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Old 10-28-2005, 12:01 PM
  #61  
hally
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Originally Posted by jy951
U give me a quote from Llyeton Hewitt - ha!!!!!
What has he won lately????
I'd say the Roger Federer has HIS NUMBER - mate !

Well his new soapy star wife is pregnant so I guess he is performing well off the court LOL
nice looking car btw, i reckon some of those clear indicator lenses would top it off. PS i am running with a high flow cat, noise wise it is much more refined, though it is a little richer through the spoolup zone as displayed on the wb02 against when the test pipe is swapped in.
Old 10-28-2005, 01:32 PM
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Before this turns into a political/religious debate: anyone know a design engineer at Garrett or Borg Warner (KKK), etc that we can contact? Find out if there is any merrit or logic behind turbocharger performance improvment due to intentional/designed back pressure?

Common sense and some basic engineering/physics principles would dictate that the higher the delta P (difference between inlet and outlet pressures), the faster the turbine wheel will spin, the more air the compressor will pull/push into the cylinders, the more power/torque the engine will make.

But I have heard this backpressure argument before and from various sources. Some of whom should be or claim to be subject matter experts. However, all have been from a wrenching/mechanic background - not a design/engineering position, so I would be curious what the turbocharger manufacturing industry theory is on this topic.

My belief would be that, yes removing the cat "could" reduce driveability on a car that is designed and setup to run with a cat. Removing it could throw off some of the fuel curves, since the turbo is now making a little more boost. Maybe some of the engine control systems are not able to compensate for these changes, or do not compensate correctly. And it runs too rich (which would certainly cause poor throttle response in the midrange). There are chip tuners out there that will burn a chip for a specific setup, type of exhaust, cat delete, etc. Ive seen custom chips more with the 964s than with 944s.

But with all that said, having owned and messed around with 944 Turbos since '93, I do not believe that removing the cat adversely affects the performance in any part of the rpm range, from idle to redline. If you found that performance was lower, I believe that there was some other issue with the car. Either some aftermarket trinkets were not tuned correctly, or there is some other engine/mechanical/electrical/exhaust problem.
Old 10-28-2005, 04:43 PM
  #63  
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Originally Posted by jy951
Oh God, another HP junkie (thinks that performance equals mo' powah period)!!!

Any REPUTABLE dyno/performance shop will TELL YOU - You should do dyno comparisons (before / after mod) on the SAME DAY, under (relatively) the SAME ATMOSPHERIC CONDITIONS, if possible!!

The fact that you don't GET THIS POINT - means I don't take YOU SERIOUSLY - that's Perfromance Car / DYNO 101 stuff!!!!!

Especially when capturing turbo car performance - you MUST take atmospheric conditions into account (that's why it's ON THE DYNO SHEETS) - and when doing comparisons - make sure that the conditions are as CLOSE as possible - thus the SAME DAY, SAME TIME approach - jeeeeez!!!!!

As far as your point about techs trying to keep cars stock - who the HELL cares - that's an irrelevant rant - that means NOTHING!

You better stop believing your OWN rants and talk to people who WORK on Porsches and Audis for a living (and also OWN them) , that's what I do!!!!!

In fact, I use one of the SPONSORS (AWE Tuning) on RENNLIST for mods on my Audi B5-S4 biturbo - and have had many a turbo perofrmance conversation with the 20 and 30 yr old techs in their shop which is LOCAL to me (shot your ' a tech doing oil changes for 30 yrs' rant - down the hole - where it belongs).

I also use an independent shop to wrench my 951 and S4 that specializes in forced induction cars - I'll take the opinion of the tech there over YOURS any day. He also OWNS an Audi 2.7T biturbo and has done MANY mods to it. I've seen it with my own eyes.

When I need a backyard oil change - I'll call you - make sure you have a lift in your driveway.


Do you build 800-1000 horsepower 996TT's, or even have the knowledge to do so? Is your shop owner the Porsche PCA turbo tech advisor or sit on the PCA board at all? Those cats that were supposidly good after 170k miles....do you have your flowbench results on that to prove how good they were? Do you realize what happens to a cat for every thousand miles of use?

Please provide some information on your shop and it's reputation. You can find our shop's reputation by doing a simple search. Our reputation is known nationally.

