2.5 L conversion help!
#34
1st - John Banks, thought you had the internals uprated...nice power figures with standard I must say. I'll be the same, road only anyway, as I've spent shed loads on her to risk a track day...You're running a 6 speed too and AP clutch?
2nd, Whats the best head bolts for the conversion then? As I'm really only wanting to do an engine strip once...and once only. Having the gearbox changed was pain enough!
3rd I've got 02 Wrx heads...whats the cost for the re-shape to suit 2.5L and do the valves need changing or not...I've thought about buying JDM items, but I don;t want the cost going through the roof!
4th, whats the best gaskets for it? Are the Subaru items weak?
5th, Would uprated pistons and rods but oe 2.5L crank be okay for 450+ power?
2nd, Whats the best head bolts for the conversion then? As I'm really only wanting to do an engine strip once...and once only. Having the gearbox changed was pain enough!
3rd I've got 02 Wrx heads...whats the cost for the re-shape to suit 2.5L and do the valves need changing or not...I've thought about buying JDM items, but I don;t want the cost going through the roof!
4th, whats the best gaskets for it? Are the Subaru items weak?
5th, Would uprated pistons and rods but oe 2.5L crank be okay for 450+ power?
#35
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Std internals, I'm just silly though, wouldn't recommend it just yet. However, my previous failures tended to happen fairly quickly after a power hike, this is holding better than previous setups so far, although previous setups have failed whilst holding 25 PSI at least in the midrange, I am holding 20 now... I'm not going to touch any nearby MDF and make a wish though, but I think this present setup might be onto something. I saw one episode of detonation the other day in 2nd gear when it overboosted to 24-25 PSI due to using gear judge on the AVC-R and a few traction issues, but it just doesn't need it turned on as it makes adequate boost without in 2nd gear. I'm trying to keep the peaks below 22 PSI, and the timing is very safe generally. Other than that I have not detected a single detonation event on this turbo so far.
#36
Did you have any problems with the build (ie fitting) as I'm sure I heard the head bolts was an issue.
I think I'll be happy with the power figures near yours for sure, as I'm not keen on going mad again and having to buy more gearboxes - want to keep my 6 speed nice and have very decent power - no more.
What do you think re the shaping of the heads and what cams are you using?
I think I'll be happy with the power figures near yours for sure, as I'm not keen on going mad again and having to buy more gearboxes - want to keep my 6 speed nice and have very decent power - no more.
What do you think re the shaping of the heads and what cams are you using?
#37
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Cams are P1/STi5/6. I have head bolts in there now - standard. Previously had studs, but they seeemed slack coming out, and I don't think were ARP. Only Pavlo knows in detail what was done to my heads to be honest.
#38
Okay thanks John. I'm hoping to contact Pavlo shortly re the heads...as I'm not sure if my local garage can do the head work, plus need to know what is required to fit p1/sti v5 cams.
Did you replace the oil pump, pickup and sum with uprated items?
Did you replace the oil pump, pickup and sum with uprated items?
#40
I sorted John's heads out in a one off deal as I happened to find a pair that came available from a crashed car. They were ported skimmed, chambers tidied up and the valve seats recut. They used standard Sti5 cams which were fitted and both heads reshimmed to suit.
My new heads are being ported next. You are looking at about £500+ for a port, skim and reseat of a pair of head!
Paul
My new heads are being ported next. You are looking at about £500+ for a port, skim and reseat of a pair of head!
Paul
#47
How much did they cost and where from John?
Is 740cc#s plenty for 420/430 bhp? Would 800cc's be over the top since I'll not be going higher on bhp (as it would require another engine upgrade and another gearbox before long!).
Is 740cc#s plenty for 420/430 bhp? Would 800cc's be over the top since I'll not be going higher on bhp (as it would require another engine upgrade and another gearbox before long!).
#48
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740s are plenty for 420/430 BHP. I reckon they will reach sensible capacity (approx 85%) at about 500 BHP at 3.5 bar fuel pressure, very rough guide.
I got mine from Phase2motortrend as linked in the other thread.
I got mine from Phase2motortrend as linked in the other thread.
#49
85% for 500 bhp is plenty I agree - wont bother with 800cc's then...does having the 740cc's help with low down pull over 800cc's or is it just a matter of mapping with the injectors, just out of interest?
Thanks again John.
Thanks again John.
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Paul, wasn't slagging off , they were the best we had easily available back then. Just that I think some of us got a bad idea about what the manners of bigger injectors were like, I thought 740cc would be horrific based on the 550s, was pleasantly surprised.