Dear James, Rocket and CDW...

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[rocket 5979]

You guys have brought up the point quit a few times about not losing any torque or hp when going to bigger throttle bodies (with the correct tune). CDW, you have tried to make a point that you could have huge heads, intake, cam, etc, and with a proper tune will not lose anything on the lowend, but gain everything on the high end. Can you guys please explain this to me? I know you have tried before, but obviously there is something I must be missing and it's bugs me. You are all very knowledgeable and experienced and you must have good reasons for saying this and a few real world dyno examples to prove it. You all say that there has been great advancements over the past 15 years in tuning (which no one can deny). But I would like to know how much is from the technology that has come along with it and how much can be applied to older vehicles? For instance, in a recent post James brought up the 2011 Mustangs and how they come with 80mm TB and can even put on a 100mm if someone wanted and not lose low end. How much does Vi-VCT, wideband O2's and sensitive MAM and it's much more sophisticated computer have do do with it? If we were talking about a regular pushrod GT40 motor with an ECC-V, are you saying you can hog out the intake throat and slap on 90mm TB and gain on the top end and not lose bottom? Must you use a wideband or expensive data logging equipment to make this happen? What is the limits and justification of this? I know I've probably ruffled you guy's feathers in the past, but all I'm looking for is to prove myself wrong in what I know and hopefully learn something new. Please educate me and everyone else on this subject who has questioned this is the past.

Nick

Actually I don't believe I ever said anything to this affect. I am actually an advocate of not bothering with going with bigger TB's or MAFS on a relatively stock 5.0 Explorer or 4.0 Explorer because I feel it is a waste of money for the minimal gains you get. Now if we were talking about highly modified ones with serious N/A or FI combos then I feel there is more worth in changing those out for something that flows better or has a higher airflow metering range. Still, this is Explorerforum. Most of us serious gearheads and racers who have been around here for a while understand that most will never want to take their Explorer as far as some of us have. So I tend to cater my advice towards people in that situation most of the time here; unless I get the impression that they have bigger plans and are likely to be able to achieve them.

Allot of the better modern day technology can somewhat extend back to early OBD-II vehicles because we have better access to more parameters in the tunes, have better datalogging equipment, better aftermarket MAFS with finer hardware resolution, and fuel injectors that meter real well even into the 100+lb/hr range. All these are a big part of the reason why you can put together a 1,000+rwhp combo and daily drive it everyday today while 10 years ago it would have been a trailer only rig. Variable cam timing and even variable valve timing has helped tremendously with giving newer vehicles the best of both worlds when it comes to achieving great top end hp but while also keeping low end torque as well. Before the use of this came along you would have to pick either one or the other with a naturally aspirated vehicle. Even nowadays there are tradeoffs with performance modifications that no amount of custom tuning can eliminate. For instance the innate difference in power curve between a positive displacement blower and a centrifugal blower. However, there sure as heck are allot less of concessions that need to be made when you use better technology, such as MODERN custom tuning, than approaching things the way we were forced to do 10-15 years ago.

I will also say that any sort of porting whether it be heads, TB, blower, or intake manifold needs to start by taking into account airflow AND airspeed in addition to flame front propagation (with cylinder heads). There are allot more physics involved than just "hog it out bigger" to make more power or torque. When making any major modifications to the airflow ability of an engine, or when changing a major item that affects air load calculations or fuel metering you will always want to datalog to ensure that everything is still within calibration. In most cases you will need to retune for the differences, in some cases you may not. Revisiting the "recalibrated aftermarket MAFS for a given size of injectors" discussion from the other thread. In THEORY, and theory only, if you take a vehicle that is already tuned correctly and install an aftermarket MAFS that is larger in diameter but outputs the EXACT same voltage vs airmass AT EVERY VOLTAGE RANGE that the stock MAFS did then you will not need to retune the vehicle ECM to account for the different MAFS because it is seeing the exact same signal at the exact same incoming airmass as when stock. Now this is all fine and dandy in theory but the MAFS flowbenching is simply not done nearly accurate enough in the real world to allow the MAFS to output the exact same voltage vs airmass as the stock meter did. Let alone that different vehicles have different MAFS calibrations than one another even while using the same size injectors which means it is hard to know where you are going to if you don't understand where you were coming from. Inconsistencies in the calibration here or there will throw your load, AFR, spark, auto trans shifting and etc off which is what necessitates datalogging and a retune to dial everything back into proper calibration again. I am all about not spending money that I don't have to but you bet your ass when I change something like a MAFS or fuel injectors I will be retuning my vehicle.

