the squiggle

I need to know, how you came to the conclusion that you only dump half the air or less than half the air and recirculate the rest. The pressurised volume of air contained between the throttle butterfly and the turbo outlet will be expelled to atmosphere, not half kept and recirculated. At 1 bar of boost, 14psi, which is the equivelent of atmospheric pressure times 2. The dump valve will try to equalise the pressure in the intercooler and the pressure in the atmoshere, so in theory there is still atmospheric pressure present in the intercooler ready to go in the cylinders. Since the throttle butterfly is now closed and the car is idling through the Idle Control Valve the pressure in the intercooler/turbo area is now trying to pul vacuum conditions. On a std recirc this area would now be filled with the volume of air the the recirc has rerouted into the turbo outlet but on a VTA that volume air is expelled until both intercooler and atmosphere is equalised. On throttle lift off condtions, on a std recirc the AFR would be 12 - 1 with the volume of air being accounted, if you expell this volume of air to the atmosphere then it will drop to 6-1 or even lower. Grant

Chris at East Linton Service Station is fully conversant with the ins and outs of the Scoob. He owns a peach of a Version 5 STI and has serviced numerous rally cars on events. Grant

Agree with you on that one. Grant

<< u should have stopped & pee'd over the side then! Or kept the bottle in the van till you got to a bin - think of the poor young lads that are going to have to go pick all them bottles up! Yeuch! >> It is really hard to just pull over in heavy traffic on the Kingston Bridge due to the lack of hard shoulder. It was not the van, twas the car with ANDYJDMSTI behind me. Troosers round ankles, steering with my kneecaps and not spilling a drop is a skill even Tiff Needel does not possess I do feel sorry for the poor sods but when needs must and all that Grant

[cough] I have no idea mate [cough] Grant Heading sheepishly for the door Well it was rush hour and there is a distinct lack of facilities on the Kingston bridge

<< BTT and bring it on >> Oh dont worry i will.. Squirrel lightweight version.

<< lmao i must remember that, I was refering to any details like even meeting place, if they know where you are meeting then they know where you are leaving from. or is that not a valid point? >> Yes valid point but they do not know what direction we are taking and as always the first leg of the roote will be taking at a sedate pace until we reach the fun area. This stops us attracting any undue attention until we hit the deserted area and it will conserve fuel For any Bacon Butties that might be reading this A, We are all heading for Fife area in a big convoy to create choas at Crail. B, Why you not out looking for Spince's car Grant

<< Yeh the lotus thing bothered me, I think there is a chance some switched on traffic cop browses these forums for dates and times of run,s. Maybe a bit of work but why not post times and dates of runs to interesed peeps through p/m. >> The only thing at the moment that has been posted is the departure time ad place. The route details are handed out on the day in a handy wee booklet type thing. We do not give the route guide to peeps who turn up in white pimp mobiles with flourescent marzipan down the side and stupid blue neons on the roof. Grant

Started of with a bad Mon at work, hit the traffic jam at Newton Mearns, jct at Kilmarnock closed off Southbound. Had to toddle my a*se all the way to Symington to turn round. Got there to interupt a full on discussion about gold plated Almera's. Had my usual Bacon/Cheese Surprise. Yawned for an hour then went home. Got as far as the round about and had to turn round because the belly did not feel right. Pebble-dashed the Brewers Fayre toilet for a while. Got to the A77 to find it closed Northbound as well turned round to head up the back roads through Irvine . One i shoud not have turned up for i think. Grant

Aye right you are! So what if i hate Max Power and all it stands for, i am after all 32 year old and completly happy with the look and performance of my car. My choice of literature aims more towards the JDM specialist end of the market. No disrespect to anyone who may buy this particular publication, after all we are all allowed to have opinions. Grant

Ok. A general rule of thumb is the further south you go the cheaper the imports are. I paid £5500 for my 1995 WRX with 35.000 miles from Folkstone when a similar car up here was £8500 The STI 4,5 and 6 wagons had the top power of 280bhp as std. The imports do have a chronic thirst for Optimax and will need booster if your a planning a solo spirited drive. It is your Donald Duck[luck] to wether you get a good import or not but it is a good start by finding an importer/garage with a good customer service feedback. Grant

