Ecoboost Performance Forum

Tom took his car down to PPE to get catless and catted pipes dynod. Power is calculated at the crank for this dyno session
Car is a stock 13 non PP SHO without a tune
First up is stock vs catless
Picked good power down low due to quicker spool and power up top before the throttle closed.

(https://lh6.googleusercontent.com/-q4k65IhAAvI/UvxIOWV-DnI/AAAAAAADrGs/IFqi-xPCWbY/w1598-h899-no/2014-02-12+14.37.46.jpg)

Here's the dyno comparing catted vs catless pipes.
(https://lh5.googleusercontent.com/-mtij-tnhPW0/UvxIOpXCgRI/AAAAAAADrGo/WA7vfaHR0QU/w1598-h899-no/2014-02-12+18.16.28.jpg)


What we noticed is that the car is limiting the power, this is a stock tune and it's doing torque limiting to maintain power across the power band. We didn't data log the boost which would have proved this out.
Tom is going to allow us to retest with a tune comparing stock downpipes vs catted pipes.

Calculated at the crank? Why no wheel HP?

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mine should be here tomorrow.  Got a tax appt tomorrow night, so try and put them on friday.  Going to the track Saturday.  Previous best is 13.12.  Hope to get into the 12's.

Looks really good but Why is that his TQ numbers stayed the same?

Quote from: Josephm on February 12, 2014, 09:32:49 PM
Looks really good but Why is that his TQ numbers stayed the same?

While TQ numbers didn't increase much, it does build and peak faster.

Today is my second day driving with my new DP's, they are using the stock modified cats(I tried to use larger cats but found out there is no room to go bigger :( ), I'd have to say to me it feels like the same result as the dyno graph, response/spool is much better, in the middle RPM range they are so so but up top it just keeps pulling now 8) Mine were added to an existing custom 2.5" dual exhaust so I'm wondering if the only potential corks are the cats themselves or the inlets into them.

I am guessing the TQ is limited electronically

What we noticed is that the car is limiting the power, this is a stock tune and it's doing torque limiting to maintain power across the power band. We didn't data log the boost or throttle opening which would have proved this out.
Tom is going to allow us to retest with a tune comparing stock downpipes vs catted pipes.
So can you make more power with upgraded exhaust and downpipes on a stock tune? My answer is very little as the ECU will limit you massively, the good and bad of being closed loop all the time.

Ha 4DRHTRD. Is the cut-out exhaust dump ready for sale and how much? http://shop.ecoboostpowerparts.com/Ford-Flex-SHO-Explorer-Sport-MKS-MKT_c2.htm (http://shop.ecoboostpowerparts.com/Ford-Flex-SHO-Explorer-Sport-MKS-MKT_c2.htm)

Quote from: shoman04 on February 13, 2014, 01:12:31 AM
Ha 4DRHTRD. Is the cut-out exhaust dump ready for sale and how much? http://shop.ecoboostpowerparts.com/Ford-Flex-SHO-Explorer-Sport-MKS-MKT_c2.htm (http://shop.ecoboostpowerparts.com/Ford-Flex-SHO-Explorer-Sport-MKS-MKT_c2.htm)

Paul has it at his shop, just waiting for it to be replicated.

Quote from: 4DRHTRD on February 13, 2014, 08:32:22 AM

Quote from: shoman04 on February 13, 2014, 01:12:31 AM
Ha 4DRHTRD. Is the cut-out exhaust dump ready for sale and how much? http://shop.ecoboostpowerparts.com/Ford-Flex-SHO-Explorer-Sport-MKS-MKT_c2.htm (http://shop.ecoboostpowerparts.com/Ford-Flex-SHO-Explorer-Sport-MKS-MKT_c2.htm)

Paul has it at his shop, just waiting for it to be replicated.

every good I may get one depend on the price.

