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Mr Morse

1g-fe And Modifications

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OK petrolheads....

It's been established that there are a few problems associated with modifying the standard 1G-FE 6 pot inline lump fitted to the IS200.....

It seems to be the case where 0.5bar is the maximum acceptable boost on standard internals. Any thoughts?

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OK petrolheads....

It's been established that there are a few problems associated with modifying the standard 1G-FE 6 pot inline lump fitted to the IS200.....

It seems to be the case where 0.5bar is the maximum acceptable boost on standard internals. Any thoughts?

just before you start this what are your interests on this subject and were has it been established about the boost but lets talk facts not theory

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my interests on this subject are that there have been numerous intances of the 1F-GE failing due to some reason or another.

- No fingers of guilt are pointed

- Feedback gained is feedback shared

- A pooled resource of information is of benefit to everyone

- The likelihood of further 1F-GE failures is reduced

Does anyone have a problem with that?

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First off.. Who says 0.5 bar is the maximum? It is still not known what the maximum is. 0.6 / 0.7 bar might be ok to run.

Mike (RoadRash) was running 0.6 bar on his turbo'd IS and had no problems with it what so ever. Daz run 0.7 bar on standard internals with no probs.

I had a rod brake at 0.7 bar. Maybe due to overboosting at 0.8 bar that caused the brake. This is still yet to be determined. Sami (Spock) had a similar problem.

We all know and are aware that the weakest link in the 1F-GE engine is the con rods. This is due to them being extremely thin and brake under stress.

As Daz said there is a lot of theory on this subject but nobody has the proof to back it up. Its easy to say 0.5 bar is the safest highest boost to run. But why is that? Why not 0.6 (as run by Roadrash). What if somebody was running 0.5 bar and had a con rod brake? Would we then say that 0.4 bar is the safest highest boost to run?

Who is actually running a permanent 0.5 bar? With out boost drop off? Its ok saying I'm running 0.5 bar but if the boost drops off then you are only running 0.3 / 0.4 bar. You cannot then say that you are running a safe 0.5 bar.

Until more engines blow and it is known what boost they were running we'll never know the true safe boost to run. This is because so far out of all engines we only have 2 really to go on. This being Spock's and mine. This I don't think is enough to give a true idea of safe boost. Just more theory for the time being.

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presumably as TTE warranties the supercharger install running at 0.3 , then the only proved safe boost level is 0.3 !, they dont recommend any higher , presumably they have data on effects of boost on the 1g-fe to back all there theorys up

what do we call safe ? how many miles ?, what type of driving ? who knows what damage is occuring or not

just because it doesnt blow , doesnt mean it will last the same distance as an unboosted car

the engines blowing seem to be put down to what boost they were running, im sure there are plenty of other factors involved or possible causes , chris`s car was deemed by lexus to not be caused by the supercharger

the bloke from nemesis blew his because of negligence

who is to say that spocks and ady`s were not just bad conrods which could have broke at any point !

what boost is kieron running ??

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presumably as TTE warranties the supercharger install running at 0.3 , then the only proved safe boost level is 0.3 !, they dont recommend any higher , presumably they have data on effects of boost on the 1g-fe to back all there theorys up

what do we call safe ? how many miles ?, what type of driving ? who knows what damage is occuring or not

just because it doesnt blow , doesnt mean it will last the same distance as an unboosted car

the engines blowing seem to be put down to what boost they were running, im sure there are plenty of other factors involved or possible causes , chris`s car was deemed by lexus to not be caused by the supercharger

the bloke from nemesis blew his because of negligence

who is to say that spocks and ady`s were not just bad conrods which could have broke at any point !

what boost is kieron running ??

Wherever did you learn all lot?

Perhaps copy n paste?

You tool

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If you ask me, I'd say the stock engine is reliable for 0.6bar.

In my opinion 0.7 is a bit risk, cause you can hit 0.1-0.2bar overboost very easy so I would call it a bit dangerous. :shutit:

Stay @ 0.5/0.6bar and everything is OK unless of doing a 24h racing on the Nürburg-Ring.

I also didn't drive carefully with my car and didn't have problems with the engine.

