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  • #31
    Awesome Shep.
    Fantastic insight.
    The reason for my initial post was that I had been formulating similar thoughts, but had nothing to really back them up.

    I look forward to your tests. I am going to be doing some of my own as well.
    I have a very experienced flow bench operator, cylinder head porter that I am old friends with.
    My goal is to get some of these items on a bench and do some testing as well.

    Great stuff. Thanks for adding to the thread.
    Cheers
    jimmy p
    jimmy p.
    87 E30 M3 Prodrive British Touring Car
    88 E30 M3 Zinnoberot - Street
    88 E30 M3 Lachsilber - Race (#98 SCCA SPU)
    92 E30 M Technic Cabrio - S14 POWERED!
    98 318Ti M44, Base - Morea Green
    04 Ford F350 - V10

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    • #32
      Originally posted by jimmy p. View Post
      Awesome Shep.
      Fantastic insight.
      The reason for my initial post was that I had been formulating similar thoughts, but had nothing to really back them up.

      I look forward to your tests. I am going to be doing some of my own as well.
      I have a very experienced flow bench operator, cylinder head porter that I am old friends with.
      My goal is to get some of these items on a bench and do some testing as well.

      Great stuff. Thanks for adding to the thread.
      Cheers
      jimmy p
      Hi Jimmy,

      I have a good mate who's a well respected head porter and engine builder myself. He also designs throttle bodies too and have Jenvy make them up for him. He also confirms that the 48's are not needed for anything standard-ish or clocking on to full race spec, BUT, this is what we are researching so we have hard facts and not heresay.

      You would think all this R&D has been done in the past, and hey, BMW did fit 48mm TB's to the 215hp engines and the Sport Evo. But for me the best TB's are from the Evo2 where they taper from 46mm to 48mm. I can't explain why, but to me it makes sence.

      Also, I believe the 46's will make the car nicer to drive, but it will not be a dramatic difference on a atandard car.

      To be fair, there is alot of wool pulled over the eyes of alot of people about these engines. It doesn't have to cost the earth to build a 275/280 bhp engine either.

      Paul.

      Note to myself... buy up as many 46mm TB's as possible before the value of them goes through the roof on :ebay:
      Last edited by ShepsEVO3; 08-25-2009, 12:37 PM.
      E30 M3 Sport Evolution Black
      E30 M3 Sport Evolution Red
      E30 M3 Evo II Red
      E30 M3 Evo II Blue
      E30 M3 195hp Black
      E30 318 is White
      E30 318 is Red

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      • #33
        I think it's time to update this thread. Here is a link to my 2.5 build running 46mm TBs. Also, as a reference, it is tuned on 91 octane. This weekend, we plan to install the 49mm TBs and I will publish the dyno plots.

        http://www.s14.net/forums/showthread...&highlight=2.5
        Several E30 M3's.

        More than I need but not as many as I want....

        Comment


        • #34
          Originally posted by ShepsEVO3 View Post
          You would think all this R&D has been done in the past, and hey, BMW did fit 48mm TB's to the 215hp engines and the Sport Evo. But for me the best TB's are from the Evo2 where they taper from 46mm to 48mm. I can't explain why, but to me it makes sence.
          I personally have always maintained that the fitting of the 48mm TBs to both evolutions was always "homologation" of the TBs and the bigger head,,, NOT that it was needed to make their respective 215, 220, 238 HP.

          At that time BMW Motorsport were ramping into the 360+ HP range in the factory S14 race engines where they "did" need the bigger TBs.
          I maintain you dont need 48mm TBs for anything under 280-300hp.
          I hope some day to prove this.
          I know my current 2.3s far outstrip the Evo 2 - 220HP on 46mm TBs.

          Originally posted by ShepsEVO3 View Post
          Also, I believe the 46's will make the car nicer to drive, but it will not be a dramatic difference on a atandard car.
          Agreed.


          Originally posted by ShepsEVO3 View Post
          To be fair, there is alot of wool pulled over the eyes of alot of people about these engines. It doesn't have to cost the earth to build a 275/280 bhp engine either.
          Paul.
          Agreed again. We just built two very nice, super fun to drive 2.3s for what I consider a pretty reasonable number (and it was under 10K each).

          Inastrangeland,,, thanks for adding your link to the thread.
          I cant wait to see your results.
          Someday I hope to add some more to this (if I can ever get home long enough to play with some parts)...

          Cheers
          jimmy p
          jimmy p.
          87 E30 M3 Prodrive British Touring Car
          88 E30 M3 Zinnoberot - Street
          88 E30 M3 Lachsilber - Race (#98 SCCA SPU)
          92 E30 M Technic Cabrio - S14 POWERED!
          98 318Ti M44, Base - Morea Green
          04 Ford F350 - V10

          Comment


          • #35
            This will be about as close as you can get to a one for one swap to see if there really is a difference. Since this is a low octane pump gas motor, it should be a good indication as to the effect of larger TB's on a mildly tuned S14.

            This may not be conclusive since I am running the stock exhaust piping which is pretty restrictive and may be the current restraint. At least I will know for sure once we do the swap and dyno again.

            I am building another 2.3 and the cost is a lot less than the $10K number without any corners being cut on the build.
            Several E30 M3's.

            More than I need but not as many as I want....

            Comment


            • #36
              Shall we place or personal predictions?

              I'll say, no worthwhile change.

