Carbon Buildup Porn
05-08-2010, 06:27 PM
#32
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05-26-2010, 03:57 PM
#33
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I'm not a mechanical engineer, so what follows is what I understand the problem to be. There are several very knowledgeable MEs that post here, so please step in and correct me where you see fit.
The carbon comes from two basic sources. The PCV system and valve overlap ("internal EGR"). Most agree that the cyclonic separator in the RS4's PVC system has proven itself to be very efficient (when functioning as designed and the crankcase oil level is not too high), leaving most of the carbon problem coming from valve overlap. Not much (legally) can be done about that due to federal emission regulations. Maybe an alternate cam profile could work, but that's extremely $$$$, and I doubt if they're even commercially available.
There are some reports that certain newer Audi designs run the engine coolant 10 degrees hotter for carbon buildup reasons. I'm not sure why that would work, but perhaps it has something to do with cyclonic separator efficiency, since a coolant pipe attaches to the body of the separator. Audi literature calls it a "heater".
The carbon comes from two basic sources. The PCV system and valve overlap ("internal EGR"). Most agree that the cyclonic separator in the RS4's PVC system has proven itself to be very efficient (when functioning as designed and the crankcase oil level is not too high), leaving most of the carbon problem coming from valve overlap. Not much (legally) can be done about that due to federal emission regulations. Maybe an alternate cam profile could work, but that's extremely $$$$, and I doubt if they're even commercially available.
There are some reports that certain newer Audi designs run the engine coolant 10 degrees hotter for carbon buildup reasons. I'm not sure why that would work, but perhaps it has something to do with cyclonic separator efficiency, since a coolant pipe attaches to the body of the separator. Audi literature calls it a "heater".
They also replaced all 4 shocks with the newer parts...
05-27-2010, 12:55 PM
#34
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Does anyone have any more info as this all sounds very feasable to me... I am just about to go to the dealer to pick up my 2008 RS4 with 11K miles on it. It had a second check engine light and it wound up being carbon build up. The build up wasn't as thick as above, but it certainly wasn't pretty for an intake with so few miles.
They also replaced all 4 shocks with the newer parts...
They also replaced all 4 shocks with the newer parts...
My CEL's just come on a few days ago at 40k, and I've only used Tacoma Larson for oil changes thus far.
Not sure if it's the ignition coil or carbon issue, but I've a noticeable loss of power + shuddering at low RPMs.
I'm still on original shocks as well.
TIA
05-27-2010, 02:12 PM
#35
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Which Seattle area dealer are you using?
My CEL's just come on a few days ago at 40k, and I've only used Tacoma Larson for oil changes thus far.
Not sure if it's the ignition coil or carbon issue, but I've a noticeable loss of power + shuddering at low RPMs.
I'm still on original shocks as well.
TIA
My CEL's just come on a few days ago at 40k, and I've only used Tacoma Larson for oil changes thus far.
Not sure if it's the ignition coil or carbon issue, but I've a noticeable loss of power + shuddering at low RPMs.
I'm still on original shocks as well.
TIA
05-28-2010, 07:17 AM
#36
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Its a long ways out of the way for you guys, but I use Roger Jobs in Bellingham for mine and can't say enough good about them. Eric in Audi Service has taken care of several Audi's for me for years and is a great guy -
05-30-2010, 07:15 PM
#37
"That's too bad because all the latest and greatest are FSI for better or for worse."
The new 5.0 Ford Coyote motor is not FSI, and the rags are saying Ford has underrated it by maybe 30 Hp by advertising it at 412 Hp. Yes, its not German or an Audi, but some of "old" folks used to own and drive 66 Mustangs for our first car. With 3.73 gearing, it will tear a hole into the B6, B7, and B8 S4. The RS4 crowd should be real careful too. Missed shift or bad launch and its over. Would I buy one? Maybe, but I'll go for the GT500.
The new 5.0 Ford Coyote motor is not FSI, and the rags are saying Ford has underrated it by maybe 30 Hp by advertising it at 412 Hp. Yes, its not German or an Audi, but some of "old" folks used to own and drive 66 Mustangs for our first car. With 3.73 gearing, it will tear a hole into the B6, B7, and B8 S4. The RS4 crowd should be real careful too. Missed shift or bad launch and its over. Would I buy one? Maybe, but I'll go for the GT500.
06-01-2010, 06:01 PM
#38
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the new AMG twin turbo 5.5 is a DI
536 HP
590 lb ft from 2000 to 4500
with performance pack option
563 HP
664 lb ft of torque, 2000 to 4000
25% better mpg than the old 6.2
I'm not too sure that the stock 412 HP 5 liter Mustang will be spanking too many RS4's or possibly S4's
Saleens car built on the 5 liter platform makes 440 HP with its tuning
1/4 mile 13.5 sec
536 HP
590 lb ft from 2000 to 4500
with performance pack option
563 HP
664 lb ft of torque, 2000 to 4000
25% better mpg than the old 6.2
I'm not too sure that the stock 412 HP 5 liter Mustang will be spanking too many RS4's or possibly S4's
Saleens car built on the 5 liter platform makes 440 HP with its tuning
1/4 mile 13.5 sec
06-01-2010, 07:45 PM
#39
"Saleens car built on the 5 liter platform makes 440 HP with its tuning"
Saleen built their cars on superchsrging the 4.6 Liter engine. The new 5.0 is just out now. I don't think they got ahold of the new 5.0 yet. 0-60 times for the new GT is mid 4's. B6, B7, and I doubt the B8 S4 can beat that time.
Saleen built their cars on superchsrging the 4.6 Liter engine. The new 5.0 is just out now. I don't think they got ahold of the new 5.0 yet. 0-60 times for the new GT is mid 4's. B6, B7, and I doubt the B8 S4 can beat that time.
06-02-2010, 03:20 PM
#40
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"Saleens car built on the 5 liter platform makes 440 HP with its tuning"
Saleen built their cars on superchsrging the 4.6 Liter engine. The new 5.0 is just out now. I don't think they got ahold of the new 5.0 yet. 0-60 times for the new GT is mid 4's. B6, B7, and I doubt the B8 S4 can beat that time.
Saleen built their cars on superchsrging the 4.6 Liter engine. The new 5.0 is just out now. I don't think they got ahold of the new 5.0 yet. 0-60 times for the new GT is mid 4's. B6, B7, and I doubt the B8 S4 can beat that time.
R&T July 2010 page 23
SMS 302 built on the 2011 302 4V Mustang GT, stock HP 412, tuned 440
Motor Trend
5.0 Mustang 12.7/111
avg mag tests for RS4 12.9/110
I would have serious questions about the stability of the universe if the mustang wasn't faster, since it weighs 10% less (mass) and has 25% more torque (force)
that would render F = ma (or a = F/m) null and void and we'd have serious issues...but since its wt/torque ratio is almost 40% better, I'm surpised that the mustang isn't much faster...rather than barely faster...