Mike pretty much summarized it.  With less restricti cutbacks and tune the increase should be better since the car ECU won't limit performance then.  I definitely will
Be doing that and the cutout.  Tune is next.  Then Dyno, then cutout, then redyno.

The coating is awesome in appearance, and my hardpipes will
be coated for that reason, but currently I cannot recommend the extra $175 for performance improvement as gains at this time seem not to be worth it (minimal).  Clearly the DPs are worth the plunge.

I'll get some pics up later... Buried at work right now!

BTW, Mile's V cannot be fully appreciated in pics and it's performance is out-of-control awesome.  He graciously gave me a ride during the cooling waits while dynoing.

Any numbers on differences in exhaust gas temps and/or external temps (of the downpipes themselves)?

Quote from: SHOdded on February 13, 2014, 03:07:06 PM
Any numbers on differences in exhaust gas temps and/or external temps (of the downpipes themselves)?

I don't have objective measurements (thermometer).  The ambient temp was 74-79 degrees and humidity at 18-19%.  Touching them, and confirmed with Paul at PPE, after running for 15-20 min (street and highway) between BMR and PPE.. the PPE DPs (all are stainless) cool off MUCH faster than stock and the thermal coated DPs (which not only has "insulating" value but also helps with heat dissipation) cooled the fastest.

Again... it's subjective based on when each of us could grab the pipe without pain or need to let go.  Best i can do right now.

Sorry to be so slow to get this up.. some of the pics will be old hat to those who have had their SHO up on a lift. I apologize for the dirty car... 4 days of sitting outside parked often on an unpaved road and the drive to Tucson.. Anyway...

We all spent 10am - about 6PM doing this.

First, All thanks to Mike (4DR) both personally as well as Ecoboost Power Parts... the DPs are his brainchild, to Jeremy and the crew at Black Market Racing for running the equipment and putting up with me through 9 dyno pulls and data analysis, and to Paul and the crew at PPE for making the DPs a reality and doing 3 installs (including my DPs) on my car as well as some development work. Left click the pics to enlarge


Remember the SHO had no tune or performance mod except the downpipes. example dynos were posted by Mike earlier in this thread... we lost one data set... the best catted and coated pull. We dyno'd hood up and hood down.


Bottom lines after Mike, Jeremy, and I filtered all the dynos several ways is below:[/b]
-All the pipes resulted in an earlier and stronger HP and torque increases and it started up way faster... likely due to earlier spooling of turbos.  See the dynos 4DR put up earlier
-The thermal coating itself did not demonstrate any significant performance gain.  I cannot recommend it at $175 based on our data unless you just like the look... It is sexy!... My hotpipes are ordered coated because of aesthetics, and perhaps a minimum gain with heat control.
-non-catted gains were about 16-17HP with similar increases in torque and catted thermal coated pipes coated were the least gain at 11-12 hp on the best pull (this data lost... sorry, We were all three standing there and saw it) and similar torque gains. (catted were done last and the effects of heat saturation were evident in the minimal gains in the last 2 pulls of the 9 total.... and driving back and forth between BMR and PPE several times.
-The car idles noticeably slower, about 600rpm now, likely due to the early power onset and Ford's torque based ECM algorithms for the 3.5EB
-See my earlier post for heat data as best we had it.
-We all believe that on the dyno the ECM limits use of all the available increased power... The idle speed could be an example. A tune...better yet with specific mods for the DPs should overcome this.
-Subjectively...The car definitely accelerates quicker and crudely has an improved 0-60... WOT launch on dry pavement snaps me back before the steady pull and the traction control is working hard to keep it straight. 60-100 continues strong pull.  I was on streets and didn't go farther.  The dynos indicate a steady pull and increase through about 6800-7000rpm.  It's certainly more fun!
-Sound at idle is deeper but not much louder, cruise at any speed below 100 is plain quiet, there is never a drone, and when you ask for quick acceleration the exhaust is a bit louder than stock, but definitely has more authority.
- So after I tune we'll pull some more to confirm our thoughts on needing a tune to get the largest benefits (by preventing the ECU from limiting use of available power) and how much those are.  Indictions are that we will see a synergistic rather than just additive effect

Enough of my BS and on to the pics.  Left click to enlarge. Labels are above pics.

