Another Ebay rip off?

[FeeYat]

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=32094&item=7940544031&rd=1

I'm not gonna buy it, just looks dodgy!

 

[HP]

Another 5p resistor that does no good at all.

 

[joecinq]

Shame its not for the cinquecento, i would of snapped that up......

 

[dave]

merged with the sticky i put up,
those that are good at writing should write an complain to max power also if what its says on that auction page is true

 

[FeeYat]

I'm a firm believer in the phrase 'You get what you pay for'

2 people have bought them from that auction as well....

 

[etsm]

Gaz you mean them fake dump valves on non-turbo cars? if so there totally retarded . Oh and those ones that go in your exhaust pipe reduce engine power tbh for no benefit except a stupid whistling noise. Best way to communicate with them people is by shoutting "Timmmmmmmmeeeeeh!!!!".

Official Chav <s>Beater</s> Spotter

I notice you say they reduce engine power from the ones that go in the exhaust, explain your answer, I dont understand...how you can say this

**Just to ADD the Whistle , Chip, V/Chip DONT WORK , Dont Waste Money.

 

[Helz]

Surely they reduce airflow out of the exhaust don't they?

 

[etsm]

Surely they reduce airflow out of the exhaust don't they?

maybe on q 2 inch pipe, surely not enough to effect the system

 

[FeeYat]

Why you would want one is beyond me!

 

[etsm]

Why you would want one is beyond me!

I DONT WANT ONE AHHHHHHHHHHHHHHHHHHHHHHH.

I was just pointing out sometimes people GIVE advice without really knowing what they are talking about or how to explain there answer, we all know the products are CRAP !!! but other people might want a reason and some of the answer anit Upto IT !!!

As i like to follow the rule if I dont know the answer, I wont say anything.
Not just reply cos i m add post counts.

Not Having a go but somepeople really need ADVICE or REASON's before they act and giving the wrong advice is worse then saying NOTHING..

Just My view.. Sorry People

 

[FeeYat]

I DONT WANT ONE AHHHHHHHHHHHHHHHHHHHHHHH.

I didn't say you did.

Just cos my post followed yours doesn't mean it has anything to do with it. I was just pointing out that it is beyond my comprehension as to why anyone would fit something to their car that would eventually break it.

mmmkay

 

[Helz]

And I am one of those people who does indeed like to always ask 'why?', hence why I asked what I did . Not always good to just take something at face value.

 

[arseofbox]

maybe on q 2 inch pipe, surely not enough to effect the system

I thought most systems upto 2L, maybe 3L were 2"

Not enough to affect airflow? really...nah. A propeller is going to act like a big bluff body (very un-aerodynamic) in any pipe, when its vanes are perpendicular to airflow Id say.

So personally, id say its gonna be a damn big restriction to airflow, especially given for the prop (whistle part) to turn, its gonna need to be accelerated in a direction that the airflow isnt going...

If im being too technical, or just thinking too hard, tell me !

 

[Helz]

Thanks Tom, I had hoped I was right

 

[arseofbox]

Thanks Tom, I had hoped I was right

Well...im only thinking In theoretical terms. Airflow has to speed up to get round an obstacle without dissipating energy to it to retain the same Mass Flow rate...If it dissipates energy, then the flow rate goes down, so theres a restriction there*....I just cant see how placing a bloody great big propeller in the airstream can help in any way! (unless its in a larger diameter pipe), and Im sure it doesnt take a rocket scientist to figure that much!!!

*- This may be BS, I'll need to read up on fluid mechanics

 

[The Negotiator]

It will affect airflow and as Mr Fiat spent money designing it to give a volumetric flowrate X, I think it's a bad thing.

As Tom has said, the object in the path of the flow will have a big affect, the problems come from two areas:

Friction
Form factor

Friction:
The air has to flow past the object and has to have friction against the wall of the pipe, sticking in an extra object to cause additional friction won't help.

Form factor:
The shape of the object can cause eddies to start on oneside and not the other (depending on the Renold's number of the flow right Tom?). From this you get a pressure drop hence the flow won't be as strong. Of course at very low Re numbers the form factor problem is practically zero but you still get the friction problem.

I expect the Re to be moderately high in an exhaust (without calculating it) and hence both will have an affect on the volumetric (therefore mass) flow rates Q and M.

On a more basic level, you're taking energy out from the flow to turn the prop hence by by flowrate. Not sure what affect it will have on engine performance though guys?

 

[Liam]

Most performance 2 Litres benefit from 2.5inch zorst pipe.

Liam

 

[arseofbox]

Form factor:
The shape of the object can cause eddies to start on oneside and not the other (depending on the Renold's number of the flow right Tom?). From this you get a pressure drop hence the flow won't be as strong. Of course at very low Re numbers the form factor problem is practically zero but you still get the friction problem.

Yeah. Think so.

As for the type of flow, Id reckon its turbulent, so an unstreamlined blockage would have a damn big effect.

Liam, cheers for the advice on pipe sizing...I thought 2" seemed a bit small.