112.8mph Lucky Poos Needed

What's Hot
1246714

Comments

  • FX_MunkeeFX_Munkee Frets: 2477
    The stock exhaust manifold and downpipe actually flow pretty well anyway IIRC (somebody tested them a long time ago). Just not shiny enough :)
    Shot through the heart, and you’re to blame, you give love a bad name. Not to mention archery tuition.
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • RiftAmpsRiftAmps Frets: 3113
    tFB Trader
    Silverstone GP - 27th October


    I have to admit that since I was a small boy, I've dreamed about racing at Silverstone. Not just on the National or International circuits mind, but the entire F1 layout - all 3.661 miles of it.

    This coming Sunday, I get to do that.

    Silverstone is such a large venue that both the National and International layout can be used at the same time, so not uncommon to find two club meetings on the same weekend. The 750MC Summer meeting at Silverstone National (22/23rd June) was cancelled owing to the full resurfacing work ahead of the British GP.

    Every year, the 750MC run a 6hr race called the Birkett Relay on the GP loop, where teams of multiple cars run in a relay fashion. Apart from the Race of Remembrance in November at Anglesey, it's considered the be the last hurrah for the club racing season.

    The Birkett relay runs this Saturday 26th October, so as the 750MC was already at the circuit and the full layout was configured, they pulled in a few favours and managed to bag an extra race meeting for the following day. Allowing all those who missed out in the Summer to get a chance to race at Silverstone.

    A standard club meeting on the GP layout is practically unheard of, so of course, we jumped at the chance.

    We're testing on Friday as usual. Unlike MSV testing which is 4 x 30min sessions, this is open pitlane so we will get far more running in.

    In order to break the 3-minute lap time barrier, we'll need an average speed of 73.4mph which hopefully we can manage.


    Who's racing?

    - Royal Purple Hot Hatch Championship
    - Demon Tweeks Classic Stock Hatch Championship
    - BMW CCR Championship
    - Tegiwa Roadsports Series
    - Tegiwa Club Enduro Championship


    Prep

    Engine - After our engine blew up at Snetterton, we removed the cylinder head and saw that the head gasket had blown. I fully stripped the head, had it skimmed at the machine shop and then I reassembled it - all in one day.

    Yesterday we refitted the head, drained and refilled both the coolant and oil, fired it up and voila - back to normal :)


    Tyres - We've bought a full set of wet tyres (Uniroyal Rainsport 3s) in case it rains - our dry tyres aren't bad in the wet, but we may as well have a wet set at only £40 per corner and maximize our performance.

    Exhaust Manifold - stock manifold and downpipe arriving Tuesday along with the bell housing mounting bracket. Hopefully no more cracks!


    Tickets

    From £10 each, children under 16 go free.



    Live Stream

    All races are being live-streamed by Alpha Live on YouTube. Our Race is at 11:40 am.





    Our last chance for some silverware - let's go.
    *I no longer offer replacement speaker baffles*
    Rift Amplification
    Handwired Guitar Amplifiers
    Brackley, Northamptonshire
    www.riftamps.co.uk

    0reaction image LOL 2reaction image Wow! 0reaction image Wisdom
  • FX_MunkeeFX_Munkee Frets: 2477
    Jealous? Moi?
    Great opportunity for you, that sounds fantastic.
    I've got 2 spare exhaust manifolds and downpipes in the garage, lol.
    And coincidentally I run Rainsport 3's on my BMW daily driver. They're very good in the wet and nice and progressive when they start to slip, no sudden surprises.
    Shot through the heart, and you’re to blame, you give love a bad name. Not to mention archery tuition.
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • RiftAmpsRiftAmps Frets: 3113
    edited October 2019 tFB Trader
    Silverstone Race Report


     Testing

    Friday testing was wet, varying from greasy to full-on apocalyptic monsoon. This gave us the opportunity to try out our new wet setup - softer damper settings and full wet tyres. Something amazing happened, I could drive the car with the same level of confidence as I do in the dry. The only difference is the extended braking zones and the lines that you take through the corners. Having taken a confidence knock at Snetterton in the wet I was now feeling great about our wet performance. Both Nick and I set identical fastest wet laps - 3:02s - which was very close to our 3-minute (73.4mph average) target and crucially within 1 second of our competitors.

    The Uniroyal Rainsport 3s are brilliant, although amazingly when the track started to dry up a little their performance dropped off, I was 4 seconds per lap slower in those conditions than I was in full wet. When it started raining again I started to go faster - mad!

    One thing I did notice was how strong the slipstream is around SS. Get behind a car and they suck you along gaining 8+mph. Three long straights and it quickly adds up to free lap time.

