Username or Email Address
Do you already have an account?
Forgot your password?
  • Log in or Sign up

    VWVortex


    Page 1 of 2 12 LastLast
    Results 1 to 35 of 66

    Thread: A Brief History (2.5L + Performance + Dyno Charts + Build Thread)

    1. Member H3LVTCA's Avatar
      Join Date
      Oct 27th, 2004
      Location
      630
      Posts
      2,669
      Vehicles
      2008 VW Rabbit
      12-06-2011 01:00 AM #1
      It's taken me a while to finally write this novel of a thread, but I hope it encourages discussion and it helps other 2.5L owners.

      In February/March of this year, I came across some (what I felt) really good deals on a gently used Magnaflow exhaust and a never-used Eurojet header.

      I’d owned my 6-speed automatic 2008 Rabbit for a little over three years and wanted to begin modifying it beyond aesthetics. (I didn't want to delve into turbocharging the car for a number of reasons.) But I wanted to “do it right,” so I read up on exhaust headers and eventually even went and had it ceramically coated (to encourage heat resistance) before installation.

      In addition, I was going to get Unitronic’s Stage 2 software installed simultaneous to the exhaust and header. I thought that doing all three of these upgrades would make a respectable, but not enormous, difference in the power my car was creating. Since there hadn’t been too many other 2.5L owners that had done such modifications, I was going to document the transition though dyno’ing the car after each mod.

      After all, Magnaflow posted a Dynojet graph declaring a “10HP & 10LB•TQ Gain!” from the exhaust on a 2007 Rabbit.
      (Granted this was the year where the engine was rated at 150HP, not 170HP like 2008+ years.)


      Eurojet was claiming “Dyno-proven HP gains,” on every retailer’s website, without any dyno graphs.
      Unitronic suggests a “15HP & 13LB•TQ” gain, albeit also without any dyno graphs.

      Now granted, Unitronic’s numbers are going to be at the engine, not the wheels, for horsepower and torque gains. Which is why, quite honestly, I’d be more inclined to believe Unitronic’s claimed numbers out of all three manufacturers, because they do the testing with just the engine outside of the car. As we all (hopefully) know, there is approximately a 15% drivetrain loss, so let’s assume for the sake of argument that Unitronic’s software actually puts out around 12HP and 10LB•TQ. If you’ve been paying attention, the hyperlink above was to Unitronic’s Stage 1+ software, not Stage 2 - I’ll get back to that in a few paragraphs.

      I brought my car to Mobile One in late April of this year. Aforementioned, I wanted to “document” the progression from stock to modified by dyno’ing the car after each installation. Mobile One has a Dyno Dynamics dynamometer, which have been known to be brutally honest about the power your car is delivering to the wheels. I don’t care to argue about Dyno Dynamics VS. Mustang Dyno VS. Dynojet.

      The first dyno graph revealed almost exactly what I was expecting - about a 15% loss in the horsepower and torque figures that Volkswagen suggested for that year - 170HP & 177LB•TQ x 15% (loss) ≈ 144HP & 150LB•TQ:


      The shop then installed the header and exhaust, and dyno’d the car a second time. The posted dyno results from Magnaflow of 10HP & 10LB•TQ from their exhaust - in addition to Eurojet’s claim of “Dyno-proven HP gains,” I was expecting a result of maybe 15HP & 15LB•TQ. Two runs in, the results show a gain of almost 14HP and 5LB•TQ:


      After searching the databases and eventually calling Unitronic, Mobile One couldn’t find the Stage 2 software for my Rabbit’s engine/transmission combination, so they flashed my ECU with Stage 1+. The owner of the shop (Jason) even called Unitronic’s headquarters to escalate the problem and explained that he’d notify me once Unitronic notified him of the release of Stage 2 for my drivetrain combination. He also mentioned to them that I had a Eurojet header and a Magnaflow exhaust installed, so maybe they could further tune it for me. After Stage 1+ was flashed, the shop dyno’d the car a third time, but the results were interesting. To our surprise, we saw a decrease of about 6HP when this software was installed:


      Mobile One kept in contact with both Unitronic and myself on the status of my Stage 2 file until July. After nearly five months of testing, Unitronic adamantly concluded that the Eurojet header that I have installed, actually lost power when tested by them on their engine dyno with my specific engine/exhaust/header combination. The shop and myself were surprised, and not quite sure how it's possible. Obviously they are not going to spend any time making a file for a piece of hardware that produces negative results.