If the engine blows (conrod brake) below 0.6bar on street-using, then I would check the conrods for

steel-quality.

I'd say there must be a material defect. :o

And if somebody notices an overboost, then get off the gas and check it out.

Check the wastegate, setup the boostcontroller correctly (duty cycle, rpm/boost setup and so on).

I had a pretty good BC setting then, the boost was straight raising at 2000-2500rpm, full boost @ 3000-3500rpm and had a maximum overboost of 0.05bar so I got a max boost of 0.65 which is not dangerous.

Watch out for a good boost setup (wastegate & BC) and you can prevent 99% of engine blow risk. ;)

The other 1% is a material-defect which we can't prevent. :yawn:

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You tool

miiiiiiiike,, keep it civil now, you dont want to be known as another pippa

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half a bar half a bar half a bar................half a bar half a bar

as in the football chant cadence :D

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presumably as TTE warranties the supercharger install running at 0.3 , then the only proved safe boost level is 0.3 !, they dont recommend any higher , presumably they have data on effects of boost on the 1g-fe to back all there theorys up

what do we call safe ? how many miles ?, what type of driving ? who knows what damage is occuring or not

just because it doesnt blow , doesnt mean it will last the same distance as an unboosted car

the engines blowing seem to be put down to what boost they were running, im sure there are plenty of other factors involved or possible causes , chris`s car was deemed by lexus to not be caused by the supercharger

the bloke from nemesis blew his because of negligence

who is to say that spocks and ady`s were not just bad conrods which could have broke at any point !

what boost is kieron running ??

Wherever did you learn all lot?

Perhaps copy n paste?

You tool

mike you ask for peoples thoughts

you ask to keep it clean

i can only presume you were in your typical drunken state, my only advise to you is to sober up and stop being a complete ****

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Guys, mates and friends.....

Can you stop wasting threads then with throwing $H!T another?!? :unsure:

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I think it will be very difficult to identify the facts (without scientific destructive testing analysis), so perhaps the best we can hope for under the circumstances is to make a conservative decision based on the balance of probabilities.

We have supplied over 10 stage 1 supercharger boost upgrade systems which raises the boost pressure to 0.5 bar. The first car is still running several years later, and I am not aware of any of the others experiencing any problems.

It seems to me that in the LOC community there is 1 failure at 0.3 bar and a small number (2 or 3?) of failures at 0.7/0.8 bar (which is a massive 150% tolerance/difference).

For the above reasons TDi recommends caution if using more than 0.5 bar without uprated connecting rods.

On a side note, evolution has provided well developed Humans the capability of being able to disagree without falling out or starting a war. Civility, acceptance and respect are normally good signs of a good person.

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Who is actually running a permanent 0.5 bar? With out boost drop off? Its ok saying I'm running 0.5 bar but if the boost drops off then you are only running 0.3 / 0.4 bar. You cannot then say that you are running a safe 0.5 bar.

Adie,

I was running a constant 0.5 bar on mine and the boost actually crept up a bit in higher gears when climbing the rev range. Only ever crept up to about 0.55bar though.

Generally, I never had any probs at all although I have not had the car running for more than 6 months with this setup.

I, like yourself still think there is not enough info or consistency to make a reliable judgement on possible safe boost pressures. I was gonna raise the boost a step at a time before stripping the car again to see what happened but the bigger 1g-gte injectors I had wouldn't fit so I don't have the fuelling to do it.

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On a side note, evolution has provided well developed Humans the capability of being able to disagree without falling out or starting a war. Civility, acceptance and respect are normally good signs of a good person.

I'll second that.

But on topic, I think that just talking about boost levels is over simplifying things, there are probably other contributory factors as said by Bazza.

The conrods are designed to take the stresses induced by a N/A 1G-FE and will have a bigish "factor of safety" designed in (say at least 3x the normal loads expected). To increase power output, and hence loading, by a factor of 0.3 (150 to 200bhp) at 0.3 bar seems to me to be well within the design tolerances of the rods. I just don't buy the argument that the extra boost/power is solely to blame even running up to 250bhp.

