I studied fluid dynamics as part of my automotive engineering degree, so I was also going on what I was taught by accredited professionals. Please don't jump to conclusions about your customers...
I've seen that video, I've seen others where performance increases massively just by increasing downpipe diameter - as you say there are many factors.
The downpipe you advertised on your site showed crush bends, which I had no issue with, as the area doesn't change much. But it was
nothing like the one I was sent... The one in question was a series of severely crushed bends with a sharp welded joint immediately after the turbo - the flow must be shocking. Even my wife who knows diddly squat about cars said it looked terrible. That was my 1st issue, the second was the disparity to your advert and the 3rd was your (continuing) lack of admittance of the poor quality - you never replied to the facebook post
I don't really want to open the can of worms again and haven't brought it up publicly for a long time, but suggesting I blindly believe the internet has wound me up.
I'm pleased you've changed supplier tbh, the UK needs a supplier of high quality Volvo tuning parts and I genuinely hope ClassicSwede can be that, but in my experience your quality control & customer service needs some polishing.
Quote:
Originally Posted by classicswede
Reading and believing everything you read on the internet.
Don't get me wrong in theory a mandrel bent system is better and flow rates are higher. In real world situations are mandrel bends the be all and end all then teh answer is no.
Where you have mandrel bends butt jointed to pipes this tends to create a situation worse than a crush bend. Where the joint has a slight step this sends reverse direction shock waves into the exhaust gas stream. Very few mandrel bent systems use correct lap joints that remove that problem.
There is a interesting video on youtube showing dyno tests of a exhaust manifold all nicely bent and then the results after hammering dents into it and then more dents. The dents on this engine gave better results than without! Would that happen on every engine? Certain to say no but what it does go to show is if you want to extract every last possible bit of power you need dyno time and sometimes try teh unlikely.
BTW that downpipe has been fitted on another car (customer collected teh pipe in person and shown the exessive crush) and has made some good results on the dyno. Would it be better with a better made downpipe? Who knows without back to back dyno testing.
I am much happier with the new downpipes but with a RHD car and the factory manifold the flow is never going to be ideal
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