Rhyscar Posted January 20, 2019 Author Share Posted January 20, 2019 Been doing some more work/destruction on this after the summer break. I managed to motivate myself to have a racecar I can hoon around the country in in the near future (before travel/kids) so need to crack on. If I can get all the fab work and body painted in the next 12months I’ll be happy then I’ll just wait for a cash injection to finish it off adding the ecu and expensive bits. Have done some some work on the top of the fuel tank but not finished just yet I’ve come across a few challenges that are hindering further progress. (Mainly my brain not being able to figure out how it will work/come apart) Needed to remount my steering column as it had too much flex and wasn’t happy with it. Not finished yet but happy with the direction I’m heading in and getting good use of my pipe bender! makes mounting the motorbike dash and a few other things a lot easier too. 3 Quote Link to comment Share on other sites More sharing options...
Rhyscar Posted January 20, 2019 Author Share Posted January 20, 2019 Cut out the front tubs to make the appropriate clearance needed for the ride height and got a bit carried away with the grinder. Long story short I’ve got a bit carried away again and want to manage the airflow in the dead spaces of the car such as this from high pressure areas to reduce drag Made some cardboard CAD templates but not yet happy with the result so watch this space Decided the radiator support also will go once I replicate the headlight mounting points also as I won’t have a radiator in the front and will free up space for the air box. In summary not much actual progress but a swell of enthusiasm and motivation which is generally the predecessor to shit getting done! 3 1 Quote Link to comment Share on other sites More sharing options...
Rhyscar Posted April 1, 2019 Author Share Posted April 1, 2019 Have been making some progress on the first tub. Holyfuckshitballs it is heaps of work! Cooler will sit on top of the tub and be fed from bumper below as such. 4 Quote Link to comment Share on other sites More sharing options...
Rhyscar Posted April 1, 2019 Author Share Posted April 1, 2019 Will be vented out the bonnet when I get the rest of the ducting done 6 Quote Link to comment Share on other sites More sharing options...
Rhyscar Posted April 13, 2019 Author Share Posted April 13, 2019 Today’s progress. Headlight 95% mounted Quote Link to comment Share on other sites More sharing options...
Rhyscar Posted April 13, 2019 Author Share Posted April 13, 2019 Quote Link to comment Share on other sites More sharing options...
Rhyscar Posted April 13, 2019 Author Share Posted April 13, 2019 4 Quote Link to comment Share on other sites More sharing options...
Rhyscar Posted April 14, 2019 Author Share Posted April 14, 2019 so much room for activity at full lock. Time for some caster you say?? I’m really trying not to talk myself into making some bottom arms for this... 2 Quote Link to comment Share on other sites More sharing options...
Rhyscar Posted April 14, 2019 Author Share Posted April 14, 2019 Added a few more braces to the mounting without trying to make it too strong so frontal impact etc isn’t effected too much. Has some movement so I’m sure will rattle with solid engine mounts but shouldn’t effect night driving too much Hopefully saving some weight too I’ve cut heaps of shit out of the front end and not a lot going back in.. got oil cooler mounted and will start ducting that when I convert my shed back to Ali after I’ve finished all this mild steel fab. Any opinions on what colour/coating these headlight mounts should be?? They unbolt so I can remanufacture when I crash it/bend it. a) zinc passivated like subframes b) powdercoat white c) powdercoat gunmetal grey d) other options?? Im 76.9% sure engine bay will be painted white. Tossing up gunmetal cause it looks tidy but like the idea of the carpet matching the drapes etc. 3 Quote Link to comment Share on other sites More sharing options...
Truenotch Posted April 15, 2019 Share Posted April 15, 2019 I reckon white /white or white engine bay with gunmetal steel tube. 1 Quote Link to comment Share on other sites More sharing options...
Roman Posted April 15, 2019 Share Posted April 15, 2019 Def white engine bay i reckon. 1 Quote Link to comment Share on other sites More sharing options...
Rhyscar Posted April 16, 2019 Author Share Posted April 16, 2019 Yeah I’m liking the white on white option I think. Quote Link to comment Share on other sites More sharing options...
Popular Post Rhyscar Posted June 25, 2019 Author Popular Post Share Posted June 25, 2019 Been chipping away at this even though work has been crazy busy the last few months. Competed the front passenger tub and headlight tubeframe. Have left the inner quarter panel for now due to: a) I didn’t like what I did on the drivers side and need to change it and b) I couldn’t figure out the best solution here so will move on and come back to it when I find more enlightenment. So so much room for activities up front. Airbox is guna be huge!! so I bought my old road car back as a rolling shell that I sold to @Robbo a few years ago. I know it’s a tidy shell and still certed etc. don’t know what I’m guna do with it yet but for now it will sit in a shed at the farm just need an engine so may slap it together for something like 24hrs of lemons or other endurance racing event/get it back on the road and do some doorts or just keep it for when I eventually write off this shell (it will probably happen one day) Had a real lol moment when the strop broke and it rolled off the back of the trailer in the middle of Rotorua! Haha it came with a fibreglass bumper the same as the one I have for the racecar, spare facelift side skirts and most importantly a bumper support so I can mount the racecar one without more fab work woohoo! result is the front end is together for good now. Going to be challenging to drive anywhere on the road at this height (not a bad problem to have) while waiting on more materials for the exhaust I started ironing out my fuel supply pipework. Have used 1/2” stainless tube as an alternative to braided lines as I hate smelly fuel lines inside the car and the ID of 1/2” is the equivalent of -12an or something stupid so will be plenty big enough. Made some fuel line clamps lamps from some Ali I had lying around. Very happy with the result. any recommendations on fuel pump/filter to use? Want something reliable with a no-bleed back feature so I can run two pumps in parallel. Dont need much flow approx 200lph will be ok I think (need to check calcs) I’ve seen too many fuel pump failures at the track or beginning of stages that stop people completing events. Not going to take that risk. 15 Quote Link to comment Share on other sites More sharing options...
