo (Why they heat wrap the header/turbine housing) and not the psi of the exhaust. My case proves that, no matter how hard it is for me to understand. I feel in order to move air/ gasses you need to have a difference in psi.
Going with a larger volume will bring the exhaust gas temperatures down by itself and this will reduce the kinetic energy. Wrapping the tubing and/or turbo will keep more of the gas energy in the tubes and hence reduces the losses and the only thing the system can react to it is a faster rotating/spooling wheel. That's why I have ceramic coating inside and outside my headers and the hot side of the turbo (see attached pic).
Of course you need a pressure difference to move air/gas, but it is always volume in combination with temperature and fluid speed that moves things.
Having said that, my new exhaust from 911tuning has a 2nd pre-cat O2 sensor style plug for doing ECU independent O2 measurements and also backpressure tests. Pictures will follow soon.
You see: there are some others who care about backpressure
The probe on the pic is for EGT.Regards,
Andreas
very nice please share your results. what turbos are you using on your car ? looks like a factory style hotside.
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997TT SilverSpool - 210.8 mph 1/2 Mile WR Apr 2019, 9.2 @ 168 mph 1/4 Mile Manual World Record , 3.15 60-130 mph , 2.72 100-150 mph , 1400whp E85
996TT SpoolBus - 204.6 mph 1/2 Mile 996TT WR Aug 2018, 9.5 @ 154 mph, 3.23 60-130 mph, 2.5 100-150 mph Manual Porsche World Record, 1400whp E85
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ESMOTOR | DO88 | TPC DSC | SYVECS | COBB | IPD | KLINE | XONA | AMS | ID | ERP | SACHS | TURBOSMART | CSF | DODSON |
#TeamAIM
997TT SilverSpool - 210.8 mph 1/2 Mile WR Apr 2019, 9.2 @ 168 mph 1/4 Mile Manual World Record , 3.15 60-130 mph , 2.72 100-150 mph , 1400whp E85
996TT SpoolBus - 204.6 mph 1/2 Mile 996TT WR Aug 2018, 9.5 @ 154 mph, 3.23 60-130 mph, 2.5 100-150 mph Manual Porsche World Record, 1400whp E85
997TT SlowBerry - 205.0 mph 1/2 Mile WR Nov 2018, 9.7 @ 170 mph 1/4 Mile , 3.2 60-130 mph , 2.4 100-150 mph , 1420whp E85
ESMOTOR | DO88 | TPC DSC | SYVECS | COBB | IPD | KLINE | XONA | AMS | ID | ERP | SACHS | TURBOSMART | CSF | DODSON |
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Joined: Jun 2012
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From: evil lair
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You get a lot of bad things going on with backpressure(ie small hot housings, etc). Exhaust valves, a/f ratio's etc.. it all suffers!
Tim, while your at it, install a turbo compressor "speed sensor" from Garret. A lot of great data fom that too. Knowing this is fantastic for plotting your turbo points.
Tim, while your at it, install a turbo compressor "speed sensor" from Garret. A lot of great data fom that too. Knowing this is fantastic for plotting your turbo points.
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From: CT
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[QUOTE=evil 996tt;3826190]You get a lot of bad things going on with backpressure(ie small hot housings, etc). Exhaust valves, a/f ratio's etc.. it all suffers!QUOTE]
Don't I know it!! Stupid RS6 turbos...hot side the size of a plum...
Don't I know it!! Stupid RS6 turbos...hot side the size of a plum...
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Joined: Oct 2011
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From: Germany
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Thanks, will do. The turbos are K24 2480 - 18Gs are close to them.
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Joined: Jul 2010
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From: Long island NY
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Tim,
your setup for sure is like you say and I agree with what you are saying - but only for what you are doing. For the rest of us - or most of us - the emap vs map is more like 2-3 : 1. Having a lower backpressure is a good thing for all of us, that's no question. There is a point of diminishing returns though.
