EA 81 + T3 Turbo Charger

[birdy]

I would be more conserned with the exhaust gas be,n in the prop disc from so close.I hada header pipe blow off a 912 head and the consentrated hot thin gas was enuf for me to have to stand on opposit rudder for the rest of the day.

[tonydenton]

I"m sure there was a asra directive or " not recommended " by asra that said " your not allowed to do it " . the one in the photo is also a smaller engine and I would think less volume of exhaust gases coming out [ maybe , cause I don"t really know that much ]. only that some one on here with all the knowledge could give the correct info. I"m done.

[birdy]

2bnanger exhaust gas is generaly much cooler after go,n through all that tuned muffler than a streight through 4banger.

[birdy]

2bnanger exhaust gas is generaly much cooler after go,n through all that tuned muffler than a streight through 4banger.Also, gas passn through the prop near the hub wont effect performance much coz theres not much thrust come from near the hub.Exhaust termination near the tips robs the most efficiant area of the disc of cool clean air.

[RossM]

I"ll be the silly bugger and post link to Airworthiness Alerts (AA)- Advisorieshttp://www.asra.org.au/documents/AD_AA/AA_2010.01_Propellers_and_Exhausts.pdf

[tonydenton]

I don"t know why you would think your labeled " silly bugger " ross, your in contention for the top bloke award . ;D ;D ;D I remember when waddles was having problems with his auto flight gear box overheating and that at some stage he commented that how could he have not known that an [ probably AD , from memory ]

[MadMuz]

My comment about the radiated heat from an exhaust close to te prop blade or hub when the engine is hot and then switched off and the blade stops right near the hot exhaust pipe can be investigated by getting a wood or plastic ruler and waving it back and forward over a hot soldering iron..... as long as the ruler doesn"t stop close to the iron it will not burn/melt.... sort of like lighting a candle and waving your fingers thru the flame, a bit warm, but you wont burn your finger. Stop your finger near the flame and it is a different story.I have seen what others have talked about, where an exhaust pipe outlet on a gyro ends just short of a prop blade, this cant be good for the prop I agree, but given the ASRA required 300mm it should be fine as long as it is not pointing directly at the hub in the low pressure area in front of the hub.... it will act like a heat sink.... You can try with a car exhaust outlet, run the engine fast and put your hand 300mm away and it is just warm gas.... once you get too close, the temp soon becomes unbearable, within a couple of inches, you will burn your hand for sure. As well as the heat issue, noise will prolly be greater if the prop blades are too close to the exhaust outlet..... neither being a good thing....

[MadMuz]

Does anyone know if an IHI turbo from a Subaru has a carbon seal or a dynamic seal? I want to run mine as a draw thru (if the wolf 2D computer is too hard to get sorted) and I need a carbon seal for a draw thru system. With a dynamic seal, when the carby is closed, oil gets pulled thru a dynamic seal, whereas a carbon seal contains the oil better.

[WEST OZ FLYER]

Muz, pretty sure that it would have a piston seal (dynamic). My understanding is the IHI Subaru turbos are classified as "non rebuilable" throw away turbos. Mitsubishi TD04 and 5 on the other hand have huge aftermarket support.

[Sean]

Hi browny,I noticed you have some type of air bag suspension system on your gyro. How good is this system working, who makes them & what price as I have never seen them beforeCheers Sean

[Darrell Jones]

G"day Browny, What ECU are you using ?

[NiqueNaque]

Browny,On my machine I paid particular attention to balance between the heads for gas flow and water flow.As close as possible, the exhaust pipes up to the turbine are the same length. The pipe after the compressor to the top of each of the carburettors is the same length. They"re all 50 OD stainless x 1.6 wall. Both sides have the same tees and elbows to connect-to maintain equivalent flows and back pressures, it is very important.I ran it and found quite some differences in vacuum & EGT as it progressed up the rev range. I have vacuum guages on each carb and was able to balance it by making sure the throttle link arm lengths are the same to 0.1mm, and the throttle link bar was equal to the centre distances of the carbs. Even then they yielded different vacuum levels until tweaked by adjusting the link length and only one link arm length. Once this was done the Vacuum & EGT values were the same or about 10c different. After running at 3500 RPM for 30mins with a 72x73.5 prop it was at 700c on both sides, boost was 1.5psi and vacuum was 5"hg. It would run at nearly 0"hg at 3900 but it was like a caged & very pissed off werewolf on a bad day.. it was barely 1/2 throttle and really howling. after 3900 it would sputter due to fuel starvation, where the turbo pressure would defeat the fuel pump pressure and fuel would not be able to leave the carb. To fix this I"m paralleling the fuel pump with another so it runs a higher fuel pressure but not much higher, I"m worried about turning it into a metal milkshake..

[NiqueNaque]

One thing mine has that yours might not is a balance tube between the heads under the carbs, it is 22 ID (a piece of 1" copper pipe) .

[NiqueNaque]

so, if it doesn"t have one, make a "H" pattern manifold for the t/b"s to sit on, the larger the link pipe, the better.

[MadMuz]

nick, how many carbies have you got on your engine? And how many turbos for that matter? I am just wondering.... it sounds like you have one turbo and more than one carb? that is a bit strange, normally one turbo and one carb (like an inch and 3/4 SU) works really good? If you have one turbo trying to suck thru 2 carbies, that might be where the problem is? Or are you blowing thru 2 carbs? What are the carbs?