Turbo outlet pipe diameter and EA82T's ?

[discopotato03]

Long post , you have been warned .

I can see where Julian is coming from but I don't agree with the use of the term "pumping loss" in this case .

With virtually all pumps you can't pump what you don't have so hard to fathom how you can have a power loss or drain here .
What you can have is a drawing loss but its not really the same thing .
I think the point he is making is that the restriction around small throttle openings means the dynamic compression ratio stays very low and power is required to drag the piston down the bore increasing the cylinders volume against low flow or cylinder charging .

What you have to remember is that engines not in a supercharged state are charged by atmospheric pressure and thats mostly all you have to fill the cylinders with . An engine CANNOT - suck , it can and does develop an area of lower pressure when the pistons go down on the induction stroke and then its up to atmospheric pressure minus flow losses (pressure drops) to get any air in .

With spark ignited petrol engines you have to have some means of controlling airflow into the cylinders , mostly it is a throttle valve/valves but the more sophisticated engines do it purely with electronics and valve actuation .

Its not hard to see why the engineers are turning more and more to egr as a means of thermal control . Because of ever tightening and forced emissions and consumption legislation they are being forced to try to run leaner (numerically higher AFR's) even at higher and full load situations and you have to have a thermal "brake" on combustion temperatures to be able to do this reliably .

I hope the mention of direct fuel injection or as some manufacturers call it GDI was not lost to anyone here .
It changes the whole world a petrol engine sees when you have direct injection . Clever injection timing cam make GDI engines run leaner without damaging things because you are not chained to getting the fuel in with the air when the valves are open . At light load part throttle operation you can inject the fuel at close to top dead center to get better mixture distribution into the smaller compressed volume than trying to do so with port fuel injection .

The devil is always in the details and this little sting is where all the technological finery comes crashing down .

What About The Electronics ?

Manufacturers love electronics , mechanics/maintainers hate them .
Mass produced electronic controls are cheaper that mechanical ones and more accurate whilever they're - working . What happens when they don't ?

What do most people do with a dead sealed control box if after hours days weeks of diagnostics locating it ? Bin . What do the manufacturers do ? They rape you financially of course .
Cars are past being at the stage where most control functions are capable of being "handled" by electronic devices . Forget the engine for a sec , we can now do accelerator/auto trans/steering/brakes - most things of any consequence - with fallable electronics .
They can and do kill people as well . Think Toyota ATM and its not just them or Mr Toyoda that have lots of explaining to do .

So , next time you're wondering why Adrian drives a 1986 RX L Series piece of automotive archaelogy and a times a 1996 one remember this .
I don't want ABS , I don't want die by wire throttle , I don't want/need electronic stability control , I don't want electronic automatic gearboxes .

I like cars that you have some hope of getting going if they try to lay down on you . I prefer mechanical/electric/hydraulic/pneumatic saystems wherever possible because I stand a much better chance of fixing them even temporarily if they try to lemon out .

Now Gannon , an intercooler will be on the cards if I keep Ellie long enough and I was recently scrutinising some capable looking bonet scoops on late model Jap turbo diesel SUV things . Unlike bling performance cars light truck bonnets are flat like an L Series one so scoops don't need anything fancy to go on Ellies lid . Some of their intercoolers are capable looking as well and maybe cost effective at wreckers down the track .
With the sort of performance my 82 will have I don't think it justifys a more sophisticated engine management system . From what I've found the air and exhaust flows aren't going to be what I'd hoped for so why fit expensive things only to remove them when she's parted out . I think I'll save that computer and coils for an engine that can justify them .

Out of fingers and time , cheers A .

[steptoe]

die by wire trottle control must have been coined by a BA Foulcan driver perhaps?

I am with you on the techno reduced beasts. Thrift is not the only reason I play with LPG.

Was thinking traction control on some monsters is a great innovation, but think Subaru or any AWD not need it

[discopotato03]

Its a worry to see vehicles run away almost out of control when the electronics screw up .
A little while back someone in the US went for a longer drive than intended in their SUV when the cruise control failed in active mode . It was able to out muscle its brakes (Cruise cont) and the electronic auto said sorry sir can't let you select what I think is an inappropriate gear at this speed .
So "cruising" along with a police escort whilst talking to a traffic controller via mobile and 911 they eventually ran out of road and punched it through a T junction luckily not killing anyone . From memory hand bag control activated and shut down the engine .

