The iron law of tuning (important)

[shogun32]

f I was going to boost my GT, I'd go the opposite way. I'd find an engine to build - with FI in mind from the get go. As in compressions ratio, clearances, pistons, etc etc. But maybe that's just me.

I wouldn't dream of boosting a 12:1 ratio engine. Knock it back to 9.5 or so, sure. And forged rods and pistons.

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[mavisky]

yspareyeah this guy was doing non stop drag launches and burnouts so theres that. He was also running full drag tires and skinnies...

But It's funny that he doesnt get how all that will have an impact on clutch life

You can't fix stupid.

 

[Jmtoast]

1. Don't get a Youtube channel...

 

[1MEAN18]

I just can't justify the costs of FI. But then again, I'm middle class and not obsessed with wasting money...if I were wealthy and had more money than I knew what to do with, I'd probably already have FI'd my '18. But low 11's around here is quick enough 99.99% of the time and there is always someone faster/quicker than you no matter how much money you are willing to spend/waste.

 

[Zinc03svt]

E85...

 

[3star2nr]

While I agree with the general premise of your post - the "Cheap, reliable, fast" pick two - well that greatly depends on how you define "fast" and how you define "cheap".
What a lot of people seem to overlook is that today's factory performance cars are tweaked pretty hard from the factory. They aren't leaving tons of power on the table in many cases and often the weak link isn't the engine in the first place (axles , clutch etc).

I think it's more of a problem with the "look at my peak HP number from the dyno" contest that seems to creep in with FI builds. I've had several different cars dyno tuned by local, reputable tuners. Each time I told them - I DRIVE the car, every day - so don't worry about peak HP - I want gains under the curve - where I'll be able to use it without going to jail or breaking something.

I also don't see a lot of 'safety margins' built into Forced Induction builds on naturally aspirated engines already pushing higher and higher compressions ratios - granted direct injection bumps that margin a good bit...but still. Shit happens. Electronics can fail / hiccup. You can get bad gas etc etc. So when the margin is razor thin and something does give / fail - well there ya go.

If I was going to boost my GT, I'd go the opposite way. I'd find an engine to build - with FI in mind from the get go. As in compressions ratio, clearances, pistons, etc etc. But maybe that's just me.

I agree 100% to me boosting 12:1 compression is crazy... Thats barely safe on pump gas NA lol.

I mean just what 10 years ago running that high compression was only done on racing engines now you can get it with a warranty.

The fact that these engines rev like they do, get the fuel efficiency and put the power down like they do and still be reliable is in itself a huge engineering accomplishment

 

[brucelinc]

I think these Coyote engines are MUCH more robust than what some people seem to think. Ford is fine with running 87 octane fuel in these 12:1 engines....although I don't do it. Roush and Edelbrock are fine with including a 3/36 warranty with their supercharger kits. Shelby even offers a supercharged GT as a rental for any Tom, Dick or Harry who has the money to rent one and flog it.

Obviously, if one goes for all the power they can get, there is danger of catastrophic failure. Likewise, it is excellent advice to monitor engine parameters on a regular basis. I would be 100% comfortable with a supercharged 2018+ Coyote tuned by one of the reputable tuners as long as you keep the WHP goals in the low to mid 600s and keep the shift points at stock levels. As long as they keep the spark at reasonable levels and the maximum boost around 10-11 PSI, I would not be overly concerned. Even with those "safety" measures, I think you can have a reasonably reliable, nice driving car capable of high 10 second ETs on DRs in decent air.

A good tuner does not want your engine to blow up and should make certain that you have appropriate fueling mods as well. I think it is important to let your tuner know your goals. If you want a 9 second car, you should be willing to take a lot more risk than someone looking for a high 10 second car. Many folks have the "never enough" mentality and that is where problems arise.

 

[Zelek]

The amount of money it takes to fully utilize and have traction on a car that is pushing more than 800+ whp is insane. There's a huge difference between usable horsepower and dyno queens gloating about their horsepower numbers only to find out they'll end up in a ditch if they gas it at any point on a regular road. It's very easy to lose the back end on E85 while N/A. Hell, I can do it on 93 octane too. Cold weather doesn't help either.

 

[brucelinc]

The amount of money it takes to fully utilize and have traction on a car that is pushing more than 800+ whp is insane. There's a huge difference between usable horsepower and dyno queens gloating about their horsepower numbers only to find out they'll end up in a ditch if they gas it at any point on a regular road. It's very easy to lose the back end on E85 while N/A. Hell, I can do it on 93 octane too. Cold weather doesn't help either.

Very true! I rarely find a suitable place on public roads to go WOT for more than maybe 3 seconds or so with my flex fuel tune. On cold streets with street tires, even that is iffy.

 

[ctandc72]

I'm just waiting for E85 to start getting more popular here in central VA. Not enough stations here to go that way yet.

 

[crcpdx]

Warning: long read...

"Cheap. Reliable. Fast. You can only have 2 of the 3. Pick your poison."

This is the iron law of tunning people who don't get this are in for a fucked up day...

I give you exhibit A:


Now before you make fun of him, or dodge the truth is his experience is far too common and can happen to anyone... His specific engine failure is actually very common. And regardless of brand all cars are essentially the same and usually fail for the same reasons...

People watch YouTube, go to car meets and read blogs and think it's "easy" to build a "9sec daily driver".

The truth is its NOT easy, and the people who succeed often have a long trail of blown motors and transmissions behind them. Yes the manufacturers have stepped up and have built us amazing motors, so the "cost" to get into the 9 sec club seems cheaper than ever. But its an illusion... the iron law still stands.

I'll disect this video as a case study of what can go wrong so hopefully you dont make the same mistakes. My goal is for people to avoid alot of heartaches by being better prepared and approach tunning in a different way.

