trubwrx

Having been offered silly part exchange money for my immaculate low mileage, new tyred MY01 WRX I decided to keep it, extend the warranty and fit the PPP, Prodrive big brake kit and the Prodrive springs.
What a difference! It is like having a totally different car but the biggest change is the torque the engine now produces.
I now rarely have to rev the engine above 5000 rpm to produce exhilarating performance.
Can any one explain, in relatively simple words, how they transform an engine, with no internal mechanical changes, by altering the electronics and more importantly why do Subaru not run the PPP set up as standard?
they would sell many more WRX and surely could likewise upgrade the STI to maintain the difference in performance.
interested in your responses (especially from Mike Wood).
Merry Xmas everbody.

MattW

I believe the problem with the remap is the emissions. They wouldn't conform to Euro regs, however a loophole allows the car to be modified afterwards.

Valkeerie

Ever-increasing EEC requirements on noise and emissions. Bikes now end up with something the size of a small waste bin.

Improving the airflow through the exhaust permits the turbo to spool up sooner and achieve better boost at the same revs. Changing the map compensates for the fact that the engine will run slightly leaner, and irons out any anomalies introduced by EEC legislation (e.g. any OE tweaks to the map needed to meet legislation).

fuji

How much difference have the springs and brakes made - worth fitting?

IanK Spec C

In simple terms the ECU mod fools the ECU into thinking the boost is lower than it is and allows you to run higher boost. The centre decat and the backbox free up the restriction of the original backbox and centre cat. The samco intercooler hose flows better than the standard item and doesn't blow off at the increased boost level. The wastegate restrictor changes the rate at which the wastegate is closed.

Subaru can't sell the car like this as standard as it doesn't meet the strict EEC noise and emmision regs. However the rules for modifications are more relaxed.

If any one else want's the above benifts for less than the £1600 a dealer want's for a MY01/02 WRX I've got my PPP for sale.

Regards,

Ian

EBRWRX

You call that simple ?

For idiots like me, where checking oil requires a week's pre-planning , all I need to know is - my Scooby - non-PPP - very fast thank you very much - add PPP - much faster.

trubwrx

the brakes have made a tremendous difference - it was the one area of the basic WRX I was always less than happy with.

the problem is I now brake too early for roundabouts and have to lift off and then drive up to them - but I am sure I will get used to the new brakes gradually.

the springs make the car look so much better and, I think, improve the handling and ride but this is very subjective as you do not notice these parameters as much as the 'go' and 'stop' parameters.

trubwrx

[QUOTE=IAN K UK300]In simple terms the ECU mod fools the ECU into thinking the boost is lower than it is and allows you to run higher boost. The centre decat and the backbox free up the restriction of the original backbox and centre cat. The samco intercooler hose flows better than the standard item and doesn't blow off at the increased boost level. The wastegate restrictor changes the rate at which the wastegate is closed.

Subaru can't sell the car like this as standard as it doesn't meet the strict EEC noise and emmision regs. However the rules for modifications are more relaxed.

If any one else want's the above benifts for less than the £1600 a dealer want's for a MY01/02 WRX I've got my PPP for sale.

Regards,

thanks for that.

I thought the early PPP ECU modification worked by 'fooling' the various systems but I understood the recent PPP ECU (for a MY01 car) actually totally remaps the ignition and fueling etc.

I am amazed at the difference it makes to the car and was just looking for a simple explanaation of what the changes are and how the basic car has so much untapped performance and driveability just sitting there; without it being available as standard - seems such a waste!

Apple

one simple answer - SUK can screw you for a further 1600 spondulicks which they woudn't get if it was fitted as standard unless they put up the base price of the car and suffer a potential buyer backlash as well as the EU approvals problems as mentioned...

lots of people have bog standard WRXs and are perfectly happy with them without wanting to make them go any quicker - little do they know what they are missing in driveability as you've found

The early PPPs were a boost tweak but later ones are a remap created by Prodrive using the Ecutek system AFAIK - a lot better solution all round

I've got an MY02 WRX and had PPP fitted at approx 20K miles - I've seen the benefit over standard rather than having it from new and wanting more "instantly"

Enjoy it!

Andy

trubwrx

thanks for the input everybody.

I was hoping someone from Prodrive or another expert might venture a layman's explanation as to how they alter the parameters, the mechanically unmodified engine works under, to totally change its performance and power delivery.

MikeWood

The current versions of the performance pacakges all use a re-calibrated ECU to alter the way that the engine is allowed to perform. We make some basic mechanical changes such as various elements of the exhaust as necessary in order to keep things like exhaust gas temperatures within reasonable levels. Changing parts of the exhaust also helps make the car noisier and may change emissions which would need a re-homologation, hence it's not done as std.

The ECU recalibration is very comprehensive, changing a huge number of maps in some cases and isn't just a case of turning the boost up and fiddle with the fuel and ignition to stop it detting. We actually fundamentally change the way some elements of the ignition contol system works for instance but as you would expect, this has cost a huge amount of money to develop and we aren't about to tell everyone how it's done..

Hope this helps to explain some of how it works

Mike

trubwrx

thanks for that even if you will not tell me (and the rest of the world) how it is done!

I am still in awe that electronics and simple exhaust changes can transform a stock engine so noticeably.

what is the 'safe' limit for the standard MY01 WRX engine and does the PPP come near this limit?

MikeWood

A 'safe limit' is very difficult to quantify exactly.

The limiting factor on a WRX PPP will be the fuel injectors as running them any harder than we are doing and still retaining any safety margin is not possible.

In our experience the basic engine is still reliable at 265ps, how reliable it is above that is not something we have investigated in any great depth.

Mike

trubwrx

thanks again.

no more questions - i will just enjoy the car!

p1doc

even i have to say the 05 stippp i drove was superb,very little lag/heatsoak and good performance up to redline-very impressive
martin

Chris Barn

What do you mean 'Heatsoak' ???

ARRON BIRD

And my WR1 certainly does what it says on the packet....eh Martin

fuji

I had the PPP fitted to my O3 WRX last year and have been fully satisfied with the upgrade but I am just wondering how you would improve the performance still further. Would an induction kit/free flow panel filter and dump valve help matters, if so why don't Prodrive fit them as part of their performance package?

Gear Head

iTrader: (2)

Because they don't increase performance. Every scoob has a re-circulating dumpvalve which is fine and still used on some cars producing 400bhp +.

Induction kits have caused problems with the MAF (mass air flow meter) and if they are to work properly, they need to be insulated from the rest of the engine, and fed with a cold air supply.
All of this costs money, + induction kits do increase the noise from the engine bay, not something I imagine subaru wants from its new cars.

hades

Personally I don't like the sucking noise of some induction kits when you're driving gently. A lot of 'normal' (non enthusiast) drivers wouldn't. VTA dump valves are also much more about noise than performance. The PPP exhaust note would also not suit many drivers, although it is a lot easier to live with than many aftermarket exhausts

Regarding the safe limit of the WRX engine - depends on how much you want to change. A lot of people with decat/sports cat and ecutek have got ~20bhp more than a PPP, and done a lot of miles with it (I've done nearly 40k like that for example). Not warrantied, can't say for certain it will last as long as a PPP.

After that? Getting on for 300bhp is achievable with uprated fuel pump on standard injectors and turbo. Any more than that, you need bigger injectors and turbo. After about 320lbft torque, the gearbox and clutch are likely to break. Change them, the most I'm aware of being produced by the standard WRX bottom end (pistons etc) was a little over 380bhp. The owner then tried to tune a bit more and blew a hole in a piston.