john banks

MY00PPP - what do you think of the catted DP options to preserve legality/MOT ease/theoretical insurance issues with it otherwise being illegal? Do PE T75 DP give similar gains -ie up to 20bhp/lbft? Would running with ITG panel filter cause it to be too lean? Would octane booster help this in addition to 97RON (or forthcoming shell 98RON optimax?)? Is Millers still the best choice OB? Is it worth using OB with just PPP or PPP+ITG or PPP+ITG+DP?

Thanks all yet again - uncanny 555 posts! - must mean the Scooby demands more mods!

[This message has been edited by john banks (edited 15 August 2001).]

john banks

2 other things -
1. there were rumours that decatted cars with the original centre section could scrape through an MOT - is this a workable option, or do you have to put the original DP on every year - thankfully - wouldn't be required for >2yrs yet or unless stopped for roadside test. Even if decatted the Prodrive centre section still looks like there is a cat in there.
2. what sort of noise increase for adding say Falkland Grp A downpipe to PPP? Would it be kind of same again as normal to PPP or more noise increase - ie will the wife notice?

Pieman

John,

Same thoughts entirely! Currently got MY00, ITG and OB,and want DP as well.I too don't want MOT hassle/legal issues, so must have a cat somewhere!
Can't decide between catless DP (SS?) and OE mid-section (if it really will pass an MOT), or sports cat in the downpipe (e.g. GGR system) with PPP mid-section.
I definately don't want to buy a catless DP AND a sports cat mid-section – then I'd have a total of three mid-sections, and only one car!

Pieman

Hello?
Surely we can't be the only two owners in this situation? Come on lads, and lasses - help us out!

john banks

Yeah, come on guys! When getting overboost fixed yesterday, dealer said that DP + ITG would not lead to overboost. Could it run lean though? They said if I left the original centre section in the boot when putting in for an MOT they would see if they could get it to pass on a decat DP. They thought the noise increase by adding DP to PPP would be like going from no PPP to PPP again. Sounds like OB would be a bad idea in my car as it may overboost again.

Also, catted DP do sound expensive. But what sort of labour charge to swap a DP and then back again for an MOT? 1 hour?? more??

WillieF

Where in the world are you John?

I have the above set up and it runs very sweetly - well except for the blue smoke which might be an oil leak but ...

john banks

I am in Fife. Can I come for a passenger ride in your car please??? Would really appreciate that.... You have Falkland grp a and ITG otherwise std PPP? Has your blue/white smoke settled?

[This message has been edited by john banks (edited 17 August 2001).]

WillieF

See your mailbox

john banks

Thanks to Willie and a passenger ride/trip to Falkland I have still more questions, or more the above still not answered.

With my car overboosting (just) on a 1.2mm restrictor with std PPP and SUL, and fixed on a 1.3mm restrictor and running nicely, I am still puzzled what to do next (despite having searched all the posts on Scoobynet on the issue from time immemorial). Some say panel filter and DP don't result in increased boost. If that is the case then how do you get the power gains? If a decatted PPP car is running the same boost as a catted PPP car, then are they likely to be pushing out the same power and torque all other things being equal? Or does it run more advance? If I decat/filter and then have to put a larger restrictor in again to cure overboost, do I gain anything? If I run OB will I run into overboost problems?

Just more than a bit puzzled by the whole thing. If my PPP had gone on and not overboosted, I think I would have merrily just got on with it and put the DP on. Now I am more cautious. Dowser had prev. posted about alarmingly high boost with PPP + DP, but I don't know what he found out after fitting Knock/Lambda link. GaryC seemed delighted by the whole thing without problems as did Sunilp. Please advise!

bob

I have a P1 but the principles are the same. The car boost at 14/15 lbs held and peak boosts to 16lbs. I then had the full SS exhaust fitted. The car still holds 14/15lbs but peak boost now is 17/18lbs. Only had overboost once when we had a sudden downpour on track the temp dropped 15 deg with the rain.

WillieF

Hey John

Thanks also to you for the passenger run. I agree that there is also some unanswered questions. So much so that my DP might have to come off and a boost guage might be getting fitted.

Anybody in Scotland wish to buy a Scoobysport DP??

Will be keeping in touch John....

john banks

Still puzzled - if the boost increases by decatting/fitting filter, then what do I gain if I then have to put a larger restrictor in to keep the boost in check? Should a PPP usually require a larger restrictor? Now it has a 1.3mm in should it be OK to mod further? Sorry if these are stupid questions, but I am no further forward in answering all these questions - HELP! It does seem like these cars run a bit strange to start with, with all kinds of funny results of RR's and people running half boost and never knowing etc, and then a PPP car with filter and downpipe (Willie's) being apparently marginally slower than mine with just PPP despite lower mileage? What is going on? There seems to be little reproducibility to all of this?

john banks

Still confused.....

dowser

Hi John

I've run without a resonator for over 80'000km's over two cars with no problems..and it does rain here in Swissieland (maybe not as bad as Scotland tho' ).

