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Relentless V3 manifold installation and testing

Discussion in 'A3/S3 Forum (8L Chassis)' started by slappy_dunbar, Nov 29, 2012.

  1. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Nov 29, 2012]
    Recently I took delivery of an inspection sample provided by Relentless Performance here. As most of you know, this is the product repped in the UK here, but it's every bit as available Stateside.

    I have followed the various threads covering this product sufficiently to come to one conclusion: I don't like all that glowy, heat-generating business. So I knew I'd be immediately tinkering with modding the thing. Firstly, though, we gave it a test fit to a spare cylinder head:

    [​IMG]

    [​IMG]


    Clearances were good and the flanges were flat. So it passed one test that its Ebay "equivalent" absolutely did NOT. Clearly, the V3 is the Real McCoy. Having passed that test, I set to getting it ceramic-coated.

    Into the sandblaster:

    [​IMG]

    Post-sandblast surface, ready for ceramic:

    [​IMG]


    We applied our everyday-grey thermal barrier to the unit, with the following result:

    [​IMG]


    Lovely, eh? Well, it's non-descript. And that's a good thing, because it's a honking-big piece. With preparation done, it was time to install. Coincidentally our test car was under the knife for clutch work, so with the sub-frame and transmission out, it was a good opportunity to undertake it. And by "under" I mean, install from underneath.

    [​IMG]

    [​IMG]

    [​IMG]

    These pictures illustrate the "easy" portion of the installation. What followed was the challenging turbo-manifold flange. Good grief that one bolt hole directly under a runner is very difficult. But the TT225 has less room to work in than does a Mk4 or A3/S3. So this was probably the toughest of workspaces. But here we are with the whole works together.

    [​IMG]


    The downpipe connected just as it should, and the clearances for oil/coolant lines were excellent. Lastly, the TIP also fit as before, albeit a bit snug around the ESP hardware.

    [​IMG]


    With everything buttoned back up in the bay I was pleasantly surprised by the unobtrusiveness of the thing. My impressions of others' finished products had led to think it was really, well, ugly. But not so. With all the other eye-candy under the hood, it simply disappears.

    [​IMG]


    At startup, we of course got the usual billow of smoke coming off the dirtied metal tubing (when you see that yourself, don't panic! It's not an indication of a leak). Since it was very late at the shop performing the install, the space was otherwise quiet. So one thing was immediately apparent: it sounds LOVELY. There is undoubtedly a change in exhaust note from the cast iron stock manifold. But what's surprising is a complete lack of metallic rasp that I'd expected. Instead, ForceFed's workspace was filled with the mellifluous growl of a jungle cat! Suddenly, the nightmare of that flange stud was forgotten. On sound alone, it's a winner.

    On the drive home, owing to the late hour and a fresh clutch, the turbo and manifold were tightly reined in. But at highway speed, the new exhaust tone was equally pleasant. Quiet. Undoubtedly quieter than the stock manifold (paired to a 42 Draft Designs 3" system) and absolutely free of "drone". The manifold's out-of-car horsey appearance is without a doubt misleading. This thing is stealthy.

    But how about power? How's it compare to the stock unit there? These questions I will be able to answer shortly. And with a great deal of data (logging is kind of my thing). But we're off to a great start.
    #1
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  3. s3dave
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    s3dave TFSI Hybrid

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    [Nov 29, 2012]
    Nice write up Doug...:icon_thumright: Do you think the ceramic coating will last?
    #2
  4. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Nov 29, 2012]
    It holds up very well on our own tubular, mild-steel product. I think the sandblast prep makes a great deal of difference.
    #3
  5. Prawn
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    Prawn My other car is a MINI!!!!

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    [Nov 29, 2012]
    I guess the sandblasting greatly increases the surface area over which heat can dissipate compared to the shiney polished product as standard.

    Nice work Doug, I look forward to your results!
    #4
  6. gez
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    gez S3 hunter

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    [Nov 29, 2012]
    Nice write up. Just a few questions though. I was planning to heatwrap/ceramic coat my v3 manifold but advised not to as the heat from the manifold will transfer straight to the turbo and will raise the temp picked up by the EGT sensor and effect the map and cut power???
    I also test fitted a spare turbo and down pipe to the manifold on the bench, I couldn't fit the downpipe as the flange would not go past in between the stud on the turbo and the runner on the manifold, did you come across this problem?
    I was planning to fit downpipe and turbo to the manifold and then fitting to the head in situ, do you think this is possible??
    thanks in advance
    #5
  7. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Nov 29, 2012]
    We've been ceramic-coating our manifolds and housings for years. It's a benefit: "thermal shock" to the metal is abated by the increased heat cycling times, and heat energy gets applied to the turbine rotor rather than wasted through metal conduction.

