Pete,
I can not wait to see what my freshly built "high compression" 2.5ltr engine achieves next week when it has been mapped for full boost. I hear it is a tad lively and responsive. ;)

Standard compression is so yesteryear. :D

Stock cams and valves R4LLY, but mild porting work carried out in house.
The Evo version has proven itself to be capable of 500+hp on many occasions both here and abroad, and the Subaru one should follow suit very soon.

how much diffrence did the mild porting make? and how does it help?

Cossies have been doing this for a while now too Shaun, well Sheadys have..:norty:


When you popping round??

Shaun,

What will be your boost peak?? 2.3/2.4 or more?? :norty:

What sort of C/R are you looking to run Shaun?

Or is it a secret... ;)

Pete I think 2.3/2.4 bar may be a little over the top for a Higher C/R engine, however it's good to see more development in the Subaru world.


Martyn when will you be running the S206 on meth or race fuel?

That will be :cool:

I think TerryB still has the record for the highest MD321T on race fuel and that IIRC was a tad over 500, which your already close to on straight V-Power.

Have to say it's good to see the top tuners in the industry making breakthroughs with turbo's/engines everyday.

it would be good to compare terry B graph vs s206. as they are both ver5 i think.

Martyn's is the V2, the V5 heads flow better as standard, however with the mild porting it will probably bring them up to par.

No Mus is correct, mine is a version 5, my number plate is a private one.

r4lly your loosing your touch lol

wheres terry b graph to compare the two?

Now now lads....don't let me have to put up my graph.... :lol1: ;)

jp the first newage with solaris how is going matey. put it up it would be an intresting comparison

Feel free Jag, I am sure it will reveal the following, more power earlier due to smaller turbine size and VVT, but less overall power and torque.

Lol, got confused by the Plate.

Jag you should think about the S206 on your new 2.1, would be interesting to see it on the VVT heads and with Solaris...

i think the s206 its in own league in terms of overall package. and the sc46 and the md are quite similar.

or would you say they are all in the same cateogry r4lly?

Each one has it's merits, however from Martyn's own car though for VFM the S206 is top of the board for me.

Once there are a few 2.5's out there with it as well, it will get alot more coverage.

Pete,
Give me a chance to get the car back!!!!! :D

I thought I would try 3bar this time and see if my headgaskets last more than 10mins. :D

R4LLY,
More than 9.0:1 and less than 10.0:1 :D

We have no idea what affect the compression ratio will have on BHP.... it may go up, it may go down for VPower. Theorectically, it should prove beneficial for higher octane fuels.

We have no idea how much an affect it will have on ignition advance, compared to it's previous ignition curve, or allowable boost...... EGT's will have to be monitored closely on this one. The engine has never seen DET.... this obviously needs to continue.

Nothing is certain, but I am willing to give it a punt as the theory is sound. Based on Tracktives initial comments when running the engine in on the road, they say it drives extremely well and makes boost from little revs. Even based on a much earlier state of tune, the engine made 480lbft (this was not peak torque) as low as 3500rpm. Figures increased since then with further mods, based on comparison of hub dyno figures, but I never had a chance to run the car on the road.

ON VPOWER
1. Initial HUB DYNO Figure achieved - circa 440bhp
1a. Dastek Flywheel Figure achieved at same time as above Hub Dyno state of tune - 498.5bhp
2. HUB DYNO Figure achieved later on after more work - 477bhp (the car was never run again on the Dastek Dyno, as the HG's went pop)

What the engine will produce now.... who knows.

I absolutely trust Tracktives mapping capabilities and this will be key to ensure the best set-up with reliability.

Apologies for taking the thread off topic, but just thought I would give you some background information.

Shaun,

Ask Richard to reply to my email please?..:brickwall;);)

And don,t give me any of that, he,s busy preparing his car nonsense...:lol1::lol1:;)


Are you heading up to Elvington today??

Pete,
Phone him today you gimp...... better still, drag your arse up to Round 1 and you can speak to him tomorrow!! :D

Just about to leave now for York.

Less of your lip you, respect your elders..:nono::lol1:

I,ll speak to him in the week if i don,t make it tomorrow best of luck with it all...BIG-UP Tracktive...........:D

Its always interesting reading these threads..there are so many different opinions out there and is still ever so confusing LOL

Each engine spec has it's own merits and plus points.

