blow-off/ diverter valve EA82T :)

steptoe · Post by **steptoe** » Sun Nov 17, 2013 6:45 pm

RSR 555 wrote:Oh.. forgot to mention yesterday.. I love the colour coded numbering system

Been using it with decoding my tax this year too Q1 red, Q2 bloo ......

RSR 555 · Post by **RSR 555** » Sun Nov 17, 2013 10:18 pm

Good idea. When are we going to see the tyre smoking video?

steptoe · Post by **steptoe** » Mon Nov 18, 2013 6:39 am

Shees, hope that is all that smokes

I dunno Paul, how many unfinished projects are you sitting on? I think it will be out there before your Murtaya hits the streets!

RSR 555 · Post by **RSR 555** » Mon Nov 18, 2013 9:37 am

LOL.. a couple

Bit hard to use the Murtaya as a comparison, as this is a joint venture and not just my doing.

As for my own projects.. the Gen2 B4 converted Outback will be on the road for the SA trip.

tambox · Post by **tambox** » Mon Nov 18, 2013 8:52 pm

Come on, fire it up, there are so many variables in this system that recirculates a "hot" mixture, it will be intersting to see what happens.
If I can see(flames) or hear(bang) from Melbourne, I will be impressed

I gave up on the flow rate maths there are too many variables, as well as possible reverse feeds.
Theoretically, the mixture will be rich at the point the BOV opens, this hopefully will be enough to stop a lean backfire, but it depends on how much, if any is forced backwards into the mixer, I dont think it will be quick/strong enough to worry the converter. Again this depends upon if you do a hard acceleration gear change or just cruise after the gear change.
Looking at that picture, if you have problems, flipping the mixer over and connecting directly to the air cleaner outlet, then use the curved pipe to feed it to the turbo, will give you a bigger baffle area for the BOV to dump into, after the mixer.
See many variables.

Yes Paul, LPG burns completely, but more slowly, unless you you pre-heat it, but thats another story.

Take more photos, in case it all vapourises on the test drive

I still like the idea of venting it to the atmosphere, with an ignitor.

A clarification to protect my liability, yes, all my Ls are on gas and when I was running petrol turbo I had this setup, not on gas.
"hot" mixture recirculation is called that for a reason.

PS That was a good idea to leave the clamps off, hey Jonno.

RSR 555 · Post by **RSR 555** » Mon Nov 18, 2013 10:55 pm

Great help there Greg and love the disclaimer

But does gas still burn slower at higher compression?

And I want videos of the first run

steptoe · Post by **steptoe** » Tue Nov 19, 2013 6:29 am

I also have a disabled ute parking the turbo sedan in ...so will be some time

Trying to keep the mixer as close as to the throttle for best,fast as possible fuel mix changes. In that being said, my guru said it should not matter - citing an old turbo gas falcon with about six feet ducting between mixer and turbo.Yet to find said guru for comment on current thinking.....

tambox · Post by **tambox** » Tue Nov 19, 2013 7:15 am

Turbo's and LPG are a good mix, LPG burns slower than petrol. The draw through system mixes the gas mixture very well and Impco stuff is capable supplying what is required.
The hotter the gas mixture is, the easier it is to ignite and the quicker it burns, therefore more efficient. The turbo also helps this.

The BOV would be like sending a pulse of water upstream towards a dam wall with a small overflow it could trickle over. The higher the boost, the stronger the pulse, the longer the distance, the more it will fade. The closer it gets to the wall, the harder it is to go upstream.

So many theoretical variables.
Somebody else must have been inventive/brave/silly enough to have done this before, hard to find any info, or maybe they just didn't survive...............

Gannon · Post by **Gannon** » Tue Nov 19, 2013 8:20 am

So can you make more power with lpg compared to petrol because of the increased knock resistance?
Have you had your rig dyno'd Jono ?

