Pinched purple pipes...

[Phil_Edge]

My brother was nosing around under the bonnet and noticed something about the purple pipe configuration which I thought I might try and shed some light on, by asking the better educated populace of PH...

The pipes look to be in pretty good nick, with the usual discolouration, but apart from that, no wear or anything... Looking closer though, given they all squash together in their bid to connect air to engine - some are considerably more squashed than others. Particularly, there are a couple which appear to be squeezed, where others remain much in their original shape.

He suggested that there would be significant negative impact on the car given the uneven distribution, and further, the aparent "throttling" of air via the squashed pipes... Without expert knowledge myself, I would guess that he's right!

Given all the work gone into porting and balancing, I would have thought this a fundamental issue to be resolved before the final remap (after another 250 miles of running-in)...?

Thoughts?

[itsallyellow]

Get a TCS induction kit!

Its what we use on the race car and is a big improvement over the standard set up.

Mike

[Phil_Edge]

itsallyellow said:

Get a TCS induction kit!

Its what we use on the race car and is a big improvement over the standard set up.

Mike

Costing around....? (gulp - following full engine rebuild plus additionals)

[MackemPete]

If your sticking to a budget can you not pick up some second hand purple pipes off ebay? Though I would highly recommend TCS pipes + remap

[Phil_Edge]

... just aside from the all-too-appealing upgrades for a moment, on a technical note - would these differences in the pipe shapes and persumably throughput make a 'significant' difference to the engine/performance?

[WorAl]

if you are just after replacing the pipes cant you have a look at samco hoses and make your own?? im doing that on the S6 intake

ETA for example: http://www.samcosport.com/uk/rp_straight_hoses.asp

Edited by WorAl on Thursday 8th January 11:30

[grahamn]

Phil_Edge said:

... just aside from the all-too-appealing upgrades for a moment, on a technical note - would these differences in the pipe shapes and persumably throughput make a 'significant' difference to the engine/performance?

When I had mine done it went from 340ish bhp to 398 bhp, that was with a remap though.

[Phil_Edge]

They taper quite significantly on the V8... ie. aren't "straight", so not sure...

WorAl said:

if you are just after replacing the pipes cant you have a look at samco hoses and make your own?? im doing that on the S6 intake

ETA for example: http://www.samcosport.com/uk/rp_straight_hoses.asp

Edited by WorAl on Thursday 8th January 11:30

[markh1]

WorAl said:

if you are just after replacing the pipes cant you have a look at samco hoses and make your own?? im doing that on the S6 intake

ETA for example: http://www.samcosport.com/uk/rp_straight_hoses.asp

Edited by WorAl on Thursday 8th January 11:30

I spoke to a couple of hose companies at the autosport show last year. if you want to get the pipes to fit properly you will have to get tooling made, the pipe are also laid up by hand. The cost of this means its cheaper to buy new.

[WorAl]

markh1 said:

WorAl said:

if you are just after replacing the pipes cant you have a look at samco hoses and make your own?? im doing that on the S6 intake

ETA for example: http://www.samcosport.com/uk/rp_straight_hoses.asp

Edited by WorAl on Thursday 8th January 11:30

I spoke to a couple of hose companies at the autosport show last year. if you want to get the pipes to fit properly you will have to get tooling made, the pipe are also laid up by hand. The cost of this means its cheaper to buy new.

oh right wasnt sure about how the 4.5 pipes are...its ok on mine as it is just a 6" straight pipe...

[pjac67]

Why is no one bothering to answer the OP's question?

I don't think 'pinched' pipes make much difference (so I'm told but happy to be corrected).

Induction costs £1k++ depending on how far you go....

HTH

[Phil_Edge]

pjac67 said:

Why is no one bothering to answer the OP's question?

I don't think 'pinched' pipes make much difference (so I'm told but happy to be corrected).

Induction costs £1k++ depending on how far you go....

HTH

I'm thinking you might be right - on the basis that even though they look pinched from above, I suspect that the actual cross sectional area remains pretty much the same in all of them - ie. the round ones have the same, or, very similar cross sectional area as those which appear pinched, as they are simply more oval - so not really reducting the volume of air throughput... hmm...

[volospian]

I'd agree, I doubt they would make much difference unless they are actually "collapsed". If they are only oval instead of round, then there is still, theoretically, the same volume or capacity in the pipe, merely a different cross sectional shape. Well, to a degree anyway...

[Gazzab]

Surely if you are spending money on a rebuild to special spec and you are having a bespoke map then it is a no-brainer to get short induction? Surely you could negotiate a good price with Austec for such?

[ridds]

Phil_Edge said:

pjac67 said:

Why is no one bothering to answer the OP's question?

I don't think 'pinched' pipes make much difference (so I'm told but happy to be corrected).

Induction costs £1k++ depending on how far you go....

HTH

I'm thinking you might be right - on the basis that even though they look pinched from above, I suspect that the actual cross sectional area remains pretty much the same in all of them - ie. the round ones have the same, or, very similar cross sectional area as those which appear pinched, as they are simply more oval - so not really reducting the volume of air throughput... hmm...

What happens when they are so squashed that they are flat though? CSA is not the same then.

Pinched pipes will have quite a significant difference on cylinder to cylinder AFR. This will then have an effect on cylinder specific BMEP. A few cylinders running at say 9-10:1 is going to have a massive effect on power output.

[FarmyardPants]

ridds said:

Phil_Edge said:

pjac67 said:

Why is no one bothering to answer the OP's question?

I don't think 'pinched' pipes make much difference (so I'm told but happy to be corrected).

Induction costs £1k++ depending on how far you go....

HTH

I'm thinking you might be right - on the basis that even though they look pinched from above, I suspect that the actual cross sectional area remains pretty much the same in all of them - ie. the round ones have the same, or, very similar cross sectional area as those which appear pinched, as they are simply more oval - so not really reducting the volume of air throughput... hmm...

What happens when they are so squashed that they are flat though? CSA is not the same then.

Pinched pipes will have quite a significant difference on cylinder to cylinder AFR. This will then have an effect on cylinder specific BMEP. A few cylinders running at say 9-10:1 is going to have a massive effect on power output.

Not to mention that a tube with circular X-section has a much greater resistance to collapse under vacuum than an oval one.

Edited by FarmyardPants on Thursday 8th January 18:21

[Byker28i]

Got to say if I had a 4.5 then helping it breath better with the short induction mod would be top of my list.

[Phil_Edge]

Byker28i said:

Got to say if I had a 4.5 then helping it breath better with the short induction mod would be top of my list.

Work was "directed" by the problems caused from a cooling problem on a long run... *sigh* Hence the focus on the block et al.

Breathing - I enquired - but given the expenditure on everything else - was something that could be added at a later point. Not much saving in terms of labour in having it done with this lot.

Interesting it would be top of your list though... I'm enquiring as we speak. Is a short pipe replacement really a grand?! That sounds a lot for short pipes, or is there more to it? Off to research.................. clicking "Search"...........

[ridds]

Another thing to remember is what happens to the purple hoses without the steel wire inside is that they virtually collapse when subjected to high pressure pulsations.

Watched them on a dyno run and it's quite horrifying tbh.

[Robscim]

I was warned that the ones with steel wires in had the possibility to come away and get ingested into the engine!! I can't confirm its true, but I wasn't for taking the chance.

There's only one solution - get them replaced with some of the various upgraded ones (that are more resistant to the fuel vapours!!

Had mine done, plus remap. Not cheap, but if I wanted cheap, I'd be in a micra , and once you've spent it, you won't look back

Cheers

Rob