0. Engine failure is very rarely caused by "one thing" it's usually caused by a sequence of issues that add up to failure. We have a tendency to fixate on the one broken part and often this leads to misdiagnosis of the problem, and causes us to fail again...

In my opinion His specific failure was caused by a combination of factors:

1. Fuel:
A. Use the correct fuel. The guy in this video was running 900 whp using only boostane... As you can see from his motor there is a ton of varnish build up. This is because addatives like boostane were NEVER intended to be used as a permanent fuel solution... If you cannot afford or have access to the proper fuel for your application build your car to run on pump gas.

B. Monitor fuel pressure.
He suspects that the OEM fuel rails is the problem, while they certainly dont help the issue they werent the cause in and of themself. The fuel system is a pressurized system so once the system is pressurized and functioning properly all injectors should see the same pressure and fuel.

It's important to log fuel pressure and be aware of pressure drops because this can cause the engines to run lean...

It's also important to maintain a full tank of gas. Not only does this help fight sloshing and reduce pressure drops in the rails, Low fuel also causes fuel pumps to overheat, that heat has to go somewhere right... The logical place is to your fuel... Which compounds issue 2.

2. Understand heat. Cylinder 7 is usually the cylinder that will blow on 99% of V8 engines... This isn't rocket science its because of heat...

Most cars cooling systems has the water pump feeding cylinder 1. The coolant flows through the water jackets around the cylinders absorb heat then to the radiator to dissipate it... Since cylinder 7 is at the rear of the motor it's the last one to recieve oil and coolant, this causes this cylinder to run hotter than all the others and in most cases will be the most sensative to detonation,

This is also true in V6 and 4 cylinder engines.

Ford on the aluminator engines added extra cooling lines to help fight this issue. To the best of my knowledge our coyotes never got this neither did the gt350s.

This was an addition specifically for their racing engines. Heat is your number 1 enemy both stock and in tunning and is also the thing everyone glances over...

Changing the radiator and thermostat may not be enough for your specific application.

So you need to monitor your cylinder temp, at the build phase, And make sure that your cooling system is keeping up. There are mods you can do to improve circulation in your motor, and the more heat you can take out of the engine bay the better. You can do this by, upgrading your fans, running larger lines, installing a header heat shield etc.

Using a ir thermometer to monitor temps on a dyno during the pull may not be a bad idea. Or taking before and after readings after a few pulls and hard driving. Remember your cooling system was designed for stock power levels and driving. And your cooling system is just that a system of parts not just a radiator and thermostat...

3. Choose the right parts. This is the number 1 thing to take from all this... There is a HUGE DIFFERENCE in parts designed for racing and parts designed for street, performance applications. In this video he has a mcleod RXT clutch. He is shocked and dissapointed to find that the clutch he just bought is almost toast...

Reality is the RXT is a full on racing clutch. It's designed to survive 1 racing season at most... Not designed for a street car application. Racing clutches prioriterizes clamping loads over, reliability, driveline protection and comfort.

If You have a 250k drag car with millions in sponsorship money on the line then you need a clutch that will hold and take you down the track. Then during the winter you replace the clutch. That's how these clutches are intended to be used... Most racing clutches will last less than 1 year of street driving... The clutch was wearing exactly as it should. He just made a poor choice... Now mcleod is getting an unfairly earned bad reputation.

4. Build it right or build it twice. After an engine failure ALWAYS get your fuel injectors cleaned and flowbenched, or replace them.

I suspect the buildup from the boostane could have been a contributing factor to this engines failure. But without testing there is no WAY to know for sure. Also be careful buying used injectors... Especially with modern engines proper fuelling is critical.

After a failure rebuild your supercharger or turbos, or send them to a professional to be thoroughly cleaned and rebuilt if necessary.

Replace all coolant and oil lines, and heat exchangers... You don't want a piece of a piston blowing up your new motor... This happens very often.

So to summerize there is no shortcut to power, and even when you do everything right it's just the nature of the beast that parts will fail...

Even F1 Teams with the best engineers and mechanics on the planet still struggle with reliabilty issues. High power engines are extremely delicate, the more power you make the more delicate the engine becomes. Make the right choices and be realistic with your goals...

Not because You can buy a cheap craigslist blower... mean you should. Take an honest look at your situation, and plan before you pick up a wrench.

Always assume The absolute worst thing will happen, and have a plan for that before you start, because 90% of the time that will be the result.

I don't pretend to be an expert on octane boosters, but I did do some research when deciding between Boostane and Torco. my findings on MMT (Boostane) were that the negatives mostly pertained to cars running cats (clogging up)and also some environmental effects. Someone running a catless system with Boostane would be relatively safe. You agree?

 

[Nevyn]

This is a really interesting post. And good to see proper engineering thought being put into analysing a failure.
In the early 90s I used to drag race. (Only a beetle) but I learned a lot about how far you can push things and where the weak points are. I also learned there’s no such thing as cheap power.

modern engines have us spoiled these days. They are far stronger and more powerful out the box than what we had to play with.

I’m UK based so the big V8 cars were rare. I used to talk to the guys in the pits running the V8 cars and the ones hitting 1000hp would routinely take the heads off the engine and the sump to inspect everything after each run.
They also had Kevlar blankets strapped over the top of the engine to protect bystanders from shrapnel if something did blow.

A friend of mine with a modified bug was pulling 9 - 10 second 1/4 He once wound the diff up through the casing and it landed in his back seat on a run. so it’s not always the engine that fails.

I could never go full power in 1st and 2nd for fear of blowing my gearbox. And I always took a spare to the meets with me.
Used to run 14sec 1/4 with 1974 beetle running an NA 2.4 type4 engine with about 150 horse

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