793 replies to this topic

[jonnyboy]

Is quite interesting really as TA requires a very quick car to be competitive but you have the added pressure of needing reliability on highly modified cars. With series racing yes there are more controls but it's more focused getting consistent reliability, setup and driving on a more level playing field. I can't help thinking its going to be an expensive and frustrating exercise. Me personally I'd be looking for the thrill of driving/racing rather than the thrill of building and I think that's the point of time attack.

[turbotoaster]

exactly, if I wanted to prove I was a good driver and that I can beat other people in equal machinery then straight away I would be looking at a spec series, but I understand my limitations and I enjoy designing and building vehicles, hence If im watching f1 im more interested in the technical aspects rather than the drivers.

 

For me i just lets my imagination run riot and I love that the only thing stopping me designing something is my limitations rather than rule restrictions.

 

As daft as it sounds im not looking for fair racing, im looking for my designs to be better than others, that my car is faster than theres taking driver skill out of the equation.

 

I would rather be last in a car i know could win than be second knowing my car will never be fast enough.

 

Once the car was fully setup I was thinking of asking Randy to drive it, but then that would take the fun out of actually driving it, I would only do that if I suddenly picked up aload of sponsorship where winning was very important, which due to my setup looks unlikely.

 

Took my doors off today ready to fit my kevlar ones next week, lighter than I expected, 13kg with all fittings, mirror and window, will be interesting to see how light my new setup is.

[speedster]

It will be interesting on 2 counts in regards of the K series engine.

 

I know the pistons will be able to take the heat as they have been subjected to 10psi of boost at 16afr and have held together, the 2 points im unsure of will the the lifting the head and rod strength.

 

Both currently are untested as I plan to run around 15psi of boost pressure and im not sure if that will lift the head or not, im hoping not as ive been recommended not to fit studs and nuts but to stay with the stretch bolts, now I know a 1.4 k series has been running 22psi so I dont think the head will lift, so that would make move onto a head gasket issue, I can replace that with a copper head gasket if the gasket is actually failing.

 

The second is is rod strength, I know the rods have been tested to 235bhp on a supercharged engine, so will crank loss probably a 250bhp engine, im wanting another 70bhp on top of that, this is where I will go into the unknown, the good thing is that if worst case scenerio the engine does fail I have options for each part.

 

Crack liner.....have stronger liners made(done this before on another engine) pistons and rods I can get easily enough, head gasket I can sort.

 

Overall its a more cost effective solution that paying £15000 to have a 300bhp audi/honda engine fitted.

 

Interestingly Re amemiya has gone the same route on their revised version of their rx7 race car in regards of the rear wing and diffuser, they came back this year and ran faster so it seemed to give them a bit more performance.

 

http://www.yokohama....shx?h=332&w=590

 

 

Mine diffuser is fully adjust able from 5 deg up to 14 deg so I will be able to get it setup pretty well

 

 

Never thought about elise trophy to be honest, didnt really interest me, I like Time Attack because of the variety of cars that enter, the completey free rules that allow me to inovate and the none wheel to wheel aspect(I wouldnt want to cause damage to someone elses car or vise versa)

 

Would people be interested in seeing updates on here, im happy to share the project with people who want to read about it? I dont mind constructive critism but abuse will mean I just wont bother

 

Have you read this?

http://kengine.dvapower.com/

It's old (2002) but still relevant. 

[turbotoaster]

Yep, read it in detail a while back, even spoke to dave andrews about my vehicle when it was supercharged.

 

Ive updated the seloc forum with some pics, will people just log into there to view every so often or would people rather me add updates to this thread aswell?

[chris_uk]

Add them here aswell.

[Claws]

Add them here aswell.

Not all of us are on/can view SEPTIC

[turbotoaster]

Not much of an update as I have to go and fetch some parts on saturday and im going to a concert sunday night so I dont know if ill have time to fit the kelvar doors and upper wing element.

But in the mean time my Quaife ATB diff arrived, feels like its made from the suns core its so heavy for something so small!


Next to my favourite book haha

Also mocked up all my downpipe and exhaust system and welded it all together.