      I plan to remove the Eurojet header and replace it with the stock header, then dyno the car again to see the results.
      It’ll be interesting to see what the outcome is.

      If something positive has come out of all the work that’s been done thus far is how gnarly and unique my exhaust note is.

      Really laying into the throttle brings a smile to my face. My girlfriend has a 2010 Jetta with the same engine/transmission combination and in comparison, the Rabbit is undoubtedly quicker. It's difficult to describe, but the car pulls away smoother and it's a lot more fun to drive.




      I went into this blindly, not knowing what to expect. If there's one thing I've learned, it's to patiently wait for the proven numbers by a manufacturer. A lot of us 2.5L owners are holding on to our money, waiting for new and improved performance parts to arrive. Keep waiting, there's a lot of stuff on the horizon and I have a feeling 2012 will be a good year for us.

      I'd still recommend Unitronic software and the Magnaflow exhaust to any 2.5L owner. Unitronic put in the hard work behind the scenes to finally reach an (unexpected) outcome. I also highly recommend Jason and the team at Mobile One in Glenview, IL.

      I plan to continue updating this post.
      In a way, it’s my build thread.

      PERFORMANCE MODIFICATIONS (as of 12/6/11)
      •Eurojet Stainless Steel Exhaust Header
      •Magnaflow Stainless Steel Cat-Back Exhaust
      •Unitronic Stage 1+ Software

      Added 8/6/12
      •Black Forest Industries Stage 2 Transmission Mount
      •Black Forest Industries Stage 2 Torque Arm Insert
      Last edited by H3LVTCA; 09-13-2012 at 12:57 PM. Reason: Spelling Corrections, Flickr Photos, YouTube Videos, Modification List
      Quote Originally Posted by TrillyPop View Post
      The 2.5L forum is full of high hopes and huge disappointment.
      MKV Rabbit Dyno Thread
      MKIII Cabrio Build Thread

    2. Member thygreyt's Avatar
      Join Date
      Jun 7th, 2009
      Location
      fort lauderdale, FL
      Posts
      12,792
      Vehicles
      1k-m-cbta-02q-PTE5858
      12-06-2011 01:54 AM #2
      awesome.. now i want to do a dyno! lol...

      as per the headers loss, i think that if you were to add an intake mani, you'd see better gains.

    3. Member itskohler's Avatar
      Join Date
      Jan 7th, 2011
      Location
      Jacksonville, FL/Dallas, TX
      Posts
      4,426
      Vehicles
      2012 Jetta, 2008 Jetta RIP
      12-06-2011 07:39 AM #3
      Interesting the the headers caused that issue.
      Sub'd.

    4. 12-06-2011 10:26 AM #4
      Quote Originally Posted by thygreyt View Post
      awesome.. now i want to do a dyno! lol...

      as per the headers loss, i think that if you were to add an intake mani, you'd see better gains.
      I would say even just a cold air intake would help out a lot.

    5. Member bunnyfufu's Avatar
      Join Date
      Jan 24th, 2011
      Location
      Pasadena,MD
      Posts
      209
      Vehicles
      2010 cw golf 2.5l(mine) 2002 audi a4 3.0(wifes)
      12-06-2011 12:11 PM #5
      Quote Originally Posted by itskohler View Post
      Interesting the the headers caused that issue.
      my thoughts exactly.. i mean some low end torque loss would be expected but an overall loss of power doesnt make sense.


