m1tch_87 Posted February 4, 2016 Share Posted February 4, 2016 Hi all, I am new to RCs but I am wanting to build up a car to run at a ROSSA event, I enjoy drag racing and was looking at building something to take to the salt flats for land speed records etc, but I figured that RC records are slightly more cost effective plus the fact that its slightly more fun in terms of tuning and tweaking. I wanted to start a thread on here with my initial thoughts on the project and what my research has lead me to - will also need some input as well! Basically I will be going with a IC or EC engine - might look at different things like steam turbines as well, not really interested in electric so will probably go with a nitro engine, I might also look to make engine parts myself on a lathe rather than off the shelf. I am still deciding which class to enter into, tempted to go with the mini class or the IC open class as then I would have the flexibility of engine size rather than the small block/big block engine limitations. The car will only be used for straight line speed but need to decide on a chassis - tempted to see if I can get a basic cheap chassis off the shelf and then mod the components to give additional space for the engine etc if going the IC class or indeed find a 1/12 scale chassis and look to uprate the power. I am quite tempted by the mini class as these will be small and lightweight plus an open choice of engine etc - this would mean that I could go with a small chassis but powerful engine to give a good power to weight. Please note that I am a complete newbie to all this but will be researching into the hobby to see what off the shelf parts I could look to get as well as the tuning options. Happy to take any feedback on the idea, nothing is set in stone, just out to have a bit of fun tuning without the project taking up loads of space! Quote Link to comment Share on other sites More sharing options...
Carpmart Posted February 4, 2016 Share Posted February 4, 2016 Good to have you on board and interesting in participating in the ROSSA events. I guess you need to expand your thinking and move from musing about what your doing, to having a concrete plan. I shall watch with interest and help where I can! Quote Link to comment Share on other sites More sharing options...
ajlovering Posted February 4, 2016 Share Posted February 4, 2016 Hi Dave. I'm in this forum also. There are a few things to consider. If you are looking at IC then I would start with a 1/10th or 1/8th on road car and just up the gearing. People that have done this in the past can get up to just over 100mph but over that seems to be a challenge. Radio range is an issue if you are trying for high speeds with IC. The Futaba system is pretty good with range but if you want to have max range try the Immersion 459mhz system. If you need any specific info let me know Cheers Quote Link to comment Share on other sites More sharing options...
m1tch_87 Posted February 4, 2016 Author Share Posted February 4, 2016 (edited) Thanks guys, I am still looking at options, interested in the IC open class as it states any engine size (but limited to chassis size) - I have a 37cc Blata B1 engine in the garage, compact 2 stroke which would make around 8.5bhp, although might look into some of the air cooled 50cc engines, my thought is to run the single gear with a certain gearing to give the top end I am wanting. Due to the very compact nature of the engine it should easily fit within the maximum 300mm x 1500mm class size. I could then therefore look for a rolling chassis and see how best to mount the engine as well as the bodywork around it, I can then uprate the range of the transmitter further - would transmitters/receivers from some of the RC aircraft be ample? I guess I could look to get a nitro 1/10th or 1/8th scale model with standard nitro engine and mod that plus gearing, then when I am in need for additional power I can then use that chassis and running gear to have the different powerplant. Is there a particular make I should look to go for to allow me to get the most in terms of bodywork or are they all interchangeable? I am in the researching phase at the moment to see what platform and goal I should go with. I am thinking that the mini class might not be for me due to the smaller scale and I am guessing preference towards the light electric powerplants. I am thinking of trying this in stages: Stage 1 - Find a chassis in 1/10 or 1/8 scale with a small block/big block nitro engine and get used to tuning it as standard Stage 2 - Mod the stock setup with gearing changes, bodywork changes, engine work Stage 3 - Add on more extreme mods to the engine such as a supercharger or nitrous Stage 4 - Run in the IC small block/IC big block class Stage 5 - Research and build a more powerful engine setup Stage 6 - Modify the stock chassis to accept the different powertrain setup Stage 7 - Run in the IC open class Thoughts on the above? I know that this might be a bit of a faux pas on this forum but I have noticed that you can get a cheap 1/10th scale FTX Carnage NT with the small block 0.18cu engine it also has a low CofG it seems which might make it ideal for prototype bodywork. Am I correct to say that the engine mods are free as long as the engine is still 0.18cu eg no bore kits? Edited February 4, 2016 by m1tch_87 Quote Link to comment Share on other sites More sharing options...
