P20SPD

iTrader: (1)

Tweenie, yes i am.

ChristianR

iTrader: (1)

if you say so!!

Mark A

iTrader: (1)

I sure I'd read on NASIOC or JUN that if the 6sp is fitted with an oil cooler then it's good for 600 ft/Ib's

Absolute Shower

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?

john banks

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.

Absolute Shower

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?

john banks

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.

Absolute Shower

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?

Absolute Shower

oh, one more thing....where did you source the cams from and do they have more?

Pavlo

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

Absolute Shower

OKay thanks for the reply Paul. Whats chances of finding another set of STi5 cams?

P20SPD

iTrader: (1)

Plus parts presumably Paul. eg shims

Absolute Shower

Anyone know if its okay to fit STi v7 heads with vv timing to the 2.5L block? Would I then just need to sort the lip and high spots?

Absolute Shower

Ignore last reply as I've found the answer...NO. Needs sensors and STi ecu plus mapping etc...

Absolute Shower

John, are you using modified oe injectors to flow 740cc? Is that the only option for injectors of this size and are they okay to use?

john banks

Tomei SR20DET Red 740cc injectors, my car is MY00 UK spec.

Absolute Shower

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!).

john banks

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.

Absolute Shower

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.

tweenierob

IIRC Pavlo and Andy F have them in stock

Rob

john banks

740s behave as well as 440s for idle quality and emissions when measured on my car. Denso 550s were far worse on my car.

V5-APS

iTrader: (1)

GGR has a new 2.5L US STi short engine on E- bay !!

Pavlo

I don't have Denso 550s, they are old hat now John

john banks

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.

Pavlo

Latest 550s I have are a 12 hole nozzle design, similar to new age injectors, should behave better than stock 380s or the v3-4 STI 440s.

Paul

Absolute Shower

Excellent John, glad the 740cc's work well for low end and MOT's etc...I really thought they would be a problem lower down the rev range...

Absolute Shower

Not being an expert of STi scoobs...would 1996 WRX STI heads be okay with a 2.5L conversion...ie is this a Sti v5 cam setup?

Absolute Shower

Think the 96 WRx STi is a version 3? Anyone confirm and what are the cams like for running with a 2.5L conversion?

Tim W

iTrader: (1)

Dyney has Sti 3 heads on his 2.5 and it seems to be rather fit

ScoobyDuck

iTrader: (1)

those heads are good ones to choose and work well, but could end up limiting timing.
ultimatly, you will have to do work on any heads if you want them to well suited to the 2.5