A NB8B Turbo progress.

[NitroDann]

There only one extra 90* bend there than mazda built it with and its much larger internally than OEM.

Dann

[IanR]

Progress continues.

So the car car was run in on the dyno gently before creating a mild safe 98 tune at 11psi.
The idea is that we have a safe tune for 98 and then run it hard on e85.

It made 225whp on 98 at 11psi (made 218 previously at 19psi w/ t2554)

Then change fuel to e85.

It made 256whp on e85 at 12psi



Then 270whp on e85 by about 5000rpm then wouldn't budge above 285whp in the top end. Apparently a restriction in air flow somewhere, either intake or exhaust...

This is the overlap showing gain over t2554 tune at 213 hp. Huge gains... with zero loss in response, well it will be more responsive by the look of things on the road lol.



A few things to do especially with the cooling system as it showed up as still running hot (so im not imagining it) and start looking to find the extra top end horses, but I'm sure by the look of the power curve on the dyno sheet its going to be very much a different car to drive. Dann and his team of mech/builders/machinists/dyno tuners have got me a great result. Motors nearly there...

[IanR]

I am making 285whp which estimates 335 at the motor. http://www.mk5cortinaestate.co.uk/calculator4.php



The stories abound that the 2860rs can make more hp that this,

Dann has had one setup which made 360whp on the same turbo, e85, flowed head, ideal bolt ons etc
so im looking to see why the top end power stays flat at 285.

Time to do the math that I didn't do prior.

The 2860rs can flow bit over 35 lb/min, so need an air intake that is not a restriction to 35+ lb/min



35lb/min = 500 cubic feet /min

500cfm = 305whp on 98 and 350whp on e85
(http://turbochargerspecs.blogspot.com.a ... me-in.html)

Now to calculate required surface area.

Area req is flow rate/face velocity.
are req = 500cfm/130 ft/min = 3.85 or so into inches is 553in2 in area required to flow 500cfm for making of horses...
http://www.sonicperformance.com.au/docu ... sation.pdf

Does this thing have that surface area...I have no idea.



"The Apollo is ideal for normally aspired engines up to 250BHP and turbo engines up to 350BHP." from the K&N website...

So it could be fine but...confession time, mine is an ebay copy lol
so in all this crazy engine building horsepower chasing I have an $80 unit that's a copy of a $300+ unit and it may not be identical and flow as much as the genuine unit.

[Magpie]

You need to measure the pleat height/depth/number to determine the surface area of the filter in question. Flick an email to K&N and ask them what they have that matches your needs. You will need to have an idea of the duct size that you will be using.

The other thing that you may need to consider is friction loss on the duct being used.

[TrackAttack]

Simple test would be to remove the suspected restriction for a single dyno pull?

[NitroDann]

Most filters are bellmouthed on the inside and previous tests show that removing a bellmouthed pod and leaving a straight pipe can lost up to 10% on the spot, Ie its not really a valid test.

[IanR]

So, from the calcs I need for (optional example only) a "round straight" pod with a length*diameter that is greater than 25.6"
Working out requirements for Universal Round Straight is: Diameter x Length x 6 x 3.14
ie (500cfm=6*3.14* (height x diameter))

So a 5"x6", 4x7" dimension pod etc

The k&N Apollo system is:

http://www.knfilters.com/news/news.aspx?id=1684

7"diameter and tapers to 2" but has a pleated design, so yet again maybe it will flow enough but quite likely not.


for reference:
http://www.gnttype.org/techarea/turbo/airfilter.html
http://www.knfilters.com/search/univround.aspx

[IanR]

or use ebay to calculate the right size, ...that one flows 600cfm for a 160x130cm size, pleated with hollow core.



From all this I'm bloody sure that the fake k7n Apollo unit measuring allot smaller than the above is limiting horsepower.



Its been doing my head not knowing where the restriction is and just buying another pod and booking dyno time without knowing what we are testing and have the correct gear to test was keeping me awake. At least thats done now. Ill go buy a correctly sized filter. It will be worth it if we can take 285whp to 300 or 320.

[NitroDann]

Where have I heard the words "fit a 3a pod filter" before?

[IanR]

On the last tuning session which was several hours including the run in period with rebuilt motor, the crankcase pressure built high enough to push some of the gasket sealant out at the sump, causing a micro spray oil leak all over the fans...and engine bay.

The leak was originally thought to be the front main but now its the sump gasket its clear that a better breathing setup is required to deal with the crankcase pressures exceeding the std breather capacity. Seems like the the combination of 285hp and perhaps rings that are yet to fully bed in leading to enough blow by to cause this issue. Makes sense.

Solution, add a barb to the rocker cover and run a catch can, this doubles the rate that the crank case pressures can be released.

Dann is today resealing the sump, I'm driving up there hopefully this afternoon to catch up and get the next lesson in "Things that go pop while chasing non std horsepower"...learning and breathing, plus add funds. Repeat.

[IanR]

This will not be a restriction point.



Comparo for size.





The sump has been sealed up and drying before catch can is installed to deal with blow by.



A few smart folks have mentioned the reality that the wastgate spring may need another external spring to keep the gate shut at full power. Seems weird unless the diagram spring doesn't match the turbo, but easy to watch under full power and remedy Dann tells me.

[NitroDann]

On the dyno we screwed the power right up to close to 300whp and we had some breathing as you can sometimes expect from a still fresh motor on tonnes of boost, so while we are playing with some other things on the car, the decision was made to do a full US race miata style catch can build. There is more details, including pics of the inside of the can somewhere on my camera (steel wool, baffles etc) But here are some pics taken, some in the dark my apologies.










Its next to the throttle body pipe. (Black and round, big hoses running towards the back of the engine coming off of it)





Dann

[IanR]

....

Very happy with how this has turned out, It's functional, emissions compliant and looks super tidy! Brilliant.

[IanR]

Results are in.

[bear2230]

When I see 300 it makes me smile
Well done Ian/Dann