Here' the stock pipes.  Nasty looking...narrow tubing, unnecessary bends and compressions (it has a flat side), and a long flex tube.  Pay attention to the rear hanger's vertical position.


When you get then off it looks like this.. oil filter is front side and you can just see the turbo manifold flanges...harder on the rear. You'll need some long extensions and wigglers to get these bolts out... we also used a breaker bar and a lot of penetrating oil. Re-bolt with anti-seize compound!!! Three total sensors..two on the front (long) pipe and one on the rear (short) pipe.


Here's the stainless DPs for comparison (rear non-catted and front (long) catted... Much improved... bigger, straighter, and with shorter flextube. Note the O2 sensor hole at the top of the front pipe...for stock pipe removal I recommend removing it from below to minimze chance of damage, but it must be disconnected from above first in any event. It can be brought out on the pipe CAREFULLY and removed on the bench... but space is tight Houdini!  Get a sensor wrench socket if you don't have one to prevent cussing and buying stock in bandaids.


Here's the stainless pipes installed (without sensors)


Here's my stainless ceramic coated babies! On the install pics notice the hangers again... vertical no significant spread... there may be a few millimeters spread due to keeping the bigger tubes from contacting each other or the driver's side posterior motor mount (which allows the engine to rock front to back on two pivots).  I recommend final tightening with a screw driver held between the posterior ends of the pipes just forward of the flex-tube to prevent the above mentioned contact.  Minimal hangar spread is safe due to the direction of the pins for the rubber hangar...see the pics
Ain't they purdy!


I recommend all the folks involved in this endeavor... the PPE downpipes are definitely a worthwhile mod... I can hardly wait for my cutout and Corsa catbacks. Paul has the cutout now and I got to take a look... Great job developing it Mike!...but we'll dyno with a tune and just the downpipes first.

Again the REAL thanks goes to Mike(4DR) & Ecoboost Power Parts, to Jeremy & Black Market Racing, and to Paul & PPE without whom none of this would have happened!

Thanks for taking a look.... hope this helps a few folks.  I certainly learned a lot!

Great write up Tom!  I'm really excited.  Three more hours and we start on my install! 

Quite the story!  Those wheels look awesome spinning on the dyno, and the coated pipes are killer :thumb:

Quote from: SHOdded on February 14, 2014, 05:39:27 AM
Quite the story!  Those wheels look awesome spinning on the dyno, and the coated pipes are killer :thumb:

Thanks.... I love the pipes... and I love the way the wheels disappear at speed.  :beer2:

Awesome ..

Great write up and Pics !

Ordering my catless DP'S from 4DR next week !

tom:
great write up. i too was amazed by the bends & flat areas of standard down pipes & how ugly they were. my SS ones were really nice looking ones but your coated ones are just unbelievable. those are the kind of things the real top cars have at car shows then they put those standing side mirrors around the car so you can under the car.
mikev

Thanks Mike! 
I think the stainless are way awesome also... but with my black ride.... and theme, it is as you point out, one of those little details.

It's also frankly an attitude thing... like having confidence because your underwear is clean without a racing stripe!.  :P

Quote from: BiGMaC on February 14, 2014, 09:30:46 AM


It's also frankly an attitude thing... like having confidence because your underwear is clean without holes.  :P

You must not be a RedNeck  ....   L O L     :crazy1: :crazy1:

Thanks to Tom for letting us use his car as a test vehicle and again in the future.

Thanks for sharing.  Did you leave the third shared cat on??

Quote from: Needmoreboost on February 14, 2014, 10:27:33 AM
Thanks for sharing.  Did you leave the third shared cat on??

Yes, as pictured... saving space for the cutout.Then depending on gains with that I'll have to decide on catbacks vs just tips. 