      @ OP either way good to see others are still interested in the 2.5l. good luck with build
      magnaflow catback - Unitronic Stage 1+ -FK Coilovers - Neuspeed P-Flo Intake- NLS Short Shifter-c2 sri(pending install and tune)

    6. Member pennsydubbin's Avatar
      Join Date
      Mar 3rd, 2010
      Location
      Pa
      Posts
      1,145
      Vehicles
      2005.5/08 Jetta 2.5T
      12-06-2011 12:15 PM #6
      my guess is that the stock airbox is limiting the amount of air in while the full exhaust is allowing too much out.

      I'm sure an intake will solve this problem and an SRI will make it perfect.

      edit: This is with the assumption that you do not have an intake already
      Last edited by pennsydubbin; 12-06-2011 at 03:45 PM.
      United Motorsports 2.5T

    7. Member thygreyt's Avatar
      Join Date
      Jun 7th, 2009
      Location
      fort lauderdale, FL
      Posts
      12,792
      Vehicles
      1k-m-cbta-02q-PTE5858
      12-06-2011 12:19 PM #7
      i would assume he as an intake...

    8. Member itskohler's Avatar
      Join Date
      Jan 7th, 2011
      Location
      Jacksonville, FL/Dallas, TX
      Posts
      4,426
      Vehicles
      2012 Jetta, 2008 Jetta RIP
      12-06-2011 12:46 PM #8
      Exactly what I was thinking. the amount of back pressure needed is something that can be debated, but if you dont have more air passing through the engine, you really don't need the exhaust headers.

      It's good that he has those though, it's almost all down hill from there.

    9. Member pennsydubbin's Avatar
      Join Date
      Mar 3rd, 2010
      Location
      Pa
      Posts
      1,145
      Vehicles
      2005.5/08 Jetta 2.5T
      12-06-2011 01:02 PM #9
      i would hope he does too, but i don't see it ever mentioned that he has an intake.
      United Motorsports 2.5T

    10. Member
      Join Date
      Oct 12th, 2009
      Location
      Burlington, ON
      Posts
      1,810
      Vehicles
      2006 Static Sedan, 2002 GTI 337, 2006 CBR600RR
      12-06-2011 01:35 PM #10
      This is very interesting to see. I'd like to know if there would be a difference with moving to a stage 2 file. OP you should post up a comprehensive list of all mods you have that will affect the dyno.

      Sent from my BlackBerry 9700 using Tapatalk

    11. Member bunnyfufu's Avatar
      Join Date
      Jan 24th, 2011
      Location
      Pasadena,MD
      Posts
      209
      Vehicles
      2010 cw golf 2.5l(mine) 2002 audi a4 3.0(wifes)
      12-06-2011 01:37 PM #11
      Quote Originally Posted by lessthanalex View Post
      OP you should post up a comprehensive list of all mods you have that will affect the dyno.

      Sent from my BlackBerry 9700 using Tapatalk
      2nd this
      magnaflow catback - Unitronic Stage 1+ -FK Coilovers - Neuspeed P-Flo Intake- NLS Short Shifter-c2 sri(pending install and tune)

    12. Member
      Join Date
      Jan 16th, 2011
      Location
      Chicago burbs
      Posts
      711
      Vehicles
      10' Golf Mk6 2.5 MT
      12-06-2011 03:09 PM #12
      yo broski are u in chicago? I went to mobile one too and got a dyno on my 2010 golf. 163whp, 156ft tq with intake and 2.25 catback with crush bends.
      Last edited by jaja123; 12-06-2011 at 03:14 PM.
      5 cylinder FTW

    13. Member vento 95 GL's Avatar
      Join Date
      May 25th, 1999
      Location
      Canada
      Posts
      4,956
      Vehicles
      2011 Golf 2.5
      12-06-2011 03:16 PM #13
      Like the others said, you should put a cold air intake like bsh or carbonio or short ram like neuspeed and dyno again before getting rid of the headers.