Sent from my new touchy phone thingy

steptoe · Post by **steptoe** » Tue Nov 19, 2013 7:34 pm

Don't start Greg on that for it takes in a history lesson about a man who did things differently, his impression on a young Greg, a modifed water pump and intake air temps around 87 degrees C. Normal sytems seem to lose power at the higher end of things with LPG, but lower end where it is torque not HP that counts - LPG has that 'feel' to it

Paarrr.ppp dyno only

tambox · Post by **tambox** » Tue Nov 19, 2013 7:46 pm

Good to see you remembered what you were taught, young Jonno.
If the right approach is taken with LPG, some amazing results can be achieved.

steptoe · Post by **steptoe** » Wed Nov 20, 2013 6:25 am

I need to add a temp probe into that casting, but suspect the power increase gained by that theory might be too much for the good old EA82 heads.....

steptoe · Post by **steptoe** » Mon Jan 20, 2014 7:52 am

Right. For starters...mention blow off valve without the hyphen, blow off valve, BOV, B O V and might just help search function find this again. Search did not find it with hyphen I used!

It is official - I can now reveal the joint venture between the postal service and nncoolg - a handy little alloy welding service - if you can post it, they can weld it. None of this tearing around workshops begging for a small job to be done, being directed to the minimum workshop charge sign. PM nncoolg, arrange for pics and drawings, instructions, wrap it all up, pop it into the post with tracking and insurances if need be. They (making operation sound big

) will keep you informed, raise any questions to minimise stuff ups or disappointment ,takes payment in form of rare Subaru items, cash, eft and maybe paypal too

How's that Neville ??

It has been nearly impossible to find anyone who knows much about BOV of draw through LPG turbo systems, so we just went ahead with what best seemed to work in theory, taking AS1425:2007 into account, including the volatility of the fuel, where it was at pre BOV, where it must not go post BOV, where its venting can only go, what its exhaust side pressure effect is going to have on other sensors (diaphragms) ,emissions etc.

A boost of confidence came just the other day talking to a confident fella telling me his old man once had a draw through turbo with a BOV and was nothing wrong with it - worked well. FINALLY !! Found some positive news ! Then, he tells me of its one draw back - smelled bad of gas

. Sounds like it was a big no-no ...venting to atmosphere

So, with some confidence, some reservations the test drive began....

We have been out on a test drive. A gingerly two mile run. Then next day a 50km trek, a within the speed limit haul up an incline just torquing up it, no probs, running nice engine temp too, stop at intersection, and we are off on a slight downhill run. Maybe it was spirited driving or sumptin' coz next thing I get this WHOOSH and WHEEZ and no go, chuck her into neutral and engine stalls.

A slint hint of vapours reaches my nasal tissues. Engine off means safety sytems act and gas delivery is automatically cut at two points.

Being hot and sunny at the time, did not pull over straight away - was able to glide off the main road and into a schools empty carpark and stop under the only shade tree.

With the sympathetic reflex nerve system kicking in, feeling a bit shakey (no keys for the workshop, tow truck drivers expensive time -Sunday!) lifting the bonnet to see what had happened , checked all the blue silicone hoses and clamps - all still safe and secure of course, hmmm ?? then spot the alloy cross over 'intercooler' (does more intercooling than the tin thing Cordia GSRs had !) the alloy duct had come unstuck in its factory rubber hose coupling with a bit of boost behind it, thumped the underside of the bonnet

As luck would have it, the most useful tool here, the 10mm spanner, was in another place, luckily the factory clamp was also Philips phriendly

Was it rally drivers of old, told me they used Subaru part # FENC EW IRE to strap the 'intercooler' down to prevent this hapening any further!

Done, checked and rechecked, Started up, rechecked, all good, back on our merry way. Have tested up to 5000rpm and all seems to run fine, including the O2 monitor. Next test will be to get it back into the workshop to hook up the flash mobile exhaust gas analyser to ensure emissions still spot on.

Then, maybe open up some of the restrictive baffling I left in place on the exhaust side of the recirculating valve, which BTW is a copy of a FORGE style, styled on the BOsch recirculating valves of turbo euro cars, nothing big and fancy of HP turbo cars, just a nice tidy little unit, does its job. Though, reckon it needs some matte black paint to reduce its under bonnet bling.

The feel in the accy pedal ...?? .. not sure if it is fear related, but pedal feels harder for some reason - reluctant to squeeze too hard in case..... It is six months since I have driven it, and the efi throttle body combo of springs has always been stiffer...always a different way to driving a torquey turbo EA82 than a NA foot to the floor for go EA81

RSR 555 · Post by **RSR 555** » Tue Feb 11, 2014 3:42 pm

Glad that we live on different sides of the country.. otherwise I'd have to hand back my license and sell off all my cars