The turbo is v-banded with a 2.5" outlet, that then turns into a 90* bend, straight over the gearbox, through a flexi down to another 90* into the backbox then a 90* exiting where the fog lamp would normally go(bit like an s2 gt3 box), I did think about directing it vertically down into the outer element of my diffuser(set at 100mm as a sacrificial barrier to let the inner elements work without any high pressure air interference) as the sound would bounce down the strakes cancelling the sound, but in the end decided that the risk of potentially upsetting my underfloor ground effects and the fact that a turbo should quieten the engine down a bit made me keeping it point out the back for the moment.

Ordered some m10 stainless bar to make the back box hangers and also make a bracket from the gearbox to help stop and snag when its hot.

Got some 15mm ID stainless tube aswell for making the oil drain

Finally I wanted the turbo core running vertical to help oil evacuation to hopefully not blow an oil seal and the outlet of the turbo comp housing running horizontal, that way when I sort out a chargecooler there it should look a nicer that having to twist silcone pipe to weird angles.

But when I had finished the actuator was in the wrong position and moving it around didnt get it as straight as I liked, so the bracket was bend to get everything lined up, but to make sure it didnt flex when used a little brace was added.


Also the wastegate outlet has been massively ported out so allow maximum flow to help control boost and creep, this should hopefully allow us to run really low boost, ie about 6-7psi, which means we can spend time testing doing the suspension and aero rather than worrying about the engine.

 

[turbotoaster]

Picked up my kevlar doors and upper element wing yesterday,
Picked up my kevlar doors and upper element wing yesterday,

Fitting the upper element was fairly easy and I followed simons suggestion about spacing between the elements.

Currently they are both set to maxmum downforce 29* AofA which is how ill run it for the first couple of laps and see how much out it is, then turn them down to get a better balance




Next i attempted to fit my drivers door, took some fiddling to get on and its not a perfect fit but for the cost if them and the weight saving I cant complain to much, total weight saving is 17kg, I was going to get them cleaned up at a bodyshop and polished but I may aswell wait until the full car needs painting after a few seasons of abuse
Also fitted the poly window but as you can see its no where it needs to be, so im going to get some ali plate to where the old cant rial used to bolt to with velcro on it, then attach velcro the window and see if it will hold



Next will be putting my lightweight mirrors on and getting the engine running

 

 

[smiley]

When is the first shakedown planned to see how she behaves?

[turbotoaster]

I was hoping for mid december at the start of this, but to be fair I think thats unlikely now.

 

I still need to get the engine running(bit of a delay as my welding friend is ill) then its having a full suspension refresh and atb/flywheel fit, that will take me up to the end of the year, then down to randy in january, so maybe the end of january is the next aim

[turbotoaster]

Front is getting there now, just need to put my canard end plates on and get the clam trimmed to let the high pressure air out of the back and top. That should mostly cover it.

It looks pretty mad from the front but its all functional so I hope it all comes out as planned, due to the size the splitter that should be effective no matter what happens.



Im looking forward to seeing what it looks like on track as all time attack cars look pretty mad in the confines of a garage.



I also added to the splitter end fences today, ive made them the same height as the lower canard so that if that does flex from the airflow then it pushes down onto the end fence and into the splitter which is transfered to the chassis, no point having aero if any downforce they create never gets to the chassis


I have thought about actually making them higher than the lower canard and then shrink as the get closer to the canard(which would help more against any washover of high pressure but I could really do with someone like Simon to tell me it that is ok or that the front edge of the end plate will cause issues with clean air getting to the canard.......I could spend hours in a wind tunnel testing stuff if money was no object!!

Also added the mirrors, very easy to fit, weigh hardly anything and after checking adjustment I can see clearly behind me

 

[Tony H]

How about this

 

 

[Mangham54]

Crikey... there was an Exige in there.

[smiley]

I hope it goes well, but damn that construction will catch wind.

Look at the youtube at the end here.

http://shwainc.com/a...e-aerodynamics/

 

 

 

[turbotoaster]

How about this

 

 

 

I did think about this at the start actually, but I decided that the reduced visibility would get on my nerves, plus I did wonder if the first wing would disrupt the airflow enough before it got the rear wing, as it will try and throw the air up at an angle which may cause issues, and trying to run it lower again means visibility issues

 

I hope it goes well, but damn that construction will catch wind.

Look at the youtube at the end here.

http://shwainc.com/a...e-aerodynamics/

 

 

Im happy with everything on the car up to yet apart from my wing uprights, but they are there for testing, ive already designed version 2 which I will make once the positioning has been proven

 

Edited by turbotoaster, 26 November 2013 - 10:41 AM.