But for road car i think the bigger displacement the better and better for quicker spool...along with AVCS.But it comes to a point when issues will raise it's ugly head and bite you in the butt.
So i would agree with Shaun here and have a strong 2.5 with head work to match for the nicest combination.I'm sure Shaun will be and does drive it harder than most of us on here and pushes more bounderies than we know!Go on Shaun keep us updated on your build.:thumb:

The options are huge...much really depends on your budget and engine tuner/builder.:D

Is your plan to bolt your standard heads to the forge bottom end?
Or are you going for head work to=££££:idea:
Everything is money related and that does predict your end results whether your are buying new engine/turbo/injectors/clutch etc etc.

So please consider the cost of every and i mean every aspect of your build as it can soon escalate and the last thing you'll want to be in serious debt for having fun!

Mines has escalated out of control ages ago and still have no car YET:sleep: but will be back soon tho.:luxhello:

The 2.5s are famous for their great torquey abilities. However aren't these blocks (non-closed decks) restricted to how much power they will take before "liner" issue comes into play? I understand that you can push out say 550+ but isn't it a case of how long before the liners give way? :wonder:

some say 450/450 some even say 500/500 is ok before the liners has issues. if you run too much boost it causes a lot cylinder pressure which in return can cause the liners to say goodbye. correct me if im wrong

but apprently if they are mapped correctly and mapped det free they can last a long time.

the mapping is key it can make the diffrence of your car lasting 1 year or a week lol

Fai17,
Nothing is certain at these kinds of power levels, as we are asking a fair bit from 2-2.5ltrs. 500+bhp is a lot of power, which is backed up by the fact that they exist few and fair between in the UK.

You are absolutely correct in that the options are huge, and there is more than one way to skin a cat. Some work, some do not..... unfortunately development costs money, which is the main reason that progression can be limited. This "hobby" is not cheap and others need to be aware of this along with the potential pitfalls. You are obviously all to aware of this... I suspect others are not.

Just when I thought I'd had enough of this game I gathered a second wind, which has mainly been down to the enthusiasm of my current tuner.

I have the enthusiasm for one more engine rebuild or radical change after this current one, but I am hoping it won't come to that! :D

I will of course keep people updated on how the current spec behaves. :)

JP4,
I am not convinced to be honest. I have been running 500 for circa 10k miles and really using the engine and revs hard. On strip down at 10k miles, the standard 2.5ltr block case showed no signs of integrity issues. I am not the only one to not have problems with the standard 2.5ltr case at this power level. Be aware that the Litchfield/PowerStation Time Attack winning Spec C was producing in excess of 600bhp on the same block (in fact exactly the same engine spec - apart from compression ratio) as I currently have.

I am not suggesting it won't split the liners, but evidence suggests that if they are built and mapped properly they can be A OK.

to be frank just looking at time attack lately the 2.1 seems to be the one to go for if your going to be doing a lot of trips to the strip. rcm are dominating the strip and drag events. 2.5 havent really broken any records in the u.k maybe in america but they seem to be the best for the road. 2.33 are great but you got to have deep pockets cause you might aswell do head work if you are going 2.33. 2.1 is proberly the cheapest out of the lot you can buy yourself a 2nd hand cdb on here for around 200. if your gona go 2.33 you will need to source an ej22 which are quite hard to find and they cost anything from 700-1200. its all about what suits your driving style ask shaun to take you in his 2.5 r4lly on his 2.35 or martyn on his 2.1. lol

I will say that driving a 2.5 Impreza is a different experience to the norm. It's strange changing up and having the torque there instantly. My car with 2.5 and an old snail of a 20g makes my other impreza (2.0L with td04) feel like a lag monster.

When I had a VF35 (and other mods for 1.4bar) on a 2.0L that felt laggy compared to the td04 so it goes to show how the 2.5 (even with a big'ish turbo) is great low down and after gear changes.

Onbviously not quite as flash as most but gives you an idea of what I'm talking about..

Stock 2.5 bottom end, P1 heads, TD05-20G, my own ported headers, 3" system.

I think (after looking at the md results, mine isn't too bad for spool and how it holds onto the torque and power.

http://homepage.ntlworld.com/james.greenfield/dyno1.JPG

Now that's impressive m8 :) - only if i could have a 600 bhp scoob!. Question is how long did the Litchfield car sustain at this power level i.e. 600 bhp driven at it's maximum?

Re the 2.1s:
I also hear there is a lil bad boy of a Latereal P "2.1 scoob" which Jolly Green Monster has mapped in excess of 500 and making 10 sec 1/4 mile :notworthy

Martyn can you post up the boost graph for the S206?

Banny

Indeed very interesting, more specs and figures on this would be nice if you have them Jag? :thumb:

I've got a few blocks in my garage at the mo, so guys i'm following the thread with great interest and it will help in making that final decision.

Baly