m1tch_87 Posted February 5, 2016 Author Share Posted February 5, 2016 Having another think about the different classes, there are a few classes I could enter by modding the same car: Small IC - with the .18cu engine, streamlined body IC Open wheel - with a larger 0.45cu engine, partly streamlined but not covering the wheels IC Open - larger engine still to be decided, streamlined body - although the IC open wheel 0.45cu engine might yield a better power to weight Non wheel driven, pulse jet subclass - try and build a small model pulse jet to fit in a custom chassis (unsure if anyone has a record for this subclass yet) Quote Link to comment Share on other sites More sharing options...
ajlovering Posted February 5, 2016 Share Posted February 5, 2016 Hi Dave I would consider a 2nd hand 1/10 nitro car and fit a 0.18 OS engine. That should get you heading in the right direction Engine mods are allowed. I have tried almost everything to modify engine and found some things that work and a lot of stuff that doesn't The thrust class doesn't have an official sub class. Pulse jets are really cool but the actual power compared to the weight is terrible. If you want to go fast there are plenty of easier alternatives. I have a B300F turbine I'm selling. 72lbs of thrust if your interested. Check the projects section of the Fast-RC forum for the Dash Hound car. Also check put Dale Cotes solid fuel rocket car. I have predicted he will win the outright speed for 2016 with something in the region of 230mph. Hes in the USA so has restrictions on engine sizes. In the UK there isn't those restrictions :-) Cheers 1 Quote Link to comment Share on other sites More sharing options...
m1tch_87 Posted February 5, 2016 Author Share Posted February 5, 2016 42 minutes ago, ajlovering said: Hi Dave I would consider a 2nd hand 1/10 nitro car and fit a 0.18 OS engine. That should get you heading in the right direction Engine mods are allowed. I have tried almost everything to modify engine and found some things that work and a lot of stuff that doesn't The thrust class doesn't have an official sub class. Pulse jets are really cool but the actual power compared to the weight is terrible. If you want to go fast there are plenty of easier alternatives. I have a B300F turbine I'm selling. 72lbs of thrust if your interested. Check the projects section of the Fast-RC forum for the Dash Hound car. Also check put Dale Cotes solid fuel rocket car. I have predicted he will win the outright speed for 2016 with something in the region of 230mph. Hes in the USA so has restrictions on engine sizes. In the UK there isn't those restrictions :-) Cheers Thanks for the input, I will have a look at what is out there and perhaps buy something next month, I think I will go with a 1/10th scale car with the 0.18 engine to start with - I have found with things like mountain bikes that its usually better to buy a good branded 2nd hand one rather than a cheap new one - guess this might be the same with RC cars. I will have a think about engine mods but the gearing will also play a part and I will also be looking into forced induction as well to be able to pull the slightly longer gearing - I am guessing I can't run a hybrid setup with an IC engine with an electric boost? I will start off the IC engines and then perhaps work towards a solid fuel setup, I know pulse jets are pretty low power and so wouldn't be competitive but would be a bit of fun! I might also look to make some 'R Candy' which is a way to make your own solid rocket fuel, might be an interesting idea. Quick question on the length of track for the speed events - guessing there is a fair sized runway or drag strip with timing gates half way down? Just seeing how much acceleration I would need to get to the top speed in the space required. With regards to the turbine, I think I will stick with the IC for this year, will then work my way up once I get experience - remember that I am a complete newbie to the sport! Looks like the plan for this year would be to run in the Small IC class this year with a mods to the bodywork, tyres, suspension, gearing and a few engine mods - will actually be interesting to see what happens with speed runs with a stock body vs a custom one as well. Looking forward to getting cracking with this project now that I have a few things figured out and a possible upgrade path! Quote Link to comment Share on other sites More sharing options...