[FLD]

Have you done anything with underfloor aero other than the diffuser?  Tunnels perhaps?  I'm just curious given how much effort you've put in and thought I may as well tap into your research!

[turbotoaster]

Yes I have.

 

At the front the splitter is actually much wider than the old one in the wheelwell areas, so much so that when the vehicle is jacked up the ARB just touches it, this width is extended to the tub.

 

One issue that sprung out to me was trying to get plenty of low pressure air to the rear of the vehicle, you have this big wide splitter and nice diffuser, but just after the splitter you have a tiny slot for that low pressure area to pass through and any that doesnt either enters the wheelwell area or  more likely because the wheelwell area is a high pressure zone, will try and push high pressure air under the car and lower the pressure differential(bad)

 

So running a wider area here helps stop that happening and keep the pressure low helping front downforce, of course you cant go to wide on this area as every time you turn the steering wheel the tyre will fit the splitter so there is a balance.

 

Ive remade my under tray, this is now as wide as the tub itself and where normally there is a large cut out to let the wishbones droop I dont have that anymore, also the naca ducts are gone as I dont want my precious low pressure air going anywhere that wont help with downforce (I dont have a hot exhaust underneath the car anymore)

 

The undertray also have end fences(skirts) that point vertically down so that when the car is sat at 110mm rear then they are 40mm from the floor which is mandated by Time Attack when the car is stationary.

 

These skirts connect up to the diffuser so allow no high pressure air to enter the under body, also if you look at my diffuser you will notice that the diffuser has a narrow 'tunnel' at end, these are sacrificial tunnels in that you can never 100% stop high pressure air getting into your diffuser, so these are used to contain any potential cross contamination and stop it effecting the rest of the diffuser, hence they are narrow to minimize overall loss over the diffuser.

 

The tub is also pop riveted in 3 places along its sides and to that ali angle bolts to which skirts attach to them(40mm from the floor and can easily be replaced if damaged), again inline with the skirts on the diffuser and undertray, creating one entire low pressure section from the front wheels back.

 

The car also is raked at 20mm to again enhance the underbody effects and the diffuser is fully adjustable for rake so that will be tuned with wool tuffs to check for attachment as I crank up the angle.

 

I did look at tunnels but due to the engine being transverse and not longitudinal then it doesnt really work well as they would be pretty narrow and either have alot of items in it the the airflow stream or the angle of the tunnel would be so shallow as to not really gain you anything.

 

Hope this helps

[Claws]

normally there is a large cut out to let the wishbones droop I dont have that anymore

This jumps out at me a bit. Have you re shaped this section to allow for the wishbone if you have done away with the slot?

[FLD]

Its good to hear that you've done the underside too (esp end fences on the trays).  It is possible to get a venturi effect on the splitter (not sure if its in the book you pictured or another I have) which helps with front end downforce.  I'd considered naca type parts in front of the front wheels as a kind of splitter come diffuser part at the front (I'd expect very minor effect from this) and the same in front of the rear wheels.  I expect they'd work better if the wheel arches are vented out.

[turbotoaster]

 

normally there is a large cut out to let the wishbones droop I dont have that anymore

This jumps out at me a bit. Have you re shaped this section to allow for the wishbone if you have done away with the slot?

 

At the very edge where the wishbone meets the upright I can cut a small section(1"x3") just large enough for it to pass through when the car is fully jacked up

 

Its good to hear that you've done the underside too (esp end fences on the trays).  It is possible to get a venturi effect on the splitter (not sure if its in the book you pictured or another I have) which helps with front end downforce.  I'd considered naca type parts in front of the front wheels as a kind of splitter come diffuser part at the front (I'd expect very minor effect from this) and the same in front of the rear wheels.  I expect they'd work better if the wheel arches are vented out.

Your on about front diffusers, yes ive thought about them and it might be something I will do in the future but how I have attached my tiebars the diffuser would be directly where they are bolted to.

 

What you would basically do is use a foam triangle and mould carbon over that leaving a 1inch flange on each edge, once its set you would cut a section out of the splitter and glue it from underneath(so the diffuser glues its flanges to the underside of the splitter for strength)

 

As mentioned its just trying to work out the best way to be able to attach that side of the splitter to the crash structure, it might be possible to attach on the far side of the diffuser its just working out the angle you would need to go at and if there is anything in the area on the crash structure you could bolt to.