      The biggest bottle neck on this engine is the airbox. just putting an air intake yields some good results.

      give it a go, you might be surprised with the results.

      edit: if you already have an intake then I have no clue...
      Last edited by vento 95 GL; 12-06-2011 at 03:20 PM.

    14. Member H3LVTCA's Avatar
      Join Date
      Oct 27th, 2004
      Location
      630
      Posts
      2,669
      Vehicles
      2008 VW Rabbit
      12-06-2011 04:35 PM #14
      Quote Originally Posted by DerekH
      I would say even just a cold air intake would help out a lot.
      Quote Originally Posted by pennsydubbin
      I'm sure an intake will solve this problem and an SRI will make it perfect. My guess is that the stock airbox is limiting the amount of air in while the full exhaust is allowing too much out.
      Quote Originally Posted by thygreyt
      I would assume he as an intake...
      I think you're all right - an intake would help the situation but I don't have one on my Rabbit.
      I did pre-order the BSH intake when it was first released; soon after it arrived and I read the installation instructions about cutting the wiring loom to re-route the MAF sensor, I decided against it. I've heard that they've re-done the installation procedure, but that kind of worried me.

      I do have my eye set on the Neuspeed P-Flo intake, and I plan on installing in addition to an intake manifold once they become more widely available for the 2.5L.


      Quote Originally Posted by lessthanalex
      I'd like to know if there would be a difference with moving to a stage 2 file. OP you should post up a comprehensive list of all mods you have that will affect the dyno.
      I have update the original post with the list of "performance" modifications currently on the car, which really are the three that I talked about in the original thread.
      Quote Originally Posted by TrillyPop View Post
      The 2.5L forum is full of high hopes and huge disappointment.
      MKV Rabbit Dyno Thread
      MKIII Cabrio Build Thread

    15. 12-06-2011 04:52 PM #15
      You don't cut the wires you just separate the wires from each other, no big deal.

    16. Member Monkeyslord1's Avatar
      Join Date
      Jun 9th, 2009
      Posts
      109
      Vehicles
      2006 MKV Rabbit, 2010 MKVI GTI
      12-06-2011 05:10 PM #16
      ^ like said above, you just carefully cut through the tape and separate the wires of the MAF sensor from the other wires, tape them back up and have the wires that go to the MAF on the right side of the battery coming to the front rather than behind, if u wanna see how i did it just pm me and ill send u a pic....there really wasnt anything difficult to do in the installation.
      They make cars soft now so you can hit pedestrians.

    17. Member LampyB's Avatar
      Join Date
      Apr 2nd, 2007
      Location
      Boston
      Posts
      1,155
      Vehicles
      MKVI GLI + Rabbit
      12-06-2011 06:07 PM #17
      ^ it's not difficult, you just need a small pair of finger nail scissors to cut the tape wrapped around the wiring harness. nail scissors were the best recommendation given to me, as they are very sharp, and very small so that you don't accidentally slice anything on accident!
      2006 GLI / 2008 Rabbit - United Motorsports (used to be Flex Fuel)
      Quote Originally Posted by pete@blackforest View Post
      I remember when people modified their Volkswagen to enhance the driving experience. What ever happened to Fahrvergnugen?
      Bags are for kids that grew up watching Pimp My Ride. Turbo is for all of us that enjoy actual motorsport.

    18. Member
      Join Date
      Jan 16th, 2011
      Location
      Chicago burbs
      Posts
      711
      Vehicles
      10' Golf Mk6 2.5 MT
      12-06-2011 07:53 PM #18
      have you looked at the carbonio intakes?.
      5 cylinder FTW

    19. Member b1aCkDeA7h's Avatar
      Join Date
      May 27th, 2008
      Location
      Bordentown, NJ
      Posts
      347
      Vehicles
      '08 Rabbit, 6MT
      12-06-2011 11:20 PM #19
      I'm planning to get C2's SRI Installed at the end of the month as well as a Eurojet Header and Eurojet High Flow Catalytic Converter.

