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  • Project: RS2 ABY

    So, now that the cosmetics and handling of the car are complete - power becomes top of the list.

    The plan is, and has always been, to bring the power up to around 360bhp with lots of torque, to provide that extra "you know who's the daddy" feeling

    IMO the S2 is all about the 3-400 bhp range, any more and you ruin the low down surge of torque, less and you feel like your missing out.

    I want the car to be capable of producing this kind of power without any real bottle necks and with everything running comfortably within its performance range. Ultimately i want a reliable porno looking car (which i have) that is capable of keeping up with those 911's.

    Currently i have a pretty standard ABY, in terms of engine spec, homefried with a forge DV, bilsteins with H&R's, RS2 FARB, whiteline RARB, milltek turbo-back, samco's, 996's up front, some S4/S6 rear upgrade, re-built gearbox with new synchro's.

    As for the new parts, im in love with the Wagner reverse IM and IC combination and to compliment this im thinking the Wagner EM also. An RS2 airbox, turbo and injectors should finish this off.

    Im no mechanical wizard and rely on everyone else for my technical overview. My main questions are:
    1. RS2 vs 3071 - i understand this costs a similar amount but provides more power?
    2. Should i install new rods for max torque and have the engine re-built whilst im at it, even at a cost of another £5k?
    3. Will the gearbox and clutch take the additional power?
    4. What about the fuel pump?
    5. Ive heard people mention the 7A and RS2 exhaust cams - are these necessary?
    6. Will the 2.75" milltek take almost 400bhp?


    Comments and tips welcome - also, what have i missed or not thought about?

    As for a timeframe, im in no rush as i love the car at the moment and am enjoying it after a lot of time and money having been pumped into it... that said id love to have this underway by the end of the 2009
    S2Forum.com Administrator

  • #2
    Originally posted by Sonic View Post
    1. RS2 vs 3071 - i understand this costs a similar amount but provides more power?
    2. Should i install new rods for max torque and have the engine re-built whilst im at it, even at a cost of another £5k?
    3. Will the gearbox and clutch take the additional power?
    4. What about the fuel pump?
    5. Ive heard people mention the 7A cam or something - is this necessary?
    6. Will the 2.75" milltek take almost 400bhp?
    both turbos are good, most would say a remapped to the limit rs2 is a very good setup.
    you mentioned earlier you wanted the most from the turbo so rod's would be necessary.
    gearbox should take it, clutch would be on the limit i'd say depending how you drive.
    rs2 or 044 fuel pump would be required
    you can run your standard cams but 7a would give a bit more poke and cheap enough.
    the exhaust i'm not sure about i'd probably say a 3 inch "might" be required tho I doubt it as rs2's iirc have a 2.75 exhaust and milltek's quite a good one.

    Comment


    • #3
      1. RS2 vs 3071 - i understand this costs a similar amount but provides more power?

      RS2 will make more torque, 3071 will make more power and spool quicker but not as much torque.

      For your power range I would say the turbo for you is the 2871r.

      If you want an easier install at a cheaper price with less hassle RS2 it is


      2. Should i install new rods for max torque and have the engine re-built whilst im at it, even at a cost of another £5k?

      My advice? No don't install new rods if your car is going to be a daily driver. Simplicity is the key here and IMHO having gone down this road it's a damn sight easier and cheaper to miss out on a little grunt in mapping for the money to spend.

      The 2871 and 3071 will not bend stock rods in normal mapping, the RS2 being a torque monster will if it is not checked!

      3. Will the gearbox and clutch take the additional power?

      6 speed gearbox will take it, standard clutch if newish will, I would suggest going to a single mass flywheel and 3B Sachs Racing clutch.

      4. What about the fuel pump?

      Update it to a Bosch 044 5 bar or 10 bar

      5. Ive heard people mention the 7A cam or something - is this necessary?

      You will loss low down torque but gain bhp at top end. If you can source an RS2 exhaust cam it is the better choice.

      6. Will the 2.75" milltek take almost 400bhp?

      Hmm it will certainly make take you to 350 bhp no issue but for true power unleashing 3" would be better.