Truenotch Posted June 25, 2019 Share Posted June 25, 2019 It's so cool seeing this car on the ground with a front bumper and bonnet. Looks staunch as fuck. 4 Quote Link to comment Share on other sites More sharing options...
Rhyscar Posted June 25, 2019 Author Share Posted June 25, 2019 Thanks Markku. Yeah agree it’s the first time I’ve really seen it all together and it blew me away how low it was and how unlike a teenagers-first-car spec it is. Very motivating. In other news I’ve been doing some reading of this book that arrived. Interesting read even though some of the data/engines are old it’s still very relevant. Interestingly after a bit of ready I’m leaning towards a 4-1 stepped header instead of a 4-2-1. Not as much info on expansion chamber design as I’d hoped though. They damaged the book in transit so I’ve got a replacement on the way if you want it? 2 Quote Link to comment Share on other sites More sharing options...
Truenotch Posted June 25, 2019 Share Posted June 25, 2019 34 minutes ago, Rhyscar said: Thanks Markku. Yeah agree it’s the first time I’ve really seen it all together and it blew me away how low it was and how unlike a teenagers-first-car spec it is. Very motivating. In other news I’ve been doing some reading of this book that arrived. Interesting read even though some of the data/engines are old it’s still very relevant. Interestingly after a bit of ready I’m leaning towards a 4-1 stepped header instead of a 4-2-1. Not as much info on expansion chamber design as I’d hoped though. They damaged the book in transit so I’ve got a replacement on the way if you want it? I'd be keen for a copy. If you want some interesting header data, go over to KPR's starlet thread. He has a dyno now and has been testing a couple of different 4-1 headers (38 and 44mm) and tried a 4-2-1 and an expansion chamber a while ago too. Here's the link: Quote Link to comment Share on other sites More sharing options...
Rhyscar Posted June 25, 2019 Author Share Posted June 25, 2019 Oh thanks I dont so much os browsing these day I’ll take a look. Quote Link to comment Share on other sites More sharing options...
Truenotch Posted June 25, 2019 Share Posted June 25, 2019 You got me started... Now you receive homework... Some systems have them after the header, some have them on the header: Here's a reading list about anti-reversion chambers: https://crateinsider.com/using-anti-reversion-to-create-free-power/ https://thumpertalk.com/forums/topic/1075515-megabomb-header-explanation/ https://forums.seatcupra.net/index.php?threads/exhaust-design-and-anti-reversion.319359/ https://nasaspeed.news/tech/engine/the-art-of-scavenging-myths-and-methods-of-getting-burned-gases-out-of-an-engine/ https://nasaspeed.news/tech/engine/the-art-of-scavenging-myths-and-methods-of-getting-burned-gases-out-of-an-engine/ A bit about megaphones: https://www.hotrod.com/articles/post-collector-exhaust-add-ons-can-affect-exhaust-tuning/ ... This hole is almost as deep and weird as the black magic of 2 stroke expansion chambers... 2 Quote Link to comment Share on other sites More sharing options...
Rhyscar Posted June 25, 2019 Author Share Posted June 25, 2019 Yeah it is a black hole indeed. Interesting data about the megaphones. Looks very weighted towards v8 collector sizes though! The book describes them as tail pipes and has similar data around 7-10deg angle and lengths. There isn’t much about the angle of the reverse cone but my understanding is the steeper the angle determines the sonic power reflected and over what rev range. I suspect picking something in the middle of the recommended angles (similar to dads expansion chamber) is the way to go unless you are doing all the calcs and can test 2-3 designs. 1 Quote Link to comment Share on other sites More sharing options...
Truenotch Posted June 25, 2019 Share Posted June 25, 2019 I’m curious about whether reversion/reflection cone would ever be beneficial on a 4 stroke. The diversion cone makes sense to me - the taper creates expansion waves heading out and at the same time creates a negative pressure wave that heads back up the pipe to aid scavenging IF the wave is timed correctly. I don’t see why adding reversion would work on a 4 stroke because there’s minimal fresh fuel/air in the pipes to shove back into the cylinder. Quote Link to comment Share on other sites More sharing options...
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