With as far as computer technology has come, in the regular world and the vehicle performance one, I do think that we aren't too far away from having vehicles with enough sensors and programmed intuition into the ECM's where they will essentially be able to tune themselves so-to-speak. You can already see a rudimentary version of this already on the market with some aftermarket ECM's and euro cars. What I am suggesting goes FAR beyond what adaptive learning does with current vehicles which is nowhere near as comprehensive or intuitive as most seem to have gotten the impression of.

My issue with you "ruffling feathers" isn't the questions you asked or even any statements you have made. It was the inflammatory manner and tone in which you chose to make them. When people start posting like that and generally conducting themselves like an a**hole then I don't want to take time out of my day to teach them why they are mistaken or what they could do to achieve more performance out of their vehicle. This is the reason why I opted to unsubscribe myself from the MAFS and TB thread because I didn't feel like dealing with yours and Eddies attitude problem. Even in this thread I can read between the lines and see your semi-cynical tone and know that you aren't simply "trying to learn" as you so benignly put it. Until you get past that I doubt you are going to learn much. Good luck with the performance education.

 

[jah81592]

Nick,

Years ago computer technology and head technology isn't where it was now. For example the thoughts of using a 75mm throttle body on a 2v 4.6L would have been unheard of now with proper tuning, variable cam timing and head technology the losses are minimal to a point. For example a 120mm throttle body and a boss intake on a 5.0L coyote will yield lower torque and power in the lower range but an upgrade to a 90mm throttle body and stock intake (which flows mountains) won't yield a loss in the lower rpm. Fortunately everything now is matched almost perfectly and we reap the benefits of this.

TiVCT is basically variable camshaft timing for each individual camshaft. Think of it as a mechanic always degreeing the cam timing to reflect the best possible torque and power delivery. Please remember when you adjust cam timing it changes total timing. Now with that being said, when you make big power we have no alternative but to lock them out. I have done this many times with GM cars/truck and Ford 3V vehicles. I expect this will have to happen on the latest coyote project in my shop right now. So far we have made 700 wheel and the vct is still active.

I do support the thought that the bigger throttle body does give minimal gains with a stock motor but it then becomes a necessary evil when the airflow is changed with aftermarket components. It is like a tune, the tune doesn't give you power it just brings everything together thus releasing the power potential of the combination. Power gains are the end result but it is not solely the tune it starts with the parts the vehicle owner has already provided.

In response to tuning there is so much to do, just in the drive by wire section there are hundreds of tables to make everything correct not to mention all the timing table now. Things have changed significantly since even 2010 processors. This new copperhead processor has changed everything for years to come.

 

[Jakee]

This may help your understanding...

http://www.musclemustangfastfords.com/tech/mmfp_1109_throttle_body_guide_air_apparent/index.html

 

[ssp.interceptor]

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[Jakee]

All I know is my explorer is faster than yours. LOL

But all kidding aside, with common sense, it all boils down to one thing...

$$$$$$$$$$$

And that's taking the BS out of it.

 

[ssp.interceptor]

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[ssp.interceptor]

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[ssp.interceptor]

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[Jakee]

You will not beat me in 2 weeks, so as a fellow explorer forum friend, I will not take your money or put you thru that. But if you would like to post a vid of you at the track running under a 13.1 then I may take your offer.

 

[CDW6212R]

Hello guys, I just ran across this thread.

I appreciate all of the time James and Rob put into this forum over many years, they are the best sources I know of here for performance and tuning advice. I agree with with they have said here, and Nick, I think you have pushed the attitude limits occasionally, but I have as well. As long as we take it slow and work through any disputes, I think we get along fine.

I've been the one who has said the most about high flow parts and retuning for them to regain power. I agree with Rob that this forum is mainly seen by stock to mild performance vehicles, so most of that subject is unnecessary here. I also think that money is wasted often by jumping to high end parts and not resulting in big gains.

My whole points were based on examples and experiences of others on the SBFtech.com forum. That forum has many dozens, maybe hundreds of Ford owners of high performance vehicles, which push the airflow limits and philosophy of typical applications. I'm not talking about the typical kind of plain/common Mustangs you see on the Corral, but engines with actual race level airflow parts on fully streetable EFI cars with sedate idle qualities and neck snapping acceleration. I have only mentioned examples from there such as a bone stock 302 engine car with name the high end heads, 90-105mm TB/MAF, Victor level(high rpm) intakes, 3-4" exhausts etc. You cannot slap those kinds of parts together with a stock EFI computer and stock tune. But they can be tuned and easily drivable, that was my only point.

From them I have learned that so many examples seen here and any typical car forum, speaking of power losses due to new parts(exhaust especially), they are full of myths and bad information. I have obviously conflicted with just about everyone in those threads about low end power losses, but my intentions have always been to help everyone.