      I would say however it really does depend on how serious you are on the final max bhp figure

      Comment


      • #4
        @Sonic...

        Don't discount the might of the 2871 - it sits between RS2 and 3071 broadly speaking. I have that running safe (but impressive) torque levels for standard rods and cams. For me the 2871R is a great turbo for dailydriven machine - its easily over 400bhp but doesn't have horrible lag. To your other questions...

        2 - With 2871 you don't *need* uprated rods, but they are always best practice - lighter/stronger etc
        3 - Gearbox will be fine on roaduse. Clutch will need uprated for reliable launches on this monster. Go with SM flywheel and Sachs clutch for 3B
        4 - Factory pump getting close to limit on the 2871 config - could relay power to it for headroom, but better upgraded if you can
        5 - NO... My 2871 setup runs ABY/AAN cams just fine
        6 - 3" would be better but I don't imagine the Milltek will limit you greatly
        Paul Nugent
        Webmaster http://S2central.net
        Administrator http://S2forum.com

        1994 S2 Coupe ABY - aka Project Lazarus
        2001 A6 allroad 2.5TDi - family tank
        2003 S4 Avant 4.2 V8 - daily burble

        Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

        There are only 10 kinds of people that understand binary - those that do, and those that don't

        Comment


        • #5
          Cheers guys

          The car is no longer a daily driver, hardly a garage queen and it gets thrashed on weekends, but the bilstein suspenion and fuel costs make it very impractical day-to-day. The main purpose of it is as a toy and weekend car.

          QuattroDan mentioned the 2871 to me, but i wasnt aware quite what it was capable of. Perhaps i should be seriously considering it then?

          The heritage and bolt-on low-hassle nature of the RS2 route really appeals to me though.

          @Jamo - Its interesting you say the 3071 produces more power and spools quicker, but produces less torque. I assumed it made more power but spooled slower. What im after is acceleration over speed. Do you have any rough 0-60 times or power comparisons between the RS2 and 3071 off the top of your head?

          The clutch sounds like a good one, cheers. Quite how will a SM change the characteristics of the car? Im assuming it will rev free-er and quicker, but wont this take away some of the refinement of the ABY?

          @Paul - As i understand it the limit of a 2871 or RS2 turbo without uprated rods is approx 380 ft/lb torque, torque being the thing that turns them into banana's. How much more torque and hp could each turbo be mapped for with the uprated engine internals, and how do they compare against each other?

          You say the 2871 produces over 400bhp, the limit on the RS2 is about 380bhp right? And also the 2871 picks up as quick as the RS2?

          I dont have any burning desire to have more than 400bhp or drive the next supercar, i just want a quick, comfortable car that picks up like a bat out of hell. Being a relative mechanical n00b the RS2 route was the obvious choice as i could get involved with it, albeit leave the majority of the work to the professionals.

          As for the rods, i dont like the idea of them going, so i think id play it safe and do them, are SCAT the one i should be looking at? Also, whilst im in there, is it worth rebuilding the engine? I understand its not as simple as it sounds and costs a **** load of wonga.
          S2Forum.com Administrator

          Comment


          • #6
            The rods are limited by torque not bhp

            RS2 = 380 bhp 3071 = 450 bhp

            The best member to speak to and read their project thread is Newsh

            He has gone from RS2 to 3071r and can give you a direct comparison

            Comment


            • #7
              I rebuilt my ABY to RS2 specs and finally to GT3071R with ADU cams.

              What I can tell you is that the GT3071R gives me a bigger rush when boost kicks in than the RS2 turbo did. The RS2 turbo does really push hard in the lower RPMs though as Jamo told!

              The RS2 turbo starts building up power a bit earlier (say 200-300 RPM), however once the Garret turbo kicks in it goes more agressive and Garret turbo's keep on pushing in the higher RPMs compared to the older KKKs. The RS2 turbo looses a bit of it's punch in the higher RPMs is my experience.

              But if money does not allow for a Garret upgrade (wich is a lot more expensive IMO), than I am pretty sure the RS2 turbo with a MRC chip will make you very happy!

              Comment


              • #8
                I think a 2871 is the way forwards for daily use, stock internals, RS2 everything else and about 400 ponies on the right setup. Paul is testing one now so might have a chipset for it in the future.