You are correct on the fact that you should dyno on the same day when testing products, but you do that when you are looking for 5-10hp gains, which can vary due to weather....fact of the matter is, the car has run 25-30 dyno runs at 200hp over the course of a few months and all were consistent. You are telling me on a day that was 3 degrees warmer, that it added 50hp to the rear wheels, of which is still consistently runs...i have run the car another dozen times at least since then. I don't think so. I have hundreds of dyno pulls on various cars, and for various testing purposes utilizing our in house mustang dyno, not only on my car, but on any product we test. Does your shop have an in house mustang AWD dyno?
Old 10-28-2005, 09:06 PM
  #64  
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Originally Posted by Karl2bdc
Do you build 800-1000 horsepower 996TT's, or even have the knowledge to do so? Is your shop owner the Porsche PCA turbo tech advisor or sit on the PCA board at all? Those cats that were supposidly good after 170k miles....do you have your flowbench results on that to prove how good they were? Do you realize what happens to a cat for every thousand miles of use?

Please provide some information on your shop and it's reputation. You can find our shop's reputation by doing a simple search. Our reputation is known nationally.

You are correct on the fact that you should dyno on the same day when testing products, but you do that when you are looking for 5-10hp gains, which can vary due to weather....fact of the matter is, the car has run 25-30 dyno runs at 200hp over the course of a few months and all were consistent. You are telling me on a day that was 3 degrees warmer, that it added 50hp to the rear wheels, of which is still consistently runs...i have run the car another dozen times at least since then. I don't think so. I have hundreds of dyno pulls on various cars, and for various testing purposes utilizing our in house mustang dyno, not only on my car, but on any product we test. Does your shop have an in house mustang AWD dyno?
hmmm....ACTUALLY...ONE of MY shops is a RENNLIST SPONSOR...AWE Tuning.

Yes, they DO have a NATIONAL and INTERNATIONAL REPUTATION in both AUDI and PORSCHE circles.

Yes, they DO have a MUSTANG AWD.

Now that I've answered your questions, thank you for agreeing with my point about having dyno runs under the SAME or SIMILAR test conditions.

I'm no performance car guru, but my research (talking with techs about performance enhancements formy 951 and Audi S4 2.7T biturbo) has yielded me much more knowledge than many of the listers that I've seen posting in the 944 turbo forum. Many posts that I've read are URBAN (turbo) LEGEND which keep getting repeated by ppl who have never really data logged their car, or for that matter, have a clue about data logging key sensor metrics (MAF gps, IAT, timing, knock/retard, etc.) to tell whether their 951 is REALLY getting the POWAH that they think it's getting.

I used to be like many of these posters before be-friending and really talking to the techs who were wrenching my 951 and Audi S4 2.7T. First, you have to find a reputable and knowledgable shop; then start finding out who is really a star there.

Like I've said in other posts on this board, I also have a secondary independent shop that specializes in Audis and I know the owner personally, he wrenches my Audi S4 and 951 too. He also owns an Audi Allroad 2.7T (biturbo) and does all the mods himself, he's also a REVO (chip) dealer.

So, I'm quite comfortable with the information (about turbo car performance) that I've gotten from AWE Tuning and my independent shop. I've read a few of your posts and it's obvious that you know what you are talking about. I can't say the same for many of the other posters whose posts that I've read. The posts run 'hot or 'cold', there are posters who post great stuff in the forum, and others who are completely clue-less and happy in their ignorance.
Old 10-28-2005, 09:20 PM
  #65  
jy951
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Originally Posted by Oddjob
Before this turns into a political/religious debate: anyone know a design engineer at Garrett or Borg Warner (KKK), etc that we can contact? Find out if there is any merrit or logic behind turbocharger performance improvment due to intentional/designed back pressure?

Common sense and some basic engineering/physics principles would dictate that the higher the delta P (difference between inlet and outlet pressures), the faster the turbine wheel will spin, the more air the compressor will pull/push into the cylinders, the more power/torque the engine will make.

But I have heard this backpressure argument before and from various sources. Some of whom should be or claim to be subject matter experts. However, all have been from a wrenching/mechanic background - not a design/engineering position, so I would be curious what the turbocharger manufacturing industry theory is on this topic.

My belief would be that, yes removing the cat "could" reduce driveability on a car that is designed and setup to run with a cat. Removing it could throw off some of the fuel curves, since the turbo is now making a little more boost. Maybe some of the engine control systems are not able to compensate for these changes, or do not compensate correctly. And it runs too rich (which would certainly cause poor throttle response in the midrange). There are chip tuners out there that will burn a chip for a specific setup, type of exhaust, cat delete, etc. Ive seen custom chips more with the 964s than with 944s.