Sadly we have mobs like the NRMA screaming that all new cars must have these "safety' devices" such as 50 drivers hand bags and ASC and pushing laws forcing the manufacturers to provide it . Remember that olympic swimmer female that got on the NRMA's board , never ever had a drivers licence did she but will still preside over these things ...

Cars continue to get heavier and more expensive and lot of what goes into them is non essential garbage IMO . We need this trash because we're told we do not because we actually asked for it .
I live for the day when someone smashes through legislation and manages to produce reasonably compact reasonably light weight cars using conventional control systems . The safety system will be 2/3 of the mass crunching into something else .
You only have to read the papers to see people wiping themselves and others out and the mountains of electronics aren't saving fools from themselves .

Now back to conventional EGR from an 80's perspective !

Cheers A .

[Gannon]

Yes i think Julian is referring to the power required to pull the air past the throttle plate. Creating manifold vacuum uses power. Either that or it was easier to explain than changes in dynamic compression to 99% of Autospeed readers.

An engine CANNOT - suck , it can and does develop an area of lower pressure when the pistons go down on the induction stroke and then its up to atmospheric pressure minus flow losses (pressure drops) to get any air in

When i open my mouth and expand my lungs, does that mean im not sucking in air, im creating a low pressure in my lungs and atmospheric pressure forces air in.

So what is the definition of suck? (other than EA82 head design)


Whats your aversion to ABS, stability control and automatic gearboxes?

Are we talking racecars here or daily drivers?

ABS is awesome, gives me confidence when the mrs is driving and for when cows, roos etc. jump out in front of me. I can just plant my foot and let the computer apply enough pressure to pull me up asap without skidding.

I bet on a wet road, anyone could pull up a car with ABS quicker than you could the same car without ABS

I havent driven with VDC, but by the description in the FSM, its very well designed.

Electronic automatics are designed for fuel economy and smooth gear changes, once you drive one for a while, you lean how to make it do what you want. If it was a race car i would have bought a manual.

Jono, AWD isnt a substitute for stability control. And AWD car might hang on better round a corner under power because the torque is distributed between 4 tyres as opposed to 2 (on a FWD or RWD car), but if coasting or braking through the corner, it will behave like a 2wd car.

[ORX-18]

Without dabbling too much into the technical side of things, i can shed some light on the REAL LIFE experiences ive had with larger than you would think turbo's and 82t's. The single biggest upgrade you can do if you are looking for supporting mods to make it all work better and in harmony, is an aftermarket computer and a good tuner on a dyno. I dont care about the Ydivided by X=wtfwhotoldyouthat, it is hands down the best. Second is the desired power output goal you have in mind, AND, the drivability you want to have. If its a lazy 150hp at the treads, then driveability wont be compromised too much, however, anything after that and its a downward spiral, a real steep one. next in the line of supporting mods for a large turbocharger upgrade is cams, the duration and lift needed is best discussed with the camshaft maker. This mod can really open your eyes. Since you have the headers sorted, id like to know if they are unequal or equal length. the size of the primary and the size of the collector pipe. too large in the collector pipe will cause issues. Then, its the exhaust. You say you have a 2.25"? With that turbocharger, i would have a minimum of 2.5" as ball bearing turbos react very well to free flowing zorsts and are alot more sensitive that the bush type. What are you doing with the distributor, is the boost retard unit modified to suit your current boost level? a good idea to have the thing graphed while its out to make sure its all sweet. After that, its the inlet side, the dear as poison stuff. Like custom inlets and a larger TB. im out of time, the outlaws are here, ill try post more up later

All in all, Good luck, you are gonna need it lol

Cheers, allan

[discopotato03]

Most of these later implied safety features are intended to give a wider safety margin for error . So what does Joe average wood duck do ? He feels safer and better equipt to walk er drive on the wild side because he now has bling technology , or so he's told , to save his expensive car and butt .
Goes harder brakes later travels closer to other vehicles . Statistically he's in a safer vehicle BUT the road toll isn't decreasing is it ?
People still have monumentals because they are doing ever more extreme things on public roads .