Mind you, I've never checked air/fuel ratio before (going in soon) - but the last 30k have been with a knocklink, and no problems.

If I recall, the problems were down to water blowing the oil off the panel filter onto the MAF & screwing up the readings (very bad!). I can't see water doing bugger all to the green goo in the ITG Risk vs. Benefit makes it worth it for me.

Mind you, if you're worried about noise as well then an induction kit or resonator removal does increase wastegate and turbo spooling noises.

Also, the Scoobysport (or any stainless steel?) d/p does resonate a bit and introduces a turbo whistle effect. And with the Prodrive backbox things get *really* manic on full chat

I swapped my Prodrive bb for this reason in the end, fitted a Supersprint.

I hear that mild-steel with the special coating (ie; MRT) are much quieter? Did I read elsewhere that the new Falkland d/p is twin pipe?

Richard

john banks

Might try the resonator removal trick then! The new Falkland pipe is twin dump which is part of the attraction - also they are not far from me at all. Do you think with my already fairly high boost figures I might run into problems with DP then?

markcp

What exactly is involved in removing the resonator?

Thanks,

Mark.

dowser

John

I'm no mechanic, but this is my explanation following a d/p change on my PPP;

Fitting the decat downpipe will decrease the spool-up time - everything happens *much* quicker

However, the standard boost control still reacts at the same speed.

Hence the higher peak boost figure - your boost builds quicker, but the wastegate still takes same time to react.

I've also a my00-PPP, induction mods & d/p. I got overboost last winter when it was cold - guess I'm going to have to do something about it soon Have you removed the induction resonator too? If not, I doubt you'll have a problem as this is also a big restriction.

You can apparently fit a 2nd restrictor in the return pipe from the solenoid (if I understood correctly the advice I got) - I've got the 2nd restrictor but haven't fitted it yet. Will either play with this or fit electronic boost control and get rid of the issue altogether

I'd also be wary of dealers fixing overboost problems - they're interested in a customer not returning again & again.....not in giving you the peak performance available. Hence they may fit a bigger restrictor when just cleaning the solenoid/piping would have fixed the issue. What peak/held boost are you getting now? I get 1.3 peak & 1.15 held up to about 5k, where it starts trailing off.

I'd advise getting yourself to one of the Scooby shops (BRD or Scoobysport spring to mind) for some advice.

Richard

john banks

Thanks Dowser.

1.25 peak, 1.15 held according to Select monitor. Dealer were quite good - we tried my (unknown) restrictor, 1.3mm, then a 1.2mm and went back to 1.3mm with a 5 mile run for each one on the select monitor. They couldn't do 1.25mm, but I think the 1.3mm gives me a small margin for colder days - this testing was on a day when it was about as hot as it gets in Scotland - certainly it will get up to 30 degrees Celcius colder than that! Unfortunately Scoobysport et al are about 400 miles away. Falkland are nearby, but I think they would rather I fitted their Superchip - mmmmm...

I still have my original restrictor. It sounds like a panel filter alone would make little difference from your other post - I still have the resonator on and want to keep it that way - don't want too wince whenever I drive through water - ie all the time in Scotland! Don't want to have faff with the MAF either. Might try just the DP, but trying to decide on the noise levels also.

john banks

Sam Elassar

removing all the restrictions will also make the engine rev/ breath better which in turn will make the car faster. because of that the engine will run a little leaner, a UK car is usually producing something silly like 10%co level reducing that to 8% co at same boost level will gain you a lot of power/torque. i am not saying that every car is running at 10% co but a lot of uk cars do. also it reduces the spool up time for the turbo so you power will come lower at the rev range.

1.3 bar sound a bit high for PPP ? i remember not too long ago a lot of people were panicking if they got overboost to 1.2 bar. saying that if your fueling is right and your car is not knocking then you should have no problems really what ever boost you elect to run. i ran 1.25bar held 1.3 peak for over a year. and i have been running 1.35 bar help and 1.4 peak for the last couple of months ( but this is with a FMIC )on a MY99 car.

so i you want power get a DP as it will help. noise wise you can hear my car, it is noisy only when i floor it . i found the major factor for noise was the back box and not the DP.


sam

Dundee

dowser

Can't really say John I know that I didn't have a knocklink (but did have boost guage) when I first fitted the d/p. I then had two overboost experiences (probably one was me hitting rev limit in first showing off to a friend ) as well as very cr*p boost control;

The peak was much higher than b4, then swung under the normal held value b4 coming back to held.