      Currently have a Neuspeed Intake and Techtonics Dual Borla Exhaust so I'm curious as to what my car will put down in the end, especially after reading this thread. Unforunately, I'm not sure when I'll ever get the car dyno'ed but I'm still looking forward to the finished product nonetheless.

    20. Member
      Join Date
      Jul 20th, 2001
      Posts
      4,646
      Vehicles
      Fahrvergnügen
      12-06-2011 11:42 PM #20
      H3LVTCA,

      That you for your contribution to the forum.

    21. Banner Advertiser nothing-leaves-stock's Avatar
      Join Date
      May 16th, 2006
      Location
      5780 Main street center valley PA 18034
      Posts
      23,279
      Vehicles
      a few.
      12-07-2011 09:06 AM #21
      good info. thanks for sharing.
      we found the same with the EJ header/test pipe combo.
      best header/test pipe to MAKE power is the EVO header. designed right to make power. not just to look good.
      www.nothingleavesstock.com
      NLS's full line of parts on our online store!http://nothingleavesstock.com/online...=0&sort=normal
      Email us at sales@nothingleavesstock.com 5780 Main St. Center Valley PA 18034 610 282 5487

    22. 12-07-2011 09:45 AM #22
      Quote Originally Posted by nothing-leaves-stock View Post
      good info. thanks for sharing.
      we found the same with the EJ header/test pipe combo.
      best header/test pipe to MAKE power is the EVO header. designed right to make power. not just to look good.
      I would imagine a proper tune makes all the difference with the ej header. Seeing as the evo header is similar in size to the stock mani, where the ej header is enough different the programming could be optimized better. However you would know better than me.

      Also, i do remember seeing a dyno chart for the ej header on a stock car and it only making a few peak hp difference but bumping the power up all along the curve. Could be mistaken though it was probably more than a year ago now so it could be something else that i am thinking of.

    23. Member thygreyt's Avatar
      Join Date
      Jun 7th, 2009
      Location
      fort lauderdale, FL
      Posts
      12,792
      Vehicles
      1k-m-cbta-02q-PTE5858
      12-07-2011 10:14 AM #23
      Quote Originally Posted by DerekH View Post
      i do remember seeing a dyno chart for the ej header on a stock car and it only making a few peak hp difference but bumping the power up all along the curve. Could be mistaken though it was probably more than a year ago now so it could be something else that i am thinking of.
      i have seen it too... but long ago.

    24. Member H3LVTCA's Avatar
      Join Date
      Oct 27th, 2004
      Location
      630
      Posts
      2,669
      Vehicles
      2008 VW Rabbit
      12-07-2011 10:45 AM #24
      Quote Originally Posted by DerekH View Post
      You don't cut the wires you just separate the wires from each other, no big deal.
      Quote Originally Posted by Monkeyslord1
      You just carefully cut through the tape and separate the wires of the MAF sensor from the other wires... there really wasn't anything difficult to do in the installation.
      Don't get me wrong, I'm not doubting the difficulty of the installation, but cutting the wiring loom open as it was suggested just didn't feel like a good idea to me. The last thing I wanted to do was to screw up the wiring/electrics of a new car.
      Quote Originally Posted by TrillyPop View Post
      The 2.5L forum is full of high hopes and huge disappointment.
      MKV Rabbit Dyno Thread
      MKIII Cabrio Build Thread

    25. Member H3LVTCA's Avatar
      Join Date
      Oct 27th, 2004
      Location
      630
      Posts
      2,669
      Vehicles
      2008 VW Rabbit
      12-07-2011 10:52 AM #25
      Quote Originally Posted by DerekH View Post
      I do remember seeing a dyno chart for the ej header on a stock car and it only making a few peak hp difference but bumping the power up all along the curve. Could be mistaken though it was probably more than a year ago now so it could be something else that i am thinking of.
      If anyone stumbles across that dyno chart, I'd love to see it/put it in the original post.
      Quote Originally Posted by TrillyPop View Post
      The 2.5L forum is full of high hopes and huge disappointment.
      MKV Rabbit Dyno Thread
      MKIII Cabrio Build Thread