    A good day's testing on an incredible circuit.


    Qualifying

    The weather on Sunday was sunny but cold. We put a full dry setup on the car as the track was drying quickly and I went out first to set my three laps. A cold, damp(ish) track + cold tyres + low tyre pressure = scary shit. The car was all over the place, I could not get the tyres up to temperature so I was sliding all over the place. I actually went slower in the dry than I had done on Friday in the wet. We swapped over and Nick went out in much better conditions and set a 2:56.83 lap to put us P5 in class.


    Race

    Remember the orange Toyota MR2 from Cadwell Park? Well, he was back for more.

    Nick started the race and spent 6 laps fighting and being blocked by the big orange buffoon. He's clearly got the power on the straights but has very little cornering performance. Just watch the opening few laps below to see a great Class D vs Class C battle. Unfortunately, by the time the Class A leaders started to lap us he'd managed to get away and Nick couldn't do anything to stay with him. The top 3 in the class had disappeared by this point so we were out in no-mans land. We were half a lap ahead of P5, whilst P6 had retired.

    We were running in P4 at the time Nick brought the car in to swap drivers. Our pitstop was an absolute mess and we lost 15 seconds trying to get the harnesses done up. I took the car out and just set consistent laps to bring it home in P4. We were hoping for someone to retire at the front so we could get a podium, but that didn't happen. P4 felt good though in a car that now feels awesome to drive. We lapped in the 2:50 - 2:52 range all race, which is great. The class winner did a 2:42.99 - so some way still to go :)




    We still feel that the car is down on power, or more accurately doesn't accelerate as fast as the others. Watching the onboard footage of another MX5 in the race confirms this. The plan is to now optimize our powertrain and transmission, with a freer revving engine, lighter flywheel and clutch, a higher ratio LSD (4.7). We figured that whilst the car's top speed to relatively low, we want to get there quicker than anyone else.

    Other plans for next season included a big brake conversion (1.8) and switching to a different brand of dry tyre. We run Giti GTR2s from the Funcup series but want to try the more popular Nangkang NS2Rs or similar.


    No trophies in our first full season of racing, and many hurdles have been jumped, but we've both learnt a lot and it's been worth every penny.






    *I no longer offer replacement speaker baffles*
    Rift Amplification
    Handwired Guitar Amplifiers
    Brackley, Northamptonshire
    www.riftamps.co.uk

    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • Thanks for sharing your experiences. I'd love to do that. I settle for my MX5 (with Rainsport 3s coincidentally?) as my daily driver though. 
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • RiftAmpsRiftAmps Frets: 3113
    tFB Trader
    Now that the season's racing is over and I've got to wait until April to get out on track again (I had planned to enter the Plum Pudding races at Mallory Park on Boxing Day but bloody family gets in the way!) it's about time to start thinking about next year and what we plan to do.

    Firstly, now that my Novice cross can come off it's time to level up my gear with a custom paint job on my helmet. Here's the design that we came up with. The brief was "Red, black, and aggressive". Think we nailed it. Love the way they've incorporated the F into the main design.

    When it's back from the paintshop I'll take a few pics to show you all.


    Secondly, I've got a new engine to build :)

    This was an engine that I disassembled earlier in the year and have had the parts sitting around for ages waiting for me to get on with it. The idea is to have a bulletproof bottom end that'll go on forever, and a high-performance cylinder head that'll eventually take ITBs when we decide to move up a class.

    I sent to the cylinder block to my machinist, who along with a basic deck skim has overbored the cylinders to the next standard size up (78mm to 78.25mm) taking it from a 1.6 to a 1.61 - phwoar. I know that sounds silly but the weight of the removed material outweighs the increase in piston size, resulting in a slightly lighter engine and a higher compression ratio.

    The new pistons are not forged but I've taken the opportunity to buy forged connecting rods. The conrods in the B6 engine are the weakest point by far, so a lighter forged set is definitely the way to go.




    The first job was to fit new brass core plugs into the block before painting it black (all race engines are black). I hate the gloss enamel look so went for a VHT satin instead. The plug on the end of the block is covered by the gearbox bell housing so it didn't get painted. They're fitted by hammering them in level with the outside edge coated in RTV sealant.



    Here you can see the cross-hatching on the cylinder walls





    Here's the underside of the block. You can see where the crankshaft would sit in the journals. It'll be held in place by the main caps with bearings in-between.



    As a hangover from its time as a turbo engine in the Mazda 323, the B6 block has the luxury addition of piston oil squirters, firing high-pressure oil right at the underside of the piston to help cool them down. Absolutely not needed in a low powered NA street application but arguably useful in a race engine. When I took these out they were gummed up with sludgy oil and varnished, so a soak in brake cleaner and a tidy up on the brass wheel made them looking like new.