But with all that said, having owned and messed around with 944 Turbos since '93, I do not believe that removing the cat adversely affects the performance in any part of the rpm range, from idle to redline. If you found that performance was lower, I believe that there was some other issue with the car. Either some aftermarket trinkets were not tuned correctly, or there is some other engine/mechanical/electrical/exhaust problem.
Your explanation makes much sense. With a 18-20 yr old car, yes, other issues could cause mid-range loss, which would then surface as a result of the CAT removal.

I would suspect that your reference to a change in fueling (running rich) by the DME, as a result of a change in turbo boost/spool-up, could have been a plausible explanation in my case. Thanks. Nice post.

Old 10-28-2005, 09:25 PM
  #66  
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Originally Posted by jy951
hmmm....ACTUALLY...ONE of MY shops is a RENNLIST SPONSOR...AWE Tuning.

Yes, they DO have a NATIONAL and INTERNATIONAL REPUTATION in both AUDI and PORSCHE circles.

Yes, they DO have a MUSTANG AWD.

Now that I've answered your questions, thank you for agreeing with my point about having dyno runs under the SAME or SIMILAR test conditions.

I'm no performance car guru, but my research (talking with techs about performance enhancements formy 951 and Audi S4 2.7T biturbo) has yielded me much more knowledge than many of the listers that I've seen posting in the 944 turbo forum. Many posts that I've read are URBAN (turbo) LEGEND which keep getting repeated by ppl who have never really data logged their car, or for that matter, have a clue about data logging key sensor metrics (MAF gps, IAT, timing, knock/retard, etc.) to tell whether their 951 is REALLY getting the POWAH that they think it's getting.

I used to be like many of these posters before be-friending and really talking to the techs who were wrenching my 951 and Audi S4 2.7T. First, you have to find a reputable and knowledgable shop; then start finding out who is really a star there.

Like I've said in other posts on this board, I also have a secondary independent shop that specializes in Audis and I know the owner personally, he wrenches my Audi S4 and 951 too. He also owns an Audi Allroad 2.7T (biturbo) and does all the mods himself, he's also a REVO (chip) dealer.

So, I'm quite comfortable with the information (about turbo car performance) that I've gotten from AWE Tuning and my independent shop. I've read a few of your posts and it's obvious that you know what you are talking about. I can't say the same for many of the other posters whose posts that I've read. The posts run 'hot or 'cold', there are posters who post great stuff in the forum, and others who are completely clue-less and happy in their ignorance.

Um, ok so you are a customer who does what the shop tells you...ok now i know where we stand.

Edit: And you didnt answer all my questions.
Old 10-28-2005, 09:29 PM
  #67  
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Originally Posted by hally
Well his new soapy star wife is pregnant so I guess he is performing well off the court LOL
nice looking car btw, i reckon some of those clear indicator lenses would top it off. PS i am running with a high flow cat, noise wise it is much more refined, though it is a little richer through the spoolup zone as displayed on the wb02 against when the test pipe is swapped in.
I must admit - his 'lady' (wife) is HOT! - better looking than Kim Clisters - what he thinking when he was ******** her???!!!

Regarding your 951 set-up, better to run slightly rich (with your hi-flow cat) than lean (but u know this already!) under boost.

There are several posters like yourself who make statements that are reasonable and it's obvious that you've done some research - some of the posts that I've read from other posters are....well...u fill in the blanks

Old 10-28-2005, 09:31 PM
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"I'm no performance car guru, but my research (talking with techs about performance enhancements formy 951 and Audi S4 2.7T biturbo) has yielded me much more knowledge than many of the listers that I've seen posting in the 944 turbo forum. "

I can't resist, as this is the first true statement you've made. So by your own admission, you are not a guru, thus your opinion has ZERO relevence over anyone elses. Your info comes from "talking to techs" and has somehow given you more knowledge than all of the books that any of us have read, AND you don't even do the work on your own car, as I and SO MANY of the responders on this board do. So again. I give up for the last time. Your vast conversations, lack of wrenching experience , and general ignorance are far too powerful for me too refute. All of those who have disagreed with you are wrong and spouting urban myths. We stand corrected. Thanks for the help.

by the way it's spelled P-O-W-E-R, not powah.
Old 10-28-2005, 09:34 PM
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And dude, bone up the 18 bucks and become a member.
Old 10-28-2005, 09:42 PM
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Originally Posted by Karl2bdc
Um, ok so you are a customer who does what the shop tells you...ok now i know where we stand.

Edit: And you didnt answer all my questions.
uuuhhhh...I've ALWAYS said (in my posts) that I wasn't a WRENCH, TECH, or RACING PROFESSIONAL.