                If it's a track toy then I'd say 3071, or even 3076 with new rods etc.

                Don't forget the Turbo Dynamics MD357 that DJones is running with awesome results.

                If you're on a budget then you'll do well with an RS2 setup and high boost map, should see 370+.

                Another option could be a small hybrid. Should see early 300s with great torque and spool like stock.

                Final option is to leave the k24 in there, sort everything else for big power later on and drive like Si! I'm aiming to beat the 300 barrier and have not spent money on anything that would not be required for 400bhp & have saved the 3k that a bigger turbo, injectors & remap would cost. Next up is an engine rebuild and clutch... thinking 2.5k to 3k with flowed head.

                I'm running VAG clutch on a 3B flywheel and it's OK but I would upgrade to Sachs for any more power as Jamo suggested earlier.

                I'm sure you'll have fun going through every possible option!
                Cheers'en, AndyC
                1994 ABY Coupe - Projekt Alpinweiss

                Comment


                • #9
                  Sonic, my suggestions are:

                  1) if you dont want to spend soo much money,go for the rs2 setup and a perhaps milder torgue setting on your map to save the rods.

                  2)If you are going for seriously more power on all rev range,then go for the 3071.I think the 3071 can produce more torgue than the rs2 turbo and that is dependant on mapping.The garrett unit can even go on 2.5bar on overboost if you like it that way,and the torgue there will definitelly be more than the rs2.Mine mapped at 1.9bar makes a very good torgue and the good thing is that it keeps going as you rev when the rs2 turbo will be quickly over.

                  3)Rods,IMO change them because at some point you may want something more and you will end up changing them.It is not that expensive,plus you can also change the piston rings if needed and have an almost brand new block!

                  4)Clutch.For daily driver i would stick with the dual mass flywheel.I havent been in a high hp car with single mass conversion,but mine is like stock,no rattle,no vibration which you can get with the single mass flywheel.As for revving and lower weight in those components,i agree the single mass is lighter,but for daily driving i like the fact that it is like stock.Sachs organic clutch would be adequate.

                  5)Better fuel pump for sure and perhaps bigger injectors if going for 3071R although they may not be needed

                  6)A friend of mine has an RS2 with similar equipment and mapping as mine,and has original rods and stock clutch.He is pushing it at the edge but it still hasnt had any problems and he was going for 2.1bar overboost coming on at 4000rpm or something.I have tested him on the PB before i left greece but since i have my baggage missing thanks to the french F&(&^@()@ CDG paris airport and their lack of management,i will post the results later so you can see what the 3071 can do.I agree that the setup of the 3071 can be quite costly,but you might be able to get it cheaper used from people going for more power.

                  Comment


                  • #10
                    My vote is still for 2871R here... The RS2 runs out of punch, circa 5k, but the 2871 is a scream machine to the redline. When I say its over 400bhp - its way easily over 400bhp - do not think of it as a lot of hassle just for 20bhp more than well settled RS2. It doesn't have the same bend crunching torque low down but here's the boost profile I have on the test machine (actually a big heavy UrS4) and thats with factory WG spring - there is scope for faster spool with a stiffer spring.

                    3k - 1.5bar
                    5k - 1.7bar
                    6k - 1.6bar
                    7k - 1.5bar

                    Pretty sure there are motorgeek/034 users who have dyno'd 360bhp at the wheels on the 2871. Even assuming 15% as conservative drivetrain loss, thats into 420bhp country.

                    Wait till I have it finished off and some G-Tech plots - its quick - very quick - not a 'binary turbo' at all.
                    Paul Nugent
                    Webmaster http://S2central.net
                    Administrator http://S2forum.com

                    1994 S2 Coupe ABY - aka Project Lazarus
                    2001 A6 allroad 2.5TDi - family tank
                    2003 S4 Avant 4.2 V8 - daily burble

                    Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

                    There are only 10 kinds of people that understand binary - those that do, and those that don't

                    Comment


                    • #11
                      I would be interested in the results of that GT2871R! Do you have surge under control, or no problems at all?

