Off the turbine scroll ? Martin has it but we were not sure just how well it would work .
What boost were you running Steve ?
Off the turbine scroll ? Martin has it but we were not sure just how well it would work .
What boost were you running Steve ?
Std swing on the arm is about 10 mm max before it fouls on the housing .I can get the full 15mm movement now on the machined housing so the actuator is the limiting factor .Originally Posted by Andrew Cooke
ok, so at 22psi (ignoring the backpressure blowing the wastegate open) you'll go from being 7mm open to 15mm open. That ought to make a difference.....
I got sidetracked today fitting an aerial to a neighbors camper van which meant removing half the feckin interiorso I haven't had chance to test the low hold setup .
Is this what you found lee ?
http://cgi.ebay.co.uk/T3-T3-EXHAUST-...es_CarParts_SM
I think with a bit more looking you could find a 44mm version maybe. Or you could use a 38mm in conjunction with the existing internal
Its not about boost, its about volume of exhaust gas.
That's the very fella
I was running 18psi.it did work well, the only worry I had was welding to cast but that obviosly wasn't a prob
TrueWe mapped it beyond 20 on the std engine but ran out of turbo ,injectors and fuel
volume is good
Low boost holds at about 6psi then just creeps up the same as before with no signs of stopping so external it is .
Scoff get yer thinking cap on son and I'll start saving
I thought you were looking for mid 20s, the wastegate won't even be open at 6psi, so no chance of controlling that. I think it'll control better at higher boost.Low boost holds at about 6psi then just creeps up the same as before with no signs of stopping so external it is .
Scoff get yer thinking cap on son and I'll start saving
btw, my Gordini engine made 7psi with the wastegate wired open, it controlled to 20psi just fine.
What I mean is it will rise to 6/8psi then halt slightly before ramping up to 25 and beyond .I'm seeing this effect on all combination's of gate ,it's just the point at which it pauses that is altering .
I can't shift enough gas through the divorced wastegate pipe .I'm sure that's the problem .If I remove some of the the 'dam ' in the housing between the main downpipe and the wastegate this might prove the point .
ahh, Ok you're stuffed then
mind, it's gonna be a bit optimistic controlling a T3/4 with an internal gate esp with 3L of engine driving it. Just fit the twins, you know you want to
I'm putting the 60trim one we used at POD back on for now .I need to prove a few things with a single turbo before we go twins ...Also I need a small lottery win ,not greedy ,a couple of k would suffice
Scrap that ...I'm taking the dam out first and stick with the big bugger .
Agree, if necessary it's not that hard to weld in a larger tube for the divorced gate pipe. I think we could even cut and use one of the the spare GTA header tubes for the job.
Pikey .
I really think we are just going to get the same effect to a lesser degree .I'll remove the dam and if we still get creep then fk
feck-it !! not enough
I think this is getting silly now ...+ I ran out of fuel on the dual carriageway ,sure is thirsty these days
time for some thinking out of the box..
could you remove the penny totally, grind out the hole in the housing to 35mm or so, re-connect the divorced pipe and install an external gate part way down the divorced pipe instead. I don't know how large that divorced pipe is, maybe it'll need to be larger than it is currently and maybe you'll need to work on it a bit to be doubly sure that the divorced pipe is isolated from the turbine discharge.
Bit tight to get a bigger bore in there but possible .I still think the divorced idea is at it's limit .If we can dump the gas pre turbine then I think that will be best ?
I'm going to remove the dam completely tomorrow ,if I still get creep then I really don't know what's going on .
I remember back towards the start of this project ....there was some discussion about not having any wastegate and binning the boost via a valve/solenoid just after the compressorOr I might have dreamt it ....Martin will know .
that would be a horrible way of controlling boost, but yes getting the wastegate in before the turbo is ideal of course. I think you'll need to be doing this, I'd be going for 44mm too I think.
Dam is now completely removed so just out to see what happens .No pre load on the new actuator .
I think Chris's idea is a good one, at least you are not completely losing the setup you have, in that it bolts up and fits etc.
I think we probably have several things going on here, the very open turbine and large diameter blades means that it's the lowest flow restriction path compared to the waste gate circuit. Had it been a more closed turbine like a std T3 (you can look straight through yours, but drive torque is generated from it's large overall diameter), then the pressure restrictions between the turbine circuit and the waste gate when fully open would have been more balanced. The net increase in back pressure would substantially increase the flow through the waste gate circuit, but we don't have that, lower back pressure is a good thing for big bhp numbers. So we need a well flowed waste system end to end for the gases to even take that circuit, at the moment they just won't, and the physical evidence is there. In fairness I don't think a turbine of the size you have now was originally considered so we are at a different point of reference.
