What next after the PPP

2000 miles in after having the PPP fitted to my STi Im wondering what next?
A less restrictive exhaust pipe?
A flowed 3 inch downpipe?
A bigger intercooler?
A CAI?

Thoughts?

these are my engine mods for 380bhp 403ft/lbs
Engine:-
AEM Wingtype Cold Air Induction Kit
Hayward & Scott Open Mouth De-Cat Downpipe
Hayward & Scott 2nd De-Cat Pipe
Hayward & Scott De-resonated Centre Section
Hayward & Scott Quad Exit Backbox
HKS SSQV Dump Valve
NGK LFR7AIX Spark Plugs
Walbro Motorsport GS342 255lph Fuel pump, Mounted in Modified Anti-Surge Canister
Ported & Polished Headers
Coolant Delete On Throttle Body
Prodrive Oil Filler Cap
Prodrive Alloy Battery Clamp
Custom Made Oil/air sepearator piped into cam cover breathers and crank breather system also retaining pcv on inlet manifold
Andy Forrest Custom Ecutek 3 Remap

Rob wrote:these are my engine mods for 380bhp 403ft/lbs
Engine:-Prodrive Oil Filler Cap
Prodrive Alloy Battery Clamp

Impressive

This is more like it, some detailed info...

Walbro Motorsport GS342 255lph Fuel pump, Mounted in Modified Anti-Surge Canister
Ported & Polished Headers
Coolant Delete On Throttle Body

Sorry to be a pain but can you explain a bit more about these mods please mate

What are the mods to the Ant-surge canister? (have heard getting an upgraded fuel pump in the 08 STI is not an easy job)

Did you port & polish the headers yourself, get someone to do it, or buy upgraded ones?

What is the coolant delete on the throttle body & what are the benefits of doing it mate?

the Headers I did them myself, carbide burr set and a die grinder with a flexi shaft only ported in the direction of flow of the gasses then polished out with a sandpaper wheels passed down the ports. I also ported the base of the uppipe to. turbo comes onto spool a little quicker than before thats about the only benifit.

throttle body coolant delete, now i basically took the coolant hoses off and connected them together so the hot water doesnt pass through the throttle body so it lowers the charge temps down a little.

the fuel pump was an absolute bitch to fit, basically took the canister out and as advised on iwsti i set to cutting the unit appart until the fuel pump would fit perfectly it takes a good few hrs to complete

Interested as well in the options after PPP.

Would love more noise but i assume that changing the PPP exhaust will then mean some type of re-mapping is required...... or perhaps not ??

First thing I did was full Miltech exhaust and Litchfield cold air intake and remap to about 355 BHP. Also did AST ssuspension, drop links, plastic inserts, rear subframe mounts, uprated ARB, top strut, u/c brace, etc, revalved P/S, and Alcon F+R brakes.
Each one made a noticeable difference so recommend them all.

After looking into more power/torque and talking to the usual respected suspects about the 2.5, I decided that to increase the output further than about 380BHP/400ft-lbs was risking problems, so I am going for:
Cosworth pistons, rods, head studs, head gaskets, FMIC, baffled sump, oil pump, bearings.
Litchfield twin scroll LM480 turbo, 850 injectors
Equal length headers, oil cooler, bosch 044 pump, swirl pot, catch tank, 3"intake, turbosmart solenoid.
Apparently this should be good for a reliable-ish 450/450 although people with larger wallets (ie still working !! ) are running that spec at over 500.
Unfortunately, not cheap

Stan

StanS wrote:First thing I did was full Miltech exhaust and Litchfield cold air intake and remap to about 355 BHP. Also did AST ssuspension, drop links, plastic inserts, rear subframe mounts, uprated ARB, top strut, u/c brace, etc, revalved P/S, and Alcon F+R brakes.
Each one made a noticeable difference so recommend them all.

