Aspiration Types

[hightower99]

How smart do you have to be to work out IT BROKE?

What part of it broke in less than 4000km for whatever reason means that it is reliable?

It doesn't matter why it broke in this instance - just that it broke. Less than 4000km makes it unreliable in my book, but if you want to pull the engine out of the car and replace pistons every couple of weeks thats your call.....

Ok so if you run a tuned engine on regular gas and thrash it and it breaks then the engine is unreliable? That is just braindead... I would like to see how your turbo car handles running on regular gas as you thrash it. According to your reasoning if somebody tanks up with water and turns the engine over until the battery dies, if the engine is damaged then it was faulty to begin with?

Well most of my time for 3500km in 4 days was between 5-12psi - so I suppose I was driving a bit harder than they were, must be a meaningless comparison then.

If you kept it in the boost for 10 hours a day then yes good job. Of course you also need to think about the temperature difference (they drove the matrix through the desert during mid summer) What was your point anyways? are you saying that a unreliable turbo engine could easily handle this?

Bathurst, very demanding on both driver and car. It looks a lot flatter on screen than the 174m elevation change, ...

Good Bathurst is a demanding track I agree. What sort of trouble did it cause for your car?

Someone let you - too young to have a licence - behind the wheel of their 944 Turbo at the Nuerburgring? They are either a lot braver or sillier than I am.

How much other experience have you had driving high performance cars? How much track experience have you had at track days? Is your other track day experience in high or lower performance cars? What sort of (Nordschleife) times did you do?

I have a license I will be 19 in less than 3 months. I have had a drivers license since I was 16. Yes my friend let me drive his 944 (with him in the passenger seat). I don't have huge experiance with trackdays as they are not frequent in denmark, I have been to a few (5. 6 if you include me lapping the north ring) As for cars I have driven several performance cars, most of them new ones (it is ridiculously easy to get test drives here in denmark especially when your father's friend is a salesman at Lamborghini Denmark) I haven't done any long trips in them though (the longest I loaned a car was 2 days). As for cars I used during track days I have used a caterham R300, Evo VII, and a pretty highly tuned 745i. other than that i have used my 325i (not a high performance car) When I had the chance to use the 944 on the north ring I didn't go for it much. It was my first time there so it was basically a sightseeing tour. I believe the time was something over 12 minutes.

Asking for proof of this will just get ignored so I won't bother.

As you havn't yet seemed to comprehend alcohol fuels allow more energy to be released during the burn, giving different outcomes to the "same" octane rating. This allows higher compression with alcohol than petrol without detonation.

Alcohol has less energy than gasoline because basically 1/3 is already burnt. Alcohol has higher octane ratings that is why you can use higher compression ratios but for the same compression ratio gasoline produces more power. Why do I have to expend effort to prove if he indeed makes alcohol in his backyard? it isn't a relavent point. If you think it is illegal it isn't so long as there is some methanol in it to make it inedible.

Silly me for thinking that the failure must be instant for it to be considered as not a good idea....

This just proves that I'm foolish for thinking 4000km is FAILURE of the experiment - an experiment that you are trying to claim as a blinding success........

It was a great succes. they successfully turboed a 11.5:1 compression engine with no detonation on 91 octane gas. had some idiot not put regular in and thrashed it then it would have lasted a long time. breaking an engine with bad gas doesn't mean the engine is unreliable. Try running your turbo car on regular and see what happens.

If creating and running a return line, changing the regulator, rewiring the injector system to a stand alone ECU and then patching that into the existing ECU is a small job to you then obviously you are a brilliant mechanic and we should all be grateful to your presence here.

It certainly isn't difficult, time consuming yes, difficult no. Your average car guy should be able to handle it with the help of a good manual or a local garage.

If like normal people if would take you some time to plan, set-up, install and test, it's not a small job.

That is without having to remove and replace the fuel pump because it isn't adequate for the new fuel load.....

They used a planned kit so they just had to install it (not difficult) and test it (can be tricky)

Initially you said McLaren NA engines required race fuel.
Then you said they would run boost with 91.
Then you said they would run boost on 91 and octane booster.

Have you worked out which it is yet?
Do you even know the difference?

The McLaren uses a BMW engine intially designed for racing and was designed to run on 100 octane race gas. You can run a McLaren with zero detonation on 91 octane and if you boosted an engine like that then it should be able to run on 91 if not there is always octane booster (or higher grades at the pump) get it?

Because obviously your experience is much more valid than mine......

again you misunderstand... I dont just voice my opinions I give values and numbers that quantify my thoughts and the proof to back it up. you fail to do either.