As far as doing what the shop tells me...make that SHOPS (AWE Tuning, Independent Audi Shop)..good researchers should always use MORE than ONE source for their information.

Hmmm, I guess I should IGNORE the information that I get from my SHOPS and listen ONLY to Internet GURUS...yeah ok...amazing...some things NEVER change...Shops = BAD...Internet Advice = GOOD...I've been trolling these boards (Audi & Porsche) for FIVE YEARS and that POV (point of view) never changes...simply amazing.

As far as answering ALL your questions...it's my prerogative (as the responder) to PICK and CHOSE.

Old 10-28-2005, 09:54 PM
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Maximum Bosst Designing, Testing, and Installing Turbocharger Systems Bell, Corky. p 131
"For our purposes, we shall call the exhaust system everything after the turbo. Virtually all turbos require special tail pipes. Stock, non-turbo tail pipes don't cut it. Seldom to aftermarket tail pipes prove satifsfactory either. An exhaust system is an accumulation of optimized, carefully thought out features. The objective that must be met in correlating these design festures is the creation of a clean-running, acceptable noise level, lowest-possible-back-pressure tail pipe.
RULE back pressure in an exhaust system is evil.

If the turbo could step up an dictate terms for design of exhaust systems, it would categorically state: NONE!"

pg 139 "Make sure the exhaust flow area is maintained through the tips."

But I suppose I got that from urban myth.

Last edited by ehall; 11-03-2005 at 06:39 PM. Reason: spelling
Old 10-28-2005, 10:01 PM
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Originally Posted by ehall
"I'm no performance car guru, but my research (talking with techs about performance enhancements formy 951 and Audi S4 2.7T biturbo) has yielded me much more knowledge than many of the listers that I've seen posting in the 944 turbo forum. "

I can't resist, as this is the first true statement you've made. So by your own admission, you are not a guru, thus your opinion has ZERO relevence over anyone elses. Your info comes from "talking to techs" and has somehow given you more knowledge than all of the books that any of us have read, AND you don't even do the work on your own car, as I and SO MANY of the responders on this board do. So again. I give up for the last time. Your vast conversations, lack of wrenching experience , and general ignorance are far too powerful for me too refute. All of those who have disagreed with you are wrong and spouting urban myths. We stand corrected. Thanks for the help.

by the way it's spelled P-O-W-E-R, not powah.
You have superseded CLUE-LESS STATUS... You are truly a MORON (keep it up, and you'll reach the lofty position of DUMB-A$$).

I DELIBERATELY MIS-SPELLED THE WORD POWER WITH P-O-W-A-H!!!!...It's a SLANG version of the word POWER..Just like K-E-W-L is SLANG for COOL!

You MUST BE 50+ years old to make the dumb reference that you did...truly BELIEVING that you were CORRECTING ME...sheesh!!!...I'm TOO SHARP for a guy like YOU!.

BTW (BTW = "by the way" - spelled it out just 4 you), I DO WRENCH MY OWN CAR - I DON'T DO IT PROFESIONALLY...BIG JOBS LIKE HEAD GASKET, TRANNY, and DP (down pipes - u got that?) are done by my SHOPS (AWE Tuning, High Performance Specialties)..cause I DON'T HAVE A LIFT IN MY GARAGE nor the TOOLS (or time - I have a DAY JOB and earn my LIVING in hi-tech)...AGAIN...I'm TOO SHARP for a guy like YOU!

Old 10-28-2005, 10:12 PM
  #73  
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I guess you weren't sharp enough to realize that I pointed it out because it's so retarded.
Down pipes i do myself. Head gasket? Yep that too. I don't know of more than a handful that do Trans work.
BTW how do you do your own work without tools? BIG GUY?
Old 10-28-2005, 10:13 PM
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I noticed how you were only able to address the trivial language of my post but not the technical aspects. Come on. You claim to be smarter. Bring some tech.

Last edited by ehall; 10-29-2005 at 09:16 AM.
Old 10-28-2005, 10:37 PM
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Originally Posted by ehall
I noticed how you were only able to addressed the trivial language of my post but not the technical aspects. Come on. You claim to be samrter. Bring some tech.
<YAWN>...I've finished making my points....Enjoy your weekend in the Sunshine State..say 'Hey' to Jeb (Bush) for me...I have better things to do with my weekend...and it doesn't include responding to your posts all day and night....<YAWN>



Quick Reply: Cat delete completed - WOW! Big difference!



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