As an example, it does not make sense to agree with people that exhaust modifications will result in low end power losses with no possibility to correct them. The same goes for restrictions, it's not true that any exhaust needs any restriction. But it's very hard to prove that to the millions of people who believe that, especially when they keep reading the same wrong information countless times.

It's easier to discuss non exhaust parts, upgrades or modifications. There is more logic that people can agree on about what parts are appropriate, best, or possible. The exhaust is just a hugely common subject because everyone alters their exhaust. It's hard to kill myths which have existed for decades.

I think the keys are that everyone needs to understand that altering the tuning of the factory computer is very necessary for anything but a trivial modification. I agree with James and Rob that the newer PCM's are much better able to handle modifications, and I do hope that at some point the new computers can handle the common upgrades that everyone typically does to their vehicles. We are not there yet, and unfortunately most people think that older PCM's can do all of that now.

The "adaptive learning" thing you hear about, that does not in any way mean that a 1990 computer or a 1998 computer can adjust for a high flowing exhaust, or intake manifold, or camshaft, heads etc. That subject does not really apply for anything older than the currently new models, and I don't know to what extent those handle modifications. The point is that most of the time we are discussing an older vehicle, an 86-95 Mustang, a 91-01 Explorer etc. Those vehicles do not have any learning capability in the computer which will significantly "handle" a high flow intake/head/camshaft upgrade. They do fine with very minor changes. But look at the number of threads which relate to exhaust system upgrades, and the loss of power in each one. Those are examples of the PCM not being able to sufficiently control the A/F ration to maintain the low rpm power. All of those are lean running engines, they all need more fuel, due to the higher airflow at those lower rpm's where they think they lost power.

But then how many people are willing to buy a flasher or tuning software, the wide band O2 etc, and retune their vehicle for the new exhaust. That's the point I think Rob eluded to about these forums being about stock to mild vehicles. We don't need to speak for hours about how to tune a stock vehicle that has a new much bigger exhaust. Just say that it could gain some power when/if the owner ever does reach a point of tuning the PCM.

 

[ssp.interceptor]

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[ssp.interceptor]

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[ssp.interceptor]

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[Jakee]

CDW never gives me any credit for knowing anything.(whining) But that's okay, I still love him.

But yes, it is possible to do that. And then you get to the track, all tired and wore out from the build, and have to learn how to drive it. Are you going to get lucky that first pass? It's a huge gamble and not worth all that. You don't have nothing to prove to me. I don't think my explorer is "the bomb". It has it's limits and the guys here know what it's capable of. Not many v8's that are faster (explorer)

You also have to be careful when you're comparing a result from a mustang. The weight of those cars put less strain on the motor making that power, compared to an explorer. The weight of your ride is going to put more stress and strain so you'll be looking at a disadvantage right off the bat.

PS - James and Rocket tout me A LOT. So yes, you should listen to them, especially with making an explorer go fast.

 

[ssp.interceptor]

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[rocket 5979]

Come on now Jakee, we're talking about a 12-13 second truck and not an 8 sec Outlaw car. Heat the slicks up, stomp the gas, push a button and enjoy the ride.

How many 1/4 mile passes have you made on slicks? It is not the same feeling and same way that you drive a radial tire at all. Steer a slick vehicle the way you drive a radial one and I bet you will put it into the wall about 1/2 to 3/4 down the track when you steer into the "ass wag". The initial combo shakedown runs are almost never remotely as good as ones you make once you are used to launching the combo at the track. This goes for 8 second through 14 second cars. It has nothing 100% directly to do with just power but rather a multitude of things. But if you think it is cheap and easy then you might as well go ahead and do it and race Jakee or someone else comparable in here. If it is such a sure thing then what do you have to lose?

 

[ssp.interceptor]

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[Jakee]

I'm was kidding and picking, yes. And in a way trying to "push" you into doing something other than theory talk. Sometimes we all need a push from an explorer friend; I've needed them before.

And I have this itch to always pick on the V8 explorer dudes, sorry. Some of them use to mess with me up until I posted vids and times. Now they just talk about how fast "they will be". But that's all I hear from the most of them. (no offence to anyone, my opinion only)

 

[CDW6212R]

I'm sorry Jake to seemingly have ignored you, my post was intended mainly to address the first topic and acknowledge as Nick did, James and Rob.

You, Jake do have a very fast truck, heavy SUV. I applaud you and the countless hours you've put into it to make it what you wanted.

I'd love to have a turbo V8 combination, but as lots of people have discovered, it isn't at all simple or straight forward. The V6 pre-2002 Explorers have an advantage in packaging, space, and headers. I'll stick with a V8, but I haven't decided whether I can find space for a turbo or supercharger, intercooler, and air cleaner under the hood.

I doubt many people can slap together a fast Explorer in a short time, most of this is all custom stuff and takes time to do it reliably.