ABS brakes . People racing on the dirt back in the 60's learnt to do the jack hammer thing on the brake pedal to get some retarding effect on low friction surfaces . Don't need an ABS pump to do that . Serious off road people , and Europeans who get snow every year , will tell you how good ABS isn't . Some European cars even have dash switches to disable it .
Maintenance . A vacuum assisted brake system is simple and effective , not so when you add a control unit/ABS pump/wheel speed sensors . ABS pumps are generally sealed units and not servicable , if you want to scare yourself go price the box and pump . 20 years down the track when wirings getting a bit chatty how reliable will these things be ? You can't legally remove ABS even if the same model was available without it . They consider it a reduction in OE supplied safety devices and thats a legal no no . Needless to say I looked around for an R33 without ABS when I bought my Skyline .

Active Stabilitry Control . This is a system of motion and steering wheel position sensors , its designed to add individual brake inputs to stop vehicles slewing around if the vehicle gets out of shape .
Even if you are switched on and have good reflexes ASC is at best inconstant and never does exactly the same thing twice . Being unpredictable is bad in a car because like Forrest Gumps box of chocolates you never know what you'll get .
Maint , one would hope that ABS and ASC fail safe and still allow you to drive the thing in std modes . The barrage of warning lights at rego time could prove expensive though .

Late electronically controlled automatic gearboxs . These are an unholly nightmare . Most people are blissfully unaware that these things are horrifically expensive to work on or replace as an assembly . It is not unusual to see cars die a quick death because the repair bill for these electronic autos exceeds the street value of the car .
At least the old wholly hydraulic Borge Warner 35's can be easily and reasonably cheaply sorted if they have issues .
Would you be surprised if I told you that for years Taxi mobs used to turf out the 4 spd electronic auto and replace with old faithfull 3 spd BW 35 ?
A million kays on a taxi is not unheard of but not with electronic monstrosity .

Traction controll . I work with two other loco drivers who are extremely luckily to be alive and nearly died because of traction control in a dunny door . They were on their way from Sydney to Yass when they encountered rain south of Goulburn on the Hume . They happened to run into sheet water across the road whilst next to a B Double truck and the car aquaplaned towards the truck . The quick witted bloke at the wheel did an opposite lock and flattened it to straighten out and then the traction control went slip - sorry mate and cut the engine power . That feller still wonders to this day how he kept the nose of that car out from under the trailers and bogies , I believe the car somehow regained grip and flicked the other way and came to rest on its roof down in the nature strip . Not funny at 100 odd km/h .

Not a fair call with roos emu's etc in the sticks , country people know where and when the bad times and places are and plan their journeys accordingly .
Roos aren't fussy , they'll hop through the windscreen of early or late model cars . Locomotive screens are too high and we always get the win .

And now the battery . Should your alternator give up the ghost you won't get too far with the sort of current draw these late cars have . They all stop eventually but the basic ones get further . If you go bush its probably wise to carry a spare alternator .

One day the old reliables will wheeze to a hault and spares will be unobtainable . I hope that day is a long way off .

Yep I'll be able to live with 150 Hp , the Spider should be good enough for that and with luck the bolt on Nissan TB and its TPS I have will work and jell with the Subaru computer . Same twin switch job and even the same connector . Its some/more mid range torque I'm after now because thats what works in a road car .

A .

[discopotato03]

I went back to the 1986 and 1987 (3 plug/4 plug) workshop manuals , EFI sections , but they don't go into the conditions that they get the computer to switch the EGR's vacuum valve .
Back when I was trying to solve the lean "mad mode" my car had I cut the earth return wire close to the ECU plug to isolate it near the computer .
I'm beginning to think I should rig up a test light earthed at this wire to see when the computer wants to open the solenoid valve .
I'm wondering if they use the TPS switches or possibly the throttle pedal microswitch to trigger this EGR business . Of course having coolant and AFM inputs gives them a few more parameters to play with .