DJE is installing his DPs today and may have the third cat deleted... Hopefully he'l have a report and pics.

good info all kind of how I expected. Once your're tuneed I'd like to see an overlay of the stock pipes versus catted, and non catted if you're willing to put the stocjers back on for a pull.

How did you get crank hp on a dyno ?

Quote from: 68_GT on February 14, 2014, 11:49:38 AM
good info all kind of how I expected. Once your're tuneed I'd like to see an overlay of the stock pipes versus catted, and non catted if you're willing to put the stocjers back on for a pull.

How did you get crank hp on a dyno ?

The dyno does a drivetrain loss evaluation by doing 0-60 pulls and coasting down

Quote from: 4DRHTRD on February 14, 2014, 12:09:57 PM

Quote from: 68_GT on February 14, 2014, 11:49:38 AM
good info all kind of how I expected. Once your're tuneed I'd like to see an overlay of the stock pipes versus catted, and non catted if you're willing to put the stocjers back on for a pull.

How did you get crank hp on a dyno ?

The dyno does a drivetrain loss evaluation by doing 0-60 pulls and coasting down

What % is the drive train loss?

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Quote from: 4DRHTRD on February 14, 2014, 12:09:57 PM

Quote from: 68_GT on February 14, 2014, 11:49:38 AM
good info all kind of how I expected. Once your're tuneed I'd like to see an overlay of the stock pipes versus catted, and non catted if you're willing to put the stocjers back on for a pull.

How did you get crank hp on a dyno ?

The dyno does a drivetrain loss evaluation by doing 0-60 pulls and coasting down

interesting never heard of that, and my guess is that's becasue I don't understand why you would dyno that way ? unless your're trying to do a comparrison at the crank to what Ford reports the stock power output to be ? What is the stock power 365hp ? that would be a 40hp gain for the non catted pipes if the correction is accurate ?!

Quote from: 68_GT on February 14, 2014, 12:31:06 PM

Quote from: 4DRHTRD on February 14, 2014, 12:09:57 PM

Quote from: 68_GT on February 14, 2014, 11:49:38 AM
good info all kind of how I expected. Once your're tuneed I'd like to see an overlay of the stock pipes versus catted, and non catted if you're willing to put the stocjers back on for a pull.

How did you get crank hp on a dyno ?

The dyno does a drivetrain loss evaluation by doing 0-60 pulls and coasting down

interesting never heard of that, and my guess is that's becasue I don't understand why you would dyno that way ? unless your're trying to do a comparrison at the crank to what Ford reports the stock power output to be ? What is the stock power 365hp ? that would be a 40hp gain for the non catted pipes if the correction is accurate ?!

The dyno treats torque #'s wrong if looking at to the wheel calculations, they're way off - the line is right, number is wrong. I would assume that he is 20HP over published numbers (underrated) compared to quoted 365.
The key is the comparison #'s not the my dyno vs your dyno #'s scenario. I wanted to get the differences between stock, catted and catless. We'll be going back with Tom's car to compare stock, catted and catless tuned as well.

Quote from: 4DRHTRD on February 14, 2014, 12:48:56 PM

Quote from: 68_GT on February 14, 2014, 12:31:06 PM

Quote from: 4DRHTRD on February 14, 2014, 12:09:57 PM

Quote from: 68_GT on February 14, 2014, 11:49:38 AM
good info all kind of how I expected. Once your're tuneed I'd like to see an overlay of the stock pipes versus catted, and non catted if you're willing to put the stocjers back on for a pull.

How did you get crank hp on a dyno ?

The dyno does a drivetrain loss evaluation by doing 0-60 pulls and coasting down

interesting never heard of that, and my guess is that's becasue I don't understand why you would dyno that way ? unless your're trying to do a comparrison at the crank to what Ford reports the stock power output to be ? What is the stock power 365hp ? that would be a 40hp gain for the non catted pipes if the correction is accurate ?!