With 100 available at my local service station, I consider the "super high octane" stuff to start with Elf's 103 octane race fuel and moving through other race fuels to 130 octane AvGas.

That is better now why the hell didn't you say 103-130 octane gas and save everybody valuable time? numbers help give you a valid opinion. Just saying option A sucks and Option B ROX means nothing you need to include details.

Installing lower compression pistons, stronger rods for the increased force, stronger crankshaft, stronger gearbox, installing deck spaces to reduce compression, creating an entire new exhaust system,installing new valves, having to modify the head for flow or new valves, modifying the engine bay, installing a stand alone ECU to control fuel delivery......

Are all of those considered massive internal mods in there own right (some isn't even internal modification...) or is all that together massive? If it is the later then No turboing a NA engine doesn't require all that for low boost.

As I said I extrapolated a graph. If you had done any advanced maths, science or engineering you would know this is pretty standard practice.

Yeah if the graph is linier or has a formula... I don't remember you showing any formula and you noted yourself that it is only roughly linier.

Correct me if I'm wrong, but the Matrix DID blow the hell out of its piston and rings.

The #3 piston had sustained damage that lead to 70% blowby yes after it was turboed and run on bad gas. According to the graph the Stock Matrix should have been detonating like mad because with it's 11.5:1 compression ratio it should have roughly 106 octane fuel to be safe.

I'd love to see better figures - especially if you can provide PROOF as to where you obtained them.

Umm try recommended octane values for any high performance car that should give you a pretty accurate listing.

I have a 1993 Saab 900 Turbo (as stated in my profile).

It has undergone some modifications including reprogramming the APC to allow constant running at up to 15psi. I am considering further increasing boost, but the fuel system needs greater capacity to allow it to cope with this.

The Oil companies claim a shelf life off weeks, but with less than ideal conditions that can be reduced to days.

First of all: Kudos on the sweet car (I like SAABs) Second you are again voicing an unsupported opinion. How many weeks? how many days? what conditions shorten the time?

[jediali]

As opposed to torque. Many people tend to think that it is the torque that moves the car and determines acceleration.

your half there, in an instantaeous sense torque moves the car, however acceleration is determined by power (which is a rate of torque) if you like.

[-What-]

Turbo-charged cars are more efficient than NA cars. Efficiency is the key to life. Engineers value efficiency. Once the lag is defeated, it will be impossible to ignore turbocharging.

[The_Canuck]

Turbo-charged cars are more efficient than NA cars. Efficiency is the key to life. Engineers value efficiency. Once the lag is defeated, it will be impossible to ignore turbocharging.

How about...cost?

[Quiggs]

How about...cost?

Don't forget added complexity.

[jediali]

Turbo-charged cars are more efficient than NA cars. Efficiency is the key to life. Engineers value efficiency. Once the lag is defeated, it will be impossible to ignore turbocharging.

engineers like efficiencies yes, but the only efficinecy you mentioned was volumetric efficiency

[Quiggs]

Turbo-charged cars are more efficient than NA cars. Efficiency is the key to life. Engineers value efficiency. Once the lag is defeated, it will be impossible to ignore turbocharging.

Efficient how? Every person I've ever seen install an aftermarket turbo setup on a car has gotten worse gas mileage.

[jediali]

Efficient how? Every person I've ever seen install an aftermarket turbo setup on a car has gotten worse gas mileage.

yeah, thats fuel efficency, as you know FI doesny necesarily mean that,

[Quiggs]

yeah, thats fuel efficency, as you know FI doesny necesarily mean that,

I know, but he only said "efficiency" and didn't mention what kind of efficiency he was talking about.

[jediali]

I know, but he only said "efficiency" and didn't mention what kind of efficiency he was talking about.

aha, he is confused. he needs to read through this thread one thinks

[hightower99]

A turbocharged engine can be more thermally efficient than a NA engine.

Turbo cars get lower mileage because they produce more power, but often for there power they use less fuel than a NA engine.

Turbos use otherwise wasted energy to increase airflow through the engine.

[Cyco]

Ok so if you run a tuned engine on regular gas and thrash it and it breaks then the engine is unreliable? That is just braindead... I would like to see how your turbo car handles running on regular gas as you thrash it. According to your reasoning if somebody tanks up with water and turns the engine over until the battery dies, if the engine is damaged then it was faulty to begin with?

With the travel I do many smaller towns don’t have premium fuels available, so it often runs on less than 98 octane. It was actually running on non-premium when I got to Bathurst, as the last town I’d refuelled at (West Wyalong) did not have it available.

