A splitter will reduce airflow under the car but it may not give downforce to stop the front floating, a set of canards or dive plates set at the right angle (say 10-15 degrees) will give just enough down force at the front.

As a non crap looking alternative, a set of LE front lips will be an improvement on a standard front bumper.

The cadmuro front bumper lip may be better:


Oh and if you do fit a splitter just for a one off run, it HAS to be level, don't just bolt it on to the under side of the bumper, get the angle wrong and you'll end up like Donald Campbell!

fabrication is not my strong point i might just try and borrow a cadamuro i was going to fit a zender anyway but if anyone has a cadamuro i can borrow at some point..i have a good undertray..anything else? i would try a splitter but wouldn't know where to start making one or the design to use ..anyone fancies getting involved they are welcome

And be held liable when you stuff it, I don't bloody think so!

i will sign a disclaimer if anyones worried and do an on camera admission that its all my own doing whilst i am making the video for my family with my final wishes

I would make the floor of the car smooth, this sounds simple but would need a fair amount of time on a chassis lift and you may not want to enclose the exhaust tunnel completely - I know the alfa 156 ST had the 'flatness' increased by bringing the flat floor towards the exhaust tunnel then turning 90deg up to the sides of the exhaust system leaving a narrow opening just under the exhaust no doubt done for heat management. A diffuser keeps the flow tidy from the exit of the rear of the car but its main aim is tidy high velocity flow to complement the air flowing under the rear spoiler - maximising its down force (needs a much large explaination really). Don't confuse flat floors and diffusers with having a tunnel and ground effect thats something different and not the aim. While you dont want lift I'd say avoid creating down force just cut drag. Thus an air dam at the front is useful rather then a splitter - but just for interest all of the wind test results I have read in RCE pretty much show splitter to be very efficient -F/D thus downforce with little drag.

Tape up door shuts, panel gaps, boot lines, reduce radiator openings (you only need 1/4 of the frontal area of the rad/ic to be effective at speed.

More drastic is venting the wheel arches that create huge drag, on the coupe louvre (sp) bonnet vents sealed to the arch liner would vent the front arches nicely but its a cosmetic change you may not like and bonnets aren't cheap. For the rear you want air to leave the back of the car nicely so a simple strip of sheet material at the boot's trailing edge blended to the top surface would work (look at a golf mkV boot edge), loose the wipers, and as much weight as you still need to get to the terminal velocity as quick at possible. The fiat has a good shape to start with so game on.

ok i have a spare bonnet here i can hack up and spare doors i was going to try and lighten for totb anyway..i would be happy to vent the bonnet to make this work but wouldn't know where to start or how to work the liners to vent through them..the nads for the job i have but the technical/fabrication skills i don't so would really be grateful if someone with at least the design ability could help explain enough for me to collect whatever items i need to make the bits to help the car up to speed..
up to now all i am likely to use without assistance is cadamuro bumper ,undertray, taping bits up and removing wipers.possible skinnier wheels..
rich so a little boot spoiler on the edge? which of the auto ds would you think best

ktm - I would go with making the under side of the car smooth and flat, from under tray back!

that will help a bit!

i can see there is alot of GOOD ideas here, i would pick the best options and get busy!!

i can see a lot of rolls of gaffer tape being picked up!!

will have to find some tape with gum that wont harm my paintwork if anyone knows of any

Sure don't knock using tape for the runs, its is effective, virtually all aerobytes sessions I ever read have taped on ammendments to the cars for testing, although they test up to 80mph so anything that develops force needs to be well attached for what could be 180mph in your case.

Rear spoiler I was thinking something a little more DIY do you have a spare boot lid?

W.r.t. the bonnet there are many ways to do this and were not talking F1 level of prep - we want a join or sorts between the top of the arch liner and a vent in a similar position on the bonnet. Vent wise you could buy something preformed and cut a hole in the bonnet to fit it - mark out the outline of the vent in bonnet in masking tape and pen, use a good HSS steel drill, pilot hole 3mm, then use a bigger drill or a step drill to open up to say 10mm, then you can use a HSS jigsaw blade to cut out the shape. Remove the tape and stick the vent to the bonnet top surface using 'serious' stuff adhesive. The vent is an exhaust vent not a scoop.

