GT30R John. Wouldnt really have a clue re power, would guess at 350 to 400 with similar torque.

Theres still lots of playing to do to the ecu, not really done a massive amount of work on it.

Just looking at old maps, whilst running in, and was typically running around 10 degrees more timing.

Will have to speak with Pat, and arrange another day, this time without the pressure of a forthcoming event.

 

has anyone seen what a td05h-20g with a exhaust wheel clip is like on the 2.5?

if i was not wanting any more than 400hp would this be a good way of doing it?

i have a ver3 sti, ej257 block, link ecu, 550cc injectors, r33 gtr fuel pump, td05.

steve murch who is New Zealands turbo legand thinks its all good but im a bit shy of backcutting as i've see some cars that take for ever to get on boost when clipped.

 

better heads would often give lower available timing as the increased flow leads to higher cylinder pressure.

on optimax only I seem to be able to run the sam 22 degrees of timing at top end (6300+) that I did with the fuel brew.

Paul

 

megrac, yes I ran a TD05H-20G with a clip and it was nice. 400 BHP without additives was about where it sat.

I tried 8-9% methanol and 2ml/litre NF today, along with 1.7 bar midrange. It was absolutely flying, ignition 20-25 range from mid to top, but with a 4 degree hole at 6000. Running lambda 0.80.

And I lost another set of headgaskets

Present plan is to put it all back together and just run the thing at 1.2 bar, 400 BHP. Wondering whether to use CPs and a new block if I do this or just put it back together as it is. I think Job will probably still have the head studs I had before.

 

john... headstuds are fine.. new set of gaskets on the old engine, build up the new one with a set of cometic gaskets.. (ahh 1 set of heads)..

sling new gaskets on, but check the bores etc first...

 

Somethings a miss if the headgaskets keep going! Heads Warped? Blocks? Studs allowing heads to lift? What headstuds are you running?

 

Heads weren't warped last time, will be checked again. Studs the first time, bolts the second. Thick gaskets the first, thin the second.

Common features, about 7000 miles, particularly enthusiastic and sustained use of power before failure, same engine block.

 

Why is that??? Different shape of combustion chamber? Cams?

I thought there was no difference in the head castings between MY99/00 Eurospec and STi.....

P.S. A little drop in advance around between about 5800 and 6300 RPM is "normal" for the Subaru's. Around 5200 RPM it should take a lot of advance though.

P.S.2 With different cams you will reach your power target with lower boost!

Mark.

 

Sorry to hear about the gaskets again, hope it's not indicative of 2.5 builds. My heads will be bolted up (maybe even this Wednesday!) using ARP studs.

Cams and valve gear are the only difference on the STi heads - a difference I'd quite like though

Will be interesting to see whether chamber design has much of an impact - mines had lots of work done to minimise the impact of ej25 bore and ej20 chambers. But then, I think Paul did with his build too?

Richard

 

Think it is cams and sodium filled exhaust valves Mark.

I hope it isn't indicative of 2.5 builds, but Paul is also having problems. The old 2.5 NA engines had big problems, mine is not the only EJ257 with problems either.

400 BHP will have to be enough.

Indeed, cam changes would allow more power without running the boost.

If I wanted a seriously powerful engine a 2.2 CDB with cams revving to 8500 RPM would be my choice now I think.

 

Or Perhaps a 2.33?

 

Not convinced they are proven like the 2.0s, but the 2.0s don't have the torque low down for my taste.

How many big power, larger capacity engines have stayed in the car for any decent length of time without some misfortune or other? Struggling to think here....

 

christian r?? , if he does have over 450bhp on the more realistic rollers.

he might not get the chance though , to pull out and pass fellow scooby owners already off the clock

 

I think these six speed boxes are screaming for a rev limit like that , for drags.

 

So John, i take it John was over taking you then

Currently got 3000 miles on my engine, but dont think at the levels John is at, but that is another problem for me to sort out.

As i said on the phone to JB, i have done a few hard runs where boost was 1.6 bar from late mid range to the redline, and disecting the odometer between the 0 and 8 of 108.5.

Another 2 months and i will be upto the 7000 mile range, which sounds like the danger zone for John, so will keep an eye on things, and will try and push it as i normally would in the mean time.

Steven

 

I'd have to agree with that, one of the things that bothers me about the 2.5 is the rev limit, i'm planning to run to 8k on my 2.5 for dragging but as you say 8.5 or 9k would be so much better on a 6MT with JDM ratios.

