Guess it all depends on the use it gets on track as well.

Some people like me, Stef, Harj, just poodle round - others aren't so sympathetic

But with all due respect to most main dealer mechanics - how many are "TRUE" engine builders and aren't trained just to bolt bits together?

Not many.

I appreciate it can shorten the lifespan of a car to a degree - but no more than those that get abused, badly serviced etc on the road.

Personally, I think it's a load of b0lloxs if Prodrive and the delaers can demonstrate on track - then void the warranty.

If the cars were built well enough it wouldn't happen.

Even TVR do this - they have their official trackdays and they ain't the best engineered cars in the world!!

Just a copout I reckon 'cos it exposes the main problems with the engines strength, or lack off.

 

What you UK lads have to remember is that all UK Subaru Dealers are connected to the net and all read this BBS! (Hi to the lads in Fenny Compton )

All dealers have been instructed to read these threads and this is how SUK are checking on individuals so I would be careful when saying your doing a track day in the events calender.

Harj....

 

Never done a track day in my life! Wouldn't dream of it. It's not fair to rev those poor little bearings over 4,000 or to apply more than a feather weight push on the brakes.

Any posts to the contrary are from an imposter whom, allegedly, has been incentivised to reduce warranty claims.

Hoppy

 

Well I'm flippin confused about IM/Prodrives attitude towards track days.

It seems that when it suits them, they actually use "track days" to promote, and help move their "slow moving" stock.

The "P1" Donnington track day, which was an OFFICIAL event not only implies that TRACK DAYS are ok, but possitively ENCOURAGES owners/potential owners to do them, as does Mike Wood's infamous exploits on the track.

Given the various advice Mike Wood posts on the bbs, and that he is fully aware of how "track day" orientated we all are, he has, to my knowledge, never warned us about the implications to warranties (well the UK owners anyway )!!!!!!!

I'm curious to know if any of the people who attended the "official P1 day" were informed that under ANY other circumstances, track events void warranties because they are concidered "ABUSE"...........and I also assume that all of the dealer/Prodrive P1's that attended the day, will eventually be sold WITHOUT WARRANTY, and that anyone concidering buying one of the demonstrators, will be informed about the ABUSE they have been given.

It seems that whilst it's ABUSE for us, it's good marketing for IM/Prodrive.......WELL, what a SURPRISE !!!!!!!!!!

Good luck stef. It's a real shame that IM/Prodrive don't have the integrity to admit there is a fault on some cars.

I'm sick of hearing about the "oil surge" problem. If it was an inherent problem, why are so FEW cars suffering from it. Just work out how many track hours have been done by so many cars, and you would expect them to be dropping like flys.

Even the quickest drivers, Pete Crony, Mike Wood, etc', etc', seem to manage many, many track days without incident (well engine failure anyway )

I wish the same effort was applied to solving the "no.3 big end issue", as is put into selling the P1 !!!!!!!!!!

Mark.

 

Well, I have decided that even if IM were to replace my engine with another new short motor, the car would still be liable to suffer from the same problem, as they have made no revisions to it's design. I would therefore need to carry out further work independantly to make the engine more reliable. Whilst this is being done, it would be a sin not to replace the internals with some stronger variants . Therefore, a new short motor is of no use to me.
I am awaiting news from my solicitor regarding the inconvenience caused by my new engine going bang after just four months.
So CK1 will spend the winter months locked away and engineless.
Roll on 2001.......

Stef.

 

Hi guys, been away on the Rally GB.

Tony, your thinking is wrong mate. The rod has no bearing (sorry for the pun ) on the piston overheating. It's the bore that is getting too hot and transfering that heat to the piston.

My theory on this is that the cooling Jacket is poorly designed (by that i mean inadequate) and not removing enough heat from the number 3 cylinder. It wont be a huge difference in temp, just enough to take the piston casting past its tolerable limits.

To fix this without actually putting a new short motor in they use a ceramic coating on the piston skirt as a heat barrier.

Like i said before i am very sorry to hear of stefs problems but changing the oil every 2 months isn't good enough, at least he was using a better grade of mobil1. I have tried this too and found it to be crap, going very thin when hot.

You have above my recomendations, use them if you want to reduce the possibilities of failure when doing track days.