If you kept it in the boost for 10 hours a day then yes good job. Of course you also need to think about the temperature difference (they drove the matrix through the desert during mid summer) What was your point anyways? are you saying that a unreliable turbo engine could easily handle this?

Well on the way down (trip to Adelaide from Sydney) external temperature was in the 28-33C range. On the return external (shade temp) reached 43C. This wasn’t the middle of summer, but I suspect it was warm enough to be comparable.

The point I’m making is a RELIABLE turbo engine CAN handle this. Even a modified one, running on less than optimal fuel that already has 280,000km under its wheels.

Their Matrix BROKE. It BROKE doing a similar trip to what I do regularly. That would have left me stranded in the middle of nowhere (look up West Wyalong’s location for some idea). That to me is UNRELIABLE. Is this too hard an idea to comprehend?

Good Bathurst is a demanding track I agree. What sort of trouble did it cause for your car?

Despite the temperature (about 35C) and less than optimal fuel, nothing more than some tyre squeal and a hole in my fuel economy.

I have a license I will be 19 in less than 3 months. I have had a drivers license since I was 16. Yes my friend let me drive his 944 (with him in the passenger seat). I don't have huge experiance with trackdays as they are not frequent in denmark, I have been to a few (5. 6 if you include me lapping the north ring) As for cars I have driven several performance cars, most of them new ones (it is ridiculously easy to get test drives here in denmark especially when your father's friend is a salesman at Lamborghini Denmark) I haven't done any long trips in them though (the longest I loaned a car was 2 days). As for cars I used during track days I have used a caterham R300, Evo VII, and a pretty highly tuned 745i. other than that i have used my 325i (not a high performance car) When I had the chance to use the 944 on the north ring I didn't go for it much. It was my first time there so it was basically a sightseeing tour. I believe the time was something over 12 minutes.

How did you get a licence at 16 when in Denmark the minimum age for a learners permit is 18?

Alcohol has less energy than gasoline because basically 1/3 is already burnt. Alcohol has higher octane ratings that is why you can use higher compression ratios

Exactly my point, you were able to fit higher compression pistons to the Porsche Turbo because you were using a higher octane fuel. This is something in many of your other posts you denied needing.

Why do I have to expend effort to prove if he indeed makes alcohol in his backyard? it isn't a relavent point.

The reason I made the comment is because you are yet to PROVE anything. You come on here and make lots of wild claims without any backup and then expect others to chase the proof to prove you right. It may be the custom in Denmark, but this is an international forum and we tend to work on the “If someone makes a claim they have to do the work to back it up” system in the rest of the world.

It was a great success

YAY, we broke an engine!!!!! Lets party!!!!

they successfully turboed a 11.5:1 compression engine with no detonation on 91 octane gas. had some idiot not put regular in and thrashed it then it would have lasted a long time. breaking an engine with bad gas doesn't mean the engine is unreliable. Try running your turbo car on regular and see what happens.

They GUESSED someone put regular in it. They don’t KNOW this. All they know is in less than 4000km it BROKE.

As already posted in this thread my car does sometimes end up on regular. Its affects my fuel economy negatively, and I try and keep the boost under 12psi for peace of mind (but this isn’t always strictly adhered to).

It certainly isn't difficult, time consuming yes, difficult no. Your average car guy should be able to handle it with the help of a good manual or a local garage.

My point was if you can’t do it in a driveway it is difficult.
You are saying it’s not difficult, but you can’t expect to do it in the driveway. You and Drakkie should meet up sometime - you would get along well together.

They used a planned kit so they just had to install it (not difficult) and test it (can be tricky)

So all the custom fabrication can be done by the average person in their driveway/home garage?
You Danes must be well equipped and trained at school to do this at home.
I have training and certification in using most types of welder, and metal forming techniques, but I certainly don’t have welders, pipe benders and a dyno in my garage.

The McLaren uses a BMW engine intially designed for racing and was designed to run on 100 octane race gas.

Wrong, again. The engine was designed as a street engine from the beginning and was a development of the then and (still under development) next generation M3 engine. It was always designed as a street engine to run on street fuels.
The race engine came later.

You can run a McLaren with zero detonation on 91 octane and if you boosted an engine like that then it should be able to run on 91 if not there is always octane booster (or higher grades at the pump) get it?

So an engine designed to run 11.0:1 CR with 100 octane fuel will run just as well (no pinging) at 22.22:1 CR with 91 octane fuel?

No I don’t get it. I don’t think you do either.

again you misunderstand... I dont just voice my opinions I give values and numbers that quantify my thoughts and the proof to back it up. you fail to do either.