                      Comment


                      • #12
                        No surge... I was expecting some, but its just not there... Probably a direct result of less aggressive spring than a lot of others would use.
                        Paul Nugent
                        Webmaster http://S2central.net
                        Administrator http://S2forum.com

                        1994 S2 Coupe ABY - aka Project Lazarus
                        2001 A6 allroad 2.5TDi - family tank
                        2003 S4 Avant 4.2 V8 - daily burble

                        Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)

                        There are only 10 kinds of people that understand binary - those that do, and those that don't

                        Comment


                        • #13
                          I do like the 2871 in principle (not been in a car with one so no experience, in fact I'venever been in an RS2 eitehr ). If you can keep stock internals then that frees up £500 (the difference between RS2 and 2871 to buy) so is the sameish price. Migth be worth seeing what GT2871 variants TD and AET can do as teh $/£ ratio has killed the £1000 034 kits for now (?)
                          Cheers'en, AndyC
                          1994 ABY Coupe - Projekt Alpinweiss

                          Comment


                          • #14
                            Cheers for your comments guys - some fantastic replies and a great help to making up my mind!

                            Id written off the 3071 and obviously things like the 3076 for now. The aim is not to produce a monster that kicks in above 4krpm, and costs the end of the earth - which is what i think id end up with, leaving me with the rs2 and 2871.

                            Whilst the car isnt a daily driver it does get a lot of road use, and the torquey RS2 really suits this. From what ive read and been told the 3071 is better for track where you are driving round at high rpm, the rs2 and 2871 for road use.

                            The 2871 vs RS2 is a difficult one, especially as the 2871 doesnt appear to have had a lot of mileage on the s2's yet. Id be very interested to hear more about what you can extract from the 2871 Paul. I like the sound of the higher hp from the 2871, and the lower lag but like the sound of the torque from the RS2.

                            The deciding factor then has to be the cost and ease of fitting. The 2871 would require more modification and more cash, so the RS2 it is, although ive not written off the 2871


                            The final aim for the project would be to have a completely re-built engine with new rods, turbo, reverse inlet manifold, intercooler and custom map, but this isnt acheivable all in one go for £££ reasons.

                            What ive done is divided the project into a potential 3 stages.

                            First stage (~£3400):

                            Turbo , Wagner EM, RS2 or ebay IC and XM, RS2 airbox, RS2 injectors, Bosch 044 fuel pump, Sachs clutch, 3 bar map sensor, generic map, labour

                            Second stage (~£2000)

                            Wagner reverse IM, IC, labour

                            Third stage (~£2800)

                            Engine rebuild, SCAT rods, labour, custom remap


                            I figure the wagner reverse IM and IC is about £1600 now due to the shocking £/€ rate, and i wouldnt get the real benefit of the combination without a custom map, so would settle with an RS2 or ebay special at a 1/3 of the cost, albeit without the reverse IM and so increased lag.

                            The engine rebuild and rods are expensive, something which i cant do on top of the rs2. My engine has to be good for about 60k miles at least so it seems silly to do a re-build on it, that said, i dont think it makes sense to crack open the engine and put rods in it, but not do the re-build. Ive decided i could wait until a later stage to do the engine rebuild and fit the new rods and then have a custom remap.

                            This way it also means if i wanted a different turbo later down the line i could have it without such a hit

                            So, where do i get an RS2 airbox (), 044 pump, RS2 IC and sachs clutch from? Also, are there any more opinions on a SM flywheel and how much do they cost?

                            S2Forum.com Administrator

                            Comment


                            • #15
                              before you start anything,let me take you for a ride and ask rob for a ride as well to see the differences of a chipped rs2 turbo and a 3071r.
                              to be honest,my chipped rs2 did not really start any sooner than the 3071 and the latter gives much more power in the end.

                              Comments are subjective and sometimes it is nice to be able to judge for yourself before you make up yourmind.Since you have the opportunity,take advantage of it.I never had anyone with an rs2 modified as mine and if i had done things differently,i may have went for the 3076r and ported head to begin with.

                              when is the next leeds meet?

                              044 pump http://www.fiveomotorsport.com/
                              sachs racing clutch: http://www.sachsperformance.com/

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