Stef, did you install a 25PSI presure warning switch as i suggested or just use the gauge and standard switch? You wont spot surge without a high presure switch, linked to a huge lamp or buzzer in your helmet

If you are seeing surge then feeding number 3 externally will do absolutely NOTHING.

Find the real problem mate, or you will be engineless again very soon!

Sorry for being so direct but it's time the pussyfooting around stopped and people realised they are driving cars in a manner they are not designed for, you have to modify to allow it to survive if there is a problem encountered when using the car beyond its road design constraints.

Test and measure is the only way to know for sure!!! If there were any decent engine shops out there who spent the time to develop a track safe kit we would all be laughing. Sadly, i dont know of any.

Prodrive, be honest with us for gawds sake!! What are you guys doing to the groupN engines to make them last a tarmac rally?????????????

John, getting very tired of all this smoke and mirrors bull$hit.

 

Stef,
I bet you are glad that your engine was covered by warranty, sadly there are people who arent so lucky.I think the impreza engine is very strong and reliable but it will only take so much abuse.Track days put a lot of strain on the cars components and if you attend them regularly you should be aware that replacement parts are going to be needed and I dont just mean brakes and tyres.
Kind regards,
Buddy (sti type r)

 

Stef,
Sorry got my wires crossed I hope you
covered rest of the paragraph applies
Bud,

 

sorry got mis informed hope everything works out
Bud,

 

Buddy - mine went whilst on the motorway. Done 2 track days - 6k limit on both.

There is a problem, no doubt.

John - Prodrive will never give us the real answer, as that is tantamount to admitting there is a problem. Don't think IM would be too chuffed if they did.

It's all a load of cr4p - there are an unbelievably small amount of people who seem to know what they're doing with this engine.

Stef

I really hope you don't get as much **** as I did And I really really hope you're car comes back less powerful

 

I'm going to look into converting to a dry sump configuration (Sledghammer to crack nut etc)

How the hell do you collect information about the failure though ? unless your logging it at the time what can you do ?

Gary

 

Craig,
Is this problem on 98 uk spec turbos only?
Bud,

 

John

Please remember that its possible to hold high g loads for much longer on a race circuit than is possible in either road or rally use, hence the surge potential.

There is no suggestion that the use the particular cars have been put too has contributed to the failures suffered, all I am doing is pointing out that high speed track use MAY have contributed.

Subaru choose to demonstrate the cars performance potential in the safest manner possible which is NOT on the road. The only places to do this are Proving Grounds such as MIRA & Millbrook as well as other venues around the country such as Knockhill, Donington and Silverstone. This is done for safety reasons as much as any other.

Mike

 

Even so, as others have pointed out - one would assume the cars used for demo do not have a warranty?

I find it amazing - don't know of any other performance marque that is affected like this - does this show a lack of engineering/development.

And as stated by Mike, a track is deemed the only safe place to access the cars performance.

So we either:

a - always drive slowly on road - as it's safe

b - drive safely on track, only to have to endure mechanical problems.

Think this is a real load of cr4p - like I've said, even companies like TVR endorse track use - and they're not the most over engineered or developed cars in the world.

No one doubts track use can contribute to this - but that's just hiding from the real problem.

And the manufacturer obviously doesn't have the b4lls to admit it - suppose it may jeopardise their precious JD Power results.

 

Even so, as others have pointed out - one would assume the cars used for demo do not have a warranty?

I find it amazing - don't know of any other performance marque that is affected like this - does this show a lack of engineering/development.

And as stated by Mike, a track is deemed the only safe place to access the cars performance.

So we either:

a - always drive slowly on road - as it's safe

b - drive safely on track, only to have to endure mechanical problems.

Think this is a real load of cr4p - like I've said, even companies like TVR endorse track use - and they're not the most over engineered or developed cars in the world.

No one doubts track use can contribute to this - but that's just hiding from the real problem.

And the manufacturer obviously doesn't have the b4lls to admit it - suppose it may jeopardise their precious JD Power results.

 

Mike,

I understand completely what you mean, re race and rally apps, but there is still plenty of oportunity for high G sustained cornering on rallies like the Manx, so i dont think you dismissing there is a need for modification in that app is apropriate.