Going with a larger volume will bring the exhaust gas temperatures down by itself and this will reduce the kinetic energy. Wrapping the tubing and/or turbo will keep more of the gas energy in the tubes and hence reduces the losses and the only thing the system can react to it is a faster rotating/spooling wheel. That's why I have ceramic coating inside and outside my headers and the hot side of the turbo (see attached pic).
Of course you need a pressure difference to move air/gas, but it is always volume in combination with temperature and fluid speed that moves things.
Having said that, my new exhaust from 911tuning has a 2nd pre-cat O2 sensor style plug for doing ECU independent O2 measurements and also backpressure tests. Pictures will follow soon.
You see: there are some others who care about backpressure The probe on the pic is for EGT.
Regards,
Andreas
your setup for sure is like you say and I agree with what you are saying - but only for what you are doing. For the rest of us - or most of us - the emap vs map is more like 2-3 : 1. Having a lower backpressure is a good thing for all of us, that's no question. There is a point of diminishing returns though.
Going with a larger volume will bring the exhaust gas temperatures down by itself and this will reduce the kinetic energy. Wrapping the tubing and/or turbo will keep more of the gas energy in the tubes and hence reduces the losses and the only thing the system can react to it is a faster rotating/spooling wheel. That's why I have ceramic coating inside and outside my headers and the hot side of the turbo (see attached pic).
Of course you need a pressure difference to move air/gas, but it is always volume in combination with temperature and fluid speed that moves things.
Having said that, my new exhaust from 911tuning has a 2nd pre-cat O2 sensor style plug for doing ECU independent O2 measurements and also backpressure tests. Pictures will follow soon.
You see: there are some others who care about backpressure
The probe on the pic is for EGT.Regards,
Andreas
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Joined: Oct 2011
Posts: 429
From: Germany
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My a/f was always spot on - before and after - and not dependent on backpressure and by modifying the exhaust I brought down my 100-200 km/h time by almost 0.7 seconds. VE is affected by backpressure and the fuel is always monitored and controlled by the ECU.
It could just be the other way around: you lower backpressure, hence get way better VE and your fueling cannot keep up if it was at the edge before.
Logging is always a good idea.
Andreas
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Tim,
your whole care is a full tilt I love it. The cops here would just drop dead if I would drive such a car here.
No FVD turbos. K24 that were on the car rebuilt to 2480 compressor side. Much like 18Gs from the flow capabilities. They were just there and the rebuild was a logical step with low costs compared to the next step. This will make me happy for about a year or two, I guess.
I am probably running half of the power of your car at the moment, so at best my car is good enough to warm up the track before you make your run.
Andreas
I love it. The cops here would just drop dead if I would drive such a car here.No FVD turbos. K24 that were on the car rebuilt to 2480 compressor side. Much like 18Gs from the flow capabilities. They were just there and the rebuild was a logical step with low costs compared to the next step. This will make me happy for about a year or two, I guess.
I am probably running half of the power of your car at the moment, so at best my car is good enough to warm up the track before you make your run.
Andreas
HEY I thought I would throw this out there..
If anyone wants to see how good their X-pipe is compared to a 100 cell Milltek system on my K24/18g car,my combo on signature,I am willing to Dyno it...But it can not be a full race system,non mufflered.. Street worthy..
I will pay for Dyno time and swap...If it makes more power with a nicer power curve I will buy it,if not I return it to you..
I have dyno time on May 15 on AWD Mustang Dyno at a shop called Boostin..
If anyone wants to see how good their X-pipe is compared to a 100 cell Milltek system on my K24/18g car,my combo on signature,I am willing to Dyno it...But it can not be a full race system,non mufflered.. Street worthy..
I will pay for Dyno time and swap...If it makes more power with a nicer power curve I will buy it,if not I return it to you..
I have dyno time on May 15 on AWD Mustang Dyno at a shop called Boostin..
LOL...I put a similar post out in a past thread of mine for an IPD test when I did a TB dyno swap and had NO response either??..LOL..
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From: Long island NY
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John,
If I sold exhausts I would send you one.. I will say some exhausts do have bungs weld on pre cat. Your milteck has them
EB Werks offered but there 3'' un muffled system would be to loud..