You will then need some hose or tube going through a hole in the arch liner in a position towards the inner part of the arch (hole saw, jigsaw, heat with a heat gun and use new stanely blades to cut which ever option you feel will work) the hose ideally will connect to the vent but there is small issue of opening the bonnet, thus you may want a more rigid tube which then meets the vent on bonnet closure. We aren't talking air tight, but more or less working on the principle that air will follw the pressure gradiaent from the high pressure arch to the low pressure air flowing over the mid bonnet line.

You may wish to test the 'solution' after doing one side, some tufts of wool or string taped round the vent opening will tell you the air direction, if they are sucked into the vent then this is a failure, bad luck, but if they stand off the vent then its doing its job, its a 2 man test with a volunteer to stick their head out of the window and see what happening say at 50mph (I suggest doing the passenger side first ).

This is my idea, heres to links to items I would consider for the job
vent - http://www.merlinmotorsport.co.uk/p6902/BLACK-SIDE-AIR-SCOOP-INLET/OUTLET/product_info.html run so the narrow end is near the windscreen

hose - http://www.merlinmotorsport.co.uk/p4227/63MM-RED-SINGLE-LAYER-DUCTING-(PER-METRE)/product_info.html need maybe 2m to play with some shrink joiners or jubilee or some gaffaer tape works well.

Not teaching anyone to suck eggs but some tools I would use
drill bits - http://www.screwfix.com/p/dewalt-extreme-2-hss-drill-bit-set-13pcs/66597

Step drill - http://www.screwfix.com/p/step-drill-4-22mm/15976

jigsaw blades - http://www.screwfix.com/p/starrett-metal-cutting-50-x-4-5mm-24tpi-jigsaw-blades-pack-of-5/39966 need a jigsaw of course. You could use an angles grinder with cutting discs but that a really rough way of making a hole.

Hole saw for the arch liner - http://www.screwfix.com/p/titan-downlighter-holesaw-set-9pcs/71760

serious stuff glue - http://www.screwfix.com/p/evo-stik-serious-stuff-adhesive-290ml/23941

what are we emulating here, well this is a high end example
of the dtm car arch venting
http://fi.wikipedia.org/wiki/Tiedosto:Audi_A4_DTM_2006_vr_EMS.jpg

ond on the rear of the N24, I think you can see a way you could do it.
http://www.reverie.ltd.uk/astonmartin_archventing_modification.php

I wouldnt fit any after market 'styling' kit as thats all they are, the only wind tunnel tested item for sure would be the std.

List of things
1. Tape shut lines - easy, simple
2. Tape radiator opening unused SMIC inlet - easy
3. Flatten the bottom of the car - not so easy but would reduce drag decently.
4. Make a front lip, air dam, or splitter - not so easy must be well held on. lower the car as much as you can.
5. Vent arches
6. Add tail strip to boot - easily done, stip of ally, some rivets and some serious stuff. like this but with less angle -http://www.hotrod.com/techarticles/body/hdrp_0609_aero_tricks_tips/photo_09.html




These are not costmetic improvements, thus you may prefer some second hand bumpers to adjust then convert back to nicely painted items after the day. If you have spare doors gut them, cut out the inned frame, cut out the impact bars (8inch cutting disc on a grinder is how I did mine - Sparco did his also), remove the window motor, and retain glass in the best wedged in bit of wood to the bottom of the door you can way!, cut the excess strengthening out of the bonnet, do the same to boot (dont cut the hinges off).

I think you really could win if the engine is up to it.

Venting the front wheelhouses has been on my mind too..
I wonder whether there's pressure or suction at the sides behind the front wheels. There should be the latter since there is a venting outlet from the enginebay already (between the hood & the wing). What I've been thinking is a vent hole at the top of the plastic arch liner, then the air goes out the existing side vent. The issue here could be a conflict with the engine bay venting.