I believe you are changing the oil system in a way that is legal under groupN rules yet eliminating any surge.

How would you feel about letting me take a look at one of your groupN engines being built up? I think it's important this problem is solved quickly for using the car on track because the subaru reputation could suffer if it isn't, something we all would not like to see.

I think another issue people are not taking into account is oil surge under braking.

If you are as agresive as some i see at the track with the brakes and especially if you are driving AP racing or Brembo uprated brakes and using there <B>full potential</B> (which few ever will) i believe this is giving a much higher likelyhood for surge than via cornering G.

If you have a gauge only, i can guarantee you wont spot surge under hard braking because your concentration level is so high at that point in time on your driving, taking corners under high G is easy compaired to getting threshold braking/turnin correct.

Next time i am on track, take a few minutes to look at my sump on the westfield, youll soon understand whats required to make a 100% safe sump system for track use.

If you get the oportunity, take a look at our forest rally car setup also, It's full GroupA magnesium casting, and it's huge compaired to the road car.

Getting this sorted isn't rocket science, it's BASIC mechanical engineering. Dont expect subaru to do this for you though, because they wont, there is no need in a road car application.

You start putting big brakes and slicks on the car and you are not driving a road car any more, its a race car, unsophisticated at that, but still a race car.

A lot of you will be thinking, why are so few failing. I think this is mainly down to driving style. Whenever i drive an impreza on track i am very smooth with the car in order to minimise the stresses it sees, as soon as you start being very agresive, the potention for damage is magnified greatly.
I am fortunate in that i can visualise whats going on inside the engine/diffs etc as i drive the car so i understand where to minimise the loadings and where it is OK to be on the limit. I gain a great deal of pleasure driving in this way, it's still pretty quick but it's very gentle on the car, some dont get a thrill from this style.

Thats why i have a dedicated track car that has uprated systems for amongst others oil feed. If i feel the need to be aggresive and a bit wild with tha car, thats not an issue at all, because the car is built to take that type of use.

Let me drive your Impreza then sit with me in the westfield, you will see a massive diference in driving style and the reasoning for that is purely down to me keeping the stresses lower on a road car setup.

 

So my cr4p driving killed my car!

Mike,

Think what John has suggested is spot on and would do your company no harm, except I believe you would gain a huge amount of credibility.

Would it be fair to say, that as the official tuning arm of Subaru UK, you have a duty to cure/eliminate problems such as these?

Would be great marketing for your company, but more importantly, great benefit to the owners.

And I think it would be safe to say John is the sort of person not to go shouting his gob off about any sensitive issues.

Be very interested to see what happens........

 

Mike Wood,

You have a reputation for being both a very quick driver, and for demonstrating the Prodrive brakes to their FULL potential. Let alone the grip, and cornering speed of the Prodrive suspension, and 18" wheel/tyre combination.

Your demonstrator cars have OBVIOUSLY been modified, to prevent a very embarrassing engine failure, due to "oil surge", during the course of your various MARKETING exercises.

PLEASE can you share this information, as it will......

A) Be good customer relations.
B) Save Prodrive/IM a fortune in claims.
and,
C) FINALLY put to rest the constant BUL*SH*T we get fed.

John F,

Have you ever seen the Scooby sump, you may find it interesting...It's not something that I feel any urgency to change.

Mark.

 

Amen.

If enough of us raise this issue, maybe we can approach Trading Standards.

I know it's a bit heavy handed, but at least we could get something moving.

Although the Prodrive admission/finding a solution etc would be of benefit to everyone I feel.

 

No mark, i havent yet been inside a scoob engine myself although i have seen a few in bits sadly, i didnt take much notice of the sump design at the time.

If there is anyone out there with an engine in bits right now, i would love to take a look.

I have built loads of race and rally engines of varying types, never had the chance of a scoob engine so far.

There could be another contributing factor for oil surge. Thats with sustained high revs the heads are filling with oil and it's not flowing back down to the sump quickly enough.

Quite a common problem on many engines when taken on track. The first engine i came accross with this was a Hillman Imp (dont laugh ) I used to rev that to 11,000rpm. The fix was to use an external oil return pipe from the head to the sump, as the internal galleries were too small.

 

Excellent reading.