ajlovering Posted February 6, 2016 Share Posted February 6, 2016 The run up at Shakespeare isnt great. you have about 400m max to the speed traps. If you are looking to go faster we have a practice event at Llanbedr in April and in September. this is 1.3 miles of super smooth tarmac. The weather normally comes into play and its a closed airfield so lots of red tape Cheers Quote Link to comment Share on other sites More sharing options...
m1tch_87 Posted February 6, 2016 Author Share Posted February 6, 2016 (edited) 1 hour ago, ajlovering said: The run up at Shakespeare isnt great. you have about 400m max to the speed traps. If you are looking to go faster we have a practice event at Llanbedr in April and in September. this is 1.3 miles of super smooth tarmac. The weather normally comes into play and its a closed airfield so lots of red tape Cheers Thanks for the info, need to get a chassis and start work on some ideas, might see where there is open space around near me, Llanbedr is a fair way away so might look to be at Shakespeare for an initial speed run this year and see what the gearing is like. I might also look to find a simple speed GPS unit to put in the car so that I can measure the speed the car gets to with various combos - I know that this wouldn't be for record runs but more for testing. I am also tempted to look into diesel conversion heads - might even look to make my own with a spare engine, the .18 engines seem fairly cheap to buy to test out. Edited February 6, 2016 by m1tch_87 Quote Link to comment Share on other sites More sharing options...
Wrighty8766 Posted February 6, 2016 Share Posted February 6, 2016 1 hour ago, ajlovering said: we have a practice event at Llanbedr in April and in September. this is 1.3 miles of super smooth tarmac. Just wondrring, with these being practice events do any of the recorded speeds qualify? Or are they not official with it being practice? Quote Link to comment Share on other sites More sharing options...
mayzie12 Posted February 6, 2016 Share Posted February 6, 2016 17 minutes ago, Wrighty8766 said: Just wondrring, with these being practice events do any of the recorded speeds qualify? Or are they not official with it being practice? If its through the traps and then speed on the two traps are within a margin of error, its official Quote Link to comment Share on other sites More sharing options...
Wrighty8766 Posted February 6, 2016 Share Posted February 6, 2016 If its through the traps and then speed on the two traps are within a margin of error, its official Good stuff There's me thinking that we only have one chance to get an official recorded speed Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
m1tch_87 Posted February 7, 2016 Author Share Posted February 7, 2016 I have now sourced an initial chassis for this project, it is indeed a 1/10 scale FRX carnage, the reason why I went for it is that most of the parts are metal, there are many upgrades and spares, it uses the cheap GO18 engine plus overall it seems to give quite a bit of car for the money. It's an eBay purchase but from the many photos it doesn't seem to have been run much, I will be checking everything over and taking most of it apart to check anyway though. Another reason why I bought it is that with the buggy/truggy set up I can run in both small IC and open wheel classes depending on which body it's running. I know that the GO18 engines aren't exactly high spec but that's probably due to the fit and finish, I will be pulling the engine apart anyway and might look into porting at some point. I will take some photos once it arrives, need to make some measurements on ride height and order some shorter shocks etc, will also look at wheel choice as I will use larger wheels as part of the gearing. I have found a local bashing group who meet up at an airfield so should be good to test and trial things. With regards to bodywork, I am going to see if I can find an LMP body like a Lola in 1/10 scale, will also be looking at under trays, lip splitters and diffusers. Initial though I just need to sort out the ride height with the suspension, might even look into fitting some 1/8 scale wheels if I do get around to making a custom body. Question on the mini class though - is the engine choice free or does it need to run the stock nitro engine? I only ask as there are nitro mini cars with the small .09 engine, perhaps upgrading to a larger engine might make it competitive in that class. Quote Link to comment Share on other sites More sharing options...