The 90 deg flow turn from the start of the turbine volute casing in through the penny drilling is a torture and small. I really don't think we can get sufficient flow with out actually "ducting" flow into it - grinding the entry side back on a taper so the flow drives into the penny hole drilling - so you will be very thin behind the penny on the top side (entry side of the volute flange)... if you get my meaning. Then bull nose round the lower side of the penny-drilling hole so flow that passes isn’t too disturbed. We need to help the flow make that transition without too much loss. Then the rest needs to be of sufficient bore.
I don't really like the spacer plates under the turbo; I think it will suffer similar. The best is where the flow is made to transition on a divergent Y - one side is the turbo, the other is the external waste gate. I think we will be modifying old GT5's (tubby5) .68 housing to match the turbine profile, I genuinely think that's where we are going...
Last edited by MFaulks; 30-08-2010 at 11:00.
No dam and still the same , I'm going down the pub ...
I'm still in favour of the pre turbine route but think we need a 60mm external
It's all your fault Faulks
Positive side is that the clutch is a lot better even on boggo dot4 and tell you what !! it don't half bloody shift as well until it hits 2 bar
oh bum
I'll bring up the housing Saturday, it may be easy to machine the profile... hope so...
I have a brand new external gate valve in my goody boxes somewhere, I will have a look... what was that about knowing lots of intelligent, independent, understanding, and eligible women?? Lol... I'll have a look, got to get this bloomen thing going properly before the light fades out this year!
oh heck, I forgot to mention good looking
Damn !
4 out of five and I'd have been able to help
you also forgot independently wealthy with full workshop facilities and a good cookoh heck, I forgot to mention good looking
ha-ha+ it gets better, heck I would even be a sex slave for that
back to reality, so what we doing then chap?
I dunno
Need a thinking session in front of all the possibles
If we know what size pipe then I can pop over to OJZ and get some .
out the box or out of his box thinking ?
Time will tell
that's gonna need 'porting' out a bitout the box or out of his box thinking ?
Time will tell
What is that for ?
It's a secret
We are going to try and dump the boost
I know you do not approve but I'm after trying it as it will at best help , at worst will use it as a massive DV which we may need .
It's that MF fellas idea
I don't think I'd want to map that Lee.
I know that .
You guys are nutters.
Love it
yes I know you can blame me
But it is a bit of pipe we can take back, honest.. and I will be more than happy to eat humble pie and I told you soooos... but go on let's give it a try sir?
Ok, how about this for a deal - if it's total bag of poo, it get's the external, and Lee will fab it on and we'll both go back to school!
isn't that going to just over speed the turbo? I'd do it on a supercharger, but it sounds dodgy on a turbo
So with that bit of pipe your going to try and vent boost pre manifold? Could you not knock up some sort of mainfold? I suppose if your going to do that you may as well make two manifolds and go with two turbos as mentioned earlier on in the thread
I'm sure it'll fix the problem I just think you'd introduce a whole load more.
I'd be worried about compressor efficiency, shaft rpm, turbine efficiency and charge temperature to name but a few. Then there's the chunk of power you'd be throwing away.
yes - yeap that's known. But we weren't too worried about turbo longevity anyway.. winkisn't that going to just over speed the turbo? I'd do it on a supercharger, but it sounds dodgy on a turbo
Technically yes and no, it really depends on the ratio of flow, hopefully it's going to offer some degree of control and not just go plain wide open - will depend on the setup. In which case, the answer would be yes.
The valve that is going on it is this: www.greddy.com/products/turbochargers/blow-off-valves , and it's the type R 47mm.
Chris, I agree and know it's not ideal. The hot side external is certainly the better of the two options, and technically superior... but I'm up 10 miles from Clee on Saturday and thought if he could get an adaptor made we would give it a go whilst I'm in the area, if nothing else give Lee a smile... it's was a 10 minute chat whilst I was driving to work on Tuesday I think.
If it does control to a suitable degree, I'll datalog the pressure profile, air-off temps from the turbo, engine rpm etc and can then decide, this isn't fixed in stone, just an option. I will grab as much data as possible.
pah, you need one of these:
Andy you're not helping
Lee you had better rescue this thread...
Scoff - sorry!
Right I'm off to go get my bottle of gas!
I'm not getting involved in all this technical stuff .Point me in a direction and I'll follow
At the end of the day we are pumping a lot of gas and need to expel it rapidly .It may work , it may not but it sure as hell won't blow me lump up so I'm prepared to give it a go .
Tune in next week ...same Bat time ...same Bat channel !!
holy rusted metal batman!!
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