After looking into more power/torque and talking to the usual respected suspects about the 2.5, I decided that to increase the output further than about 380BHP/400ft-lbs was risking problems, so I am going for:
Cosworth pistons, rods, head studs, head gaskets, FMIC, baffled sump, oil pump, bearings.
Litchfield twin scroll LM480 turbo, 850 injectors
Equal length headers, oil cooler, bosch 044 pump, swirl pot, catch tank, 3"intake, turbosmart solenoid.
Apparently this should be good for a reliable-ish 450/450 although people with larger wallets (ie still working !! ) are running that spec at over 500.
Unfortunately, not cheap

Stan

Agree with you mate, I am where you are at the moment and holding off doing anymore mods until I decide what to do about the engine. Thinking about buying the entire cosworth short block engine (about £3.8K without the billet crank)and getting it fitted along with an uprated turbo, FMIC, injectors, fuel pump and all the other trimmings to go for a reliable 425-450bhp...but keep thinking to myself hang-on, we are getting into secondhand V8 RS4 avant money now

winmoz wrote:2000 miles in after having the PPP fitted to my STi Im wondering what next?
A less restrictive exhaust pipe?
A flowed 3 inch downpipe?
A bigger intercooler?
A CAI?

Thoughts?

And in answer to your original questions mate

A less restrictive exhaust pipe?
A flowed 3 inch downpipe?

Yes, your car will benefit from a full turbo back 3" diameter exhaust system, such as Milltek, Revolution or Hayward & Scott (there are others on the market, but all these are made in the UK). Full de-cat is the cheapest option. I can't say for the others but I know Milltek make a decent high flow sports cat and that the Milltek system is quiet enough not to annoy you or your neighbours, but give you the flow rates and lovely noise you want when you floor it. Note there is not a cat in the up-pipe on the hatch STI, so you can leave the standard one in for now.

A bigger intercooler?

No, not really necessary unless you are re-building the UK 2.5 engine with forged internals and wacking a bigger/better turbo on there and chasing big numbers (i.e. 400+). Standard IC is fine for up to 400bhp. The longer the IC pipe work is the more you run the risk of turbo lag, so I would recommend staying with the standard top mount IC for now mate.

A CAI?

Yes, the hatch STI reponds well with mapping to an 'in wing' CAI.

After installing all the above and having a decent re-map you should see 350bhp+ & 380ftlb+ torque. But the main difference to what you have now will be the faster turbo spool up and better driveability (than the PPP). The editor of Jap Performance and I tested my car with the above mods against the factory 330S in a back to back test and that was the most noticable difference between the two...have to say though, the standard 330S was a good car to drive

So, if i've got the 330s (standard), what's the first thing to do for more power. I live in the country so the ride is fine for me but more overtaking performance is always welcome?

Fatneck73 wrote:So, if i've got the 330s (standard), what's the first thing to do for more power. I live in the country so the ride is fine for me but more overtaking performance is always welcome?

As suggested above mate...exhaust system, CAI & re-map

Although I know a nice man called Mog over on Scoobynet who had a 330S and just fitted a Forge/Litchfield cold air intake (replacement air box/air filter assembly) and had a bespoke re-map done. He got much better results than Prodrive got/are allowed to get out of the standard PPP (i.e. the prodrive performance pack that Subaru UK use to convert a normal UK STI into a 330S). So if you can't stretch to a full replacement exhaust system, this is a good place to start with the 330S.

I've been informed by JGM that with a PPP box and a remap I can expect numbers in the region of 350bhp with standard airfilter and fuel pump, this is probably the route I'll take once the warranty is up, or before if allowed.

Would imagine that a CAI can only help achieve these numbers though.

Personally I'd be happy with 330 as per PPP but as I already have the PPP box its a far cheaper route to for an indepdant remap, I even did consider getting hold of a PPP ECU.

Dave P wrote:

StanS wrote:First thing I did was full Miltech exhaust and Litchfield cold air intake and remap to about 355 BHP. Also did AST ssuspension, drop links, plastic inserts, rear subframe mounts, uprated ARB, top strut, u/c brace, etc, revalved P/S, and Alcon F+R brakes.
Each one made a noticeable difference so recommend them all.