<< Cheers m8 Yep my FTO is the one with the CF bonnet It's going to a new owner in the next few days.... That's the wagon I was looking at too - not keen on the red WRX they have in tho.....and the silver one on the A89 is at the golf driving range - just up from the garden centre. I have done a LOT of reading up on the scoobs since b4 Xmas when I first considered selling the car but just want a knowledgeable type to check out any potential purchase... >> Not a knowledgable type as such, more of an idiot with too much time on his hands. I could give the car an initial check over but a qualified RAC or AA inspector would be your best bet for a more detailed report. If you do get the AA or RAC to check it over i will provide an explanation of any technical gumph they throw at you. For a start the one at the top 1997 SUBARU Impreza 2L Turbo, R reg. 80000 miles, Brand new engine - done 8k miles, FSH , s/s exhaust, HKS turbo- timer, quick-shift gear kit, dump valve, dawes device , elec sunroof, Cat 1 alarm & immobiliser, K&N Cone filter. The brand new engine was probably a result of the oil from the K+N cone filter coating the MAF in oil and it melting the pistons. Not to mention the involvment of the decat and Dawes device. What is your budget and does it have to be a UK car. Grant

<< Where you coming from mate........tyres really not that important as i have a set o slicks to go on them .....but i suppose if there is some tread they will be used somewhere along the line....cause the scoob likes tyres....hahahahahhaha.......hows 75 quid sound..... >> Well could you make it £80 and its a deal. I am from Glasgow but can run them up one night during the week or meet you halfway. Grant

<< superb dude......just name your price.....any pics???? >> Ignoring the ugly bloke next to the car. This is the only pics i can find of them fitted to my car. Name my price.......OK.....how about £14200......This is open to negotiation. Wheels are straight, true and are fitted with Jap spec tyres. These would be ideal for killing at Crail or Knockhill. I paid £100 for the 4 of them last year and as i say if the offer is good enough i will stick them in the van and toddle my ar*e up to Fife Enkei wheels

I have a set of lightweight Enkei alloys available. A reasonable offer will include delivery to Fife Grant

RB5 is Richard Burns and i think his number was 5, dont know how many were built Terzo is the sperial edition released to commemorate the third manufacturers championship win, 333 were made with no number 13. Our very own Billyboy has one STI RA is the lightweight model produced for the Japanese Domestic Market. These cars form the basis for many a Grp N rally car conversion. Our resident loony, Wilky, has one and there were quite a few thousand built. Grant

After reading the above posts, i would like to clarify that i have nothing against Vent to Atmosphere Dump Valves. I just want to point out the need for increasing the frequency of the oil changes if one is fitted. Grant

<< Why is there a bulge is my groin area >> That will be from when Gayle kicked you square in the nuts for your last unauthorized purchase. Grant

<< Cheers squirrel555 for your time and effort on that one, you appear to be very knowlable, but ill have to reserch your findings before i can come to a conclusion, but this is whot its all about sharing information. Can i also ask wot if any mods you done to get your car to run without any d/v and would that not have the same efect as an atmospheric. >> The mods i have on my car is where the std dump valve would enter the inlet tract, the nipple on the inlet manifold and the intercooler have all been blanked off. This means when the throttle is closed the pressurised air is sent back through the turbo and intercooler, creating the WRC style chiping sound when the turbo tries to run forwards and backwards very quickly. On a slow gentle gearchange the pressurised air will get back out through the induction but do a quick gearchange it is possible to catch the pressurised air still in the intercooler which in turn gives you a better stating point for the turbo to build up pressure again. The pressurised air will have been metered and the corresponding amount of fuel injected because the majority of the air is still contained in the intercooler/turbo area instead of being expelled to the atmosphere. Granted some of the volume of air will get back out through the induction but the majority of the air will be contained and the AFR will be more stable due to a more appropriate volume of air being present. Granted that it cant be good for the turbo running back and forth very quickly but the TD05 turbos fitted to the early cars are strong enough to take the abuse IMHO I must ask who you are gonna refer my answer to for clarification, the guy that works down the local garage or AndyF. Absolutely everything i have ever learned about Subaru engines, i read off the back of a Frosties packet so blame Tony the Tiger if i am wrong on anything. Grant

<< Good advice front The Squirrell there - Grant you must take ages typing up those notes re your two finger typing technique you were telling me about Or do you dictate notes to the wizz Imy???????????? I think anyone trying to challenge long accepted wisdom must think why it is long accepted as technically correct - thanks for the explanation - I will STILL be sticking to my standard recirc - PPPTTTSSSSSSCCCCCCCCHHHHHHHHHHHHHHHH! (NOT) Brian >> That reply took me 2 bloody hours to type due to my infamous 2 finger typing technique. Imy was on the bed giving me advice on the structure and presentation. Grant