At the time I wasn't sure what was causing this (well, the d/p obviously!) and was concerned about det damage. I refitted the OE backbox (well, an STi one - same difference, but better looking!) which stopped the drop to under the normal held value (adding restriction, it also blunted performance). I then ordered a knocklink.

By the time I'd fitted the knocklink and confirmed for myself no det, the weather had improved. Refitting the less restrictive backbox (still Prodrive at this time) showed no issues and the peak of 1.3 dropping back to 1.15 held with no underboost. The first frosty morning this year will be interesting

I can't confirm it, but I suspect that apart from the one overboost my concerns came from the crappy boost control - the undershoot could *almost* be felt through the throttle. BRD (Branko & Bob) were particulary helpful and provided good insight - I can't confirm it until winter. I'll let it start happening (I'll have lamdalink as well by then) and then try and fix it with the 2nd restrictor in the return...this will hopefully sharpen the transition from bleeding boost to finding a nice balance for the solenoid. All conjecture 'til it's tested of course

I'd say go for it and refit the OE backbox if you've problems and tackle it that way. Or wait 'til winter & I'll let you know what I find

It should also be stated that these sorts of problems only affect the minority - most have no problems with PPP and d/p.

Richard

john banks

Thanks Sam and Richard. When I give my boost figures let me be clear about on thing to make sure I am making no mistake.

According to Select Monitor, manifold pressure peaks at 930mmHg and holds 860mmHg. I work this out to be:
18PSI, 1.25bar PEAK
16.6PSI 1.15bar HELD
[1 bar = 750mmHg ; 51.7mmHg = 1 PSI]
Above is with PPP which apparently has a 1000mmHg cut off like std UK car? Originally, on a warm day my car was boosting up to 1000mmHg - it was just slowing up as it approached it but was about 50% of the time enough to trigger an overboost cut and the boost fell to about 750mmHg and then recovered and held 850mmHg.

Now it seems to run extremely well with a 1.3mm restrictor and the numbers given at the top.

WillieF

Hey John

Well took the car to Falkland yesterday to get the steering alignment. This was done and makes the car very different to drive at speed .

I got them to change the spark plugs in the hope that that was the cause of the power dip at about 4000rpm.

But didn't fix the problem. Flakland think it might be the ECU and have suggested changing back to the standard one to see what happens.

Job for another day me thinks as I am a little busy at work at the mo' however might just ring nobles and ask them to take a look.

I just get the feeling that nobles get a little pissed of with me ringing them all the time but.....

SCOSaltire

... ur the customer.

john banks

Keep us updated - sorry to hear not fixed - was excited when I saw your message. I am toying with getting a K&N induction kit - just about to ring Falkland after reading Chiark's very helpful fitting guide...

WillieF

Well yes but could the MAF cause loss of power just above 4000 rpm? I know not..

no errors on the select monitor...

Yes SCOsaltire I know I should shout at them and point out that the customer is always right etc etc and am going to do so

WillieF

Oh yes induction kits... Don't know what the K&N is like but had a run in a car with a blitz one on and it was very noisy lots of sucking noise ...

john banks

Yes. It is on now. Chiark's guide was extremely helpful. Comment like it sucks harder than a Danish prostitute is possibly true. The wife will kill me when she finds out - about the induction kit that is

It does not overboost. It just flies and flies and flies - very noticeably quicker - incredible throttle response and hauls up to the red line like a nutter. Only really makes a loud noise under load, or at least that's the line I feed the wife - sounds like I've put a mad dump valve on it. Will have to see how we go! I think a DP would now round off the overall sound!

I think I am very pleased.

WillieF

mmm 'sucks like a danish prostitute' how did you know where my stag night is going to be

Anyway back to the subject. I am resisting put a K & N on but tonight I pulled out the air filter and found that on the side that faces down half of it is very oily and mucky and the other half is OK so I took it out and spun it round.

Result the car is better sooo I am getting up very early to take it for a wee run I will report back tomorrow..

How much was the filter?

john banks

82 inc VAT - the price has gone up this year. Very impressively built kit for the money. I am now more convinced than ever that I need a downpipe too - if only to rebalance the noise between induction and exhaust - currently it sounds like I have a **VERY** powerful vacuum cleaner instead of an engine! But it sure does go...

Vague guesses of power are difficult (i'll prob dyno it when done), but from the dyno site I wouldn't be surprised if it is now making 250-255bhp - 252bhp from just PPP with one car, 259bhp with ITG panel on another (and mine is holding at least the same boost), target is about 270bhp (one car got this with PPP + SS DP) so the DP might do that, and my car will be a cheap P1 imitation which is what I'm after really. It doesn't feel that far off just now

[This message has been edited by john banks (edited 23 August 2001).]