Heat must contribute IMHO as the cylinders will run hotter because the rate of fuel burning increases. It is possible that running clearances in the cylinders are affected due to extra expansion of the pistons, this would be most evident in cylinder #6. Could this be improved by honing out the cylinder and using oversize rings? If this is a problem running slightly lean would make it worse so fuelling is also a potential issue.

What about lubrication, as the oil acts partially as a coolant it will run hotter and hence be thinner than it should be. This could result in reduced oil pressure in the plain bearings of the main, big end and small end bearings. As they rely on a pressurised oil film at act as the bearing surface this could cause additional rotational drag and hence force on the rods.

Just a couple of thoughts, I'll keep my head down and wait for the flak :tomato:

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A bit right and a bit wrong. :P

The oil film can just get ripped by overheating.

Overheating means running too lean, running too lean causes piston melt or oil film ripping,

oil film ripping can cause rod bearing brake.

In this case you would have to do a few-hours run in red rev limit area @ 6500rpm on high boost.

The engine blow in Adie's case wasn't caused by overheating.

Overboosting means rod brake in the middle of the conrod.

The most leathal power for a conrod comes from side (horizontal force).

Horizontal force is produced by torque and rpm in rotation around the crank.

The conrod is moving around crank shaft very fast and if the torque increases in a roatation

the horizontal force increases more and more exponential.... and suddenly *BAMM* the conrod brakes, the rest of the rod on the big eye stungs thru the block, engine parts are around everywhere in the engine bay, oil is sticking everywhere, the piston is lost, due to the explosion it can shoot up, crashes against opened valves..... which are wasted too then. :crying:

That's why raising the rev limit is the most dangerous thing you can do on an engine.

Raising power and torque is limited.

The conrod doesn't brake in cause of the force working straight down on the crank shaft, it brakes cause of the horizontal force during the rotation moving at high rpm and in addition with increased torque they can

be broken like toothpicks :crybaby: .

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You tool

miiiiiiiike,, keep it civil now, you dont want to be known as another pippa

lol! :D

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A bit right and a bit wrong. :P

The oil film can just get ripped by overheating.

Overheating means running too lean, running too lean causes piston melt or oil film ripping,

oil film ripping can cause rod bearing brake.

In this case you would have to do a few-hours run in red rev limit area @ 6500rpm on high boost.

On overheating, I was making the point that due to a faster rate of fuel burn the cylinder and piston will be running hotter that it is designed to.

Extreme cases of running lean will melt the piston and/or cause detonation due to hot spots, running slightly lean would increase burn temperatures but not to the point of melting. It would also have the effect of a faster burn increasing shock loading.

In either case running clearances must be reduced due to the piston expanding more than it is designed to to in the bore.

I agree that the temperature of the oil would not get high enough to cause molecular breakdown but the oil will be thinner for a given grade than it should be. This would result in reduced pressure in the plain bearings due to the oil flowing more freely.

The engine blow in Adie's case wasn't caused by overheating.

Overboosting means rod brake in the middle of the conrod.

The most leathal power for a conrod comes from side (horizontal force).

Horizontal force is produced by torque and rpm in rotation around the crank.

The conrod is moving around crank shaft very fast and if the torque increases in a roatation

the horizontal force increases more and more exponential.... and suddenly *BAMM* the conrod brakes, the rest of the rod on the big eye stungs thru the block, engine parts are around everywhere in the engine bay, oil is sticking everywhere, the piston is lost, due to the explosion it can shoot up, crashes against opened valves..... which are wasted too then. :crying:

All materials are weakest under shear loadings and as you say, however as torque is proportional to power and the power increases are small in percentage terms. I would still say that the stresses should be within the design limits of the rod given that the revs are not above the original limits.

Very graphic and accurate description of the result of con rod failure :crybaby:

That's why raising the rev limit is the most dangerous thing you can do on an engine.

Raising power and torque is limited.

The conrod doesn't brake in cause of the force working straight down on the crank shaft, it brakes cause of the horizontal force during the rotation moving at high rpm and in addition with increased torque they can

be broken like toothpicks :crybaby: .

I totally agree that raising the rev limit is very dangerous.

What I am saying is that some people are running around on the same boost levels as Adie without any problems so there must be some other factors apart from boost/power levels

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Here we go, I agree! :winky:

For example:

Stock IS200 pistons are 74.3-74.4mm on the top end in diameter.

