Performance

[N4TH4N]

Has anyone noticed that their sport is better on performance on some days as opposed to others?? Is it to do with how cold the air is etc.. not too clued on on engines ..

or is it just my clio lol

 

[MartinR]

Re: perfomance

Cold /denser air = better

 

[Snake182]

Re: perfomance

If I do its barely noticeable, if it feels faster its normally me driving it like a loon higher up the revs where all the power is, then I am like 'oh yeah ' lol. When driving around town a lot you forget how pokey they are higher up.

 

[Munson]

Re: perfomance

Yes. More so with forced induction though in my experience.

 

[Dave..]

Re: perfomance

Yes. More so with forced induction though in my experience.

This.

An N/A engine is almost certainly a placebo effect. Anything with an intercooler is noticeably quicker on a cold winters day.

 

[Munson]

Re: perfomance

My MkII Focus RS running 22psi was a monster on a cold winter morning. That much is true. Then again it wasn't slow in the summer IIRC.

 

[Martin_172]

Re: perfomance

my twingo GT running 1.2 Bar was the same, tiny intercooler used to hold it back but on a cold morning it had a bit more punch!

 

[Chip-mk1]

Re: perfomance

The temperature compensation in the ecu is far from perfect. So not only do you get difference from outside temp meaning denser air you also find the map suits some conditions better than others too.
So yes a small variation is quite normal.

 

[105e]

Re: perfomance

Most definitely happens, I believe.

 

[Rob669]

Re: perfomance

Driving the RS Clio fast is all down to the driver, gear changes, throttle position etc I believe. So any changes you notice will be because you are driving it slightly differently one day to the next. Compared to my Subaru which always feels fast (and is therefore possibly an easier car to drive quickly) I find I have good and bad days with the Clio. It's probably just that I get fed up with needing high revs all the time in the Clio, that's all.

 

[N4TH4N]

Thanks all.

 

[Steven103]

Worth pointing out that having stuff in the boot, tank of petrol, tyre pressures, leaky dampers, type of tarmac etc. all make a much more noticeable difference just to put it in perspective. You're not gaining/loosing 10 BHP depending on how nice the weather is.

 

[llgsimpson]

seems the same to me really no matter what the weather is, only differences come from having passengers petrol or luggage

 

[N4TH4N]

In my car the difference is noticeable. Some days it feels as though it could take on the world and others it feels very disappointing. .. cant help wonder if theres an issue somewhere. Only ever used v power.. lambda replaced..

 

[llgsimpson]

In my car the difference is noticeable. Some days it feels as though it could take on the world and others it feels very disappointing. .. cant help wonder if theres an issue somewhere. Only ever used v power.. lambda replaced..

It should never feel disapointing! maybe you do have an issue if its that noticable..

 

[N4TH4N]

It should never feel disapointing! maybe you do have an issue if its that noticable..

what sort of things effect performance?

 

[Chip-mk1]

Worth pointing out that having stuff in the boot, tank of petrol, tyre pressures, leaky dampers, type of tarmac etc. all make a much more noticeable difference just to put it in perspective. You're not gaining/loosing 10 BHP depending on how nice the weather is.

Will quite likely be more than 10bhp in it between a very hot day and a cold day.


Here is the formula used on a dyno I work with that it uses to compensate for temp variations:
kWkor = kW(1013/air pressure) x sqr((273+temp)/293)


0 degrees => almost 4 percent more power than at 20 degrees
40 degrees => over 3 percent less power than at 20 degrees

So five or six percent very easy to see different and that's if the map was optimum for both, which it isn't as the temp correction is quite poor on these Ecus so could easily be more than that and hence more than 10bhp

 

[N4TH4N]

That makes sense then chip tbf, I guess i'll try and fit an extra CAF... thanks for your information.

 

[Steven103]

Will quite likely be more than 10bhp in it between a very hot day and a cold day.


Here is the formula used on a dyno I work with that it uses to compensate for temp variations:
kWkor = kW(1013/air pressure) x sqr((273+temp)/293)


0 degrees => almost 4 percent more power than at 20 degrees
40 degrees => over 3 percent less power than at 20 degrees

So five or six percent very easy to see different and that's if the map was optimum for both, which it isn't as the temp correction is quite poor on these Ecus so could easily be more than that and hence more than 10bhp

Interesting to see an empirically determined equation rather than subjective non back-to-back observations in an uncontrolled environment.

 

[mokeyat]

In my experience, the forced induction is noticeably better when the air is cooler, the N/A is hardly any different.
Both the Clios seem to run better with a full tank of fuel though and the Escort is no different. It's probably the placebo effect but I swear it just runs smoother. Strange!

 

[Chip-mk1]

In my experience, the forced induction is noticeably better when the air is cooler, the N/A is hardly any different.
Both the Clios seem to run better with a full tank of fuel though and the Escort is no different. It's probably the placebo effect but I swear it just runs smoother. Strange!

With forced induction you double up the advantages basically. Cooler air going into the turbo means it's not as hot on it's way out. Then the intercooler is more efficient after the turbo as well.

 

[llgsimpson]

on another note, is that how nitrous can have good results over other gases because its so cold/dense?

 

[Chip-mk1]

on another note, is that how nitrous can have good results over other gases because its so cold/dense?

Although during phase shift you do get a drop in temperature that can have useful side effects if you use nitrous really well the idea is to minimise phase shift anyway and inject as much of it as possible as a liquid so consequently you don't see as big a drop in intake temp as you would in a poor installation.

The real advantage of nitrous is that you can get such a large mass of oxygen into a small engine. One of my best mates has seen 600 percent gains in power on some engines from nitrous.

It's absurd the gains you can get with it but sadly it's very expensive to use for anything other than drag racing.

 

[mokeyat]

With forced induction you double up the advantages basically. Cooler air going into the turbo means it's not as hot on it's way out. Then the intercooler is more efficient after the turbo as well.

This makes sense, it's a twin pass intercooler as well.