    Fitment-wise, everything went by the numbers, excepting the one stud as noted.
    #6
  8. Yohan87
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    Yohan87 Member

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  9. peterg60
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    peterg60 Member

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    [Dec 1, 2012]
    hi doug i installed my manifold today aswell what you sent me along with f23 but havent installed that yet. suprisingly in a mk1 golf there is loads of room for fitment. philp at verdit motorsport send me machined nuts for the manifold and they helped alot. i installed it with the head on. that 1 nut was the problem i had aswell but i just fingured tighted it and grinded a 12mm spanner on the edge and took my time lol. im going to be using some studs on the manifold to turbo with some nordlock washers here some pitcures of my

    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    #8
  10. beachbuggy
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    beachbuggy Well-Known Member

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    [Dec 1, 2012]
    What turbo you got there Doug? F23? What Bhp you hoping for?
    #9
  11. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Dec 1, 2012]
    Dan -- honestly, I am trying to crack 300g/s. It's probably a pipe dream, but that's my goal. Now the car isn't really what you'd call a "typical example". For instance:

    2.0L prototype (drop-in) stroker motor
    RS4 prototype camshafts
    AEB head

    I will also be experimenting with pre-turbo wmi injection, which will serve to additionally raise airflow. To date, though, the best I've gotten the car to is ~285g/s. That's a good bit away from my goal.
    #10
  12. beachbuggy
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    beachbuggy Well-Known Member

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    [Dec 1, 2012]
    I reckon you can crack 300grams. I've seen over 290 recently so on a 2lt you should be able to push it that bit more..

    I think you if you around an S4 maf you should see it. S3 capping at 292grams is going to be the limit and a freer flowing maf will help. Also if you can spend a bit of time getting the timing spot on and get some more advance that will help with keeping EGTS lower along with the WMI you should easily crack 300grams...

    Do you run an uprated actuator?

    Nice work though... have a lot of respect to anyone wanting to push the boundaries.
    #11
  13. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Dec 1, 2012]
    The actuator has a helper spring, allowing 15psi of crack pressure but with a good bit of articulation remaining. And I've modified the 42 Draft Designs intake to accept a larger S4 MAF. The "Phatty" is dimensioned for that MAF as well.
    #12
  14. Crazypete00
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    Crazypete00 Member

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    [Dec 2, 2012]
    whats the difference between the relentless v2 and v3 mani?
    #13
  15. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [Dec 2, 2012]
    1
    #14
    bazf and Yohan87 like this.
  16. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [Dec 2, 2012]
    :p could'nt resist... soz

    V2 is the less evolved version.. go for v3 only imho
    better fitting, improved materials and welding..
    #15
  17. s3dave
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    s3dave TFSI Hybrid

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    [Dec 2, 2012]
    There is one for sale in the classifieds i believe.....:whistle2:
    #16
  18. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Dec 4, 2012]
    So, first testing was to compare the new manifold's performance when running a modest 18psi at the charge outlet. Since I'd previously logged this setting with both the FrankenTurbo and stock manifolds, I was able to gather apples-to-apples data.




    Here is the Relentless vs stock:


    [​IMG]




    And here is the Relentless vs FrankenTurbo:


    [​IMG]




    The personalities of the manifolds aren't distinguishing themselves very much when at only 18psi. The Relentless spools better than the FrankenTurbo, and almost as well as stock. And its top end flow is right in line with the figures reported with the other two manifolds. How, though, do they perform on the street?


    [​IMG]


    Here we can really see the impact of faster spool. The Relentless and stock are very comparable (the stock wins by an edge). But the FrankenTurbo manifold is clearly oriented to higher flow. It doesn't start erasing that deficit until the motor is above 5000.


    I find this chart interesting. Because if we were to translate it to dyno numbers, the FrankenTurbo unit would appear "the best". It's flowing more horsepower at the top end. But in day-to-day driving, I think the Relentless and stock units are very good options. I'm curious to see what comes of more boost.
    #17
  19. s3dave
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    s3dave TFSI Hybrid

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    [Dec 4, 2012]
    Interesting, i thought it would be a night and day difference..
    #18
  20. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [Dec 4, 2012]
    given the boosts are not the same, the correlation/comparison has more than one difference.. ie not just manifold is different in these results.