You'd almost say go with a 2.5 block with forged pistons, good rods and a 2lt crank but then if your going to get a good 2lt crank you may as well get a good 2.5 crank...I would say an "all steel" 2.5 shortblock would make 9k rpm

 

IF/When the heads on mine pee me off, then new heads will go on with the intention of a high RPM limit.

The JDM box has excellent rations for drag racing, IF you have the high rpm limit as Haldor has proven. The UK ratios could benefit from a higher rpm limit.

 

john, could you post pics of the gaskets as im interested in where they have gone..

if its between cylinders.. customscoobyiom has no chance of his staying together

I plan on revving my engine quite hard.. hmm.. must sort the revcounter out first.... that fookin red line on the rev counter makes me think its the red line :doh:

I seem to remember calder rev to 9k.

people like AdamM whinge about the piston speed exceeding 'the rule of thumb'...

hmm...

Interesting reading if you have a few mins here: http://www.stahlheaders.com/Lit_Rod%20Length.htm

David

 

Just playing atm.. tyre size is 215x40x17, no adjustments for tyre deformation at speed.

David

 

surely the line would be straight? why the slight dip in each gear

 

Thoughts on nitrating the crank?

Only one way to find out

See what happens, no rush for me putting the engine in anyway. Got the engine, turbo, heads, fmic etc. etc.

But would like to know where the gaskets failed.

Im also running a different compression ratio.

 

steven, its because it has 7250 in the rev range

 

Yes David, I'll post some pics, engine probably coming out tomorrow.

 

he was passing me .

I know where my speedo needle was and he told me where his was pointing but with jb running taller tyres and the way he just left me , he must have been 20mph+ higher. still I can pass him at the first lay-by when he tops up his coolant

possibly the daily boost v mileage , could cause the gasket to weaken/walk/loose clamping , so that with high, octane hungry boost the failure happens with the first decent held blast. I think the mileage is coincidence , so if those heads are annoying you steven , stick the boost at about 1.8bar peak, 1.7 held and add octane(if needed) to hold as much as possible higher up so we can find out

I cannot actually remember the boost the first set failed at but it had been tuned similarly hard , over anything the turbo could give on plain optimax.

it's a b4st4rd but given how hard jb is pushing so many standard parts , imo , it is most impressive that he is only loosing gaskets.

 

A reliable 400 BHP with 360-380lbft will still make a nice car, I'd be a dick if I pretended otherwise. We also know what is likely to pop first and can calculate a margin below it.

I do need a weaker actuator though, Jack is quoting $150 I think just to swap it so I can actually run less than 400 lbft (!) but mentioned something about the brackets being non standard. I've been trying to get a solution to this since the turbo was installed but it is going nowhere fast I am afraid.

 

The 2.5 is too torquey low down, to warrant going back to anything smaller capacity imo, its just so easy to drive, even with the low advance i am running.

John (tuk) even the odd 1.6bar, 7000 rpm stints i have done, should have put it under a wee bit of strain? It pulled from 30 in 3rd to 7000rpm in 6th in just over a mile on a few occassions.

Give the poor flowing heads i have, i would have thought the pressure on the heads would have been greater than that of Johns, combined with the extra boost too, so those little spirited runs should have tested it a little. Although time will tell.

Cant remember now what John said egt, oil and water temps were?

On my runs, with 7000 held for a while, oil reached 115ish, egts 1075 to 1100 and water was 96 IIRC. Pat later brought egts down a little.

Time will tell

 

steven, something tells me yours gets a little more stressed than johns, if this is the first time they have had a decent held blast...

John, speak to Andy Im sure he can make a bracket for a weaker actuator... alternatively AET Turbos will be able to sort you out.

David

 

I've just stripped my 2.5 shortblock, hmmmm...pretty basic!

 

I think my EGTs have been up to mid 900s but I stopped worrying when the pistons seemed to be standing up to it, and I don't have a continuous gauge in the car.

It seems to be about 1.7 bar that does it on mine, I've run it quite a lot at 1.5 bar in the midrange, plus up to high speed (off the clock I mean) a reasonable amount, not a lot of high speed work at 1.7 bar though, and when it did that was the problem.

Oil temp always below 110, coolant also sensible, not worried about them too much as they've appeared safe enough.

Stephen does have a bigger turbo and sounds like he is holding considerably more top end and getting used as it should be, so it will be an interesting test bed.

Stephen, were your heads matched to your block for squish or just the heads put on as they are leaving an extra 3-4mm all round the circumference? Just wondered if this could be giving the gasket a hard time on mine? With the thin gaskets Andy reckons I could radius the edges a bit and not lose too much compression.

 

John

Would ARP oversized head bolts have helped ?

What water temps do you run under high boost ?

Any thing to report about the pistons and bores?

Mark A