boost pipe routing & charge temp

[dubstar]

Hi guys,

Although it's a known that the original boosts pipes are routed through the cam-cover because of standard layout logistics, some heat transfer must occur and add to the charge temp versus not running it through the cam-cover.

Has anyone done any research or got any data on what sort of temperature difference there is, or knowledge of whether the rise in temperature is negligible enough not to worry about?

Ross.

[Jezza-7]

i think having the room or routing it would be a problem. I suppose if you made a t piece into the inlet of the charger and blanked the other inlet to charger off you could do it.

I personally found, i got better mpg with boost return mod done, but thats obviously not re-cerulating hot air. Must be a bit of temp difference.

[OCDmatt]

That's only re-circulated air anyway, so it's going back through the intercooler before getting into the engine so changing this pipe routing won't make any difference at all.

As Jezza says though getting rid of this and blanking the charger does make a good difference

[dubstar]

Thanks for your replies chaps,

It was a more general question really - my fault as I didn't give you any background. I'm going K03 turbo on my PY, but i'm not going the traditional Rothe manifold route - i'm building my own and moving the turbo elsewhere and as such I have few different piping options for charged air. The easiest may be to utilize the cam-cover to minimize pipework. It would be before the intercooler, but obviously I don't want to heat up my charge temp any more than necessary, so I was trying to understand how much putting it through there heated the air.

The fact that it's the re-circulated air will probably mean that no-one has done the research i'm after.

I didnt realise that was the case, so cheers guys.

[OCDmatt]

Ah I get ya know. Still think you must mean AFTER the intercooler?

I doubt it'd heat it up much at all tbh, but I think it will a little.

[dubstar]

nope, definitely before the intercooler    watch this space.......

[Yoof]

If it's pre intercooler then no, charge air will be hotter than cam cover. Energy flow from high to low = heat up cam cover.

Charge air temp ~ 130-180'C (dependent on boost pressure)

Cam cover ~ 70-90'C

So I wouldn't worry about the transfer temp, however the cam cover does go fairly narrow, definite flow restriction, but probably not a problem at ~170bhp (your target power?)

[dubstar]

Ahh, that's what I was after Yoof. Cheers pal. Wasn't sure what the charge air temp would be. (Actually, didn't realize it was that hot, but it makes perfect sense.) Cam cover would be around indicated engine temp, yeah - got it.

Hmm, well was looking at throwing 21psi through it - I guess that might be an issue with the restriction at that bore then? I'll do the maths on it when I get a chance, back pressure could screw it right up as you point out.

Just looking at options at the mo. Could always mill it out a bit but it all starts getting a tad tricky.

[Andy]

What's the ID of that pipe? Is it 48mm ish? From memory the K03 compressor outlet only needs 51mm ID pipe, so might not be such an issue.

On the road my post-intercooler inlet air temps were about +25°C over ambient with my old front-mount cooler if that helps. Now running a larger, better flowing intercooler which will hopefully help.

[OCDmatt]

So it it's certainly before the intercooler then the chance of the rocker temps raising the charge temp isn't going to matter? As the intercooler will cancel this out?

But like Yoof says, it's going to be hotter anyway

[Yoof]

There's no chance... it's physics!

If anything the opposite of what you suggest.

[OCDmatt]

I'm confused No chance of what?

[grungeisdead]

you are confused...

[scully]

If it's pre intercooler then no, charge air will be hotter than cam cover. Energy flow from high to low = heat up cam cover.

So basically, the cam cover works as an intercooler. 

@Dubstar: If the ID is too small, you could modify the cam cover to fit a bigger pipe, shouldn't be to much of a problem I suppose.

[Yoof]

I'm confused No chance of what?

You can't heat the charge air up with the cam cover, the charge air is at a higher temperature than the cam cover.

scully - I guess your restriction is the camshaft, not sure how close the standard pipe is...