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The iron law of tuning (important)

3star2nr

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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.
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Shifting_Gears

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That’s one hell of a post. I’ll drink to that.
 

Bladerunner70

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GREAT POST...!!!

I read every word of it. Great advice.

Thank you
 

mavisky

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I disagree with one thing, the RXT is a racing clutch, but I easily put 25,000 miles on mine making 660whp in a 4,100 lb car in Atlanta traffic.
 

BlackandBlue

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You just summed up why I haven’t boosted my car.

I figure 25k to spend on boosting and my first engine replacement.

I am just going to by a 500 instead.
 

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Zelek

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You also can boost your car and keep reasonable horsepower levels. Eventually when I stop fighting myself on a decision with FI, I want to be around 650 whp. That's a hefty chunk and with the right suspension and tires, I think I can do plenty with it. 93 octane should be plenty fine at that level. I think once you go with dedicated fuel systems and start going past 800 whp, things get dicey. Gotta pay to play at that point.

Even with an E85 tune as NA with an 18 manifold, these cars have plenty of power for the regular road. Boosting just takes so much money up front then running the risk of losing your engine.

I'm with the guy above. If I could get an MSRP deposit on a GT500, I'd be happy. Hoping one day I'll get over the scare and just boost it.
 

watisthis

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Great post! As comfortable as I may feel with my car making low 800s I am always paranoid about things like this happening.
 

Performance nut

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I so was expecting very different post. Bravo man, great post. Tuners (no offense all) can only give you one of those things. They can give you cheap at the expense of reliability and fast (canned tunes). They can give you fast but it will sacrifice STOCK reliability and likely won't be cheap. If you want dependability, I know guys hate it but stick with the Ford stuff.

Just like your post says, YOU need to provide the second part. You can say ok, I'm tuned for fast but I don't want to spend on supporting parts or better manufactured parts knowing full well I will experience a failure later. Or you can spend the cash on better supporting parts or parts that are better suited for what we are doing.

Personally, I like to overbuild like Ford does. I'm always going to make a mistake and me personally I don't need to ride the ragged edge all the time. So long as my toy is there for me the next time I want to play, I'm good.
 

Stymee

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I would think a 9lb custom tuned whipple or eb on 93 would be very safe and still make 600rw through a A10

On a tire I would hope that’s 10 sec power.

Once u start getting greedy that’s when things go bad, honestly I’d rather splash 93 with a gallon or 2 of Sunoco 260 than Boostane, it doesn’t have MMT in it.

Speed Kills:giggle:
 

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3star2nr

3star2nr

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You also can boost your car and keep reasonable horsepower levels. Eventually when I stop fighting myself on a decision with FI, I want to be around 650 whp. That's a hefty chunk and with the right suspension and tires, I think I can do plenty with it. 93 octane should be plenty fine at that level. I think once you go with dedicated fuel systems and start going past 800 whp, things get dicey. Gotta pay to play at that point.

Even with an E85 tune as NA with an 18 manifold, these cars have plenty of power for the regular road. Boosting just takes so much money up front then running the risk of losing your engine.

I'm with the guy above. If I could get an MSRP deposit on a GT500, I'd be happy. Hoping one day I'll get over the scare and just boost it.
Well you can do ot just fine just buy a second black and transmission before you buy the blower.

If A year or two later your cars fine you can sell them. People are always looking for coyote motors, so you won't lose money on it. But it gives you the pie e of mind to send it because you have a spare
 
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3star2nr

3star2nr

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I disagree with one thing, the RXT is a racing clutch, but I easily put 25,000 miles on mine making 660whp in a 4,100 lb car in Atlanta traffic.
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
 
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3star2nr

3star2nr

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Its the side of tunning you figure out the hard way, and unfortunately alot of tuners don't really know better or don't care because they need to sell you that part to make rent this month.

There are parts that have no business being on a street car, like anything that uses spherical bearings or heim, joints.

On A race car these are great because they improve steering feel. But on a street car the vibrations will cause the spherical bearings to fail. Polyurethane bushings are tge best option for a hot street car.

Parts like cross drilled rotors have no business on a race car especially one setup for autocross or road racing. Most of these parts are made from blank rotors that are drilled the repeated heat cycles causes them to develop hairline cracks and the rotor can split in half...

I've see it happen in as little as 3 laps on track. Braided steel lines are also not a great idea for similar reasons. They snap.
 
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3star2nr

3star2nr

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Coilovers and adjustable shocks are also something you dont want to cheap out on. High end brands like KW offer lifetime rebuild services and i think fortune auto also offers that. It's worth the extra money, because most adjustable shocks will fail realitively quickly in a street driven application, compared to the non adjustable versions. You can plan on a rebuild every 24k miles or so... Some people get more
 

ctandc72

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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.
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