These posts made me stop and think about this .

MY EA82T EGR works only between ~2 and 10 inHg. Watch how often you get in that mode. Won't asist heat under boost thats fer sure.

"Stuck me finger in it to feel as it opened and closed as I drove in many conditions and watched vacuum/boost gauge. you may recall i t pieced in a second unit to run in cabin to get the experience".

"Solenoid would not indicate when egr is open just when ecu lets it if it needs to...under boost or higher vacuum than 10 solenoid may still be powered up".


A .

[steptoe]

Feel like I am rewriting something here, but...3 plug ECU is meant to open the solenoid to bleed off the vacuum to EGR (stopping EGR from working) when not at operating temp (72 C), above 45kph and at idle and in conjunction that all three situations are set.

[discopotato03]

It sounds like you have access to Subie data that I don't have .
I've only got the 1986 EFI section copied here and the rest is a set of factory 87 (4 plug AFM) WSM's .

Cheers A .

[discopotato03]

Am thinking hard about getting another dump made up in 2.5 or 3" ATM , back as far as the existing 3" swivel and cat .
It makes sense to do it before any turbo alterations .

A .

[Gannon]

It seems to me that the next logical step, if a full aftermarket engine management system is out of the question. The next best thing is the best engine management that came with the EA82T,.... the 4 plug ECU. You will gain a smarter computer with leaning knock control and a pre programmed ignition table.

See if you can find a EUDM ECU because they had 136hp out of the factory.

[discopotato03]

Gannon at the moment this thing runs pig rich like less than 10 to 1 when it winds up so getting the power isn't going to be the problem .
I think the fact that it won't rev as freely as I think it should may not be entirely because of its lawnmower tech heads .

More recent thinking with turbocharged engines is that they need a sizeable exhaust behind the turbine housing that steps down along the length of the exhaust as the gas cools and contracts to keep the velocity up . Its an attemp to keep the pressure down up front with the hot expanding gasses ex the turbo but not lose the gas speed as it cools along the way back to atmosphere .

Hands down the 4 plug is a better system as is but you have virtually no control over what it does . At least with the crude 3 plug system you can make global changes to the mixtures at the air flow meter and trim the idle mixture with the air bypass screw .
Can also make global timing changes by moving the conventional distributor one way or the other which you can't do with the later CAS thing , screws up the trigger points if you do .

Real old tech but you can also play with bob weights and springs in a conventional dizzy to get a better compromise at times . Heavier weights are going to open out faster than std ones so can modify the mechanical part of the advance curve .
I have a spare dizzy so will get to that in time .

Anyway I need to make sure the dump is not creating a pressure rise behind the turbo and making it lazy at low revs . These GT25/28 turbine housings while not big for a ball bearing Garrett are larger than the EAs IHI and probably similar if a not a little larger than the VF12s R20 housing .

A .

[steptoe]

If I have followed this saga correctly, you had a well tuned and well running EA82T - then just swapped the engine block and heads and cams , retaining same turbo, turbo exhaust manifold, four legged spider inlet manifold, ECU and dizzy THEN got into difficulties?

Or did you swap another zaust manifold/turbo combo in as you swapped engines?

[twilightprotege]

that's why i'd like to 4 plug my HCEA82T - most modern of the ecu's. i've got a yank ecu on the way at the moment

[discopotato03]

No Steptoe it went like this .

Bought car with tired 249k old factory engine . Spent time finding and getting rebuilt a local Spider Vortex Turbo EA82 because that was the best road spec engine we got in Oz .

Before that went in the exhaust was done and then the spider inlet which had been adapted to take the 3 plug TB and TPS . It had to be done that way because there was no other way to mock up the throttle cable and quadrant . Was using the Vortex air plumbing to/from the turbo at that stage .
Distributor vac advance/retard can was rebuilt by mob up north because it was leaking .
Leaks , everything leaks on a factory original unopened EA82T . Every possible water line inc the turbo ones tried to kill my original engine and a couple of times nearly did .