ajlovering Posted February 7, 2016 Share Posted February 7, 2016 Quote Looking at the carnage I would go for the IC open wheel class. I wouldnt bother with the Go engine. Get something decent to put in like a novarossi .28 or similar 1 Quote Link to comment Share on other sites More sharing options...
m1tch_87 Posted February 7, 2016 Author Share Posted February 7, 2016 (edited) 2 hours ago, ajlovering said: Looking at the carnage I would go for the IC open wheel class. I wouldnt bother with the Go engine. Get something decent to put in like a novarossi .28 or similar Thanks for your insight, I will perhaps use the used GO engine it currently has as a test engine then to try out different combos at lower speeds and test (and indeed practice) to make sure that everything is working. I can see that the maximum engine size for the open wheel class is 0.45/7.5cc so I will look to upgrade to a larger engine for the speed runs - will also weigh up between a smaller engine with higher RPMs and a slightly larger engine with lower RPMs. Will initially start learning on the GO 18 engine initially though being new to the hobby, will then ramp up the speed and performance by swapping out the engine - thanks for your advice! I have also figured out a way of testing the speeds onboard - I can use an old phone and download a GPS speedo app which gives me the top speed - although not perfect it will still give an indication as to how the tuning is going. Having a think about the options I have I am going to aim for the IC Open wheel class record - might still see how close I am with the IC small block as well - the current records for both are only a few mph in it although the IC open wheel class would need more power due to the extra drag. Edited February 7, 2016 by m1tch_87 Quote Link to comment Share on other sites More sharing options...
.AJ. Posted February 7, 2016 Share Posted February 7, 2016 I use this GPS logger, it was £35 off eBay 1 Quote Link to comment Share on other sites More sharing options...
m1tch_87 Posted February 7, 2016 Author Share Posted February 7, 2016 1 hour ago, .AJ. said: I use this GPS logger, it was £35 off eBay Ah that looks good, will see what the phone is like but as it's only £35 I might upgrade to that. Interested to see what speed the standard car can do as well. Quote Link to comment Share on other sites More sharing options...
Wrighty8766 Posted February 7, 2016 Share Posted February 7, 2016 You can also pick up a used garmin forerunner 101/201 off eBay for £15-£25, they work well too 1 Quote Link to comment Share on other sites More sharing options...
mayzie12 Posted February 7, 2016 Share Posted February 7, 2016 On 06/02/2016 at 11:34 AM, ajlovering said: The run up at Shakespeare isnt great. you have about 400m max to the speed traps. If you are looking to go faster we have a practice event at Llanbedr in April and in September. this is 1.3 miles of super smooth tarmac. The weather normally comes into play and its a closed airfield so lots of red tape Cheers Any ideas yet when the practice is in April Tony? Quote Link to comment Share on other sites More sharing options...
m1tch_87 Posted February 7, 2016 Author Share Posted February 7, 2016 27 minutes ago, Wrighty8766 said: You can also pick up a used garmin forerunner 101/201 off eBay for £15-£25, they work well too I have seen those as well so will see what the easiest option is, would be good to get a good base speed. What is the main fluid dynamics program people are using to test shapes etc? Quote Link to comment Share on other sites More sharing options...
m1tch_87 Posted February 7, 2016 Author Share Posted February 7, 2016 Also another question on the open wheel class, would the below former land speed record holder, the Golden arrow, be classed as open wheel? It doesn't have any covers over the wheels, or does the open wheel class have to be basically a buggy? Quote Link to comment Share on other sites More sharing options...