After looking into more power/torque and talking to the usual respected suspects about the 2.5, I decided that to increase the output further than about 380BHP/400ft-lbs was risking problems, so I am going for:
Cosworth pistons, rods, head studs, head gaskets, FMIC, baffled sump, oil pump, bearings.
Litchfield twin scroll LM480 turbo, 850 injectors
Equal length headers, oil cooler, bosch 044 pump, swirl pot, catch tank, 3"intake, turbosmart solenoid.
Apparently this should be good for a reliable-ish 450/450 although people with larger wallets (ie still working !! ) are running that spec at over 500.
Unfortunately, not cheap

Stan

Agree with you mate, I am where you are at the moment and holding off doing anymore mods until I decide what to do about the engine. Thinking about buying the entire cosworth short block engine (about £3.8K without the billet crank)and getting it fitted along with an uprated turbo, FMIC, injectors, fuel pump and all the other trimmings to go for a reliable 425-450bhp...but keep thinking to myself hang-on, we are getting into secondhand V8 RS4 avant money now

I think its cheaper nto get the Cossie parts and have your engine builder build in the new parts rather than buy the Cossie short engine. By the time you add in all the other bits its certainly adds up
V8 RS4 may be more thirsty, but more potential - don't know transmission limits on std RS4.
Interesting alternative though

Currently Sorting out my own Engine as said above its probs cheaper to use you own block and fill it with cosworth goodies lol.

bore out to 2.6 costworth rods and pistons/bottom end shells & headgaskets.
Fit an Garrett md321v Turbo 850cc injectors, fuel pressure regulator. allready done the fuel pump and exhaust system. still not decided on front mount yet would love to by the cosworth one but It seems a little steep in price. remap again with antilag & flatfoot shift with pre gear boost selection. Should make for a very interesting drive

With the upper cylinder movement possibly causing problems, I decided not to bore mine out - keep the cylinders as thick/stiff as possible. My main target is reasonable output with as much reliability as possible.
Didn't go for a twin scroll then Rob ?

The 2.5 blocks including the EJ257 don't have a very thick steel liner insert, its thinner than the 2.0 versions, so if boring out keep that in mind.

StanS wrote:

Dave P wrote:

StanS wrote:First thing I did was full Miltech exhaust and Litchfield cold air intake and remap to about 355 BHP. Also did AST ssuspension, drop links, plastic inserts, rear subframe mounts, uprated ARB, top strut, u/c brace, etc, revalved P/S, and Alcon F+R brakes.
Each one made a noticeable difference so recommend them all.

After looking into more power/torque and talking to the usual respected suspects about the 2.5, I decided that to increase the output further than about 380BHP/400ft-lbs was risking problems, so I am going for:
Cosworth pistons, rods, head studs, head gaskets, FMIC, baffled sump, oil pump, bearings.
Litchfield twin scroll LM480 turbo, 850 injectors
Equal length headers, oil cooler, bosch 044 pump, swirl pot, catch tank, 3"intake, turbosmart solenoid.
Apparently this should be good for a reliable-ish 450/450 although people with larger wallets (ie still working !! ) are running that spec at over 500.
Unfortunately, not cheap

Stan

Agree with you mate, I am where you are at the moment and holding off doing anymore mods until I decide what to do about the engine. Thinking about buying the entire cosworth short block engine (about £3.8K without the billet crank)and getting it fitted along with an uprated turbo, FMIC, injectors, fuel pump and all the other trimmings to go for a reliable 425-450bhp...but keep thinking to myself hang-on, we are getting into secondhand V8 RS4 avant money now

I think its cheaper nto get the Cossie parts and have your engine builder build in the new parts rather than buy the Cossie short engine. By the time you add in all the other bits its certainly adds up
V8 RS4 may be more thirsty, but more potential - don't know transmission limits on std RS4.
Interesting alternative though

Spoke to a few engine builders about this & to use Cosworth or similar high quality parts (like RCM/Omega) the cost is not that far off by the time you have finished, but I won't be doing this anytime soon though, we are meant to be saving up for a wedding

Does the cossie short engine come pre honed/machined ? Apparently they need a plate clamping to the blocks (as the blocks distort slightly with the heads bolted on) then checking for ovality etc, and any reboring/done etc. to ensure bores are circular when heads are in place.

