Aerodynamics plays a big part in answering this question.

Power:weight ratio has a major effect on acceleration. Overall BHP has an effect on top speed as does aerodynamics.

Handling is fairly ignorant of BHP and is all to do with weight.

So a heavy 7 with BHP will eat up the drag strip until the CD of a 7 becomes just too much....

A lightweight 7 with a healthy power:weight ratio and good handling will be much better (and much more fun) on a track but will have a lower top speed due to the lack of BHP to push through the wall of air @ high speed.

For traffic-light grand prixs they'll probably be about equal (ie better than most other things on the road!!!)...

As a similar example of (un)useable power I drove a 2wd Sierra Cossie with about 320Bhp on a slightly damp road & it was an absolute nightmare, everytime you used the power the back end would slide down the camber of the road!! It was really horrible to drive & quite frankly dangerous.

My power to weight is way higher than the Cossie was (I have about 400bhp/tonne), but I don't have any of the same problems of driveability even on a fully wet road.

If you want plenty of power & torque then go for a standard, or mildly tweaked 'Busa or Zx12/14. You'll keep all the advantages of the lighter weight & lower cost of the bec but still have the straight line performance of the Cossie.

Another example of too much power/torque, I watched a 'Busa turbo engined Dax accelerate hard & all it did was leap from side to side leaving black lines at about £5 per foot & rubber smoke everywhere, but the acceleration was actually rellatively slow, an ordinary bec would have driven straight past it.

i have a westfield with 2 litre duratec with 5 speed sequential box giving circa 240/250bhp and weighs 540kgs approx 450bhp per tonne .this sort of power is ample if only for track work /road unless your going to santa pod i wouldnt bother with 330bhp cossie it would be un useable imho.ive had 3 westfields now blade/busa and duratec the duratec is quicker in a straight line and about the same in corners now im getting used to the extra power and handling .cosssie powered car has gotta weigh 650/750kgs plus were as bec car your looking at 540kg for a heaviest.of course if you want the biggest engine then fit it but cossie power aint cheap and nether is keeping them cool .guy on wscc had zetec turbo which he had a lot of problems keepin cool

A friend has a 400bhp Dax, which is mental! He doesn't have traction problems as such as it's a Quadra (4x4).

At Teesside it's noticably slower than my R1 Striker through the twisties, but get it on the (short) straight bits and off it goes!

What if the cossie turbo was 4 wheel drive

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Originally posted by alanr
What if the cossie turbo was 4 wheel drive

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Originally posted by hicost
Well mine will now run 430/440bhp with the two stage boost.

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Originally posted by alan wheeldon

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Originally posted by alanr
What if the cossie turbo was 4 wheel drive

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Thats a different story and opens up a whole new can of beans

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R1 hands down 4x4 or not.

Rig

125 MPH needs about 150 RW BHP (caterham aerodynamics)
160 MPH needs about 300 RW BHP (caterham aerodynamics)

With optimum gearing, the cosworth engine will have more top speed. A lot more. With all that torque though, you won't be able to use 1st gear beyond 1/3 throttle or second beyond 2/3 without burning your tyres down to the threads.

Hi first things first. What is the car to be used for. Road- track- 1/4 mile- ect.

This will be the biggest influence on a sencible decision.

Quoting a 300bhp cossie i asume would be just NA Not turbo. But even so i never see any reason to try and put more than 200-250 bhp in to a seven type car. The rest of the bhp above that is just wasted unlesss you are trying to achive a silly top speed.

cheers matt

What about the 4 x 4 Cossie turbo on Pistonheads ( Dax section) at the moment -- Its ONLY 324bhp looks like it could be fun

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[Edited on 4/9/07 by alanr]

hicost in your events what times do you post against bec cars or lower powered cec out of interest and what events are they .do you pick events to suit your car ie long straights or do you not get a choice.i can understand your thrill of speed i get it every time i press the load pedal and my bhp is lower than yours cant imagine what that powers like in a seven type car

Personally I've always gone for decent torque over a wide RPM range. I guess an extreme analogy is a big yank V8 with huge grunt but no useable rev range.

So for my recent engine install I went for the Rotrex supercharger as I knew the bottom end will be relatively weak. However the power/torque would keep on increasing right up to the redline.

For example I have 120 lbs ft at 3000RPM but 195 lbs ft at 7000RPM. So I can pretty much use full throttle from 2nd gear through to 5th. The power delivery is very linear and controllable so I haven't felt the need to fit an LSD.

One thing I have done though is change from a 4.4:1 to 3.92:1 diff. This was because I mostly drive on the road and commute when possible. The acceleration before was electric but plain silly! At least now I can cruise at 3200RPM and still out accelerate any car I've come across yet

PS I refuse to play with Hicost!

[Edited on 4/9/07 by bimbleuk]

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Originally posted by hicost

Well the answer to the question is, we never really have had a true BEC enter our events. All the mountains and large mileage usually puts them off.

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so is your cossie engine in a seven type car or something different .i wouldnt to do endurance in my car either

[Edited on 4/9/07 by higgsti]

Forget Curbough hicost, bring it to 3 sisters for the last sprint of the season, and bring factor 30 sun protection to...
Promise not to drool over it while its hot....

[Edited on 4/9/07 by Uphill Racer]

[Edited on 4/9/07 by Uphill Racer]

fantastic looking beast mate, do you have eight eyes like a spider to see all the switches, lights and dials.

Hicost - I think your navigator must be truly brave and really need those footrests.

Nice car

Just out of interest what range of pressures does the boost adjuster give you and how much does it affect lag from lowest to highest boost?

ps - to stay on thread I think that for the type of event for which your car was obviously built, a normal BEC wouldn't stand a chance - ie horses for courses.

[Edited on 5/9/07 by Ivan]

How much does your car weigh? Your engine bay looks a bit tight, is it hard to work on?

Ive had a 380bhp Sierra Cosworth before and it handles the power no problem. Ive been wonder what it would be like transfering everything into a 7 though??

My consern is the lack of weight might mean a lack of traction, you can only go so far then it will become un usable which is basically why I started this thread.

We need to get highcost to have a play against someone who has a BEC

respect

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We need to get highcost to have a play against someone who has a BEC

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I believe hicost is my new hero!

For some time I've been thinking about a locost with a late-model BMW M3 engine.. somehow it seemed just so utterly ridiculous that it had to be done. I had never heard of these endurance events before.. but I guess I now have a reason to build something delightfully silly.

...now all I have to do is move back to Europe and start building. Hmm, I guess that won't happen anytime soon.

Oh well, for the time being, I will just keep dreaming of my 333Hp 6-cylinder "locost"

Hi quote "I appreciate your opinion but don't knock it till you've tried it. "

Those comment are based upon 20+ years of building seven type cars with anything from 60 -600 bhp. And the practicality of using that bhp to its best to propell a seven in a foward direction.


Quote "It was done a few years ago at Donington against the Isonblade - very interesting - the BEC was very nimble (and Jon can really drive that thing!) ISTR The cossie beast was a tad quicker over the lap with a stupid top speed (not using the, now removed, nitrous kit) "

And what where the lap times when this took place.

cheers matt