The Underdog

no probs. i could do with someone who really understands aero interpreting the strings but i dont know anyone so i have to just judge it by my research but i could be wrong.

anyone who knows this stuff please talk to me, cheers

PaulinhoT

I'm not an aerodynamicist Steve, but like what you are doing. One thing I've often wondered on home projects opposed to rule governed motorsport is that on your diffuser strakes, would it make a massive difference if you had an additional horizontal wing running across them, i.e. enclosing them completely ? Also could you modify the exhaust to exit at the beginning of the rear diffuser in the middle ?



Sorry my photo shop skills have eluded me today

Vicar

great project thread

The Underdog

i see what your saying paul. yes i could move the exhaust to the centre of diffuser but its possibly something for the future. for a first attempt i needed it to be simpler.
as for a lower wing to the diffuser im not so sure. maybe that would be along the lines of a double diffuser but as it is now it would hinder the expansion of the air in the diffuser i think. ?

its such a complicated subject that it boggles my mind. im trying the basics first really.

iv had another blast in it tonight and i had a very large oversteer moment at a roundabout lol. it was easy to control and not dangerous but im starting to second think my stiffer springs.

everything is hitting the floor. splitter, diffuser and flaps on flat floor coming in drive. im gona be honest with myself and say its a pig to drive on the road.but il sacrifice the road for the track.. hopefully lol.

i will be taking the angle grinder out and doing some trimming.

The Underdog

thanks glad you like it

PaulinhoT

Maybe look into getting some titanium skid plates ? they would look spectacular on the evening trips to the supermarket

I've read a lot of books on aero dynamics, but have come to the conclusion it's a dark art, and also I don't know enough to comment or even pretend to

I prefer the idea of testing ideas much like what you are doing.

The Underdog

My one and only session due to powersteering pump leak

PaulinhoT

Great video, the car looks really planted

The Underdog

cheers paul

Glenn_

iTrader: (1)

Did you notice a difference in the car with your defuser fitted

The Underdog

yes my corner G went up from 1.2 to 1.4.

Glenn_

iTrader: (1)

Cool matey.

The Underdog

but its all coming off.im not keeping it lol. i cant drive over a pebble with it all as it is.

nigel b

it looked like it was going well when i saw it on track

The Underdog

Thanks. It was until I parked up and thought whys this steering so hard lol

nevsrevs

There was a dark grey super charged focus too, he was going well. It was a focus fest.

PaulinhoT

So will you be taking it back to a none aero car ?

The Underdog

yeh thats lewis denslow. nice car that one.

The Underdog

i think i will in the end. the handling was epic.i increased all my corner speeds but reduced all the straight line speed. i just havent got the bhp to carry the drag.
not only that but its got some major flaws. the exhaust tunnel in the car was almost too hot to touch after my session. that made the car like a sauna and im worried about some kind of fire under theres. driving home with leaking fluid meant i didnt want splitter on holding that fluid and causing a fire. so splitter dont fit in car its so big so now its snapped in half anyway just to get in car.

the turned down flaps on the flat floor scrapped eveywhere and are badly buckled. splitter hit everything higher than a 2 pence peice.

its been a fun experience building it all and iv learned so much about aero but at the moment its not practical. rear wing is coming off too.

nevsrevs

How did you find the tyres?
Another thing is have you lapped combe since the resurface? On a race day that alone was knocking a second off everyone's lap times,

The Underdog

Yeh I was there on new surface 2 months ago. Tyres were good but not sure they are much better than federal. I was inder steering more than expected but I ran my shocks very safe for first session because of the new rear springs. Also I font know how much fluid was getting on front tyres. Its in the wheel arch so that could have really been the cause of understeer. Next time will tell me more.

The Underdog

i had a great time at ford fair. made a few changes to car since last time. il show pics another time but i now only have a flat floor on rear half of car and kept diffuser. old spliter is back on as its not so low and car is now drivable. rear wing has gone and car is faster on strights again.

fixed the powersteering pump with another new one. that worked great but i have worries over the clutch. it slipped on one upshift and is not about an inch higher than brake pedal. its only done 9 track sessions.

anyway heres a vid of ford fair 2015.

this is a short vid of a brown pants moment


this is the full session

why it was lose on rear was because i was experimenting with new shock settings on the rear as i got stiffer springs. i gradually ramped up the stifness every session until this one then slightly dialed back.

ST Olly

Great driving Steve, watched you on track in a couple of your sessions. I spoke to you on the day with Lew, wish I had brought a helmet and came out. What settings were you on when you had the moment and what did you settle for settings wise in the end? What do you reckon to the rear spring rate change overall? I think I said I've got 8kg in the front and 10kg in the rear of my fiesta and I've got some 12kg springs to go in the rear for next time out, might have to adapt the damping slightly to suit, ran 20/25 last time out on the BCs.

The Underdog

hi mate thanks nice to speak with you and lewis. im not gona pretend i can give you handling advice on a fiesta has iv not driven one but 12 on rear sounds a lot on a small light car. as you have them though you got nothing to lose by trying it. i would try your rear shock a fair bit lower and build it back up. thats what i did.

for me on standard 7/7 springs i would run 17 front and 25-27 rear.
for my first session on 7/10 i went 17-18. next i went 18-20 then 3rd session which was the vid above i went 18-22. wound it back to 18-20 for last session and was perfect. them 2 clicks were the difference between life and death lol

i also have the whiteline rear arb that i modified to be stiffer so back is not soft.
id be interested to know how you get on so keep me updated on your plans.

