Reasons for slow variants of our cars

[Simon172]

Ive been thinking about this for a while. Why were some 172 (for example) getting like 120 bhp at the wheels and others 152 bhp at the wheels? Thats a really big difference, and there should be a simple explanation. Well, i was thinking of possible reasons to why they were "underpowered".

Engine running in - was it done vigorously? carefully? normally and then thrashed ever since?

Air box tubes - i found that when i disconnected my pipes of the airbox to get the loud ROAR that you can for free, i connected them up wrongly the first time and my car felt VERY slow and sluggish. It still was quick(ish) but no way near as explosive as it normally was, just torquey with no bhp. Anyway, i noticed the pipes were crushing one another and squeezing shut fouling any air getting through the once round pipes. Changing them back to where they were supposed to be located remedied the fault and all was well.

Throttle cable - i know the mk.2s have FBW, but this counts for all types of Clio sans FBW. I was reading CCC and they had an underpowered Exige making 20 bhp less than it should and the owner was moaning etc. The first mod they did was to tighten the throttle cable and this unleashed 20 missing bhp. Could anyone be having the same trouble here?

Can anyone think of any more reasons for such diverse RR readings??

cheers, Si

 

[rt172]

Poor quality control at Renault?!

 

[007]

Were the figures done by the same rolling road? If not then they arent really a comparason as Rolling roads appear to be a lottery. I have seen some very different figures from the same cars at different rolling roads. Some rolling roads do appear to be way out.

 

[teady172]

- Click at the bottom of the pedal on MK2s, my bro was driving around in his cup not flooring it properly until I reminded him!

- Duff tanks of Optimax, it got so bad with my car, that I only run on SU now. Never had a problem since!

Im siure Ill think of more!

 

[Griff]

Not all MK2s have the button/click under the accelerator tho...

 

[172man]

- Click at the bottom of the pedal on MK2s, my bro was driving around in his cup not flooring it properly until I reminded him!

eh?

RRs are randomly crap mines tested 166bhp then next time 155bhp?

i dont think there that accurate. Other than that there are various factors which will deplete power

 

[teady172]

Hmm, my early one had it, now my second one has it and also my bros Cup has it!??

 

[Griff]

My Feb 2002 172 didnt have one and I remember GR saying hers hasnt either.

 

[TimO172]

What is that CLick on the accelertor, is it right or wrong?

 

[Griff]

There is no right or wrong.

No-one seems to know what it is there for anyway. Some suggested its to do with traction control and some suggested its to do with cruise control.

I dont think Renault know what its there for!

 

[paddymph]

wats this about a click under the pedal?

 

[Chad]

maybe its so that if u crash the insurance co will know u had it nailed to the floor.......they already check to see if you were wearing your seatbelt the cars computer records it!

 

[Griff]

On SOME Clios there is a small "button" where the accelreator meets the bulkhead and a "click" can be felt under foot.

It only applies to FBW cars and was not present on all cars. My last 172 didnt have this but had a small circular disc of plastic instead.

 

[paddymph]

chad-thats rollocks!

I work in Insurance, why would they want to know if u hada seatbelt on? Wht would they get a smashed up car, remove the ECU, plug it in etc etc! Just doesnt happen!

 

[Chad]

Quote: Originally posted by paddymph on 10 April 2003


chad-thats rollocks!

I work in Insurance, why would they want to know if u hada seatbelt on? Wht would they get a smashed up car, remove the ECU, plug it in etc etc! Just doesnt happen!

paddy.....hate to disagree with you but Im pretty sure they do these days....dont think they would want to check for every single accident but if it were a fatal or if you were trying to claim for injurys.....Im not 100% but pretty sure all the same.....anybody else know?????

 

[paddymph]

they dont trust me! What reason would they have to check? They couldnt chuck a claim due to seatbelt? they couldnt NOT Pay a Third Party claim due to seatbelt!! Its just insurance scaremongering!

 

[Cupster]

I saw a guy who was in a ditch, I think he was unhappy about his performance at the time im not sure

 

[rt172]

They dont need to resort to an ECU to tell if you had your belt on in a crash. They can spot it by the hole in the windscreen and the strawberry jam on the pavement....

 

[Matblack]

My air intake is slightly folded where it meets the box, I have a feeling that the roar I get at 5000+ revs may be due to this. If I can get the car on the rollers at a rr day maybe I can see what playing with it to make it a cleaner bend will do

MB

 

[Chad]

rhys lol



I could be wrong but Ive heard more than one person say they they do record it but wont argue cause I dont know for def



anyway who could put up with that bloody bleeping noise in the clio if they werent wearing it

 

[Cupster]

Ha ha reminds me of an old thread when I fist got my clio. I was a virgin posterer and foolishly asked how to get rid of the beepy noise. Needless to say I got rinsed. thanks and sorry for disturbing the thread.

 

[Simon172]

The fold in the pipes are what happened when i connected them wrongly. Just think if youre sucking through a straw and its been squeezed in the middle by your fingers, then youre not getting the full potential air flow. Also, does anyone know what force the air is sucked into the engine? could it be enough to shrink the pipes to an extent? I know that on 1.8T golfs when you up the boost you have to get a stronger material pipe because the standard one gets sucked smaller than it should be limiting airflow and boost.

 

[Graham Gooch]

well as for rolling roads being well out, its true that some might need calibrating,

but remember if its a freezing cold day the car physically will make more power same way if its really hot then the car will make less power

when manufacturers quote bhp figures i.e a clio 172 making 172 bhp then that figure is obtained from temperate weather conditions and a proper renault engineer, could tell you that on a cold day it very well will make more power but they cant put it in the brochure as it wouldnt be a constant figure.

and yes airflow can seriously affect performance, hence why some people report power losse when fitting an IK, well if the cold air flow is LESS then of course it will make less, cold air is SOOOO important, and many peeps just dont realise this

 

[visceral]

i got that click at the bottom of the accelerator pedal travel - just glad i aint on me own!

 

[aaronc]

Quote: Originally posted by ralph wiggum on 11 April 2003


well as for rolling roads being well out, its true that some might need calibrating,

but remember if its a freezing cold day the car physically will make more power same way if its really hot then the car will make less power

when manufacturers quote bhp figures i.e a clio 172 making 172 bhp then that figure is obtained from temperate weather conditions and a proper renault engineer, could tell you that on a cold day it very well will make more power but they cant put it in the brochure as it wouldnt be a constant figure.

and yes airflow can seriously affect performance, hence why some people report power losse when fitting an IK, well if the cold air flow is LESS then of course it will make less, cold air is SOOOO important, and many peeps just dont realise this

If thats the case then they should have made the 172 to 180bhp on a good day so that on a bad day the 172 was still 172 and nothing lower. Surely they should expected this being professional engineers?