Firstly track days. Sorry Mike, but that doesn't wash. There is not a track in the UK where you can replicate the speeds OR extended G forces of a German Autobahn. I am sure there are owners who replicate the speeds on track, down their favorite roads. Maybe not the flat out straight stuff, but certainly some of the cornering speeds.

I sat and watched my P1 video early this year. It was full of you throwing the car around MIRA. Ed Swatman voiced over "look at that handling" as you slide the car through a very nice right hander. There was no message scrolling across the screen saying that this was for demo purposes only and the car was not intended for this kind of use.

BMW, TVR, Porsche, Ferrari, Lambo etc organise track days for their customers. Not just pre-purchase but in conjunction with the owners clubs for the respective marques once the car has been bought. I strongly agree it is the only safe place to explore a performance car's ability - who many MY01's written off on the road so far? 3 that I know of and one lightly crashed by a Police Force test driver.

I remember going to the Subaru On and Off Road Day at Milbrook a couple of years ago. The highlight?... being driven around the high speed bowl at 145mph and then straight across the the handling circuit for half a dozen laps of being sideways on the rev limiter. There was no mention of such behaviour being beyond the capability of the car.

In fact what you're saying is that Subaru will sell you a performance car, but if you use the performance, the warranty is void!!

Next onto Group N and other oil supply problems. I don't propose any solutions, but maybe my input can help the cause...

We have had cars in that have lost number three bearing in virtually every possible scenario. On track, on a (straight) motorway, in town, with oil coolers fitted, with fresh oil.

Group N cars are un modded apart from shimming the oil pressure relief spring and fitting a baffled sump. Under braking they exert far more G than your average track day road car, they are frequently airborne, but there is one massive difference... They do not use more than 6,000 rpm.

JF mentioned the possibility of the heads filling. It doesn't happen on an Impreza. The only oil feeds up there are to the three bearings on each cam and the tappets. These are tiny. The two drains are massive.

I'm with Mark on the standard sump. It could be better, but its not bad. Its certainly not a pot, like most cars, having two horizontal decks, primarily drain holed at the rear, but with a large hole in the centre, above the feeder. Surge under braking would be negligible. Extended lighter braking could cause more problems. As for dry sumping... isn't that where the crank doesn't sit in the sump oil but is sprayed with a supply of oil?

Temp...? Not sure. The rad return is from 4 and 1, but 3 is the furthest away from the cool feed from the rad. This feed is by a 20mm waterway and that is a substantial amount of water.

Something that hasn't been mentioned is fuel supply. Cylinder number 3 is the last injector on the rail and will definitely suffer from reduced pressure at high revs.

Whether this reduced pressure is sufficient to cause enough det to damage the oil film on bearing 3 is questionable. Over time, I'm sure it is... and I'm sure the damage is done over time. Then one day you are blasting along on the limiter, with a worn bearing... a bit more det... and bang.

Which brings us back to Group N cars.

Virtually every single Impreza Gp N uses a Motec engine management unit, which allows you to map each cylinder individually. Guess which one gets a bit more injector cycle


Edited to make more sense. I have a cold.

[This message has been edited by Pete Croney (edited 29 November 2000).]

 

So I've heard (ie could be wrong)

Dry sump -> scavenger pump in bottom of sump which pumps oil up into a reservoir that is tall and thin and large (not wide and flat like a sump) standard oil pump is then used fed from the bottom of the new oil reservoir.

Eliminates any possibility of oil surge as the tube from the new reservoir always has oil in it. (unless you drive upside down I guess).

I didn't think the oil channels were changed at all, dunno what happens to the crank.

I'm sure there is an easier cure for oil surge though (if that is even the problem !)

Gary

 

Some great replies, thanks guys.
It turns out now that IM are blankly refusing to do anything with my car (now there's a surprise! ) because apart from the fact the warranty is up, they are also saying that the car was used for 'speed testing' at the REVS Scooby vs Cossie shoot-out which in itself voids the warranty. That was back in July before my original engine and gearbox gave up, so all I can say is that at least I got two wheel bearings, a steering coupling, three gaerboxes and a new engine out of them anyway!
The Scoob isn't the ultra-reliable machine that is portrayed by out-of-date surveys and the like, and the sooner people realise the better. These problems have been swept under the carpet for far too long, and people need to know the truth.
I bought my car to use as a performance car.
I bought it to go on track and drive it hard.
All the time I knew I was protected by the warranty, or at least I thought I was. From what Mike has been saying, I was lucky to get any of the work done at all under warranty. When my warranty expired, I hoped to do a few things to the car to make it more reliable. I guess I wasn't quick enough.