Next the engine was changed over and retained the OE header and turbo , probably at that stage the oxygen probe was plugged back in causing and long drawn out intermittent lean out - mad mode . A tip off here eventually solved that one .
Next was the TWE style header and the Garrett ball bearing turbo was done at the same time because its mount flange is different to any Subaru one .
The turbo didn't seem to be willing to do much until high in the rev range and at that stage all I had was the factory boost light to say hey we've got at least one pound of boost happening .
Waited weeks for the Turbosmart boost gauge to arrive and fitted that so we could tell the real story . Yep , boost starting too far up the engines rev range .

A feller I know recently changed the 3" exhaust he had on an RB26 (GTR engine) powered VL to 3.5 and it made a huge difference to how it went , the dump on that is either 3.5 or 4" BTW . Close to 500 Hp at the wheels of that car ATM .

I reckon I know what the way to go turbo wise is but thats not a cheap exercise , removing any restriction behind the current one is not that difficult and we have been ratting up second hand bends and flanges to cut costs . By second hand I mean some of the bends from the VL and lucky for me I have the dump pipe section left over from my old Bluebird and it has the same turbo flange pattern as this turbo on the RX . Basically cut the 3" tube in front of the waste gate gusset , and oxy sensor bung hole , turn the bend 90 odd degres and construct the rest of it from there . Goes down under the X member and back beside the gearbox and does a dogleg to line up with the tunnel - or 3" swivel and cat in my cars case .

3" tube is about 19mm larger than 2.25" or 9.5 on the radius and the increase in volume will be heaps . If it makes a significant difference it may be enough to retain the current turbo , if not its a step in the right direction for the right one .

A .

Sending Gannon a pic of the back of my turbo so you can all have a look at it .

[Gannon]

Small fuel trimmings are possible for the 4 plug. I bought an Apexi SAFC for trimming fuel, but never got around to installing it. All it needed was a 10v to 5v to 10v converter, which are available.

Adjusting the distributor to alter ignition timing isnt gonna affect anything enough to cause a problem, even if the reference marks are used for semi sequential injection, its not like you are gonna be changing it more than 5deg

Here are those images

[discopotato03]

Off to play dump pipes now , will post again later .

Cheers A .

[discopotato03]

My exhaust is now 3" to the back of the cat where it reduces to 2 1/4" for the resonator and back over the driveshaft to the rear muffler .
I'm pleased to say that the exhaust noise hasn't changed noticeably though you can hear the odd whistle or woosh from the turbine because of the greater volume behind it .
It would be interesting to see if we can fit a 2 1/2" resonator behind the cat and continue that size maybe for the rest of the system .

Strange things exhausts , I've seen instances where people have gone larger on turbo cars and actually got them quieter . By this I mean comparing non std exhaust systems , the OE ones are always quiet .

That manifold pressure gauge should show a few differences and I'll have to hook up the Tech Edge WB to see what the mixtures are doing .

More in time , A .

[Gannon]

So how does it drive?

[discopotato03]

Was away for most of the weekend going to Parkes , Indian out and steelie part way back - both via "The Cape" or Coota West .

Ellie has made some surprising improvements .
It now has a bit more torque everywhere and has sharper throttle response .
The rub is that it's definitely boosting earlier and easier and the point to point times are shorter . I reckon I can outrun most of the small/med NA fours and the oblivious to most things traffic within posted speed limits .

My engine pipe out of the turbo takes up more real estate than a std RX does and I need to insulate it because the brake booster is getting warmer than I reckon is good for it long term .
I'm going to hold off doing any turbo mods ATM because I want to see if I can get more exhaust flow south of the cat and hopefully without much of an increase in exhaust noise .
The challenge would be to find a 2 1/2" resonator that does something useful and misses the tail shaft , the current 2 1/4" one is under and to one side of it and clears it by probably less than an inch .

Will have to look around for a recirc valve as well .

When leaned on in 5th uphill it pings briefly so will have to have a think about intercooling as well . If I could get two tubes around the radiator a front mount would work better than the top mount things , just depends what can be got through the rad support panel .

Found a free tyre mod that anyone can do , look in the wheel and tyre section for that .

Pics soon to Gannon , cheers A .