ST Olly

Yes it is quite an aggressive spring rate! I took advice from a guy from AST on the spring rates that they use in their kits for cars similar to my setup. He suggested 9kg front and 12kg rear, which is what they use in their kits in cars running semi slicks. I have 8kg front and now 12kg rear. May get around to purchasing a couple of 9kg springs for the front depending on how this goes.

Its surprising how much a couple of clicks on the damper can change the entire balance. First time out the fiesta was understeering fairly badly at an initial 22-22, so I tried 20-25 and the balance was so much better with a little bit of light controllable oversteer.

I had an Elevate RARB previously on my focus and it worked wonders, Whiteline do a RARB for the fiesta but I'm not to sure as to the benefits it would have in an twist beam rear axle.

The Underdog

sounds good. get some pics up of your car.

this was my first session of the day. i was driving frustratedly because of this red fiesta st. he hampered me on all the corners. true definition of my worst nightmare on track. power on straights and no balls on corners

ST Olly

This is the session we watched all the way through! There is too many cars out there similar to the fiesta in this video! It seemed even worse at ford fair than at a regular trackday! You got by in the end! The amount of speed you carry through the corners in comparison to basically everything out there is very impressive The car must be very well setup now!

nevsrevs

We'll done Steve, but silverstone makes me fall asleep.

track.focus'd

^^^^^^ The most annoying thing ever!

I was getting frustrated just watching the video never mind driving. Great driving considering though. Some real nice heel/toe downshifts.

Me and Olly were watching that session and just constantly shouting at that fiesta

Seemed like the 170 gearing didn't suit the corner after Brooklands very well, shame. Going round Maggotts you beast every one though apart from the nobs who ruin it then ruin your exit speed for the straight.

Cheers for the offer of taking me out, shame I didn't bring my helmet.



Lewis

The Underdog

thanks lads. to be honest i felt i drove aweful first session. i got a bit frustrated and drove feeling pretty anoyed. stupid really as looking back on it, it was a good battle.

i think my track yr is over now as im planning on new clutch and diff seeing as box is coming back out. make plans for next yr.

cheers

Straight_4_N/a

Welcome to my world steve
I think it's one of the reasons I haven't bothered with my car in a year.

If you look at the fiesta it's not that he didn't have the balls just he knew the car couldn't corner at any higher speeds, if you look at his arse end it's trying to slip out when he trys to go faster.

But good driving anyway and hope you had fun. (I thought you was gonna crash into that focus st lmfao! )

PaulinhoT

Very enjoyable videos, and looks a lot of fun

The Underdog

id started to lose my head when the blue focus past.at the time i felt if the red fiesta wasnt holding me up i could break away from the cars behind. but as it turned out the blue focus wiped the floor with me later lol.


thanks paul

The Underdog

so iv finally uploaded some pics.

to get home from rs combe the new front splitter coldnt stay on the car because i wanted the leaking fluid to not travel along the flat floor and burn on exhaust so only way i could fit itn the car was like this.



at the front it was roughly 80mm of the floor and was an absolute nightmare to drive anywhere so id decided it wasnt getting reused anyway.

the issue if it goes any higher it cant be flat under subframe at front so i went back to my original splitter but lowered it 10mm from before. this one is is around 120mm off the floor and much better to drive around with.

gave it a new lick of paint and new support rods.





next out came the flat floor.



2 reasons for this. the exhaust tunnel was getting dangerously hot and the turned down edges near the front were 50mm off floor and grounded on everything.

id spent an insane amount of hours making the new splitter, fitting the flat floor and rear diffuser. i knew it couldnt stay as it was but i couldnt bin it all as it worked well but needed some major tweaking.

i went through loads of thinking how i can make it work. i like the diffuser but knew without a flat floor before it that it was pointless and wouldnt work.

so my knew plan was to have a rear half flat floor and keep the diffuser with some tweaks.

so now iv ony used the floor on the rear section to smooth out the area under the fuel tank. this also gives the diffuser a chance to work.



the diffuser was also catching the floor so this was trimmed and re shaped to be more user friendly. no pics other than a on track pic to show this.

also the rear wing is removed as the drag was killing me.

so this a pic that popped up on facebook, no idea who took it but it shows the new look.




i think the aero now works perfectly. car felt awesome. pulled better on straight without wing.

i checked my data from last yr at trax and my top speed on pit straight last yr was 99mph gps.

this time it was 105. i didnt have the rear wing last yr so the improvement is not because thats removed. i have to put ti down to the diffuser and floor. the diffuser changes the wake and reduces drag and im pretty chuffed its working.

thanks for looking and reading.

jonfoc

I love these updates. Budget and working Motorsport. Shows you dont have to throw ŁŁŁŁŁ at a car to make it work. Do you feel you've reached the limit now and what you need now is POWER!!!!

The Underdog

thanks jon, appreciated.

i think im close to the limits of improving the handling within a cost i can afford.
id love more power on one hand and on the other no. its pretty cool having low power but passing faster cars. it gives me a big grin. i had lots of people come up at ford fair suprised to hear it was standard power. had to lift bonnet to prove to one guy it was not on throttle bodies.

id lose that excitment if i had more bhp i think although if i had the money i dont think i could fight the urge of more power.

i still have some more plans for handling but money will always be tight and even at this small scale spending im still loving it and living the dream.

PaulinhoT

Lots of changes regarding the aero, but it still looks pretty mean

track.focus'd

Great work Steve.

Whats next then?
Anymore upcoming trackdays?

The Underdog

This yrs plans are now over for trackdays. crappy clutch again. im going to get an uprated one and seeing as the box is coming out im hoping to scrounge enough money together for a lsd same time. this will be the winter projects. im also planning a RS rear spoiler instead of the wing.

ST Olly

What LSD are you gonna try Steve?