NelsonUK

I have a MY00 with PPP and not so long ago I uprated the backbox and Decatted the Down Pipe. Car soon started hesitating badly and I was suffering with power problems etc. Having read some posts I began to realise that the DeCat may not have been suitable for the PPP ECU and removed parts and sold them. Having refitted BB and Catted D/P car was back to normal running.

Now I have a mate with a Scoob who fitted a MY99/00PPP to his car - having removed the original 1998ECU. He went the Decat route and after a while began to find the car was hesitating etc. As a test he re-fitted the original MY98 ECU with a full decat and uprated BB and now finds the car to not be hesitating at all and the car is running quite a bit quicker than with the PPP ECU fitted ??? Can this be right ?

Anyone else experienced this ?

john banks

Overboost.

zenyck100@hotmail.com

i hope that aint the case. i fitted a PPP ECU last week, i already have a performance backbox. my TSL downpipe arrived today and is awaiting fitting.
i hope i dont encounter those problems. im sorting a knocklink and boost gauge this week before i fit the downpipe to keep an eye on whats going on.

Zen

NelsonUK

Overboost was what I thought - so I fitted an MBC to try and control Spikes/Overboosting and whilst it was better I was still experiencing problems

I just took it that the MY99/00 PPP ECU did not like being fully DeCatted Just out of interest is it any better with the earlier PPP ECU ?

zenyck100@hotmail.com

well im leaving the centre cat in so i hope my car will run ok.

Zen

NelsonUK

So to conclude would a MY98 Standard ECU scoob running Full Decat and uprated BB be any better than a MY00PPP with the Catted D/P and Prodrive BB ?

I am very interested in this to know which direction to take next with modding the car ?

TonyBurns

iTrader: (3)

You need to do a few things here, the first is to get a knocklink fitted, the second is to only run super unleaded/optimax, the third is to take the little brass restrictor out of the T peice and drill it out to 1.3mm (off the boost solenoid, lhs of the engine when looking in), this will cure your overboost

Tony

Blairc

This greatly interests me as I have a `99 PPP`d RB5 and was also looking at going down the route of a decatted downpipe.
Can anybody else who has a PPP`d car and who had decatted it comment on this matter?
Can you also confirm if it`s the full PPP kit or just the ECU?

Thanks,

Chris.

NelsonUK

I have the full PPP on mine - i/c pipework/ECU and centre + BB Upgrade. Thanks for your advice Tony

TonyBurns

iTrader: (3)

My old car was an MY00 PPP'd car, i had it decatted (D/P) so the advice im giving is pretty sound

Tony

SlowBoy

iTrader: (1)

MY00 PPP, decat dp (H&S open neck with splitter), Optimax. No probs. Hits 16-17 psi.

greasemonkey

As John says, this is overboost.

Lol, you could have sorted it simply by drilling a larger hole in the wastegate actuator restrictor!

Eh? If you're talking about model years there, what you are claiming is impossible. The MY98 ECU's are physically and electronically incompatible with the MY99 and MY00 cars.

It is difficult to comment on this bearing in mind, as stated above, the underlying premise isn't possible.

It certainly is possible for a standard MY99 ECU to result in a quicker car than the MY99 PPP one post-decat, if only in as much as it may avoid overboost, and give smoother running.

However, if, as stated above, you altered the actuator restrictor bore to get the boost back under control, the PPP ECU should result in a much more quicker, more "driveable" car.

Blairc

Tony,

Can you please explain to me why I will need to get a knocklink fitted once I decat the DP? Aslo what does drilling out the t peice to 1.3mm do?

Cheers,
Chris

greasemonkey

The reason you'd want a KnockLink Chris, is simply that decatting the car can make it more prone to knock, and this is something you obviously want to know about rather than carry on regardless.

It's not the tee-piece that needs drilling, it's the small brass restrictor in the bleed pipe. Enlarging the hole will make it easier/quicker for the ECU to open and close the wastegate, which is usually enough to prevent overboost in these situations.

As for drilling it out to 1.3, you may find that 1.25 is enough (it should be 1.2mm as standard), and you may even find that it's not necessary at all if you're lucky. Keep an eye on your boost gauge after you fit the downpipe, and only consider drilling the restrictor if you start to see boost spiking, or indeed feel the oscillation under boost.

TonyBurns

iTrader: (3)

As stated by Greasemonkey, its to keep an eye on the det, as you have gone outside of the parameters of the ecu remap that the PPP is, you will be more prone, the 1.3mm was what i ended up doing, 1.25 wasnt enough for safe running even though it cured the overboosting, the car still peaked at 1.3bar where as 1.2 is safer.

Tony

Blairc

Excellent stuff guys, thanks again.

Chris.

andypugh2000

I have a 98 uk spec, full de cat HKS with std ecu, used to run fine with no boost problems running the std boost controller, now fitted HKS evc v and have disconnected the std boost controller and it runs even better now with good stable boost What i understand is the PPP ecu should really only be used with the rest of the package what it was designed for

andy

Blairc

What are peoples feelings on Boost controllers such as the Apexi AVCR and the Blitz SBC I-D III? I`ve read that sometimes these controllers can bypass certain safety features of the car, is this true? What are the pro`s and cons of these items?
The reason that I`m looking into this is to try to maintain a more stable boost and to be able to tweak the boost (i.e reduce it when motorway and town driving etc?).
What are peoples feelings on these things as there`s not really much mentioned regarding them on Scoobynet?