The dyno treats torque #'s wrong if looking at to the wheel calculations, they're way off - the line is right, number is wrong. I would assume that he is 20HP over published numbers (underrated) compared to quoted 365.
The key is the comparison #'s not the my dyno vs your dyno #'s scenario. I wanted to get the differences between stock, catted and catless. We'll be going back with Tom's car to compare stock, catted and catless tuned as well.

Absolutely... the delta is the important data... how do the line's positions move in the comparison to each other with changes made.  The car is much different to drive on the low end as described...earlier spooling and hp/TQ spike up.
Just FYI... best catted pull of about 395 was 30crank HP over the advertised 365 and about 12 crank HP over the best stock pull on this dyno... again the delta is the number you want.
After driving it I am sure that on the dyno ECM controls torque limiting access to power.  The car acts like the dyno curves look on the street and not so much what those max numbers say out there at redline. Again we believe that a tune will be synergistic with the pipes.

Quote from: 4DRHTRD on February 14, 2014, 12:48:56 PM
We'll be going back with Tom's car to compare stock, catted and catless tuned as well.

oh nice,,,,yeah I'll be holding out for that info !

Great job! Thanks for all this.

no dyno numbers but I picked went from a best of 13.12 to a new best of 12.98 with the offroad DP's.  I think in stellar weather, 40-50 degrees, I could possibly pick up another tenth.

Quote from: black99lightning on February 16, 2014, 07:47:42 PM
no dyno numbers but I picked went from a best of 13.12 to a new best of 12.98 with the offroad DP's.  I think in stellar weather, 40-50 degrees, I could possibly pick up another tenth.

I think crash has a calculation to get WHP from the two numbers.  Maybe he'll weigh in and give us what they use with his car.

Man, your car even looks awesome just sitting on the dyno!

Thanks FMCS!... Appreciate it. especially with it as dirty as it was.

The part of those pics I like the best is how I get to see the wheels disappear at speed.  If the tax man isn't to hard on me the tune with DP adjustment will be on in about 2-3 weeks.  Then we'll dyno all again... expecting more from all styles.

No problem BigMac...

I am a little disappointed with the catted DP #'s.

However, I have a secret weapon I may deploy on my build to overcome the flow differences.

Stay tuned.

Quote from: FoMoCoSHO on February 16, 2014, 09:28:00 PM
No problem BigMac...

I am a little disappointed with the catted DP #'s.

Me too, but the difference seem to be about what we expected... just lower numbers.  The tuned pulls will tell us if we're right.  with no other mods I'm expecting about 5-6 more HP at least.  The feel when driving it tells me if I could hold 1st to 6000-6500rpm we'd have a bolt on rocket.... truth will be told!

Interested to see the SW... mine will be the cutout.

Quote from: Needmoreboost on February 14, 2014, 10:27:33 AM
Thanks for sharing.  Did you leave the third shared cat on??

Yes, in all cases...

So I haven't looked at this thread in a while, and I just noticed that your car made peak power at near redline?

Do the pipes help it breathe that much?

Guys I'm new to this forum and never used one before so be kind. Quick question I have a 2012 SHO about to install a tune from Livernois. I have catless DP, 3 bar sensor, NGK plugs, K&N CIA. What are the downside to catless DP I'm hearing smells like gas? Is that a big deal should I go with catted DP appreciate any info.

Welcome aboard the E.B.P.F partner,please post some pics of the new ride,great choice with going with the Livernois tune,make sure you install your 3-bar first which is located on top of the manifold and then install your tune,also make sure to have a 3-bar tune along with it,the catless DP usually have a smell but after a while it will diminish and go away,also you may need a new revised tune for 3-bar,DP and you can contact Jaimie at jtejeda@livernoismotorsports.com for any tune related questions you may have,also a 160 stat is recommened along with the new plugs to benefit the most from your tune,best of luck with the new ride and any questions you may have always feel free to ask.Z.

