Turbos

[ubersonic]

Looking for some information and Google cannot help, I was driving my friends car back from the cinema the other day and god damn that thing is quick but although its got a lot more power than mine I don't know if being turbocharged as opposed to my vtec was having an effect too, it seemed to have a truckload more low end power despite being a smaller engine im guessing this is because the turbo boosts at low revs whereas vtec doesn't engage till over 5k?

The cars in question are a Honda Prelude SIR (2.2L, 220bhp, FWD, Vtec) and a Nissan 200SX S14 (2.0L 340bhp, RWD, Turbo) now I know the SX will be a lot faster due to the bhp difference but what kind of effect would the turbo play in that?

 

[Howard]

Yeah it's all to do with the way the power is delivered. A turbo engine's power curve will generally be more of a 'hump' as the turbo spools up and starts delivering more power suddenly, where a high-revving VTEC engine for example will be a linear, progressive shape, increasing linearly as the revs climb, with relative lack of power/torque lower in the revs. It's why turbo'd petrol / diesel engines can feel faster than a naturally aspirated petrol, despite that not always being the case in the real world. Obviously in this case however, I'd expect the S14 to demolish the Prelude

 

[Matt82]

power delivery. two very different engines. thats all there is to it

 

[Firestar_3x]

^^ Indeed.

 

[Muffin`]

Was it uphill?

 

[Matt82]

Was it uphill?

loving that

 

[Siliconslave]

the 200sx has a variable cam system like vtec as well as a turbo - at stock the s14 makes about 190bhp so the ones you were in was pretty heavily tuned.

The power from turbos tend to come in at a much lower rev range than vtec engages and gives a sudden surge of torque as opposed to the surge in revs that vtec uses to deliver power thus gives more of a kick...

but as i say the sx has its own secondary cam so your getting that 'vtec' style increase in revs, its just masked by the torque increase from the tubby...

 

[Relentless81]

the 200sx has a variable cam system like vtec as well as a turbo

Its not though really is it, DOHC VTEC is different to run of the mill VVT, you're thinking of plain old VTEC

Turbo provides torque, turbo's are also the viagra of the engine world, for those that cant do it naturally

 

[Siliconslave]

Its not though really is it, DOHC VTEC is different to run of the mill VVT, you're thinking of plain old VTEC

Turbo provides torque, turbo's are also the viagra of the engine world, for those that cant do it naturally

if you want to go into detail then no - NVCS isn't the same as DOHC VTEC however very broadly its similar.

as to turbos being the Viagra of the engine world I'm not going to get goaded into an argument - they are just a means to an end, as is displacement and VTEC...

 

[LiamC]

turbo > Vtec for performance
Vtec > Turbo for fun

 

[Relentless81]

if you want to go into detail then no - NVCS isn't the same as DOHC VTEC however very broadly its similar.

as to turbos being the Viagra of the engine world I'm not going to get goaded into an argument - they are just a means to an end, as is displacement and VTEC...

Yeah I see what you're saying in that its similar

I'm not looking for argument on the turbo vs vtec, personal preference and all that I just like saying the viagra comment

turbo > Vtec for performance

Now that depends on a whole host of factors

 

[Janesy B]

turbo > Vtec for performance
Vtec > Turbo for fun

Sweeping statements =

 

[ubersonic]

Agh, the worms! I cant get them back into the can!! ^^

 

[Matt82]

Now that depends on a whole host of factors

like which makes more power and which is capable of most? haha

turbot is generally pretty hard to beat output wise

 

[Relentless81]

like which makes more power and which is capable of most? haha

turbot is generally pretty hard to beat output wise

Obviously to get the most power when talking about building the highest output engine you possibly could for a road car then you would use a turbo of some form but thats not the point

The point is there are NA cars out there that will embarress big power turbo cars and of course vice versa so the generalisation that was made for both types of engine was rubbish

 

[Will Gill]

big power FI cars will do more embaressing than NA cars will with the same amount of money spent on tuning, and I've sat here for a good ten minutes trying to think of cars that might contradict this statement!

out the box I'm struggling to find NA cars that dwarf their similarly priced FI equivalents

I'm sure there will be some odd exception but I'm pretty confident my sweeping statement is mildly accurate

 

[Gaygle]

turbot

 

[sovietspybob]

- VTEC power curve

- Turbo power curve

As you can imagine both could make 200bhp say, one will only hit it for a small time at the very top of the power band, and the other will get a good % of its power a lot lower and sustain it for longer, hence the different feel between the 2.

 

[Will Gill]

torque

+1

 

[Matt82]

As you can imagine both could make 200bhp say, one will only hit it for a small time at the very top of the power band, and the other will get a good % of its power a lot lower and sustain it for longer, hence the different feel between the 2.[/QUOTE]
i think youve got the wrong end of the stick.

bhp is just a number. what you feel is torque, look at the torque plot to see how the engine's output will feel as you put your foot down.

the lower/lower sustained torque (vtak) is fine if you have the right gearing (and weight) to match.

bhp is pub talk though