    26. Banner Advertiser nothing-leaves-stock's Avatar
      Join Date
      May 16th, 2006
      Location
      5780 Main street center valley PA 18034
      Posts
      23,279
      Vehicles
      a few.
      12-07-2011 11:49 AM #26
      long tube headers...good tune or not will kill power if not matched to the motor output. long tube headers take a lot to make right.
      www.nothingleavesstock.com
      NLS's full line of parts on our online store!http://nothingleavesstock.com/online...=0&sort=normal
      Email us at sales@nothingleavesstock.com 5780 Main St. Center Valley PA 18034 610 282 5487

    27. Senior Member
      Join Date
      Feb 28th, 2002
      Location
      chicagoland
      Posts
      27,400
      Vehicles
      91 GTI 1.8t, 07 Rabbit
      12-07-2011 05:36 PM #27
      Quote Originally Posted by H3LVTCA View Post
      If anyone stumbles across that dyno chart, I'd love to see it/put it in the original post.
      I think this is the one.

      Quote Originally Posted by VikingVR6GTI View Post
      Yep, that was my first thought too. A nice set does not automatically make a chick attractive. Especially when that "chick" is a dude.

    28. Senior Member
      Join Date
      Feb 28th, 2002
      Location
      chicagoland
      Posts
      27,400
      Vehicles
      91 GTI 1.8t, 07 Rabbit
      12-07-2011 05:37 PM #28
      Quote Originally Posted by nothing-leaves-stock View Post
      long tube headers...good tune or not will kill power if not matched to the motor output. long tube headers take a lot to make right.
      Same thing with a short runner intake. If its not matched to the motor it will loose power.
      Quote Originally Posted by VikingVR6GTI View Post
      Yep, that was my first thought too. A nice set does not automatically make a chick attractive. Especially when that "chick" is a dude.

    29. Member H3LVTCA's Avatar
      Join Date
      Oct 27th, 2004
      Location
      630
      Posts
      2,669
      Vehicles
      2008 VW Rabbit
      12-07-2011 06:05 PM #29
      Quote Originally Posted by spdfrek View Post
      I think this is the one.

      The folks at Evolution Tuning have made their dyno chart. I'd love to find the one put out by Eurojet.

      Additionally, seeing as all of their products have dyno chars accompanying them, I may opt for one of their intakes instead of Neuspeed when the time comes.
      Quote Originally Posted by TrillyPop View Post
      The 2.5L forum is full of high hopes and huge disappointment.
      MKV Rabbit Dyno Thread
      MKIII Cabrio Build Thread

    30. Member tay272's Avatar
      Join Date
      Aug 22nd, 2007
      Location
      Zionsville, PA
      Posts
      2,116
      Vehicles
      06 Sage Green Rabbit | 03 Passat V6 4-Motion sedan
      12-07-2011 08:17 PM #30
      If I wanted to get a short ram intake then Id go with the Evo one. The filter itself has a built in velocity stack to help funnel air in through it from all areas and reduce any kind of turbulence. Seems like the best one out there to me. Reading through your thread tho has made me rethink getting headers for my car, and if I do Ill most likely go with the Evo ones as they are proven to make power with my current setup. They cost a **** ton of money but Im sure theyre worth it.
      http://s529.photobucket.com/albums/d...abbit%20build/
      2006 Sage Green Rabbit 5spd| UM SRI manifold | UM 93 SRI tune | NLS Cai | Custom Eurojet exhaust | USP testpipe | ECS lightweight crank pulley | BSH motor/trans mounts |034 Dogbone core| NLS SS w/42DD bushings | GTI brake swap w/SS lines | Koni yellows w/H&R race springs | GTI rear sway |