The 3 bar tune rocks

I would always suggest catted downpipes over non-catted.

The smell is due to removing the catalytic converters since their function is to regulate emissions. With your emissions system now down two filters (catalytic converters) you are now exposing more emissions which equates to a smell, plain and simple. The noticeability of the smell depends on the design of the downpipes, gas, remaining emissions systems and other factors though I guarantee you any non-catted downpipes will produce a smell to an extent.

You're losing only 1-2hp by going performance catted over non-catted downpipes also, this was tested on a dyno, so the difference is negligible.

Quote from: MDesign on March 18, 2015, 12:25:56 PM
I would always suggest catted downpipes over non-catted.


You're losing only 1-2hp by going performance catted over non-catted downpipes also, this was tested on a dyno, so the difference is negligible.

Wonder why so many people go catless then? From Honda's to Ford's and in between...I also think depending on the motor catted and non catted can have more desparity. I'd say the main benefit of being Catless is that all the over temp shutdowns and safety measures that are meant to save the cats life can be disabled giving you the ability to run harder longer...There are some compensations in the tune tables to reduce power  when the cat temps get hot...Sometimes it can be subtle power reductions that you may not even feel.

Quote from: ajpturbo on March 18, 2015, 12:33:50 PM

Quote from: MDesign on March 18, 2015, 12:25:56 PM
I would always suggest catted downpipes over non-catted.


You're losing only 1-2hp by going performance catted over non-catted downpipes also, this was tested on a dyno, so the difference is negligible.

Wonder why so many people go catless then? From Honda's to Ford's and in between...I also think depending on the motor catted and non catted can have more desparity. I'd say the main benefit of being Catless is that all the over temp shutdowns and safety measures that are meant to save the cats life can be disabled giving you the ability to run harder longer...There are some compensations in the tune tables to reduce power  when the cat temps get hot...Sometimes it can be subtle power reductions that you may not even feel.

Very true ajp, but makes me contemplate.. since I'm not running a road race circuit..If I can't tell the power adjustment... did it happen.  Kinda like that tree falling in the woods when no one is there. I think many folks are still remembering the big carburated V8 days of straight pipes etc.  However, the only real argument I can currently fully understand is the cost the cats add to the DPs... There are of course differences in the exhaust note too.  I live in an emissions state, so given the data from development of the PPE DPs, it was very easy to go catted... different strokes...

Quote from: MDesign on March 18, 2015, 12:25:56 PM
I would always suggest catted downpipes over non-catted.

The smell is due to removing the catalytic converters since their function is to regulate emissions. With your emissions system now down two filters (catalytic converters) you are now exposing more emissions which equates to a smell, plain and simple. The noticeability of the smell depends on the design of the downpipes, gas, remaining emissions systems and other factors though I guarantee you any non-catted downpipes will produce a smell to an extent.

You're losing only 1-2hp by going performance catted over non-catted downpipes also, this was tested on a dyno, so the difference is negligible.

That is exactly why we recommend our race catted downpipes. The worst thing to me is whenever you pull your sweet looking  $40-50k sleeper that smells like raw fuel up to a nice valet, or you take the boss out for date night and she smells like raw fuel. The difference in performance like MD said is next to nothing. If your butt dyno is that sensitive you should work for dynojet lol. I run catted DP's on my ride, because I like not being in the dog house lol.

 I prefer my Catless down pipes and I'm enjoying my emissions compliance and I live in an emissions state.....You won't really notice a smell if you leave your 3rd cat on...Unless you put your nose to the tail pipe while the car is waming up. I like the sound of my catless pipes with the stock cat back

BiGMaC, I agree with you. At some point we need to realize that 99.99% of these EB cars ARE DD's they aren't race cars nor are they giant displacement V8's. If we were talking about a race application, no cats...other than that the 95% street to 5% strip car cats are almost a must.

