Rolls

go have a look at the casting in the photos, it looks fine to me.

Can you get a copy of the dyno sheet? Should show if it is cam timing out, eg power curve heavily shifted to the low end etc.

Get it on the dyno and keep turning the boost up until you either make the power you want to, or you stop making power and obviously tune to suit. New tyres, get some federal 595 rs-r or kumho ku-36 they are usually good value for money.

This couldn't be truer, it is all in the assembly, you set the clearances/tolerances wrong and your shiny $10k pile of parts becomes a $10 pile of parts. The most expensive parts in the world aren't immune to poor tuning or incorrect assembly. This is the reason I will trust a second hand motor over a random rebuilt one unless it's been built by one of the few pro workshops that build motors every week.

Yeah it pretty much fails because of this.

I was talking NA wise and yeah I agree with the twin charging comment.

I think the amount of power you'd need to remove the gas fast enough to make a vacuum would be massive, I doubt it would work. Was just explaining how the effect would delivery more torque like an extractor system does.

Not quite. Two scenarios, cams with zero overlap. Lets say the charger sucks all the exhaust out and leaves a -100 vacuum when the exhaust stroke is over. Without the exhaust charger there would be a very slight positive pressure in the chamber, maybe a few psi max, if we have a -100 vacuum this means when the intake valve opens we have a larger pressure differential between the combustion chamber and the intake manifold, a greater differential pressure will mean the intake air will rush in faster and hence fill the cylinder more. Without the charger the volumetric efficiency would be say 80% or whatever a typical NA engine makes, with the charger it will be slightly higher. Also without the exhaust charger not all exhaust will be pushed out of the combustion chamber, so if not all exhaust leaves, that means there is less room for oxygen hence less bang. So via two methods does it allow more oxygen and fuel in the cylinder. 1) the vacuum causing a greater DP which sucks air faster into the cylinder 2) less exhaust gas dilution so more physical space for air + fuel. both of these effects will increase volumetric efficiency as there is now more air in the cylinder and hence it is closer to 100% VE. Scenario 2. Camshafts with overlap. If you have camshaft overlap the same as above will happen but you can now suck the intake charge into the cylinder via the exhaust, some air+fuel will be sucked out the exhaust but this will dramatically increase the velocity of the air flowing into the cylinder. Greater intake velocity means greater cylinder filling hence greater volumetric efficiency hence more bang. Basically think of this exhaust charger as a mechanical extractor, it works the same way that extractors cause an increase in torque, extractors remove the restriction in the exhaust so the cylinder has less work to do on the exhaust stroke, they also increase the vacuum in the cylinder which increases volumetric efficiency. Both of these scenarios ignore the fact that the charger will suck a large amount of power, so whilst you get a small torque increase from greater volumetric efficiency, you'd still almost certainly have a net loss in torque.

It either works or it doesn't. Most the sensors are going to have some sort of offset error so you'd need to calibrate it each time anyway. Regardless if you do the tune from scratch surely it it won't matter, I can't see it giving different values for the same ethanol content, might vary between sensors but as long as you don't tune with one and then change it shouldn't be an issue.

yeah bro, total rubbish, you should read all 40 pages of people saying how shit they are!

I cant even figure out what you have taken a picture of?

Yep it cost about $200 in parts myself and then about $800 in tuning and paying boostworx to finish it off. I left the aircon in the car so it didn't need to be recharged. All I had to buy is 3 new belts, oil, coolant, spark plugs and some fancy new electrical connectors for the wiring, everything else I reused. The $800 was mainly labour for replacing a few broken hose clamps in flamin mongrel positions, pulling studs out and tuning. I'm not really sure what your point is though, that $3k is a lot less than building a built 20!

What has any of that got to do with it being a 25? Car had a sloppy built 25 in it when I bought it which snapped a cam shaft, doubt it would have been any different if it was 20 or a 30. Now it has a neo and is running great, 240kw with stock response, full boost at 3k. Lets see your 20 do that Cost is $11.5k (car) + $2k (neo after the 25 head blew up)+ random bits maybe another $1k max? I've got a buyer for the bottom end now so will make another $1k back on that. Not a bad upgrade for $2k. Have about 10,000kms with the 25 now, I've only owned the car for just over a year so not bad.

Exhaust gets very hot, how would it go on a track, cook itself after a few mins? What kind of EGTs do you see?

What is a 'delay' ? Is it a misfire (pop pop pop)? Does the engine completely cut ignition? Does the engine splutter, does the engine just make no power? Is the engine pinging/detonating (sounds like a can of nails being rattled around) ? Answer these questions and we can help you. This makes absolutely no sense. "Rpm hits" what doest his mean, rpm hits what? at 7000rpm theres a 1 second delay before it hits 7000rpm again?? Sense makes none. What does "boost kicks in" mean?

Perhaps you missed the part where I accepted that. I'm not a f**king moron mafia, I design gas well heads and program the computers that do flow control for them day in day out, I understand how an engine works! Have you even read my posts before? The amount of times I've said this same thing is astounding.

shouldn't you be off trolling threads?

That is an amazing power curve. Close to full power from 4-8k, thats a 4k spread of useable power!

Def drop the exhaust, didn't know you had one of those valves. Even fully open I've heard people say they can suck a lot of power if they flap around and aren't held tight.

Will soon know when they take the POD off and drop the exhaust. Other thing to check is intake heat, see if something is causing the intake charge to get super heated.

I don't have a mini cooper gbox in my garage, care to explain? haha

Yup thats me

60kw is too big a variance for a dyno.

drop exhaust got any rubber pipes that could be sucking shut?

Porsche have done it and so have many other companies, it can be quite effective.