    All four are fitted into the block with a little thread-locker and torqued to 18Nm.



    More to come soon
    *I no longer offer replacement speaker baffles*
    Rift Amplification
    Handwired Guitar Amplifiers
    Brackley, Northamptonshire
    www.riftamps.co.uk

    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • That's a great write up, after a good 2019.
    Best of luck for 2020.
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • NelsonPNelsonP Frets: 3347
    Sounds like you are making some real progress and there's a podium coming soon. Love that new lid - that's worth at least half a second.

    This thread is a really insightful look into the reality of motor racing. You clearly have skills (and presumably tools and equipment) that I could only dream about.

    Can I ask, why didn't you use genuine con rods? Are the forged ones better? Da dum, tsss - I'm here all week!
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • FX_MunkeeFX_Munkee Frets: 2477
    Absolutely right about the con rods being the weakest link but you're probably going to get more out of the new ones purely on lightness and balance seeing as you're not using forced induction. It would allow you to skim it quite aggressively though.
    Are you doing anything to the crank? balancing, knife edges? And don't forget an oil scraper whilst you're down there :)
    One day I will rebuild the spare engine I have in the garage, one day...
    Shot through the heart, and you’re to blame, you give love a bad name. Not to mention archery tuition.
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • RiftAmpsRiftAmps Frets: 3113
    tFB Trader
    NelsonP said:
    Sounds like you are making some real progress and there's a podium coming soon. Love that new lid - that's worth at least half a second.

    This thread is a really insightful look into the reality of motor racing. You clearly have skills (and presumably tools and equipment) that I could only dream about.
    Messing around with engines fulfils that little bit of my technical side that I don't get from designing/building guitar amplifiers. After all, it's only nuts and bolts ;)

    FX_Munkee said:
    Absolutely right about the con rods being the weakest link but you're probably going to get more out of the new ones purely on lightness and balance seeing as you're not using forced induction. It would allow you to skim it quite aggressively though.
    Once I've got the head onto the block and I'm at the stage where I'm degree-ing the camshafts I can also check piston-valve clearance at the same time. When I know that I can work out how much to skim off the head next time. Absolute minimum clearances are 0.080" on the inlet and 0.100" on the exhaust side so I'd like to be within 0.005" of that if I can.

    FX_Munkee said:
    Are you doing anything to the crank? balancing, knife edges? And don't forget an oil scraper whilst you're down there :)
    One day I will rebuild the spare engine I have in the garage, one day...
    The whole rotating assembly (crank, rods, pistons, rings etc) has been balanced to within 1gram. Crank has been polished too.

    As I go through the build I'll explain everything in more detail.
    *I no longer offer replacement speaker baffles*
    Rift Amplification
    Handwired Guitar Amplifiers
    Brackley, Northamptonshire
    www.riftamps.co.uk

    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • RiftAmpsRiftAmps Frets: 3113
    tFB Trader
    Next job...

    There's a turbo oil return pipe on the block that's not used, so it gets covered up with a rubber cap and jubilee clip. An oil filter is fitted at the same time, not forgetting to lube that ring.


    Our next job is to measure the crankshaft journal/bearing oil clearance. As the crankshaft is spinning around a small layer of oil needs to be able to lubricate the bearings and journals. The workshop manual requires a gap of just 0.0007 - to 0.0014 inches - less than the width of a human hair - with a maximum gap of 0.004 inches.

    To measure the gap we have to dry-fit the crankshaft into the engine, along with the bearings and main caps, and then tighten down to factory specification. Something called Plastigauge is placed in between the journals and bearings and this is used to measure the gap after it's been squashed.

    I'll explain...

    Bearings installed in the crankcase after a thorough cleaning of all surfaces




    Thrust washers (limits side to side movement of the crankshaft) installed in journal #4




    The crankshaft is then placed into the block, taken extra care not to rotate it even the slightest.



    The Plastigauge is placed onto each journal (little green strips)



    The other halves of the bearings are placed into the main caps



    Before being fitted and torqued down in three equal steps to 58Nm.

    I did 25Nm, 42Nm, 58Nm.



    Undo them all, remove the caps, and you can see the Plastigauge has been squashed down



    Using the supplied measuring tool, you can now see how much oil clearance you have.

    All 5 were approximately 0.002" which is 0.0006" oversized but way short of the 0.004 maximum. This makes sense as the crankshaft has been polished so would be smaller than normal, creating a slightly larger gap.