Quote from: ajpturbo on March 18, 2015, 12:47:32 PM
I prefer my Catless down pipes and I'm enjoying my emissions compliance and I live in an emissions state.....You won't really notice a smell if you leave your 3rd cat on...Unless you put your nose to the tail pipe while the car is waming up. I like the sound of my catless pipes with the stock cat back

And that's cool, nobody is arguing a preference. The point raised was, smell and performance. I had an 04 Mustang GT that had a full catless Basani system on it...so it is not like I am an advocate for the EPA lol.

Quote from: ajpturbo on March 18, 2015, 12:47:32 PM
I prefer my Catless down pipes and I'm enjoying my emissions compliance and I live in an emissions state.....You won't really notice a smell if you leave your 3rd cat on...Unless you put your nose to the tail pipe while the car is waming up. I like the sound of my catless pipes with the stock cat back

The third cat in place is definitely the key to minimizing any odor.  I too have left the factory catback in place... I love the 4" Corsa tips... and may try their catback if they bring back the black ones, LOL...

Quote from: ajpturbo on March 18, 2015, 12:47:32 PM
I prefer my Catless down pipes and I'm enjoying my emissions compliance and I live in an emissions state.....You won't really notice a smell if you leave your 3rd cat on...Unless you put your nose to the tail pipe while the car is waming up. I like the sound of my catless pipes with the stock cat back

Agreed - I have catless DP's and stock exhaust and there is absolutely NO smell what so ever - cost was a factor, did not want to pay for the cats and my state does NOT emission test so why spend the cash?

Quote from: vernonator on March 18, 2015, 01:14:31 PM

Quote from: ajpturbo on March 18, 2015, 12:47:32 PM
I prefer my Catless down pipes and I'm enjoying my emissions compliance and I live in an emissions state.....You won't really notice a smell if you leave your 3rd cat on...Unless you put your nose to the tail pipe while the car is waming up. I like the sound of my catless pipes with the stock cat back

Agreed - I have catless DP's and stock exhaust and there is absolutely NO smell what so ever - cost was a factor, did not want to pay for the cats and my state does NOT emission test so why spend the cash?

^^^^ I'm in the same boat, well i don't have my DPs yet, but that was my opinion!^^^^

Quote from: ajpturbo on March 18, 2015, 12:33:50 PM
Wonder why so many people go catless then? From Honda's to Ford's and in between...

Cost.

Catalytic converters are not cheap, performance high-flow catalytic converters being even more expensive. Fact is people want more for their money and that is what they get by getting hatless downpipes, though they're also expelling more emissions. I bet if there was no price difference that would be a big factor of whether people choose catted or non-catted downpipes.

I just simply wanted to say with EPA laws and emmission compliances always changing and unfortunetly sometimes for the worse in some states,you never know how emmission friendly your state can become and dont know what the future will bring us tommorrow,so for a peace of mind i would also advocate for the catted DP version as MD stated above.Z,.

BigMac, on page one you said it was revving to 6800-7000K RPM?

How is that possible?

I ask because I'm messing around with shift point data and trying to figure out what max engine speed is.

Quote from: FoMoCoSHO on February 14, 2016, 12:33:09 PM
BigMac, on page one you said it was revving to 6800-7000K RPM?

How is that possible?

I ask because I'm messing around with shift point data and trying to figure out what max engine speed is.

If you look at the dyno curves on page 1 of the thread you see the pull through to 6800rpm... Dunno how, just reading the graph. Tune was stock then. I don't know what gear the car was in when the ECU/PCM began limiting as the up and down oscillations indicate. Don't know if that's any help. Your search may involve tune revisions and testing to find the sweet spot for any individual car.

I thought the factory rev limit was something like 6200

I think the pickup wires for ground and coil pack for rpms were out of sync and or bad connection.the indicated revs from the dyno graph are not directly from the ecu they are grabbed from wire signals from the engine bay

And i think stock has a rev limiter of 6400 in gear but the commanded shift points by gear are in the low 6000's and high 5000's for 1st gear

So you think 6400 is safe AJP?