YOU have yet to provide any PROOF as to ANY proof you claims other than 1 magazine article that demonstrates the opposite of what you claim.
I have given numbers – I extended a straight line graph that you have rubbished without any reason, other than it conflicts with your claims.

Where is the McLaren compression graph?

Where is a octane rating/CR graph, ratio or formula that we can use to agree or disagree over?

That is better now why the hell didn't you say 103-130 octane gas and save everybody valuable time? numbers help give you a valid opinion. Just saying option A sucks and Option B ROX means nothing you need to include details.

Well how about some details from you?

Exactly how much octane booster do you intend to add to the 91 octane in the 22.22:1 compression McLaren engine to stop it pinging? What will this take the final octane rating to?

Are all of those considered massive internal mods in there own right (some isn't even internal modification...) or is all that together massive? If it is the later then No turboing a NA engine doesn't require all that for low boost.

Any installation of aftermarket parts that involves the removal, disassembly, and machining/fabrication of the engine or it’s components is massive internal modifications. Is this a fair assessment? Or do all Danes have this equipment in their garage and the training to use it?

Not all those listed are necessary, especially at low boost, but all are optional and all will, to varying degrees, help with the conversion process.

Yeah if the graph is linier or has a formula... I don't remember you showing any formula and you noted yourself that it is only roughly linier.

The graph is linear apart from at low values. Is it that hard to comprehend? Is it that hard to check? Took me all of 2 minutes to place the values in a spread sheet and graph it. Last I checked we were not looking at low values. I can generate a formula off it in seconds, its not difficult…..

In the scientific community if you want to rubbish an idea it helps to have a better one of your own, or you look like a fool.

Where is your graph, formula, or chart that offers so much better information than mine? Until you can provide better (and I would love to se something better) then this is the best information we have to work from, don’t you agree?

The #3 piston had sustained damage that lead to 70% blowby yes after it was turboed and run on bad gas. According to the graph the Stock Matrix should have been detonating like mad because with it's 11.5:1 compression ratio it should have roughly 106 octane fuel to be safe.

You don’t melt a piston within minutes of starting a car, it takes time.

Maybe, and I’m thinking we will both agree this is the case, if they had of used 106 octane fuel #3 piston wouldn’t have melted and the car would still be running happily today.

[Cyco]

Umm try recommended octane values for any high performance car that should give you a pretty accurate listing.

Got any to show me? Sorry, was forgetting you don’t do proof……

Second you are again voicing an unsupported opinion. How many weeks? how many days? what conditions shorten the time?

Unlike some I actually fact check before I post.

My brother works for major oil company (I’m not sure they want this published so I’ll withhold they name from public view) and they are sponsoring his Masters Degree and have offered to sponsor his Doctorate in Engineering if he wants to get it.

Winter fuel is more affected than summer fuel by heat (what a surprise), and summer fuel can be cold affected.

Both are affected by temperature and humidity during cracking, processing, transport and storage.

Under worst possible conditions (winter fuel in high heat and humidity) the fuel that leaves the plant at 98 can be down to 95 within 3 days, and 92 within 2 weeks.

[jediali]

A turbocharged engine can be more thermally efficient than a NA engine.

Turbo cars get lower mileage because they produce more power, but often for there power they use less fuel than a NA engine.

Turbos use otherwise wasted energy to increase airflow through the engine.

Well.....not exactly. IMHO:

Thermal efficiency has a lot to do with effective compression ratio, this can be just as high in NA or TC. period! how can the induction system increase the compressability of the fuel?

Turbo cars can get lower milage because the produce torque earlier thus saving fule through low running engine speeds! obviously at higher engione speeds it will consume more fuel. This is the theory of LPT's. ..How can some power consume more than others? you mean instantaneus torque!

A turbo does use the wasted exhaust gas velocity. And this is good. It stil has the disadvantage of compromising crosshead gasflow over a wide rev range. Your the one that talks about 8 phases and sh*t, so you will know that the back pressure plays a huge part in increasing pumping and piston compression efficiencies.

[henk4]

Turbo cars can get lower milage because the produce torque earlier thus saving fule through low running engine speeds! obviously at higher engione speeds it will consume more fuel. This is the theory of LPT's. ..How can some power consume more than others? you mean instantaneus torque!

True, at high speeds and high revs (relatively) the difference in fuel consumption between turbo diesels and petrol cars is not so big. They get their big advantage exactly because they can effectively be run at low revs, without being a slouch. No manufacturers of diesels have applied the Corvette trick by adding a very high top gear, reducing rev levels at high speeds considerably (and getting an acceptable EPA mileage).