[quote="StanS"]Does the cossie short engine come pre honed/machined ? Apparently they need a plate clamping to the blocks (as the blocks distort slightly with the heads bolted on) then checking for ovality etc, and any reboring/done etc. to ensure bores are circular when heads are in place.

In my experience of bolting plates to blocks for boring / honing etc its only any good if the plate actually mimics what the head does when bolted up.
I was tasked with doing distortion tests when in F1 engine employment on the V10 Ilmor / Merc engines.
It was quite alarming what effect even bolting in the mains caps with & without the bearings fitted made to bore shape.
On the V10 blocks they were linered with there own top sealing ring individually measured to ensure the correct stand off, when the heads were fitted they were fitted in pairs r/h & l/h, & were torqued by doing both heads evenly together, ie centre 2 on r/h then centre 2 l/h etc.
If you bolted up just 1 head & fully torqued it up the bore shape was not good.
So really this distortion thing is a minefield, as even in F1 when it is fully bolted up you really don't know what shape its taken, as every time its disassembled & reassembled it will be diffrent, & thats before any temp is applied.
For your info the V10 block used to grow length wise when up to temp by 0.880mm.

[quote="MOTORS S-GT"]

StanS wrote:Does the cossie short engine come pre honed/machined ? Apparently they need a plate clamping to the blocks (as the blocks distort slightly with the heads bolted on) then checking for ovality etc, and any reboring/done etc. to ensure bores are circular when heads are in place.

In my experience of bolting plates to blocks for boring / honing etc its only any good if the plate actually mimics what the head does when bolted up.
I was tasked with doing distortion tests when in F1 engine employment on the V10 Ilmor / Merc engines.
It was quite alarming what effect even bolting in the mains caps with & without the bearings fitted made to bore shape.
On the V10 blocks they were linered with there own top sealing ring individually measured to ensure the correct stand off, when the heads were fitted they were fitted in pairs r/h & l/h, & were torqued by doing both heads evenly together, ie centre 2 on r/h then centre 2 l/h etc.
If you bolted up just 1 head & fully torqued it up the bore shape was not good.
So really this distortion thing is a minefield, as even in F1 when it is fully bolted up you really don't know what shape its taken, as every time its disassembled & reassembled it will be diffrent, & thats before any temp is applied.
For your info the V10 block used to grow length wise when up to temp by 0.880mm.

Interesting stuff...shows me how little I really know when it comes to mechanics & engines, I just bolt stuff on really

And I have another question for me to annoy mechanics with now when I finally get an engine re-build done...errr, are you going to torque down those heads in the right order mate? LOL

Right started with the engine project yesterday, I now have myself a 2.5 short block assy to play with FOC, First Job bin the Crap cast pistons lol.

Going ahead with the re-bore with some decent forged internals I dont tend to push my car hard all of the time as I use it as my daily driver to work and back, so I cant see the thickness of the liners being much of a problem. So 2.6 it is gonna be...

Rob,
What pistons/rods are you planning on using, i have had some good results with no problems with Mahle forged pistons & Manley rods, with ACL bearings.
Although the std STI bolt type rods are good with no problems to 400hp.
The Cosworth pistons are very good, although a little noisy until engines up to temp.

MOTORS S-GT wrote:Rob,
What pistons/rods are you planning on using, i have had some good results with no problems with Mahle forged pistons & Manley rods, with ACL bearings.
Although the std STI bolt type rods are good with no problems to 400hp.
The Cosworth pistons are very good, although a little noisy until engines up to temp.

Heard good things about the Omega pistons from 2 different engine builders that I have been badgering for info.

A few of the guys from my local forum/club rate the Manley rods & ACL bearings as well mate, been relable in one of the members drag race cars that runs around 600bhp for a few seasons now

Rob wrote:I dont tend to push my car hard all of the time as I use it as my daily driver to work and back

LOL, I don't believe you for a second Rob, I bet you end running at least 450bhp

I use Omega pistons in the GRP A rally car builds, as Prodrive also use Omega & has a specific piston made for them.
All RCM pistons are Omega, but i think they are changing to Cosworth for there manufacture.
A lot of these forged pistons are aimed at competition type builds, so noise on start up etc is not a concern, as is road car mileage, as they get rebuilt quite frequently.