34 replies to this topic

[tmh983]

I don't think my car has aids, it has some mild retardation though.
Yeah, pretty close to pulling the pin on this motor now, it sounds like it may have a cracked piston...
Never driven a H6 before, can anyone tell me if they are any good?

[Shiv]

Never driven a H6 before, can anyone tell me if they are any good?

I drive an Outback H6 like the one you just posted.

Its a good motor. Its got reasonable power output and a healthy amount of torque. However its quite a peaky engine, so you'll find that most of that power is only really available at the higher end of the rev range. Below about 3800 RPM, its very much a cruiser of a car and not all that much faster than an EJ25 in city traffic, realistically speaking.

Once you get past 4000 RPM, it really comes alive and you get a distinct shove in the back almost like a mini turbo kicking in. Above 5500 RPM and its got some serious up and go (for a big fat wagon) although it sounds rather strained at the very top end. In contrast, the Gen4 H6 seems willing to rev out.

Overall its a very sophisticated engine; very smooth, quite and refined. Much better in that respect to a EJ20TT and significantly better than the EJ25. The Gen4 H6 takes it to another level in terms of power and refinement. That 'shove in the back' is much less prominent on the Gen4 as it has a generally smoother torque curve.

Do you really want to can this entire project? Seems odd to come all this way and then go another direction. The H6's don't have that fancy sports shift like the turbo halfcut you got. If you're considering H6's, I would almost certainly skip straight to the EZ30R H6 which the Gen4's have. Much more power + all that active variable electronic guff which makes it such a dynamic drive. Either that or do what BobbyJ suggested and create a beast with it!

[alexGT]

later model EZ = complete aftermarket ecu and that won't be cheap at all.

ez30d is a decent motor, i think your current setup would rival the output of the ez.

[tmh983]

Do you really want to can this entire project? Seems odd to come all this way and then go another direction. The H6's don't have that fancy sports shift like the turbo halfcut you got. If you're considering H6's, I would almost certainly skip straight to the EZ30R H6 which the Gen4's have. Much more power + all that active variable electronic guff which makes it such a dynamic drive. Either that or do what BobbyJ suggested and create a beast with it!

Yes I know it may seem weak to give up on the ej20tt, but I really think that my engine has some sort of fairly terminal bottem end problem, it sounds like piston slap on steroids when the engine is cold. The knocking noise eventually goes away when it warms up, but has been getting progressively worse. Also every time I drive it I am getting increasingly strong smells of burning clutch packs when I drive it, and i've started noticing some slippage on the 2nd - 3rd change. Also on top of that the engine has a minor coolant leak which is proving a real pain to track down, I would just keep thrashing it until it goes pop, but the fuel consumption is killing me.

I'm still trying to decide what to do, I really want to piss this motor and box off and start a fresh with a new one. I've rung round a few places and no-one has an auto gen3 twin turbs in sydney, a couple of places said they will get one for me, but I will need to spend much $$$ and wait probably 2-3months for them to get it. And then there is still the risk of getting another dodgy one.

Option B which I am leaning towards is picking up a aussie H6 wreck, which actually has many advantages: 1) I can start it and test drive it 2) I won't have to get the car engineered 3) I can have 'normal' insurance 4) easy to get parts 5) the change in written off car laws mean wrecks like this are cheap as anything. (I have seen a couple of gen 3's with relatively minor damage go for less than $1500 at auction). Disadvantages are: 1) in theory not as quick (but for the daily drive to work when i'm not wringing its neck it will probably be quicker without having to cain it) 2) not really any scope for modification 3) not as cool.

I'm not fully decided what to do yet, my evoscan cable should be here very shortly, and that may give me a clue as to whats going on, but i'm not holding much hope. I am currently in negotiation with Just Jap as to getting a refund...

And maybe one day in the future I can strap a disco spud (possibly the best turbo of all time) to the EZ...

[tmh983]

Come on, someone talk me back into a tt.... I really do like the tt setup, i've driven trents car and its a beast. Its probably 95% the top end of my mates sti and comes on boost 2000rpm earlier.

[alexGT]

interesting to hear that you reckon the auto box has gotten worse. pursue the justjap route, that could save you some EPIC hassles in the long run, esp if they can swap the box and engine and you keep the loom installed!

[Scuba-Roo]

Buy a WRX bottom end, and convert it to single turbo

[tmh983]

been talking with just jap today, they sound like they are going to be good about it and look after me even thought technically i'm out of warante. I'm taking the car to them next week and they are going to organise a mechanic to check it out the knocking bottem end. If they reckon it can be fixed then they will arrange it, other wise they will most likely give me at least a partial refund.
If that is the case then I will need to source a new motor, which leaves me with some options:

1)Alexxx has a spare 2.5L bottom end, ej25tt with a td04 primary would be pretty cool I reckon
2)Aussie H6 conversion, probably the cheapest and most practical option (in the long run)
3)find another 2.0L bottom end, easiest option
4)get another tt halfcut
5)4th gen 3.0R conversion, actually Alexxx, why couldn't I use a factory ecu with that?
6)???

no single turbo!!!

[Xon]

EZ30r ECU uses CANBUS, which your car does not, so the ECU isn't able to communicate with everything else in the car like the dash.

