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is it possible/safe to setup 8k revs or higher on forged 2.5l ?
how do they setup jdm 2.5l - lichfield ones
A mapper can change the rev limit in the ECU easy enough and in theory a forged 2.5 could rev past 8k rpm, but you'd have to ask why? With the larger 2.5 engines the torque and peak power is made lower down the rev range. By the time you reach 8k you really ought to be in the next gear using the torque band.
By the time you are at 8200 8400 rpm then the torque is not there any more , best torque around 6000 or so plus a bit rpm , my jdm sti reved to silly high revs but felt you were loosing the power as out of the torque band and better off changing gear earlier
Given the good condition of it I am getting the heads checked and I am going to do a magnified inspection of the pistons. If all is good I am inclined to put it back together.
Am I mad not dropping forged pistons in just didn’t want to touch bottom end as it ran like a sewing machine.
Given the good condition of it I am getting the heads checked and I am going to do a magnified inspection of the pistons. If all is good I am inclined to put it back together.
Am I mad not dropping forged pistons in just didn’t want to touch bottom end as it ran like a sewing machine.
whilst its apart in my opinion you would be mad not to refresh everything, imagine how you would feel paying for it to be bolted back together for it to fail again. false economy in my opinion.
if you plan on keeping the car then do a complete rebuild from scratch and get everything checked as its not just the pistons that can fail on the 2.5 its the actual block aswell.
definitely do pistons , the bottom end may seem fine , but you won’t know with out stripping it , in both of my fsti when hg went one bottom end went with in a year as i did not get it done , so turned into twice the price , on the other fsti i said strip bottom end , bottom end sounded fine , it was not , crank shaft was polished but bearings had gone i think it was number 3 , it’s false economy not doing it all
I hear the comments and it all makes sense but so far I haven’t found any signs of wear. Even the cam tips are exceptionally perfect. V-power and fully synthetic race oil from run in has so far done the job.
you won’t till you strip it , the failure rate of the 2.5 bottom end after hg failure is around 75 per cent , the 2 litre is much less prone , as above i had two go , even the engine builder said it sounded ok , it was only found when it was stripped , otherwise you could be on a bit of a ticking failure , the cost if the bottom end goes will be the hg cost plus bottom end , so surely best done in one whole job as it’s cheaper in the long run , your choice
Can only concur with above. Total false economy not doing the bottom end if it's already out. Unless you're about to sell it, of course. If you are just going to replace the gasket, FFS put studs in at the very least!
Not wanting to start a seperate tread, hence asking here. Recently bought a completely standards 2008 uk hatch sti, obviously I'm aware of the gasket and ringland issues. The car has been looked after Subaru main dealer throughout its lifetime and looks like it's been looked after and driven sensibly, I'm watching the coolant and oil like a hawk and there aren't any bad signs.
Car is on 80k miles - is it worth going in before it goes bang or would you say that since it's made it to this mileage that it might be ok? Any cost benefit in going in early or shall I just wait and budget for when or if?
I got it priced up , the summary from the engine builder was wait for it to go , at 80k you will need a rebore and valves doing plus heads, plus crank bearings , if you have money to burn then go for it , i even had a used engine forged a while ago with 80 k miles on it , and it’s not worth doing a half job on that it’s either the full lot or nothing , if a 2.5 does ever have just hg issue always do the bottom end too
Not wanting to start a seperate tread, hence asking here. Recently bought a completely standards 2008 uk hatch sti, obviously I'm aware of the gasket and ringland issues. The car has been looked after Subaru main dealer throughout its lifetime and looks like it's been looked after and driven sensibly, I'm watching the coolant and oil like a hawk and there aren't any bad signs.
Car is on 80k miles - is it worth going in before it goes bang or would you say that since it's made it to this mileage that it might be ok? Any cost benefit in going in early or shall I just wait and budget for when or if?
My 2008 STI hatch had hg failure at ~92,000 miles. I replaced the gaskets and fitted studs. That was about 3 months ago. I should have read this thread first. Now think my pistons need replacing.
It's difficult to say how things will fail but in my case it's very undramatic. Apart from high oil consumption, my car's running well, touch wood.
Last edited by John 37; 24 September 2019 at 11:13 PM.
28 August 2018, 10:24 AM