My forged pistons I got are only 74mm on the top. The piston driver under the rings is exactly 75mm.

So the top end must be a bit more slighter cause of higher temps and piston-expanding.

So the pistons are made for higher HP and temp. B)

What I am saying is that some people are running around on the same boost levels as Adie without any problems so there must be some other factors apart from boost/power levels

No!

Adie's rods broke cause of a load of overboost somewhere in the 0.8-0.9bar area, not because of material defect on 0.6bar. ;)

I did really hard launches with my heavy-duty 4-paddle clutch and nothing happened at 0.6 I was going with.

0.5-0.6 is the boost area that the engine can take, but you have to take care when you notice overboost.

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*BAMM* the conrod brakes, the rest of the rod on the big eye stungs thru the block, engine parts are around everywhere in the engine bay, oil is sticking everywhere, the piston is lost, due to the explosion it can shoot up, crashes against opened valves..... which are wasted too then. :crying:

Exactly what happened mate. Valves knackered, spark plugs snapped off, huge hole in the side of the block, oil covering the engine bay, the back of the car and a huge puddle of oil all over the road. Not a nice feeling :crybaby:

I do agree with Barrie that TTE must have done research into this with regards the compressor kit. As they dont want to sell kits if its going to blow engines / snap conrods etc

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You tool

miiiiiiiike,, keep it civil now, you dont want to be known as another pippa

lol! :D

wahayyyyy pip's found his sense of humour,, welcome back :P

Re neils and adies comments, your comments lead me to this thought, that it seems that the main contributing factor to oem conrod failure IS overboost. as niel says, if there is a FOS of 3x say, then 0.3 is ok, poss theres a FOS larger than 3, therefore .5 seems to be ok. higher boost will either kill the conrod (beit via lubrication, lean etc).

so uprated internals are a must for .6+.

TTE may well say 0.3 is THERE limit as its under the .6 threshold of failure,,

of course i do nto profess to being an expert, just going on what theorys being put forward now..

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half a bar half a bar half a bar................half a bar half a bar

as in the football chant cadence :D

half a bar so your saying 7.3 psi is safe

correct me if i am wrong isent 1 bar 14.7 psi

presumably as TTE warranties the supercharger install running at 0.3 , then the only proved safe boost level is 0.3 !, they dont recommend any higher , presumably they have data on effects of boost on the 1g-fe to back all there theorys up

what do we call safe ? how many miles ?, what type of driving ? who knows what damage is occuring or not

just because it doesnt blow , doesnt mean it will last the same distance as an unboosted car

the engines blowing seem to be put down to what boost they were running, im sure there are plenty of other factors involved or possible causes , chris`s car was deemed by lexus to not be caused by the supercharger

the bloke from nemesis blew his because of negligence

who is to say that spocks and ady`s were not just bad conrods which could have broke at any point !

what boost is kieron running ??

now were talking a bit of thought going into it this is very beleivable and has a tte s/charger does not void the lexus warranty so it must be within a safe threshhold

not just saying .5 is safe and thats it any one can right that is the safe barrier but have no genuine facts of this

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half a bar half a bar half a bar................half a bar half a bar

as in the football chant cadence :D

half a bar so your saying 7.3 psi is safe

correct me if i am wrong isent 1 bar 14.7 psi

now were talking a bit of thought going into it this is very beleivable and has a tte s/charger does not void the lexus warranty so it must be within a safe threshhold

not just saying .5 is safe and thats it any one can right that is the safe barrier but have no genuine facts of this

Not sure what you mean Darren ?

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half a bar half a bar half a bar................half a bar half a bar

as in the football chant cadence :D

half a bar so your saying 7.3 psi is safe

correct me if i am wrong isent 1 bar 14.7 psi

now were talking a bit of thought going into it this is very beleivable and has a tte s/charger does not void the lexus warranty so it must be within a safe threshhold

not just saying .5 is safe and thats it any one can right that is the safe barrier but have no genuine facts of this

Not sure what you mean Darren ?

are you saying half a bar half a bar

is safe

or what do you mean by half a bar

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