    The "concern" on the V3 that its long runners would hurt spool, has been shown not to be the case.
    Where there is more flow (read higher boost pressures) the merge collector vs non-merge collector should show a greater differential, like for like boost.

    thanks for sharing doug
    good work as always
    #19
  21. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Dec 4, 2012]
    The chief takeaway from the first batch of data is spool. I am confident the equal-length runner design works very well at boost onset. The second impression is more subjective: exhaust note. I like the change from stock and/or the FrankenTurbo manifold. It makes the car sound a bit more "old school sports car", where the Franken unit was more balls-ey. The tone is moved up slightly in the register, which I interpret as "fun" sounding, rather than "intimidating".
    #20
  22. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [Dec 4, 2012]
    lol at the sound it makes.. Not heard that approach before..
    :)
    #21
  23. sambryant
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    sambryant seat leon cupra r owner

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    [Dec 4, 2012]
    Glad you like it doug. As I said on vortex other cheap companies have copied our manifolds in the past and have been very poor. I admit our v1 was not good but cannot understand why another company would copy it lol.
    Anyway back to the test, add more boost and the results will show the relentless v3 to come out on top ;)
    i saw 288bhp from 20psi on stock turbo. No map changes were made. Just bolt on gains.
    i look forward to more results :)
    #22
  24. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Dec 6, 2012]
    I've been able to touch up the boost curve to more closely match that while the car had the stock manifold. Here's the result:

    [​IMG]

    Notwithstanding the brief spike at onset, boost curves are comparable. But I'd say airflows are distinctly better. How's the on-street performance?

    [​IMG]

    I'd have to say the V3 is shaping up to be the best product of the three. So long as it passes muster with EGTs...
    #23
  25. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [Dec 7, 2012]
    looks promising so far doug
    #24
  26. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Dec 10, 2012]
    Boost is up on the test car now, with additional promising results. Here is the boost level now, versus comparable levels on the OEM piece:

    [​IMG]


    As we can again see, the OEM manifold holds a slight edge in spool. But pretty slight. And the boost was a touch higher on the OEM run. But intake air temperatures were virtually identical...

    [​IMG]


    The OEM's higher boost coincided with higher airflows:

    [​IMG]


    But once again, better stats don't earn the OEM manifold the win. Clearly, that's going to the Relentless:

    [​IMG]


    Running at ~20psi, the car is now getting just about 280g/s and is running a 3.20 FATs. Boost duty is close to maximum at 90dc. Before I raise it further I want to investigate EGTs. Oh, and that blip on the red curve? That's the Quattro breaking traction. Hehe.
    Last edited: Dec 10, 2012
    #25
  27. Prawn
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    Prawn My other car is a MINI!!!!

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    [Dec 10, 2012]
    it's Quick then :)

    What actuator do you run on these F23's Doug? Interesting to hear you're at 90% DC at 20psi.

    On mine 21psi is only around 45% DC on the N75, although that could be down to a 1 bar actuator.

    How does it seem heat wise so far? I'd be very interested to hear if the coating made any measurable difference.

    Great work as always, Love to see some proper testing going on!
    #26
  28. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [Dec 10, 2012]
    that looks to be working well..
    you dont half slug the boost hard early... This has to be surging?
    #27
  29. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Dec 10, 2012]
    No compressor surge at this boost request curve. The larger 2.0L displacement (and perhaps the cams as well) has pushed the surge line well away from where it was. With the faster-spooling OEM manifold I never experienced surge either.
    #28
  30. v5 tt
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    v5 tt Member

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    [Dec 10, 2012]
    I really thought i was going to be the first person to run stroker with a hybrid
    you beat me to it:salute:

    my setup will be very close to yours nice to see no compressor surge...
    following closely here and vortex great work by the way! ...
    #29
  31. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Dec 12, 2012]

    I think this post is going to be especially pertinent to you. Because I believe I'm starting to hit the ceiling for the K04 frame. The FrankenTT has logged a handful of boost request levels. Here are the resulting airflows at the respective N75 duty cycles:

    [​IMG]

    As you'd expect, as boost requests go up, so does airflow. But the corresponding performance curves belie the airflows.