m1tch_87 Posted February 8, 2016 Author Share Posted February 8, 2016 (edited) I have had a good think about the open wheel class and my ideas on the car last night, mainly thinking about how the aero works in other sports like F1, Here are a few ideas that I will look to implement: Lowest ride height I can get - will ensure that the lower A arms are parallel so that I don't have issues with grip if there is too much negative camber - will be looking to fit shorter shocks which I can always add in preload clips to raise the ride height. I also have an idea to ensure that I can get the lowest chassis possible without messing the suspension settings up. Use of gel scuff strips down each side of the under chassis - these would be there to protect the underside of the car if it bottoms out but also to channel air under the car, partly like the skirted F1 cars in the 80s and 90s. Buggy bodywork to give the narrowest frontal surface to the air. Rounding/aero work on the leading edge of the suspension struts - much like the struts on a biplane. Covers on the back of the wheels to avoid turbulence as used in F1. Enclosing the top and bottom surfaces of the suspension arms to keep smooth airflow. Ensure any turnbuckles on the suspension are aerodynamic. Ensure that the exhaust is within the bodywork rather than overhanging chassis. The engine will be protruding out the rear part of the bodywork but I will be putting some additional ducting at the side of the engine to channel air through the cylinder head to the rear. Use of shock socks on the shocks to smooth airflow around those. Suspension struts will be angled to improve the stability, might even consider drilling holes further down to increase the angle plus reduce frontal area. Maximum anti squat on the rear. Wheel diameter for the class is a minimum of 90mm (3.5"), will look to find/make wheels that are around the 3" mark and then add on a tyre, will look to run slick/autocross type tyres. I will look to do some 'tuft testing' using cotton and a fan as a basic DIY wind tunnel, mainly to ensure that air is flowing correctly around the front suspension as well as after the engine cylinder head. I will also see if I need a rear wing but I have a feeling that it might be stable at higher speeds, I could look to fit a fin the rear after some testing though. Plan to use the GO 18 engine for testing, will then swap the engine out to something more powerful, still deciding which engine to go for as the class allows up to a .45, however the larger engine displacements do have a trade off with less maximum RPM. I will also look to get a 2 or 3 speed gearbox, I believe the upgrade gearbox on this car is a 2 speed with the 1 speed being standard - parts are cheap though but will also look to change to metal. Edited February 8, 2016 by m1tch_87 Quote Link to comment Share on other sites More sharing options...
ajlovering Posted February 8, 2016 Share Posted February 8, 2016 Dave This is the class definition for the IC Open Wheel IC Open Wheel Vehicles are classified open wheel if they meet the following criteria · Any Buggy, Truck or Truggy based kit · Single IC engine up to 0.45 Cu in or 7.5cc · Body shell must not cover the wheels · Wheel diameter to be min 90mm · Stock kit chassis with commercial available upgrades Quote Link to comment Share on other sites More sharing options...
Tamiyacowboy Posted February 8, 2016 Share Posted February 8, 2016 Fluid dynamics : you can do this kind of modeling with Blender, but be warned its for those who can already or do have a grasp on 3d modeling. heres a video of an airfoil fluid dynamics model using blender https://www.youtube.com/watch?v=WXq2fdArijM Quote Link to comment Share on other sites More sharing options...
m1tch_87 Posted February 8, 2016 Author Share Posted February 8, 2016 4 hours ago, ajlovering said: Dave This is the class definition for the IC Open Wheel IC Open Wheel Vehicles are classified open wheel if they meet the following criteria · Any Buggy, Truck or Truggy based kit · Single IC engine up to 0.45 Cu in or 7.5cc · Body shell must not cover the wheels · Wheel diameter to be min 90mm · Stock kit chassis with commercial available upgrades Thanks for that, I have been using the ROSSA class definitions to work out which class might work best for the setup, my plan would be: Any buggy/truck/truggy based kit - the FTX Carnage is a truggy Single IC engine up to .45 - still working on what will work best, looking at perhaps getting a .32 engine which will give me higher RPMs vs a larger engine Body shell must not cover the wheels - There won't be any coverings over the weeks, going with a buggy body to minimise frontal cross section Wheel diameter to be min 90mm - Overall wheel diameter will be min 90mm, will just be running a different tyre setup but it will still be 90mm Stock kit chassis with commercial available upgrades - Suspension parts and upgrades are easy to get off the shelf, need to check driveline parts when uprating the engine Quote Link to comment Share on other sites More sharing options...
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