My 200mph budget build

[Conanius]

Looks great, however with tein suspension I hope where you are running is absolutely paper flat ... In my s2000 with tein suspension it gets interesting above 55-60 on anything other than a motorway or racetrack. The car literally bounces left to right on proper bumps.

Anyone who knows the m1 into London, at 70 in the slow lane just before the split to wembley at the end of the m1 there is a series of dips and bumps which to the naked eye look flat. I've neatly had heart failure forgetting they are there.

Just take it steady, and get the suspension checked out and lined up properly.

 

[DreXeL]

Nothing really too add, other than watching with interest.

On a side note it's amazing how cheap FDs are now. Must........resist........getting.......another.....

 

[Housey]

Love this, report back when it's done though, don't want 700 pages of each additional washer being added, then gizza go.

 

[Morba]

Not wishing to be awkward here but above approx 155mph cars need especially designed aero dynamics to maintain the down force on the car.

really?

thats why bentleys, rollers and even the m5 are specially designed with aerodynamics for mental speeds can do 190mph+.

 

[pzr vr6]

Only to an extent, the coeffeicient of drag won't make that much difference, neither will the weight, just sheer power is needed.

drag makes a HUGE difference at 200 mph

 

[turbotoaster]

All serious rx7 have a V mounted cooling system surely?

track cars yes, the reason for that is to split the air between both the rad and the intercooler, the reason being if your thrashing it for 20mins on track water temps start to rise due to not enough air getting to the rad.

Since my setup forces all air to go through the intercooler and rad this wont be an issue.

the problem you have with v mounts is you need a vented bonnet to make them effective, all well and good but then you are compromising your aero package by creating drag, fine for tracks when you dont go that fast, but not for top speed

Not wishing to be awkward here but above approx 155mph cars need especially designed aero dynamics to maintain the down force on the car. I would question whether it is a simple matter to adjust a road car for such speeds. If you look at super cars they have venturi's in the body work and floor pan to accelerate the air creating low pressure.

Whilst you may be able to create a car with sufficient power and drag to reach the speed, doing it safely is another matter. I would strongly urge you before attempting this to get guidance from a specialist engineer, they may be able to suggest small changes which will immeasurably improve the safety.

the car does 158mph from factory, one of its strengths is its high speed stability over other cars, diffusers and canards help you when your cornering and you need the downforce, in a straight line this is not required unless without enough downforce you break traction, this will not be an issue from 4th gear upwards

technically you lost me before i started reading the first post, but my god, this looks like fun!

HUGE turbo!!!!

good luck fella. oh, the misses says you have too much money, but then she drives a 1.6 auto focus, so what does she know! lol

I earn a lot less money than you think, infact less than 90% of the people on here, i work part time in a call centre while im trying to get into the raf.

 

[turbotoaster]

i love how everyone thinks going fast in a straight line on a massive airfield is super dangerous, that the car is suddenly gonna flip and takeoff, that previous video was caused by wheel spin at 200mph on salt.

Just for reference now the engine has done 900miles i took it to a dyno to see how the engine was doing.

running a very rich map(so power lost) running stock boost(10psi) it made 283bhp at 6900rpm.

This is 400rpm higher than stock and 30bhp more power, so at a very low boost running super rich(11:1 afr)

This shows that my ports are flowing well, id imagine with a bit of adjustment to the fuel to where the stock afr is another 20bhp could be gained, so thats 50bhp above stock at same boost

just need to do a compression test to check everything is bed in correctly and then start saving more money to start putting things together

 

[Muncher]

drag makes a HUGE difference at 200 mph

Sorry what I meant was that a low coefficient of drag is not enough, massive power is still needed.

 

[Muncher]

i love how everyone thinks going fast in a straight line on a massive airfield is super dangerous, that the car is suddenly gonna flip and takeoff, that previous video was caused by wheel spin at 200mph on salt.

It's pretty dangerous in that if anything goes wrong at that speed you're going to have an enormous accident.

 

[Biohazard]

that is nice work on the runners, what made you go for silly shiney smooth?

 

[SoliD]

Will be keeping my eye on this, looks like a good bit of fun, good luck to you!

 

[Django x2]

I'll only say yes so that I can chuckle when it all goes wrong

 

[Gribs]

What gear box/mods are you planning to use as I'd guess you'd need to increase the gearing quite a bit to reach 200mph? I'm also surprised there's been no mention of nitrous oxide becasuse as well as being a relatively cheap way to add extra power it's good for cooling too.

 

[ethos]

I'll only say yes so that I can chuckle when it all goes wrong

Nice guy...

 

[Clarkey]

One thing, because the RX7 engine is pretty light

It isn't, it's just small. You're talking about 175kg when all's said and done.

 

[turbotoaster]

What gear box/mods are you planning to use as I'd guess you'd need to increase the gearing quite a bit to reach 200mph? I'm also surprised there's been no mention of nitrous oxide becasuse as well as being a relatively cheap way to add extra power it's good for cooling too.

if you look on a previous page it shows my calculations on how to make it to 200mph, standard gearbox is fine, auto diff for the longer gearing.

Im leaving nos alone because its not something extra i have to deal with, would rather let the engine deal with it.

dont fancy charged air, water, race fuel and nitrous to deal with, more to go wrong

It isn't, it's just small. You're talking about 175kg when all's said and done.

true, but due to its size its very far back in the engine bay behind the front wheels

and 175kg is with everything on it, the actual engine without power steering or aircon, turbo is about 70kg, so there are ways of reducing it further

 

[Conanius]

I've dropped you an email through trust, let me know what you think

 

[turbotoaster]

email to me? just checked my hotmail and theres nothing there.

my email is [email protected]

 

[Conanius]

Try again !

 

[thepharcyde]

Thank you for sharing, v.v.interesting. Good luck

5* thread for me