a man in a shed production

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  • here2learn
    S2Forum Addict
    • Feb 2012
    • 325
    • Country: United Kingdom

    #16
    due to the transmission as a whole being quite inefficient normally a power loss of around 15% i think i have read on here i will be needing some help with finding the right oils to reduce drag in these areas.

    but for now my primary concern is making the shell as stiff as possible and as strong as possible if i get this wrong at anything above 90mph i am in a for a rough ride so the design of the cage is most important and suggestions on reducing drag would be gratefully received

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    • Acidburn
      S2Forum Obsessed
      • Jun 2007
      • 13459
      • Country: United Kingdom

      #17
      tbh if it was me i'd start with an avant, they just feel 100% more planted than a coupe. But since you've got a coupe the cage will help.

      I've had 167mph on a couple of sat nav's in a modified avant and that felt fine at that speed and didn't take long to get there, be interesting to see what another 33/34mph would feel like tho as thats the hard bit. Good luck.

      Comment

      • UrS4boy
        S2Forum Obsessed
        • Feb 2006
        • 11859
        • Country: Canada

        #18
        Originally posted by Acidburn
        ...I've had 167mph on a couple of sat nav's in a modified avant and that felt fine at that speed and didn't take long to get there, be interesting to see what another 33/34mph would feel like tho as thats the hard bit.
        Any chance of a dyno print-out for your modified avant? What transmission are you running? What RPM was 167 mph at? (Just looking for data to help work out the hp requirements for 200 mph).
        RS2'd 93 UrS4 5 spd sedan
        94 UrS4 V8 6 spd manual avant

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        • Acidburn
          S2Forum Obsessed
          • Jun 2007
          • 13459
          • Country: United Kingdom

          #19
          I do have a dyno print out but will have to find it. It was a stock 6 speed and not sure what the rpm was unfortunately. I was too busy watching the road.

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          • UrS4boy
            S2Forum Obsessed
            • Feb 2006
            • 11859
            • Country: Canada

            #20
            Originally posted by Acidburn
            I do have a dyno print out but will have to find it. It was a stock 6 speed and not sure what the rpm was unfortunately. I was too busy watching the road.
            Yeh, no doubt you were watching the road (and the rearview mirror).

            If it is a stock S2 avant transmission the engine RPM can be estimated knowing the wheel/tire diameter. What were you running that particular day (if you can remember)?
            RS2'd 93 UrS4 5 spd sedan
            94 UrS4 V8 6 spd manual avant

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            • Acidburn
              S2Forum Obsessed
              • Jun 2007
              • 13459
              • Country: United Kingdom

              #21
              225/40/18's iirc.

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              • UrS4boy
                S2Forum Obsessed
                • Feb 2006
                • 11859
                • Country: Canada

                #22
                Originally posted by Acidburn
                225/40/18's iirc.
                The stock S2 avant trans (using 1994 as the example) is a CGR which has a 27/38 6th gear (i.e. 0.710:1 ratio). With the 225/40/18's the wheel/tire diameter would be in the vicinity of 25.09", i.e. 6.57 ft (2 m)/ revolution. Put that together with 4.11:1 diffs, the engine has to be turning 6550 RPM to achieve 167.4 mph (269.6 kph). I *suspect* it was just after the peak hp point on the dyno curve.
                Last edited by UrS4boy; 17 December 2012, 08:24.
                RS2'd 93 UrS4 5 spd sedan
                94 UrS4 V8 6 spd manual avant

                Comment

                • Acidburn
                  S2Forum Obsessed
                  • Jun 2007
                  • 13459
                  • Country: United Kingdom

                  #23
                  I'll try find the dyno print out and scan it in so you can have a look.

                  Comment

                  • here2learn
                    S2Forum Addict
                    • Feb 2012
                    • 325
                    • Country: United Kingdom

                    #24
                    i wasnt looking to up the rpm of the engine if at all possible


                    here is a link to the thread in relation to the 6th gear upgrade http://audisrs.com/archive/6th-gear-...__t_23627.html


                    failing a conventional build to give me the power i need that high in rev range there are a couple of possibilities i.e meth or nos

                    please do not feel i dont appreciate the input from all of you i have to admit that the engine is something i am not able to plan as i do not have a deep enough understanding of what can and can not be done within a budget of sack of potatoes

                    but i am building a shell at the moment so any advice upon aero and strength would be amazing i am properly scared of rolling from a blow out or just a poor bit of handling. with figures of 1000hp bouncing around these engines my main concern is safety as said before i need to go sailing around some remote islands trading coconuts an banging my missis on a glass calm bay at sunset.

                    not ready to die doing this

                    Comment

                    • terrybullwon
                      S2Forum Zealot
                      • Mar 2006
                      • 8782
                      • Country: England

                      #25
                      I have some one that will make you a longer 6th gear if you wish, it will be cheaper than mrc at £385 plus vat
                      Chef

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                      • here2learn
                        S2Forum Addict
                        • Feb 2012
                        • 325
                        • Country: United Kingdom

                        #26
                        that is quite a way down the line yet but i will be following that one up cheers will need to see your car for inspiration

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                        • here2learn
                          S2Forum Addict
                          • Feb 2012
                          • 325
                          • Country: United Kingdom

                          #27
                          so due to a number of issues every time i think i have a plan of attack i have to rethink.

                          i have now had a six point cage fitted into my original shell, this is a 45x2 cds cage with a 50 x 2 b pillar hoop, with single door bars for now. as the build progresses i will extend the cage through the bulkhead to the strut towers and will add more bracing all the way through but due to budget this is what i could afford for now.

                          i have also had some realy good advice in regards to over kill with the kind of parts i wanted to buy against the ones that can do the job for a price i can afford. so i have now picked up some front brake callipers and will be setting about the suspension in around sept when i am aware of budget for the winter.

                          will post pics when i collect the car tomorrow.

                          Comment

                          • bartolomeus
                            S2Forum Extremist
                            • Jan 2009
                            • 1475
                            • Country: Romania

                            #28
                            Audi S2 3B with 5 speed gearbox, 270 hp. I can hit 280 km/h easily... that's 173 mph. At 6500 RPM in fifth gear I have 280 km/h. 235/40/18.
                            I gave my car to my brother and he reported that he hit 7000 RPM in fifth gear...
                            It feels so easy doing 173 mph with my S2, I can't believe that for an extra 27 mph you have to have double the power

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                            • here2learn
                              S2Forum Addict
                              • Feb 2012
                              • 325
                              • Country: United Kingdom

                              #29
                              i have had quote anywhere between 400hp to 800hp to do this all i know is if it will cost the same to build a 500hp block or a 700 hp one might aswell get bang for buck but also make sure the power curve can be manipulated easily so i dont have to sit right up in the revs all the time.

                              i will understand in time

                              Comment

                              • Acidburn
                                S2Forum Obsessed
                                • Jun 2007
                                • 13459
                                • Country: United Kingdom

                                #30
                                Where are you planning on doing this? bruntingthorpe or elsewhere?

                                There is a real long thread on passionford about a top speed run someone was attempting in an rx7 (but smashed the car up beforehand) it has some good info in.

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