How often do engines fail because of FI?

[Matt@Cosworth]

these rods are basically one big crack waiting to happen

[mrg666]

Originally Posted by COO86L

I pushed the limits and ran 18 PSI on stock

People will say it's a ticking time bomb but really, the amount of boost etc means nothing.

18 PSI of boost means nothing?

[mrg666]

Originally Posted by Matt@Cosworth

these rods are basically one big crack waiting to happen

And you are telling this after selling so many supercharger kits but after stopping production. Will you be recalling those kits and returning their money, then?

[weederr33]

Originally Posted by mrg666

And you are telling this after selling so many supercharger kits but after stopping production. Will you be recalling those kits and returning their money, then?

Well considering they have stated many times the max safe limit is around 280-290 hp, they simply tuned the kit for that. I think Matt is simply saying it for those wishing to push something silly like 400-500 hp on stock internals.

[mrg666]

Originally Posted by weederr33

Well considering they have stated many times the max safe limit is around 280-290 hp, they simply tuned the kit for that. I think Matt is simply saying it for those wishing to push something silly like 400-500 hp on stock internals.

I understand that. But there is so much nonsense going on about people blowing up their engines and coming back to scare everyone else. I would have expected from someone representing Cosworth to be more careful and complete about such kind of statements.

[Irace86.2.0]

I feel like some people break the engine while stock and some at low boost and some at high boost but there seems to be enough people running high boost on stock internals that it makes me wonder what is the cause of their success. Is it driving style? Is it safety items like cooling measures, e85 for knock prevention, oil catch cans, etc? Is it luck for driving conditions ? Is it luck for their engine strength?

Who knows?

[whataboutbob]

Any time you deviate from the design you take risks. There are ways to mitigate the risk, but nothing is foolproof, even on a built motor IMO.

[firekat]

I just made the commitment on an FI installation. I have dedicated a lot of thought to my decision to go with FI.

Initially I thought of doing improvements and keeping it NA. I just did not feel that it would be enough, and the difficulty of keeping it easily smog-able were a rather large shortcoming.

It is very easy to get drunk with the idea of continually and incrementally increasing output on a stock engine. You know, just one more stick on the back of the donkey. At one point the donkey is going to sit down and go no further.

Most of my previous experience doing mods has been during a different time period. Back then it wasn't "FI", you either turbo'ed or supercharged. 10:1 was considered high compression, and no would think of "blowing" anything with that high of a ratio. Back then it was strongly suggested that 7.5:1 was an acceptable point to start. Of course back then there was no ECU's, VVT, and very few direct injection systems. Octane was not the big issue that it is today. You had leaded & unleaded fuel availability. They even had devices called "smog pumps", that were usually the first thing disconnected when tuning, for that initial boost in performance.

Jump up to today, with all the technological advances, multi-million dollar performance companies with rooms full of engineers, saying that 12:1 compression ratios are ok, and can take the boost. One even offers a warranty on their installations.

Now we go back to the initial thought process; What is it that you want to do?

• Do you want to make this car just more drivable and address it's inherent shortcomings

• Do you want to raise the power of this car to a realistic level that you think it should have come with?

• Do you want to make a track/street dominator, that will take 85% of the cars on the road?

• Do you want to make a track monster that will be the envy of everyone?

I think that if you going to do either of the first two, you should be able to get away with stock internals. Can you keep from ratcheting up your goals and expectations? It's more easily said, than done.

My intentions are this:

Increase in power commensurate with the intention of the build of this car.

Keeping it smog-able, with a minimum amount of effort.

Reliability

My plan is:

PD supercharger (more mid-range power)
Stock exhaust (not interested in noise - keeping it simple to smog)
Flex Fuel (better running for spirited driving)
Cooling system improvements, catch can (reliability)

For me the important thing is to keep boosted power at reasonable levels. You should be able to push the car, but not thrash it. Will I be able to keep from damaging the engine? I have no idea, but I certainly hope so.

There are some interesting articles on the FA20 on http://dsportmag.com/
This is not an endorsement, just interesting reading.

[Irace86.2.0]

I have yet to install my Harrop kit, but I can't imagine wanting more power than what the 11 psi pulley will give me. I tend to push my cars, so ringing out the power is a norm, and with more, I doubt I would need to or could use more power. I can't imagine needing more power unless we are talking high gear, high speed, highway pulls, which are not even on my list of needs. At least for the canyons, I can't imagine needing more power; maybe at the tract, it would make sense for long straight aways, but I equate the experience to people wanting more power on motorcycles.