John.
I have my original Scooby sump and a slightly more baffled one (due to have gone in my car the day after Donno) if you're ever around and fancy a look. As Pete has said, because cars are going bang even when not under high g's, surge doesn't appear to be the main concern. Nice to have a bit of extra protection though, eh?

CK1 will be back for next years track season, and I guess we'll see then whether the mods I intend to do can raise the reliabilty enough to cope with the way the car's driven.

Stef.

 

Dry sumping works like this.

The sump pan has one job only, thats to act as a collector of used oil. Most dry sump pans have 2 outlets that are scavenged by the external oil pump. This pump is driven externally via a toothed belt from the crankshaft. In a dual scavenge system the dry sump oil pump has 3 stages. The first 2 suck the oil from the sump and push it into an external dry sump tank, that if correctly designed feeds the oil in at an angle and swirls the oil round the outside walls of the tank to remove all air bubbles from the oil.
The bottom of the dry sump tank feeds the 3rd stage of the pump, the outlet from this then feeds the oil galeries of the engine.
You do not use the standard oil pump at all, that is junked as is the standard oil filter.

Thanks for the info pete, that helps a lot. I have mentioned before in seperate threads about the injector feeds, this may be contributing to the leaning off of number 3 cylinder.

I wish someone out there with the equipment would come clean and let us know exactly what is the state of play with these engines at high revs.

It wouldn't take much effort to find out, it's a shame my own experiences are of race ford and V8 engines in the main. I would love for this to be sorted out once and for all.

 

Cheers stef, i'll take you up on that offer some time soon.

If at the end of the day oil surge isnt the issue (after all this is all guess work right now) then i still feel number one priority for people is the oil they use.

Please stop using the standard oil installed at the dealers whilst on track, it's not up to the job. Also get it changed after EVERY track day, if you are a crap mechanic, pay someone to do it for you, it's not a lot of money in the grand scheme of things.

Finaly, stef, get your oil analyzed at a lab, they will soon tell you if the oil had started to break down. If you need help on finding a lab let me know, i'll see if i can find one in your area.

 

John.
I have my oil sitting here waiting to go somewhere. If you could be of any assistance please let me know.

Stef.

 

Cheers John (re dry sump stuff)

Would it be practical for some of us to chip in some cash to get this investigated properly ? or is this like mega bucks ?

Gary

 

Pete, when the Powerstation guys (Dirk) were explaining to us mainland peeps what a Motec can and can't do (well, we didn't hear much "can't"), he showed us the "fuelling per cylinder" page, and gave us the example "so you could increase the fuelling on n°3 ...". Apparently, not just coincidence. Hmmm...

About lab testing: we just happen to have a rather big debate on the Dutch bbs about oils, and a guy from Kendall oil has arranged for us to have oil samples tested when we have our next meet on Jan 21th. Of course he has a commercial intrest (he admits that) but basically he has been giving us the advice to use ... 10W60 or 5W50. But he will do an impartial lab analysis of the oil samples.

Could be a blast for those who have to time to come over as well, and have some more UK samples tested ?

Edited because even without a cold I don't make much sense

[This message has been edited by EvilBevel (edited 29 November 2000).]

 

Pete

Are you seriously saying that you can achieve the same high g loadings on the public highway as you can on a race circuit with a good surface and hot tyres (slicks in some cases)??

Whilst it's possible to maintain high speeds on a German Autobahn it is not possible to corner at 1g at 7000rpm. Firstly you would have to be very brave to corner at 1g on any high speed road and secondly you would be in 5th gear and I have never seen 7000 rpm in 5th. I wouldn't fancy having to brake or even lift off suddenly at 150mph whilst cornering at 1g without a considerable amount of space to collect it all together afterwards.