Quote from: FoMoCoSHO on February 16, 2016, 06:03:10 PM
So you think 6400 is safe AJP?

It doesnt seem unhealthy...fuel pressure would be fine at 18-20 psi boost because the high pressure pump has plenty of rpm.

But i would guess the turbo shaft speed would be incredible and im guessing its getting way out of its efficiency range....maybe if you were only running 12-14 psi it might be ok to rev to 6400 but a dyno curve would maybe be the best indicator...at 16 psi the amount of wastegate duty cycle required to hold that boost starts to really take off...mine starts to head to 80% fast...thats kind of my own self imposed limit

When i was at the dyno tuning i felt like i liked the monster boost better but only revving to 6k rather than less boost and 6500.

And the fact that the turbine wheels are something ridiculous like 38mm its just seems counter productive to rev the s*** out of this motor...seems to me that this motor was made to be a mid and low range monster

You lose all power by 5500 RPM so kind of pointless to shift that high....

Quote from: EcoPowerParts on February 17, 2016, 12:07:25 PM
You lose all power by 5500 RPM so kind of pointless to shift that high....

The dyno for the downpipes showed a pretty decent curve up top (I was surprised)

Shift calculators all seem to show more power winding out than short shifting. (PP equipped cars only)

I want to take a couple logs graphing with an accelerometer with RPM, gear, and FRP for comparison. That should be a better indicator than shift point analyzers and random dyno curves that aren't mine. If I can shift higher without breaking anything or slowing down, that cam will be moving faster in the next gear which can only help FRP after the shift.

Maybe it was just the bigger turbos but all my graphs and all I've seen with higher HP cars the power drops at 5500ish like a STONE.

Quote from: EcoPowerParts on February 17, 2016, 03:03:23 PM
Maybe it was just the bigger turbos but all my graphs and all I've seen with higher HP cars the power drops at 5500ish like a STONE.

That's why the dyno results in this thread and comments are confusing. The bigger turbo cars surely like to rev better than stock but looking at page one the car seemed to make power all the way up.

And you are correct, most dyno sheets I look at the power is definitely falling off which is why I was surprised at the on paper results. The gearing and torque multiplication of the pp cars seem to overcome the power drop off. The  suggested points of the 2.77 cars are drastically different.

I think most of the power falling off at 5500+ is due to falling boost...most data logs ive seen the boost tapers off sometimes because thats whats being commanded and sometimes because the boost solenoid is not adding enough wastegate to achieve target boost...when i hold boost to redline my power looked pretty good at 6000 rpm...fomo has my dyno sheet if he wants to post it...i have phone issues

But even if the valve train and engine are ok to run higher the turbo will be the choke point id say above 6k and i would worry about the shaft speed of those 400$ stock garrets

And at high boost and high rpm the stresses on the rotataing parts increases exponentially with rpm due to piston speed..i just wouldnt be interested in running the car ragged

I will post it in the dyno section before this thread gets too far off course.

Hey Mike/Tom, did you guys ever get to re-do this on a tuned vehicle? Would love to see the outcome.

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Following this as well.

Interested in catted downpipes.  Anyone know if it will make my Corsa noticeably louder?  Trying to avoid the exhaust being louder.

Quote from: Joeyfuzz911 on August 20, 2017, 03:19:30 PM
Following this as well.

Interested in catted downpipes.  Anyone know if it will make my Corsa noticeably louder?  Trying to avoid the exhaust being louder.

It certainly will make it sound raspier unless you install a resonator in place.
The beauty of the Corsa cat back exhaust is that emits zero drone to the cabin which is a Big Plus IMO. Z

I know catless will make them raspy. From all the vids I have scene and heard on YouTube with catted downpipes and the Corsa, there is no rasp.  However, can't tell from the vids how loud it is in person which is want I'm worried about.

Thanks for the info though.