Cheers,

Chris.

greasemonkey

There's not as much value in "tweaking" the boost as you'd think, especially if your intention is to save fuel. You don't need some form of expensive gizmo if you want to reduce the boost, just don't press the pedal quite so hard.

As for getting more "solid" boost control, the best way to achieve that is via a three port boost solenoid. I'd suggest that if you want better cruise fuel economy *and* better boost control, the way to go would be a three port and a remap. Standard Subaru ECU's run unnecessarily rich most of the time, so provided you've got a KnockLink and/or AFR meter installed to catch a failing MAF or bad tank of fuel, a mapper should be able to trim a fair bit out of the fuelling.

Blairc

Greasemonkey,

You see that`s where my problems arise, I`ve got a RB5 WR Sport and I really don`t want to go and start messing around with the Prodrive ECU (as far as I`m aware you can`t alter the Prodrive ECU in any way so removing it and getting an ecutek etc would mean it`s no longer really a WR Sport if you see what I mean)
So what I`m looking for is a way of controlling the boost accuratley and steadying it, monitoring what is going on and if possible improving MPG and increasing the longevity of the engine.

Cheers,

Chris

greasemonkey

You can EcuTeK it, but that would be just as bad (from your point of view) as physically removing the ECU. It'd no longer be a "proper" WR Sport...

Question of priorities really. You can do all the above via a three port solenoid and a good remap. However, you may then find that the resale value of the car is impacted if you eventually get shot of it through the UK Subaru dealer chain, and as far as this goes the best thing to do with the car is to leave it exactly as it is.

On the other hand, if you got it remapped at somewhere like Bob Rawle's for example, you may find the car then becomes more desirable to a more clued-up private buyer.

Blairc

Greasemonkey,

I really would love a remap like you have suggested but i`m not up for altering the PPP ECU, so that`s one idea down i`m afraid. What I would like to do is just add some "bolt on" mods which will hopefuly improve the car but can be easily taken off if required. That why I was thinking of a boost controller of some sort which I could easily remove but would a) hopefuly improve the drivability of the car b) be a bit of fun to play with.
Would just putting a 3 port boost solenoid on the car improve the cars ability to hold boost and to be more accurate even without a remap and still just using the PPP ECU?

Any other ideas that you think will be a good mod (already got a decatted DP planned) would be greatly appreciated.

Thanks,

Chris

keevster

iTrader: (1)

just a question, very interesting post. i will be in the same position soon, fully decatting my MY04 WRX. greasemonkey you seem fairly up to speed on these matters, do i need a remap when decatting downpipe back, is it essential and if i dont will it cause problems with detting ect. do i also require to get a boost guage and knocklink sensor. have heard many conflicting stories on this subject. please help

appreciated
Paul

TonyBurns

iTrader: (3)

An easy one to answer
Basically, to keep your engine safe, any alterations from the manufacturers spec should end with a remap.
This doesnt mean your car nesecitates(sp?) one as the standard ecu can adapt quite well to minor modifications. The knocklink and boost gauge (along with an EGT and oil temp/pressure gauge) are recommended also.

Tony

keevster

iTrader: (1)

tony thanks
is a full decat a minor modification in your opinion. i am not exactly flush with cash at the moment, so remap would be out of the question, however close to having the dosh for the decat system. the garage that i will be dealing with stated i did not need a remap, not that i dont trust them on there advice, but i have heard that many stories about problems if you do not remap after decat. at the end of the day, i do want that bit of extra performance but not at the sake of blowing an engine for a few extra horses.

as you stated the standard ECU can adapt pretty well, but well enough to make the mod worth while for good gains. in your experience how would my car run with a full decat, would i still have the smooth power curve that i have at present.

cheers for the advice so far, still new to this, first turbo ever, still trying to get my head round it.

Paul

NelsonUK

OK If I refit a Decat D/P and drill the brass restrictor out to 1.3mm to stop overboost on a MY00PPP can I refit the original Standard ECU MY98 with the restrictor still at 1.3mm ??

dowser

No, better to buy spare restrictors if you want to swap about a lot (or an adjustable bleed valve).

Also note: It's possible that if your MAF were knackered, then the PPP ecu (with more advanced timing) could be knocking and dropping the car into hi-det/lo octane maps. This would make the PPP ECU appear to perform worse than than a stock one.

If your MAF is the original one (ie; without green-spot on it), then I would be amazed if it wasn't under reading to a certain extent

Caveat: this assumes the high-det/lo-octane maps are more retarded and richer on the PPP, which is not always the case, lol . Also, it doesn't change the fact that a my99/00 PPP with decat will overboost and cause boost oscillation - the MAF is just another factor to consider when resolving the issues you have. It is very easy to rule out the oscillation if you're using a boost gauge, needle will be up and down like a yo-yo.

Richard

NelsonUK

Thanks for your input mate - most appreciated

crusher

Has anyone got a pic of the restrictor in place in the engine bay...just to avoid confusion...

SKS

I've posted it here:

www.arcanumdesign.free-online.co.uk/PPP3.html

Stewart.