Just think about Donington. Lets assume 1g cornering and 1.5g braking (may be more or less but this is just to establish the principle)
Redgate, 1.5g braking for several seconds then 1g cornering for min 5 secs then short straight to 0.8g right into 1g left through Craner all at 6000rpm+ and mainly full throttle. Immediately into 1.5g braking and 1g cornering for another 5 secs at least.

At this point it's probably fairly likely that the oil pick-up has become an air pick-up because the oil has been situated anywhere but in the bottom of the sump for some considerable time.

I don't believe its possible to do this on the road!
How often is it possible to get fuel surge on the road, when it happens quite easily on a race track, particularly on left handers?

One other thing about a Race circuit is that you are wearing a helmet and are far less likely to hear detonation than you would on the road.

When we do any form of demonstration on race circuits the track time is normally limited to 2 or 3 laps at a time with half a lap at considerably less than maximum to allow everything to cool down. All the driving is done by experienced professionals who are used to such events and know how to get the best from the vehicles without abusing them. That said of course, I know of many Impreza owners who are very capable and also drive sympathetically

The circuit used at Millbrook is quite narrow and I only use 3rd gear. There is one place that it's possible to get near the rev limiter (at the end of the straight), everywhere else we are signifcantly lower than 6000rpm and normally between 4 and 5000rpm. The corners are also not that long so it's hardly 'sideways on the rev limiter'

Subaru are more than happy for their customers to use the performance of their vehicles as they were intended to be used. ON THE ROAD. Abusing the performance is an entirely different thing. Absolutely flat out around a circuit (and sometimes off it !!) as well as being timed at Santa Pod is not difficult for Subaru to classify as abuse I'm afraid.


John

To minimise the potential oil surge problems encountered on our competition vehicles for tarmac rallying we do specially modify the sump with some extra baffling and we lower the oil pick-up. We also reshim the oil pump but this is not necessarily to increase the pressure as it is too high on some engines.

I thing that we are all fairly well agreed that most engine failures manifest themselves in a problem in no3 cylinder. Every engine generally has one component or area which fails first, this does not imply that this is an inherent problem in that area just that in simple engineering terms something has to fail first. There is no inherent problem that needs fixing, just an area of the engine that will fail first if something else goes wrong.


Another small point Pete, ALL our Group N cars must be the ones not covered by your 'virtually every single Impreza Gp N uses a Motec engine management system' as we don't!!!!!!


Stef

I think your dealer may have known what your car is used for but I'm fairly sure Subaru UK didn't until they saw the article in REVS.


Mr Leigh/ Craig H/ Mark

All the cars both Subaru UK and ourselves use as demonstrators/press cars etc are sold with a warranty that is still totally valid. The cars are thoroughly prepared to the highest standard and if anything has suffered due to it's previous use, it is replaced.


John

Oil surge under braking is much less of a problem than cornering for several reasons.
Generally the engine is not under load when braking so it's not so sensitive to loss of oil pressure. Also the oil is better contained under braking as it tries to follow the piston down the outside bores on a flat four engine under heavy cornering. I don't know the angle you need to tip the engine up to to make it happen, but at some point the lowest point in the engine is effectively the bore so the oil is trying to collect there.

I know this information may not be relevant, but I had a 309GTI which has an oil pressure gauge and it was possible to moderate your cornering speed by looking at the oil pressure dropping, but it never moved significantly under braking, even on a track with slicks.

This may not answer all the questions but I have tried.

Thanks

Mike

 

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>To minimise the potential oil surge problems encountered on our competition vehicles for tarmac rallying we do specially modify the sump with some extra baffling and we lower the oil pick-up. We also reshim the oil pump but this is not necessarily to increase the pressure as it is too high on some engines.<HR></BLOCKQUOTE>

Thanks for the info mike, so when are you guys going to sell us a baffled sump kit for our track cars?

Based on the above we obviously need it, otherwise you wouldnt have gone to the trouble to manufacture it in the first place.

When you say you reshim the oil pump, do you mean the presure regulator or the pump gears cover?

Incedentally, what oil do you run in your GroupN cars? i bet it isnt 5/40 mobil1.

Do you run an external oil cooler or rely on the oil/water standard cooler?

Looks like we are starting to make some progress, all we need is an open debate here, we all want the same thing, safe engines.