    [​IMG]


    Yes, the later revision gets off to a better start, but at the top-end, in the "grams counting zone", higher airflows are not helping at all. Here are the comparisons for elapsed time taken between 6000-7000rpms.

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]


    So power tapers off significantly at any airflow above ~265. I had seen this behavior with our own FrankenTurbo manifold as well, where the best power achievable was with a weak preload and airflow in the low 260s. Here was the best 6000-7000 time recorded on that manifold:

    [​IMG]

    Given a similar threshold for efficient airflow while running two manifolds, I assume the bottleneck is within the turbine housing. I make this assessment mindful of the fact that fellow board member "beachbuggy" also found very little reward from his high-flowing, big compressor hybrid K04. Also worth noting is the fact that this hybrid turbo does not share the "usual suspect" RS6 turbine rotor with its British bretheren. It has a higher flowing blade design that's meant to address this head-on. So I suspect our culprit is the turbine casting, and unless there's a simple remedy for altering it, I'm thinking that 350bhp is about the upper limit.
    #30
  32. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Jan 20, 2013]
    Testing on the Relentless V3 paired to the 2.0L FrankenTT test car continues to go well. With a 265g/s "cap" established for optimal flow through the turbine housing, we've tinkered a bit with the VVT system and fuel rail pressures. Neither of these two experiments moved the needle much beyond where we were, but we did cross one psychological barrier:

    [​IMG]

    This was done at IATs starting at ~5˚C, so there's a bit of an asterisk to this accomplishment. Nevertheless, the car now consistently hovers around 3 "dead", and that's something it's never done before on any other manifold.
    #31
  33. Prawn
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    Prawn My other car is a MINI!!!!

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    [Jan 20, 2013]
    Excellent news Doug!

    How does it feel compared to previous setups?
    #32
  34. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Jan 20, 2013]
    This is the best it's ever run. The bigger displacement (and significantly bigger stroke) make the car much stronger in low rpms. For a long while I reckoned there'd be a tradeoff up top, but that's proved not to be the case. FATs are a good .25 second faster than the 1.8T displacement as well. Take a look:

    [​IMG]
    #33
  35. v5 tt
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    v5 tt Member

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    [Jan 20, 2013]
    Nice work ! as i said my build will be very similar (hybrid/stroker) i must admit this did
    cross my mind good gain at low rpm possibly sacrificing something up top? but
    obviously not ! point proved thanks for sharing !
    #34
  36. sambryant
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    sambryant seat leon cupra r owner

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    [Jan 21, 2013]
    Great review and testing doug. We are pleased you like the new v3 manifold. Yes its tricky to fit but its well worth it as the results are awesome. My test on the gt28 is to try and max out what the manifold can actually flow, when does this manifold become a bottle neck?
    Bill will have my car next week for mapping so hopefully he can fill us all in. We know it can make 350bhp lets see if i can make more :)
    my purpose in converting the v3 for a gt28 was to see if it would be a good hybrid alternative, performances vs price. (Remember my gt2871 is actually a clone and costs under £300)
    At actuator pressure its already making more airflow than my k04 at 288bhp (badger5 dyno)
    #35
  37. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Jan 25, 2013]
    Dyno on pump gas. 2.0L stoker with RS4-style camshafts. IATs were dreadful up top, but I don't think that much impacted peak numbers.


    Last edited by a moderator: Aug 15, 2014
    #36
  38. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Jan 25, 2013]
    What the hell was that sparking?!
    #37
  39. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Jan 25, 2013]
    The catch can hadn't been bolted into place on the first pull, and it contacted the battery. The spark, combined with the scarlet-red manifold, was uh...disconcerting.
    #38
  40. beachbuggy
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    beachbuggy Well-Known Member

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    [Jan 25, 2013]
    Nice work Doug,

    what bhp you running on 2litre now?
    #39
  41. slappy_dunbar
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    slappy_dunbar Let's Do This

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    [Jan 25, 2013]
    Depending on the correction method you prefer, wheel horsepower is 300-310. That's only OK for the motor and cams. I think the manifold also performs well - albeit alarmingly hot. If you look closely in the video you will see a small heat shield fashioned on the spot by Ed at ForceFed Engineering. But I think the F23 compressor wheel overmatches a standard K04 turbine casting. So the question is whether it's possible to modify the casting (machining) for better performance.
    #40

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