    31. Member b1aCkDeA7h's Avatar
      Join Date
      May 27th, 2008
      Location
      Bordentown, NJ
      Posts
      347
      Vehicles
      '08 Rabbit, 6MT
      12-07-2011 09:12 PM #31
      Quote Originally Posted by tay272 View Post
      If I wanted to get a short ram intake then Id go with the Evo one. The filter itself has a built in velocity stack to help funnel air in through it from all areas and reduce any kind of turbulence. Seems like the best one out there to me. Reading through your thread tho has made me rethink getting headers for my car, and if I do Ill most likely go with the Evo ones as they are proven to make power with my current setup. They cost a **** ton of money but Im sure theyre worth it.
      I was about to do the same header-wise, then Bluewater went and put up a barely used Eurojet header and high flow cat at too good of a price to pass up. I've heard Evo headers come ceramic coated, a definite plus. I'm going to try and ceramic coat my newly acquired Eurojet stuff before the install at the end of the month.

    32. 12-07-2011 10:56 PM #32
      Quote Originally Posted by nothing-leaves-stock View Post
      long tube headers...good tune or not will kill power if not matched to the motor output. long tube headers take a lot to make right.
      Any chance you can enlighten us as to what has to be done to make it right? I'm not really sure what you mean, and if i can do some tweeks to get my car running better it would be cool. But I'm assuming its going to be more than tweeks.

    33. Senior Member
      Join Date
      Feb 28th, 2002
      Location
      chicagoland
      Posts
      27,400
      Vehicles
      91 GTI 1.8t, 07 Rabbit
      12-07-2011 11:11 PM #33
      Quote Originally Posted by H3LVTCA View Post
      Additionally, seeing as all of their products have dyno chars accompanying them, I may opt for one of their intakes instead of Neuspeed when the time comes.
      Honestly I don't think you will see any measurable differance in either intakes or any other for that matter. Where you will see a differance is in different intake manifolds because the differance in plenum size and shape and runner length.

      I had a VF intake on and swapped to a Neuspeed because I needed that little bit more clearance to fit the oem hids. I didn't notice any chance in power or even throttle responce.
      Quote Originally Posted by VikingVR6GTI View Post
      Yep, that was my first thought too. A nice set does not automatically make a chick attractive. Especially when that "chick" is a dude.

    34. Banner Advertiser nothing-leaves-stock's Avatar
      Join Date
      May 16th, 2006
      Location
      5780 Main street center valley PA 18034
      Posts
      23,279
      Vehicles
      a few.
      12-08-2011 08:15 AM #34
      the long-tube's torque and horsepower curves lasted longer (most of the tim), suggesting that these headers would indeed make even more power over short-tube headers if used on a more modified engineand higher RPM(will make more power at higher RPM). This is due to the fact that a long tube header can make use of the engine's exhaust pulses to "pull" exhaust gas from the cylinder, providing optimized scavenging. A short-tube header, with its much shorter primary tubes, simply does not have the same advantage.
      One of the things that impacts on exhaust scavenging is the duration of the exhaust pulse, which is inversely proportional to engine RPM. If you have relatively long primaries, the exhaust pulses are less likely to interfere at low RPM at the collector and more likely to assist in the evacuation of the other primaries, increasing efficiency. The easier your engine can "exhale" the more fuel-air mix it can process and the more horsepower it can produce.
      so in short....a shorty header will be best with 99% of you guys because you all have STOCK motors, stock comprssion etc. just doing bolt on's won't help a TON to make the header work proper.
      www.nothingleavesstock.com
      NLS's full line of parts on our online store!http://nothingleavesstock.com/online...=0&sort=normal
      Email us at sales@nothingleavesstock.com 5780 Main St. Center Valley PA 18034 610 282 5487

    35. 12-08-2011 10:45 AM #35
      So not even an SRI would make a difference with the long tube header? From what I'm gathering you are talking about valve train so you can rev higher. Which makes sense really. this engine seems to just get started past 6k with an sri.

    Page 1 of 2 12 LastLast

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •