Power...how much?

[Thooms]

Sorry if this may seem an obvious question, but how much power is deemed to be 'enough'?

I've been scratching my head about this for a fair while now...can't really figure it out.

Just been idley pricing up how much it would cost to build my 'dream car', and i'm a bit stuck when it comes to engine choices. Having done a fair bit of reading, I guess I'd be interested in either a 2 litre Duratec (similar to the RT400 spec i guess with ca. 220bhp or something like that), or an Audi 20v turbo (heavier I would guess, but more potent, and very cheap)

Now, this leads me to my biggest nag - how much power does a car like this need?

Being so light, I would imagine power isn't the main consideration as almost anything probably makes for rather...spritely performance, but would a turbocharged engine pushing 300+ bhp be usable? For a car that would be used both on road and track, what sort of power/weight is sensible? An Audi 1.8T with a Garrett GT28 or something will apparently make the best part of 350hp - putting the power/weight ratio well into the high 500s at least - but could you use that much power (at least without dying in the process)?

I know people put that kind of power in things like Dax Rushes and GKD Evolutions, but they are more in the 700-800kg range than the sub-600kg i think a Stylus (RT) would weigh?

Is it even feasible to consider a car like that suitable for road use (both from a practicality and a safety point of view)?

[stylussprinter]

Sorry if this may seem an obvious question, but how much power is deemed to be 'enough'?

I've been scratching my head about this for a fair while now...can't really figure it out.

Just been idley pricing up how much it would cost to build my 'dream car', and i'm a bit stuck when it comes to engine choices. Having done a fair bit of reading, I guess I'd be interested in either a 2 litre Duratec (similar to the RT400 spec i guess with ca. 220bhp or something like that), or an Audi 20v turbo (heavier I would guess, but more potent, and very cheap)

Now, this leads me to my biggest nag - how much power does a car like this need?

Being so light, I would imagine power isn't the main consideration as almost anything probably makes for rather...spritely performance, but would a turbocharged engine pushing 300+ bhp be usable? For a car that would be used both on road and track, what sort of power/weight is sensible? An Audi 1.8T with a Garrett GT28 or something will apparently make the best part of 350hp - putting the power/weight ratio well into the high 500s at least - but could you use that much power (at least without dying in the process)?

I know people put that kind of power in things like Dax Rushes and GKD Evolutions, but they are more in the 700-800kg range than the sub-600kg i think a Stylus (RT) would weigh?

Is it even feasible to consider a car like that suitable for road use (both from a practicality and a safety point of view)?

There 's many answers to that question and all could be correct depending on almost as many circumstances. Simple way to answer it for yourself is get a ride in one with known power and ask yousrself '' can I handle this '' ?

What's sensible to one guy will be outrageous for another

Rob.(don't forget that diff/box also play a large part)

[Pete&Matt]

its all about power to weight ratio! 300bhp in a stylus is way too much i think! been in a 230bhp zetec stylus before and that was more than quick enough!

Like Rob said, have a ride and see if you can handle it and like it!

[alecmartin19]

i've got a mere 1.8 zetec in mine with carbs and 2 litre cams. heads had a bit of work but i'm not pushing anywhere near the 200 mark.

i've got a standard type 9 box and a 4.4 ratio rear diff.

up to about 120 mph i'm quicker than most things on the road.

i suppose it depends what you intend to use the car for. if you are into straight line get to the horison as quickly as you can then yes, go for lots of power with your turbo. however if you are going to be using it mainly on the road, will you be wasting money on power you won't use? and will the power catch you out and put you backwards into a ditch? something to consider.

i agree that 300 is too much for this little car and i would say although not speaking from experience, 220 to 250 is plenty and most of the advantage comes from setting up the handling of the car. as i'm sure rob and a few other people will tell you.

yes you would catch less powerful cars in a straight because of the power difference but in the corners a well balanced car would gain the time back again.

personally, i'd stick to a 4 pot, normally aspirated engine and go for around the 200-220 mark. get some good gearing and rear diff and a good suspension set up.

definately have a ride in one first though. you may be suprised even with this amount of power.

i suppose at the end of the day everyones opinion will be slightly different and i'm sure there are people who would go for more power every time and they have their reasons too!

try a couple if people will let you and see for yourself!

[se7ensport]

..... but in the corners a well balanced car would gain the time back again....

I thought that once, and then I saw footage of a DAX hyabusa turbo at nurburg http://www.youtube.com/watch?v=3ArjcJJ2VaY


You ain't catching that no matter how well set up your car is

[Pete&Matt]

what you need is a small lightweight 4 pot lump. The toyota 4age 20v lump is good and is only 1600cc with loads of grunt! or a 2L duratech is more than enough and has a lot of torque.

