E30 top speed providing you have the power?

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jkarran
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Thu Feb 22, 2007 12:48 am

maxfield wrote:I wouldn't want to be going anymore than 170 in 17year old car.
I wouldn't want to be doing anywhere near 170 in an E30 without a fully pointed in cross braced cage, 6 point belts and a helmet :chuckle:

jk
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jaistanley
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Thu Feb 22, 2007 12:12 pm

Amen.

I was brave once and got an indicated 135 and a bit of gutter trim tried to come through the back windscreen!

I shall be gluing the new one on too!

g75yle: I did an aerodynamics module at uni (Automotive engineering degree) and by far the most useful book was by a chap named Huco {I think}. It was £125 I think so you might want to get the library to order a copy! I can't remember the exact details but it'll tell you a lot about stability, yawing moments, drag, groud effect and the like.

I hate to sound like a dick but aerodynamics are so completely abstract there's no way you can speculate until you've done some reading. Even multi billion dollar organisations like BMW have to wind tunnel test (instead of design and simulate) their aero kit as the fluid dynamics are mind boggling.

Basic rules are reduce turbulence under the car, reduce eddys from rear windscreen to reduce yawing moment (think M3 shell here) and radius any edge you can (hard to do). A front splitter joined to a flat sheet of abs will make a nice engine compartment baffle and do a LOT for the aerodynamics.

Rear soilers are very rarely to provide downforce directly, they are there to 'spoil' the flow of air over them to give the vehicle more areodynamic virtual profile. By spoiling the air flow around them they push the lamina flow of air coming from above the rear screen up and create a pocket for it to travel over. Hard to explain. but the air takes a more teardrop shape. This means there are less yawing forces from the rear and improves drag coefficient. It's easy to look at a spoiler and think its stinking up in the air so the flow 'pushes down' on it.

Jai
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Eddiejt2
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Thu Feb 22, 2007 1:14 pm

g57yle wrote: i would like mine to be doing around 120-130Mph @3k rpm in 6th for nice economical crusing.
No disrespect, but where in this country can you cruise at those kind of speeds? I have hit these speeds a a fair few times, but not for any long period of time, and this was on empty motorways in the middle of the night.
jaistanley
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Thu Feb 22, 2007 1:22 pm

I spose the economy comes from the fact you'd be doing 1600 - 1750rpm at 70!

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g57yle
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Thu Feb 22, 2007 6:10 pm

yes it does do a lot more economy @ 70 also which is what ill be doing in the UK :wink: , but the uk isnt the only country its going to be driven in :D

There are a few places you can do that sort of speed crusing

And not only that, it doesnt ever take me long to get to 120 winkeye.
Patm3
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Fri Feb 23, 2007 10:48 am

I done 265kph in my heap of shit and it is still running and nothing fell off or exploded luckily :D i was scared the hardtop might fly off. It should be capable of about 175mph, but its a long story, so dont fear guys go as fast as you like, as long as you have a private road like i do :D then you are cool, as to do such speeds on a motorway is just plain foolish winkeye
Geoff
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Mon Feb 26, 2007 12:56 am

Ant wrote:Ians 3.2 beast has done 165 iirc ? Bruntingthorpe, sure its in a PBMW somewhere.....

I've driven E30s that shook so bad @ 130 I was gripping the seat with my ringpiece ! stability would be my concern

165+ scary stuff 8O
I think they only managed to get around 155mph iirc.
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