[Scuba-Roo]

Why no single turbo?

[tmh983]

the reason i don't want to go single is cos the whole idea of this car was to give big low down grunt without having to wring the guts out of the engine. ej20's in my experience are one of the more laggy factory turbo cars i've ever driven, which isn't going to work well with the heavy outback. I want to be able to blast around town without having to destroy clutches to get it moving. even though its got problems, my auto tt outback gets away from the lights like a missile, my friends sti needs a clutch dump from 4-5k to keep up from a standstill, otherwise i'll leave him for dead (obviously once rolling its a different story).
I've had a car with a big single before, and its a lot of fun to drive fast, but the other 95% of the time its a real pain in the butt.
Yes I know this makes me sound old.

[RX25SE]

the reason i don't want to go single is cos the whole idea of this car was to give big low down grunt without having to wring the guts out of the engine.

I've had a car with a big single before, and its a lot of fun to drive fast, but the other 95% of the time its a real pain in the butt.
Yes I know this makes me sound old.

+1 to this.

Im older.

I bought a N/A!

[tmh983]

For anyone who is interested, i finally solved this gearbox trouble code problem today! I painstakingly traced every single wire on the TCU (with the help of 3 different circuit diagrams (all of which were wrong)) which has taken hours and hours. In the end I could make sense of the whole circuit except for 2 wires that abruptly ended where the turbo loom joined into the rear section of the original outback loom. Bingo! these must have been for the lateral g sensor. Looking at some FSM's for wrx's, they show a combined lateral g sensor and yaw rate sensor located next to the ABS g sensor in the centre console, also, the g sensor should output 2.5V horizontal and 1.5 - 3.5V when tilted 90deg each side.

I put a multimeter on the 2 'spare' wires, one of them showed steady 4.9V, the other was floating around zero. From that I know what the purpose of the 2 wires is (ie. voltage supply and signal) so I hooked up a potentiometer to provide 0-5v onto the signal wire, adjust it to 2.5V and hey presto! no more trouble code!.

Obviously a pot isn't a g sensor, not too sure what the original purpose of the sensor was, but i've been driving around for months without it and it doesn't seem to affect anything, so i might just leave the pot set to 2.5V in there. Maybe it tells the TCU to lock up the center diff when cornering hard? In time, if i can be bothered, I might get an accelerometer and hook it up, but for now the TCU can just assume that i'm not cornering at all...

I have to get a blueslip for the new engine pretty soon, and there is no way it will pass if there is error codes flashing on the dash, so i'm glad ive got it sorted. I'm really hoping i can get this through the blueslip without an engineers cert. I've looked closely at the rta modification guildlines, and I reckon i could argue that this is an 'owner certified modification', based on the fact its not a significant increase in power (only 20kw more than a H6 engine), the capactiy is decreased and there was zero structural mods needed to fit it. I think if i can take it for the inspection in pristine condition so there is absolutely nothing they can pick on then they will be more likely to let it through...

[Scott]

the reason i don't want to go single is cos the whole idea of this car was to give big low down grunt without having to wring the guts out of the engine. ej20's in my experience are one of the more laggy factory turbo cars i've ever driven, which isn't going to work well with the heavy outback. I want to be able to blast around town without having to destroy clutches to get it moving. even though its got problems, my auto tt outback gets away from the lights like a missile, my friends sti needs a clutch dump from 4-5k to keep up from a standstill, otherwise i'll leave him for dead (obviously once rolling its a different story). I've had a car with a big single before, and its a lot of fun to drive fast, but the other 95% of the time its a real pain in the butt. Yes I know this makes me sound old.

sounds like you need to have a drive of a turbo 2.5L

youll be surprised how good they go

ive had a couple 2L turbo sti's and the 2.5L has next to no lag compared to the 2L

[tmh983]

There has been a definite change in the gearbox behavior since 'fixing' this lateral g sensor, the TCU was clearly operating in some sort of limp mode before I fixed it. Now the gearshifts are much quicker and smoother too. Also the gearbox is much more willing to downshift when you come to a hill, for example, before when I drove up mount ousely (about 5k's of quite steep highway for those who don't know it), the gearbox would sit in 4th gear with the TC locked up and the engine turning about 2000rpm, which gives almost zero grunt to get up the hill. Now it unlocked the TC as soon as I started going up, and pretty soon it kicked back to third gear without me having to provoke it, now the engine is turning about 3000rpm which is right in the meat of the primary turbo range and now the car absolutely fly's up the hill with plenty of throttle in reserve.

Another annoying thing the gearbox would do was allow waaay to much slip on the 2nd to 3rd gearshift under certain circumstances. Like, if I gave it a bit in 2nd up to 60kph then backed off the throttle, the engine would overrev up to about 4500rpm then very harshly drop back into 3rd. Now it doesn't slip at all, and the gearchanges are almost imperceptable.

It could be my imagination, but the engine seems a bit more willing now too. I don't think its any faster than before, but it seems like there is a closer relationship between throttle peddle and actual forward movement now. I think the tt changeover is a bit quicker now too. But that could be all in my head. I'm quietly praying that it helps with this cars bonkers fuel usage too...