<< well see all the talking about the dump valves am gonnae take it off and remove my k&n and put in a panel filter back on. wullie >> Dont be daft young lad We would miss all those loverly flames on our treks. Just keep up the regularity of the oil changes and it will be cool. Grant

Hot Hatch at Knockhill.....AKA Open Class Banger Racing. Good to watch but scary to take part in the madness with a Scoob, any Scoob let alone your own. Grant

There is a plan later in the year for a combined CumbrianScoobs, TyneTeesScoobies and ourselves to do a joint "Super Run". This will be heading for the North of Englandshire with the route yet undecided but a run through Kielder a definate. Grant

<< with a d/v fitted apparently will help prolong the life of ur turbo as will a decat system. I cant understand how the dumpvale will make the car over fuel as posted by the squirrel555, excess fuel will not be able to run down the cylnder walls in to your sump past compresion rings and oil seals instead it will exit via the exhaust port and backfire in the exhaust system. And i also cant see how it will cause the car to run lean as posted by zeolite as a dump valve has nothing to do will the fuell system, plus there must be benefits of the slightly heated manifold pressure being dumped to atmopsphere, and a fresh intake being drawn, hope i have not offended anybody and im only trying to have a better understanding of this. >> Righto The Impreza runs off the MAF sensor when in open loop fuelling, when you are giving it some stick. The Mass Air Flow will meter the amount af air being drawn into the engine and inject the corrosponding amount of fuel amount to achieve a rich enough Air to Fuel Ratio. When you release the throttle on a std recirc dump valve, the pressurised air will be dumped back into the inlet tract when the throttle is closed and the ecu will inject a corresponding amount of fuel to achieve a satisfactory off throttle AFR. When you fit a Vent to Atmos dump valve, the pressurised air will be released to the atmosphere when the throttle is closed but the ECU will still dump extra fuel in trying to achieve a satisfatory AFR. The ECU thinks there is an extra volume of air being drawn in the engine and will inject the right amount of fuel to compensate, this extra volume of air has now been dumped into the atmosphere instead of the inlet tract. A std ECU has no way of knowing that the Air volume that has passed the MAF has been released outside the inlet tract instead of being drawn into the engine. This will in turn make the AFR be very RICH due to the air part of the AFR being expelled through a valve the ECU was not mapped for The extra fuel that is being drawn into the engine, minus the volume of air it was expecting will do 1 of 2 things. 1. It will explode when the rich mixture hits the piston crown, giving a flash of lift off DET. At full boost the temp of the exhaust gases can average 1000 and hit 1200 degrees centigrade after a spirited drive, the crowns of the piston can be as high as 800 - 900c. This temprature is more than enough to ignite the fuel mixture before the spark can do the job 2. It will not expolde but as the mixture has ignited by the spark from the plugs and the flame front travels across the piston, by the time the exhaust valve has opened the mixture has not fully burnt. Sometimes the rich fuel vapours not burnt from the time alloted in the combustion process will pop in the exhaust housing of the turbo. The overly rich mixture will clean the oil off the walls of the piston bore when the overly rich Air/Fuel mixture is being drawn into cylinders. The excess fuel mixture will get past the compression and oil control rings due to petrol mixture being a lot finer than oil and the excess mixture that has not been ignited will stick to the cylinder walls due to the condensation effect of the AFR mixture being around 30c and the walls of the cylinder being around 400c. This fine petrol mixture will be transferred to the oil in the sump. The classics lubricated the piston bores and under the piston crown with the end of the crank scooping oil up and throwing the oil up the bores, apart from STI RA's which had under crown oil cooling jets. Graham Goode Racing sell an uprated oil pump which helps cool he under side of the piston Personally i have no dump valve what so ever, not even a std recirculating one. This gives me the World Rally Car style wastegate chatter with the benefit of the metered air being drawn into the engine being properly compensated for fuel by the ECU. My advice for the peeps running a Vent to Atmoshere is to, apart from dump them in the bin, is to increase the regularity of oil changes. Std recirc dump valve, i would aim to change the oil every 6000 miles. NO dump valve at all, i would go for every 4500 miles. Aftermarket Vent to Atmosphere dump valve, i would aim to change the oil every 3000 miles. I change my oil every 1000 miles due to the fact i get my oil for nowt. Grant

Put my name down on the list for some. A solution for the ladies who require Pink, stick a pair of red pants in the wash with the white polo shirts and hey presto. Grant