    I'm happy with these measurements and can now move forward. If the gaps were too big we'd have to fit oversized bearings and have the crankshaft machined to match.




    Next step is to clean the block again before installing the crankshaft properly.
    *I no longer offer replacement speaker baffles*
    Rift Amplification
    Handwired Guitar Amplifiers
    Brackley, Northamptonshire
    www.riftamps.co.uk

    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • droflufdrofluf Frets: 3614
    edited November 2019
    @RiftAmps ;so the width of the compressed Plastigauge tells you the clearance?
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • RiftAmpsRiftAmps Frets: 3113
    tFB Trader
    drofluf said:
    @RiftAmps so the width of the compressed Plastigauge tells you the clearance?
    Correct!


    *I no longer offer replacement speaker baffles*
    Rift Amplification
    Handwired Guitar Amplifiers
    Brackley, Northamptonshire
    www.riftamps.co.uk

    0reaction image LOL 0reaction image Wow! 1reaction image Wisdom
  • droflufdrofluf Frets: 3614
    Thanks!
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • rsvmarkrsvmark Frets: 1373
    Nice thread.... i like the lid design too- a touch off an updated EVH design!
    An official Foo liked guitarist since 2024
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • RiftAmpsRiftAmps Frets: 3113
    tFB Trader
    rsvmark said:
    Nice thread.... i like the lid design too- a touch off an updated EVH design!
    Yes, it is a bit EVH, seems appropriate :)


    Crankshaft install time!

    After cleaning both the bearings and mating surfaces again (I just use brake cleaner and a lint-free cloth), I apply a generous coating of engine assembly lube to the bearings. Assembly lube is used in high-load areas such as bearings, camshafts etc. Unlike engine oil, it sticks for much longer offering better protection during first start-up. Eventually, it gets replaced by engine oil and is drained out during an oil change.

    This stuff is quite thick and is applied with a brush.





    The crankshaft is then lowered into the block




    The bolts are lightly dipped in oil...


    ...and placed into the main caps before being torqued in our three-step sequence to 58Nm.



    Now, I messed up. I found it very difficult to turn the crank over when it should be free spinning. Quickly realised that I'd put two of the main caps in the wrong places. Swapped them over and I can now turn it over with one hand - so smooth!


    *I no longer offer replacement speaker baffles*
    Rift Amplification
    Handwired Guitar Amplifiers
    Brackley, Northamptonshire
    www.riftamps.co.uk

    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • RiftAmpsRiftAmps Frets: 3113
    tFB Trader
    Next up is fitting the rear main oil seal.

    The seal is placed into its bracket  - btw Mazda call it a cover - before a bead of RTV is applied to the lower half



    Lube up the end of the crankshaft...



    ...before slipping the bracket and seal over and locating to the block with the dowel pins. A light tap with a rubber mallet lines it all up.



    Four bolts hold it in place, torqued to 11Nm.



    The last job is to check crankshaft end-play - how much the crank moves forward to back - this is dictated somewhat by the width of the two thrust washers in journal #4. Factory spec is between 3 thousands of an inch and 11 thou (0.003 - 0.011). My machinist recommends aiming for the lower side of that range.

    Set up a dial gauge on the end of the crank with it all pushed all the way one side...



    ...and move the crank as far as it will go with a crowbar and see how far it moves.

    We get 5thou (0.005) which is perfect!


    If we were out of spec, larger thrust washers could be ordered or I could take a few thou of the current ones with sandpaper if we needed to go the other way.

    Oil pump install next
    *I no longer offer replacement speaker baffles*
    Rift Amplification
    Handwired Guitar Amplifiers
    Brackley, Northamptonshire
    www.riftamps.co.uk

    0reaction image LOL 1reaction image Wow! 0reaction image Wisdom
  • NiteflyNitefly Frets: 4902
    Excellent, I'm really enjoying this.

    Will you be getting up t't'north next year, e.g. Oulton?

    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • RiftAmpsRiftAmps Frets: 3113
    edited November 2019 tFB Trader
    Nitefly said:
    Excellent, I'm really enjoying this.

    Will you be getting up t't'north next year, e.g. Oulton?

    Ah man I’d love to race at Oulton Park and fingers crossed it’s on next year’s calendar - hopefully they’ll announce soon
    *I no longer offer replacement speaker baffles*
    Rift Amplification
    Handwired Guitar Amplifiers
    Brackley, Northamptonshire
    www.riftamps.co.uk

    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
  • rsvmarkrsvmark Frets: 1373
    Oulton park is my favourite track on a bike. If it translates to cars you will have a blast!
    An official Foo liked guitarist since 2024
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom
Sign In or Register to comment.