With my Ducati Monster 796, I have all the torque I need in a usable spectrum for the twisties and sub 100 mph speeds, which is all I care about. The allure of a big displacement motorcycle is always there for highway pulls, but that makes up 1% of my riding that more power isn't worth it or needed.

I am assuming I will have the same perspective with this platform. The reality is that the engine is stretched already after adding 50% more power. The platform just doesn't seem capable of taking much more than 100% more power over stock, especially with the way I drive.

[firekat]

With my Ducati Monster 796, I have all the torque I need in a usable spectrum for the twisties and sub 100 mph speeds, which is all I care about. The allure of a big displacement motorcycle is always there for highway pulls, but that makes up 1% of my riding that more power isn't worth it or needed.

Not the torque "Monster" of your Ducati, I have a BMW S1000RR for the same purpose.

The BRZ is fun in it's own right, without having to go AGATT.

Just looked it up, my bike has about as much rear wheel HP, as the BRZ! Of course empty weight of the bike is only 458#.

[FRS Justin]

Originally Posted by Matt@Cosworth

these rods are basically one big crack waiting to happen

Careful you will have everyone saying you don't know what your talking about. TRUST ME

[Ryan GT86]

What's the max horsepower the stock engine can handle before you have to rebuild? Looks like a lot of supercharger and turbo kits can bump stock engines up to 300 hp from the stock 200/205 hp.

[firekat]

Originally Posted by Ryan GT86

What's the max horsepower the stock engine can handle before you have to rebuild? Looks like a lot of supercharger and turbo kits can bump stock engines up to 300 hp from the stock 200/205 hp.

The general consensus is yes, about 300 hp at the wheels. Most think that would be about the limit, though "YMMV". The variables that I have seen for that is:

Wheel HP vs Crank HP

91/93 vs E85

Most "Stage 1" kits seem to be pushing an additional 70 - 100 HP out to the wheels. That equates roughly to an additional 100 HP at the crank. The car on average puts out about 170 - 180 to the wheels stock. The Stage 1 kits mostly seem to kick that up to 260 - 290 on gas, 300 at the wheels running E85.

The addition of catless headers to these installations could boost your output to the wheels as you have a less impeded exhaust flow, which one could reason would not have an effect on engine internals. If the vehicle is on the street, you could have smog compliance issues, since there is a sizable cat on the stock header.

Empirically it appears that most people are able to accomplish the addition of 100 hp at the crank without building the engine. There are cases of people having failures within the Stage 1 range, it does not seem common, but certainly is not unheard of.

Consider that greater than 300 WHP you can get into potential drivetrain issues.

There is a lot of variables in all of this (driving habits, tracking, etc.), a fair amount of discussion and opinion has played out on these issues and will continue to do so.

[Irace86.2.0]

Originally Posted by Ryan GT86

What's the max horsepower the stock engine can handle before you have to rebuild? Looks like a lot of supercharger and turbo kits can bump stock engines up to 300 hp from the stock 200/205 hp.

Originally Posted by firekat

The general consensus is yes, about 300 hp at the wheels. Most think that would be about the limit, though "YMMV". The variables that I have seen for that is:

Wheel HP vs Crank HP

91/93 vs E85

Most "Stage 1" kits seem to be pushing an additional 70 - 100 HP out to the wheels. That equates roughly to an additional 100 HP at the crank. The car on average puts out about 170 - 180 to the wheels stock. The Stage 1 kits mostly seem to kick that up to 260 - 290 on gas, 300 at the wheels running E85.

The addition of catless headers to these installations could boost your output to the wheels as you have a less impeded exhaust flow, which one could reason would not have an effect on engine internals. If the vehicle is on the street, you could have smog compliance issues, since there is a sizable cat on the stock header.

Empirically it appears that most people are able to accomplish the addition of 100 hp at the crank without building the engine. There are cases of people having failures within the Stage 1 range, it does not seem common, but certainly is not unheard of.

Consider that greater than 300 WHP you can get into potential drivetrain issues.

There is a lot of variables in all of this (driving habits, tracking, etc.), a fair amount of discussion and opinion has played out on these issues and will continue to do so.

Wouldn't it also matter whether the kit was a SC vs turbo?

A supercharger may dyno at 300 whp like a turbocharger, but the supercharger is pulling some of the power to run itself. Say it takes 30 hp to run the SC, then a 300 whp SC'ed car would be making 330+ plus drive train losses at the pistons (if that makes sense), meaning the pressure on the rods/pistons/bearings will be higher. Also, a supercharger is more direct with more low end, so the potential for damage could also be higher for an equal rwhp to a turbo'd car.