              More specific:
              teensy bit of HP add around 6500.
              Nothing under the curve
              Probably torque fall off across the board (or no change) under 5.5K.

              I gotta tell ya, I cant wait for this test.
              Very exciting after all these years to see this happen.
              I know,,, I need a life.
              jimmy p.
              87 E30 M3 Prodrive British Touring Car
              88 E30 M3 Zinnoberot - Street
              88 E30 M3 Lachsilber - Race (#98 SCCA SPU)
              92 E30 M Technic Cabrio - S14 POWERED!
              98 318Ti M44, Base - Morea Green
              04 Ford F350 - V10

              Comment


              • #37
                Coming into this late but I agree with you Jimmy. I always wondered why the Sport Evo exhaust has twin 55.5mm secondaries, which is HUGE, for 238HP? That's just a lot of exhaust for 238HP. That's a lot of exhaust for 300, let alone 238. I don't think the 2.5 necessarily needs that exhaust but perhaps you're right on the money about homologation purposes. It makes sense.

                Turns out twin 55.5mm has more area than a single 3" system and can support upto 400HP.
                Last edited by Reelizmpro; 06-28-2010, 01:36 PM.

                88 M3 - LACHSSILBER/M TECH
                89 M3 - ALPINEWEISS II/SCHWARZ
                85 323I S52 - ALPINEWEISS/SCHWARZ
                91 M TECHNIC TURBO - MACAOBLAU/M TECH


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                • #38
                  Originally posted by Reelizmpro View Post
                  Coming into this late but I agree with you Jimmy. I always wondered why the Sport Evo exhaust has twin 55.5mm secondaries, which is HUGE, for 238HP? That's just a lot of exhaust for 238HP. That's a lot of exhaust for 300, let alone 238. I don't think the 2.5 necessarily needs that exhaust but perhaps you're right on the money about homologation purposes. It makes sense.

                  Turns out twin 55.5mm has more area than a single 3" system and can support upto 400HP.

                  I look at it this way. I have a 7.0L GTO with dual 3" exhausts. It puts down 530 at the wheels which equates to roughly 600 FWHP. This equates to less than 100 hp per litre. My current 2.5 build, in it's current state, is making 270 fwhp with four cylinders. Double that and I am at 540 fwhp or 460 rwhp. Assuming I can get another 10-15 rwhp, Jimmies, expectations not withstanding, it would put me close to the 290 fwhp mark or 580 in a V8 configuration. This means I can benefit froma larger exhaust.

                  Another consideration, a larger exhaust, reduces backpressure, and is more critical in an NA motor since you do not have boost helping you evacuate the cylinder. And, at higher rpms, you have less time to get the exhaust out so any reduction in backpressure will be more noticeable at higher rpms. So, yes, they went to a larger exhaust on the sport evo, and yes, the sport evo could not take full advantage of it, but certainly did not suffer from it. My 2 cents.
                  Several E30 M3's.

                  More than I need but not as many as I want....

                  Comment


                  • #39
                    update: I just brought a brand new motorsports rally 46mm tb. On the head side its even bigger them the 215/sports evo/evo II tb. Now I have seen 3 different 46mm tb. 200/192 46mm tb, evo II tb( head side= 215/sports evo),ms rally tb, (head side= 29.5mm intake port,even the gasket is ported ).

                    when I get a 46mm airbox, I will try to dyno the real 48mm tb,and 46mm rally tb, I think 46mm ms rally tb might be the best tb for 8000rpm redline car.

                    48mm vs ms rally tb

                    195/200tb vs ms rally tb
                    Last edited by aropro100; 05-17-2011, 01:50 PM.

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                    • #40
                      I'm running 49.5 TB's based on 48mm housings in my 2.3L now, with matching 49.5mm airbox. Unfortunately, I don't have before/after dyno results where the only change was the TB's (Did Cams, Header at the same time)
                      sigpic
                      Track Car Build | COM Sports Car Club

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                      • #41
                        This thread is awesome. I wish I had something fruitful to add. Keep up the good work fellas. I've been falling sleep reading the threads on car wax.

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                        • #42
                          hi

                          do you also have the gasket of the 46 ms rally ttb?
                          do you have pm number of it ?
                          and have you also the price of the gasket

                          greetings dave

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                          • #43
                            Hmmm. I am not disagreeing, but I am still looking for the proof on these throttle bodies and INASTRANGELAND has not followed up with his dyno sheet. Still waiting for proof!

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                            • #44
                              the gasket come with the tb, part # 1 310 865.1

                              the ms 46mm tb show that is was made 1987, which made me believe that 2.3 group A car never use the steet 46mm tb (200/195tb)

                              I guess i can do 3 dyno with street 46mm tb ,46mm ms tb, and 48mm tb, (i dont have the evoII tb). Anybody got cheap 46mm cf airbox that they want to sell me?

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                              • #45
                                Nice photos Aropro.
                                Thats also the TBs on my 2.0 BTCC motor.
                                What is the cost of those these days if you do not mind me asking?
                                Thanks
                                jimmy
                                jimmy p.
                                87 E30 M3 Prodrive British Touring Car
                                88 E30 M3 Zinnoberot - Street
                                88 E30 M3 Lachsilber - Race (#98 SCCA SPU)
                                92 E30 M Technic Cabrio - S14 POWERED!
                                98 318Ti M44, Base - Morea Green
                                04 Ford F350 - V10

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