Remove wing mirrors?

Yes! good man, remove or much smaller, forgot that, and wipers as said before

Fuel cap also needs attention. How about some slicks so you don't excite the air as much. A million cheap little things to be done (relatively).

The other thing that needs looking into is the mechanical side of things. For example what is the maximum loaded speed (RPM)of the wheel bearings? At what RPM do the brake disc reach an overspeed and burst? Are the bolts in the suspension up to holding the loads of a 170+ MPH car? Is the structure of the car up to 170+? Not to put a dampener on this, but to do this safely it'll need far more than a good engine.

Maybe also remove headlights and replace with a flat/smooth panel?

szcom..i'm thinking that 600 bhp will drag the car kicking and screaming to a serious speed even without all the little bits i have made well over 160 couldn't keep my eye on roasd and speed (sat nav) but saw the 160 and got past it with the 358 bhp i used to own that was just lowered/piu front with all the above bits done and a far better engine/power i'll be right..i am confident the car will take it as its the best chasis i haev yet had with new subframes all new drop links ,bushes,bearings,arbs comp brake kit etc its designed for big power/speed..its braced with various braces so all in all its as good a platform to try it from as there is

Wouldn't you need to fix the gearing..? I'm sure someone already maxed out the sixspeeder?

gearbox we are working on

I don't think I explained correctly. I appreciate you have a good chassis, but can you confirm that the brakes and bearings can deal with the RPM (wheel speed)? At a guess I'd suggest they were never designed for speeds you are planning. The same applies to the bolts holding it all together.

What you have to remember is that it takes roughly 4 times the power to go twice as fast. So as you can imagine adding another 30 mph or so over factory spec can mean a lot more force/load on the parts. I think you'd be wise to put a call into the manufacturers to confirm the ratings for all rotatives. Just don't want to read a thread where it's all gone wrong.

The coupe was designed to go 155mph and I'm quite sure they built a safety margin into the wheels and bolts, lets face it, he won't be breaking the 200mph barrier.

I'm sure they did. But was the Coupe designed to sustain 155? Because that's very different from getting there. Even if they did we're talking around 10-15% increase in the bearing speed to achieve the greater velocity (assuming the car breaks 170 and the effective rolling radius of the tyre doesn't alter.

I do appreciate in all likely hood everything will be okay; but for the price of a phone call I'd be on it...

got a front spoiler that may help if u are interested it looks like the cad spoiler

never seen one but if its the type of thing i need then great thanks

One thing which I don't think has been mentioned: you *will* require tyres rated to the speeds you want to go...

^^ - good point - IIRC, 'Y' rated tyres are 'only' rated to 186mph, although I don't think you're ever going to break that, even with 600bhp

ok what options does that give me on tyres

Vortex generators
or

erm dont think so, open wheel race car perhaps.

couple of things i have picked up on, firstly putting in bonnet vents,


Ill mention scoops even though your not talking about them , they are stupid! unless you need them for a top mount IC they are stupid, end of

Now back on track with vents

you have to be very carefull and watch that they do,. with airflow under the bonnet,

there also then needs to be sufficent air flow through the engine bay to give it the push that it needs in the right direction,ie not just mountains or air getting pushed in from the top .
alot of boys find that putting vents or scoops actually pressurises the engine bay and the hot air cant get out, (ME infact) being totally unproductive.

these vents are there to tease the air from under the bonnet out to a certain threshold and then to get whipped away by the airflow passing outside of the car,

ie might need to be running with a improved undertray( better sealed) and then have very well placed air scoops underneath the car flowing air into right areas to help with this,


many have found this a complete waste of time so do the very best you can , but have a spare bonnet around just incase,

Next thing, how lowered is your car?

next thing, POWER

If you decide to use fire extinguisher mod for a IC spray make sure you dont use the powder type>( yes me again)


have you thought some nitrous?



you have pm

Doh!