Fast Guy

True it doesn't. But in theory it should help you get there quicker.

Idealy you need to raise the revs you make peak power at, so that your peak power is geared for the max theoretical speed you can make. Max power at 7000 can only hold you back on a top speed run.

If you're only having one last shot, then why not fit some wild cams for the attempt and then go back to a more useable road cam after?

Anonymous

As rod mentioned in an earlier post, the weight makes surprisingly little difference over such a big distance, it might get you to 150mph a fair few yards sooner, but when you add those extra yards on the end when you are doing 210mph+ they only translate to a second or two longer to try and accelerate from that speed due to the rate you are covering ground at and hence make very little odds in the grand scheme of things.

Dan

I reckon 215+mph, best of luck!

pee vee

true..
but when you are talking getting faster than 210 surely every little helps

Stuart.W

where are these calcs Rod?

Keith B

Rod - the whole gentlemans agreement thing sounds a bit lame. Max speed is max speed. Max speed over 1.5miles doesnt really compare to anything other than for someone else thats run at Brunters. Still its your car and your mission - best of luck.

Anonymous

Hi

Some calcs & thoughts.
I use the following Formula-


For my benchmark I use a known set of figures from a Sapphire we know was running close to optimum. MADAde 185.5mph from 535bhp.

This gives the following figures.

180 – 484bhp
185 – 526bhp
190 – 570bhp
195 – 616bhp
200 – 664bhp Peak required = 710bhp
205 – 715bhp Peak required = 765bhp
210 – 769bhp Peak required = 822bhp
212 – 791bhp Peak required = 846bhp
214 – 814bhp Peak required = 870bhp
215 – 825bhp Peak required = 883bhp
218 – 860bhp Peak required = 920bhp
220 – 884bhp Peak required = 946bhp

Not that easy because we are pulling 4.8% longer gearing & going 10% more past peak Power than Ade hence the second set of figures.
Problem at the mo is we don’t have accurate Power Figures ,I use- 690bhp on race Fuel & 180 (90% efficient) from the Nitrous = 870bhp.
This suggests 214 is as good as it gets.
Before we run I expect to have Dyno figures for the engine & atw figures on the gas.

So my guess is 214mph max maybe a tad less if conditions aint perfect.
Rod

cossie350

Take the wing mirrors off and before anyone takes the piss try sitting a 150mph on your private runway and put your hand out the window
Its got to help not alot but then 215 is better than 214. And it cost nothing

Taylor

iTrader: (1)

Best of luck ,alot of time and effort in this car so hope you get as much as poss(220+???)

Stuart.W

Really Rod, hardly the kind of technical formulae expected from an aerospace engineer is it

I thought you were going to get all technical with us and only 214mph!

If you knew what distance you had covered arriving at 180mph in 17.82seconds and knowing what rate of acceleration you still had at 180mph then surely you could calculate what terminal speed you would be doing at the 1.5mile mark, especially as it'll all be done in one gear from 180mph onwards making it so much easier to calculate.

All you need to know is:

Coefficient of drag: 0.32 (assuming 4x4 undertray & bonnet)
Frontal area: 0.639 m2

You see I've already filled those in for you...........

Power & Torque at the wheels at both initial and terminal speeds. Rolling resistance of tyres. Rolling Radius of tyre. Weight of car (with lift taken into account) and finally the average diameter of Marks left and right testical (i'm not offering to measure). So you see Rod, it should be 216.5mph and not 214, you'll see


ps Got a close ratio T56 with a 0.70:1 6th gear you can borrow if you don't like the new Himalayain spec' cams.

Benni

217 mph. Wish you the best of luck aswel.

Anonymous

Yep ! your calcs are better but mine are easier to understand can I point out your formula does not include a WTF factor when you start to consider what you would do if your brakes fail at 200 & you are hurtling towards the Brunters car park. This tends to slow you up lets say by 2.5mph making my 214 about right.
Rod

dumped

I dont like your WTF calc!

What has been your topspeed at brunters - 202 to date? I know the 206s were are woodbridge. Got to be a hell of an attempt!

Sounds fun for you and your son... strange my dad refuses to go in my car since i took him out with a T35 and NOS 6 odd years ago

Big G

Doesnt the masses of air exiting the mouth in midscream of "SSSSSssssssssssssshhhhhhhhhhhhhhhhhhiiiiiiiiiiiii iiiiiiiiiiiiiiiiiitttttttt" act as another braking module

Anonymous

Have never had a proper run at Brunters since the GT 35/150 nos , restricted exhaust days have around 200bhp more Power now. Ran 201.3 in the pouring rain & passed 150 in 25.7s about 13secs off the pace in the dry those precious seconds should see our dreams realised.
The 210 was at Woodbridge also.

JTECH James

iTrader: (13)

instead of stopping at the end just make some wings and take off?

kouzman

personally i would consider the parachute as a safety device and i dont think that its difficult or expensive to install...

your front spoiler will def help as well as lowering the car just a tad...

I m sure that you will touch if not pass 215mph...

Rod team is the BIG cohones team... and that's the end of it...



i wish you good luck from Greece and NYC...

Stuart.W

No need for wings, get to 220mph and it will all on its own

Stuart.W

Don't worry about the brakes..............worry about the fresh air underneath the tyres




Correct me if i'm wrong but do you not hold the world record for going sideways at 198mph...........hail Rod, drift king

JTECH James

iTrader: (13)

deffo a CLEAN PANTS moment!

Anonymous

PMSL @ sideways at 198mph

JTECH James

iTrader: (13)

you can just imagine a squeaky parp from the drivers seat during the sideways at 198 moment.......

Stuart.W

I think that came from the passenger seat, I believe Mark said either..........

I say Rodney dear boy, would you mind awefully just releasing some pressure off that middle pedal

or

OFF THE F*****G BRAKES

JTECH James

iTrader: (13)

if the situation had got much worse he may have bailled out..... he would have been fine as long as he bent his knees when he landed.

PF Ben

iTrader: (1)

Rs1 wrote:

"If you get seme Franky detori(sp) sized chap to drive it i can well see it nudging 217"



Mate, haven't you seen Rod?!!!

Ben

Fast Guy

Is that right? The car is over 1m wide and 1metre high, so that's a minimum if 1m2 surely?

Stuart.W

Its actually around 1.94m2, it was too early in the morning ok

Its nice to know some of you are awake

Anonymous

Mark gets very verbal, He admits that having a senile old geezer with the drivin ability of a monkey is a bit stressfull at 200mph as you are about to get on the brakes. I think his worst moment was at 5th gear when I did the test run , I reached 193 & had to get on the brakes in the wet he was not sure if I could handle that, I couldnt but managed to stop somehow.
Rod

AGAR-COSWORTH

I see now, i have no real idea about the interchange-ability of cossie diffs with others etc - cheers

Mark Shead

I see you have no idea there was only 2 choises on diffs I would use,
A 9inch prob the best one at the time was to costly to use ratio would have been the easy bit,
The Jag diff also cost nothing as I already had one and a deal was struck on the beam mods ,
So in real terms it cost 1/3 of the cost of a 9inch

Mark