[alecmartin19]

awesome car!

you could always go that route and have a bike engine! they do seem to be the way a lot of people are going.

however when comparing vehicles it is a good idea to compare it to something of a similar standard. there was nothing on that track with anywhere near the same power/weight ratio as that dax. a totally different class of car! the driver looked pretty good too although the power does almost get the better of him a couple of times in the video!!

leigh pratt has a zx9r engined RT. see if he'll tell you what thats like. i'm quite interested myself actually!

maybe i'm wrong about the power thing. maybe more power is the way forward......we'll see!

[Cerberus]

You need to have a go in a few cars, but i would think 4-500bhp per tonne should be more than enough after all there has to be a point when you can't put the power down, my old TVR Cerbera had about 325bhp per tonne and you couldn't use it all the time(handling was good after i spent boat loads on Nitrons and a different anti roll bars etc)at these speeds you can end up in a whole world of hurt

Phil

[alecmartin19]

325 bhp per tonne.

if you had a 4 pot with 220 bhp in a stylus rt you could expect at least 400bhp/t. hence rt400!

if you struggled to use all the power in your tvr then i reckon 250bhp in a stylus is about reaching the limit!

i don't know! maybe i'm wrong!

[Cerberus]

325 bhp per tonne.

if you had a 4 pot with 220 bhp in a stylus rt you could expect at least 400bhp/t. hence rt400!

if you struggled to use all the power in your tvr then i reckon 250bhp in a stylus is about reaching the limit!

i don't know! maybe i'm wrong!

I reckon you're about right, but until i've had a go in one can't say for sure, the only thing with my TVR was it had sh*t loads of torque 350ft lbs which was just waiting to bite your arse:shock:

Phil

[Thooms]

Thanks for all the replies chaps

There's a buildup article of that particular Dax on their site...I seem to remember 420hp or something like that! That's probably a power to weight ratio exceeding 600bhp/tonne lol. Wonder what the service interval is on it though

I appreciate the wise words...a 350hp turbocharged setup does seem a hell of a lot for a car like this. Looking at some curves for the engine - looks like it makes ca. 317ft/lbs of torque - seems like an awful lot for those 205mm tyres (let alone a Sierra axle!!!!)

Done a bit of RC car racing and it always was the case where tyres and suspension (oh and the driver ) would win the day, not all out power.

Duratec looks like a good option...they seem quite light too which must be a bonus

Any further suggestion/thoughts etc much appreciated

[Nissanman]

Thought I'd better speak up at this point. I'm currently putting a Nissan 2 ltr turbo engine (the later all ali SR20DET lump from a 200sx S14a - not the heavy iron lump in earlier cars) in a Stylus. At £1k for the engine and all the wiring bits and gearbox (with 50k full service history on the donor) they are a bargain - try getting a Duratec or a Zetec at 220bhp for that money.

Because it would be rude not too I've fitted various relatively inexpensive mods (and there is MASSES of cheap tuning gear for these engine and the standard box will happily take 350bhp) which will easily see this engine at 300bhp. HOWEVER - I'm will have the ECU and boost controller set up for two settings - one on low boost for around 220bhp and at the flick of a switch 300bhp if I'm feeling in the mood. I will also be having the ECU and boost controller set up to deliver very smooth power across the rev range - very do-able with these modern Jap engines and ECU's - I don't want something that only spools up at 4k revs and throws the back end out all the time. I've been in a 300bhp V8 fury and I loved that kind of power - you don't have to use it all it you don't want to. For me it's was relatively cheap (£800) to add another 100bhp whenever I need it - again, try getting another 100bhp for that money for a normally aspirated car.

As others have said though a lot is in the way the car is set up (Rob's car!!) and how good a driver you are. I don't expect to be using that kind of power very much - but I intend to have some fun with it when I want to, and spend a long time learning to drive it.

I've also widened the back of the car down the wings(see a previous post) to allow me to fit 8 inch rims and 235's to help put the power down.

I should be on the road (or at least track) within a couple of months - I'll let you know how driveable it is then
Jasper

[alecmartin19]

did you have to widen the tunnel at all to fit the gearbox? what does your engine weigh then? is it as light as my iron blocked zetec? how much power do they put out as standard?

[Nissanman]

Yes, I had to widen the tunnel, but I only widened the passenger side (about 2 inches) and off set the engine slightly.

Engine weighs about 125kg without gearbox - don't know how that compares to a Zetec.... probably not far off, I think the Zetec weighs around 110kgs - though I could be wrong

Standard power output is 200bhp. Put as soon as you put it in a kitcar and add a free flow exhaust and air filter and better intercooler you've already got more power without trying.....

By far the biggest headache is the nightmare wiring.

[Bikenuts]

“The later all ali SR20DET lump from a 200sx S14a - not the heavy iron lump in earlier cars” I resemble that remark Though if you look at some of my other posts you’ll see the weight comes out about the same all be it for 200cc less. As Nissanman says there’s loads of tuning bits out there for these engines you just have to look in different places than you would for Ford or Vauxhall. If you want something a bit different have a look at the Nissan V6 out of a late 300Z 200bhp NA 300bhp turbo stock, or on the milder side how about a 16/18 hundred Mazda lump from an MX5.