Engine B303 And E303...do They Need A Tune?

Discussion in 'Fox 5.0 Mustang Tech' started by 87MustangGT, Aug 1, 2013.


  1. 87MustangGT

    87MustangGT Founding Member

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    My car (mods in sig) is currently at a local shop getting some light restomod work done. The shop owner has been a Mustang guy pretty much for life, but while discussing possibly throwing in a cam while my motor is out, he mentioned that both a B303 and E303 cam would require tuning and chipping the computer...which is contrary to what I remember (granted, from when I was really into our cars about 10 years ago). Do both cams require tuning, if I've already converted the car to MAF? Do any cams not require tuning? Just trying to avoid turning a $300 upgrade into a $1000 upgrade.
  2. mikestang63

    mikestang63 Mustang Master

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    Now this is just me, but if a "Mustang shop" told me to put an alphabet cam in my car, I'd be finding another shop. What is your goal on the setup? You already have 1.7 RR which is about the same lift as a B cam.

    IMO there are many better choices in cams. Call Ed Curtis at TFI and do it right the first time.
  3. f8tlfiveo

    f8tlfiveo My wife likes my spool and blow-off valve.

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    No tune required if you have maf
  4. TOOLOW91

    TOOLOW91 Mustang Master

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    Ok there is no tune required to drive the car with either cam... Now thats not to say that a tune wouldn't make more power and clean up drivability
  5. WLDHRSE

    WLDHRSE Founding Member

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    I agree completely. If somebody recommended one of those cams, even free of charge, you should slap them in the teeth and get your stuff out of there.
  6. 87MustangGT

    87MustangGT Founding Member

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    Fair - but I suggested the B/E, not the shop...just based on what I thought I remembered. What is a good entry level can that doesn't require a tune? I've converted to MAF and have an Edelbrock Performer intake, gt-40P heads, 1.7 RRs, full exhaust...
  7. elarm1

    elarm1 Active Member

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    Track day much? If so where at? There are better off shelf cams than these. Why not go custom grind?
  8. 2000xp8

    2000xp8 Mustang Master

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    If you put a car together correctly there is no "driveability issues".
    As for power it's debatable, but the most powerful stock shortblock 302's i know, make more power without a tune than any i've ever seen here, tuned or untuned.

    The dumbest thing i see people do is buy cheap parts, then spend another $750 tuning it.
    That $750 can be worth 50rwhp with a better set of heads. So you can have 275rwhp with a tune or 325rwhp without one.
    I take no issue with people's budget itself, but always put the money where it counts most, the heads.

    I've seen the stock computer run 650rwhp, i've even seen it run the engine out of a terminator with a distributer mounted in the valve cover without a tune.
    The A9L is probably the last (and best) adaptable system ever made for a muscle car.
    Give it the right meter and injectors and it will pretty much run anything.
    Last edited: Aug 2, 2013
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  9. 7991LXnSHO

    7991LXnSHO Active Member

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    !
    That is more harsh than needed. I like my e cam with the mods, it just needed careful setting and making sure other parts were ok to run its best down low. So it did get a tune I suppose, but it DID NOT need a computer tune.
  10. 2000xp8

    2000xp8 Mustang Master

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    The E cam really isn't bad.
    It's plenty good for a gt40p combo.
  11. TOOLOW91

    TOOLOW91 Mustang Master

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    Look , I don't no what the rest of his setup was or who's putting it together no cam will drive like stock ever and I stated that it didn't need a tune but could benefit if he did it isn't gonna hurt him


    Sent from my iPhone using my fingers
  12. Noobz347

    Noobz347 Stangnet Facilities Maint Tech... Er... Janitor Admin Dude

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    Don't worry about it. 2000xp believes that digital tuning was summoned from the depths of hell or something. :shrug:

    I on the other hand, have seen some budget builds pick up as much as 80 HP with a good dyno tune. My setup picked up a bit more than that.

    Here's the thing that's contrary to the "no tune needed" mantra. There's no A9L on the planet that is going to know what to do with injector pulse width, injector minimums, injector slope, or the duty cycle of ANY INJECTOR CAPABLE OF SUPPORTING 650 RWHP!!!!!

    Now... having said that, there are some speed density setups out there that do very well with large injectors and some tweaking of manifold vacuum through and adjustable valve. I've seen that done as well.

    You take 60 lb injector or even a 42lb injector and slap it onto an mass air computer and you'll be LUCKY if the damned thing even starts. A mass air meter calibrated for an A9L to function with 42+ injectors will still not be able to trim those injectors correctly for idle, part power, and WOT. I don't care how good the meter is.

    The A9L was programmed specifically, to run 19 lb injectors and had the data necessary to properly trim (again) injector pulse width, injector minimums, injector slope, and duty cycle. All of those variables change when injector size is changed. The larger the injector, the larger the variation.

    A mass air car making 650 RWHP on an A9L without a tune? I call BS unless it's a WOT only car. Any other power setting and that same car will be pig rich and run like crap. Untuned, that car will ALWAYS get waaaaaaaaaaaay too much fuel at any setting other than WOT. Finally, that mass air sensor would have to have been picked PERFECTLY for that car to even make a WOT throttle run with those injectors.
    Last edited: Aug 3, 2013
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  13. f8tlfiveo

    f8tlfiveo My wife likes my spool and blow-off valve.

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    Thank you..this is the Real truth.i agree
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  14. TOOLOW91

    TOOLOW91 Mustang Master

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    Thank you , you said my exact thoughts I just didn't have the patience to do type it all


    Sent from my iPhone using my fingers
  15. 2000xp8

    2000xp8 Mustang Master

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    http://www.bigdaddyperformance.com/...ustomers&srctype=detail&back=projects&refno=7

    This car was built before he even bought the dyno or moved to the new shop.
    Not the only one like it, others with a T rim out there in the 600rwhp range.

    You know there were fast cars out there before sct or dyno's were big, right?

    80hp, lol.

    I think calling what i say BS is a bit much, out of curiosity, why would i just make it up?
    The access i have to see and be around pretty much every type of foxbody setup is far beyond most here.
    Am i a race car mechanic? No, but one of my good friends of now close to 20 years (he was doing it before me too) built his entire life and career out of modifying foxes.

    I don't just regurgitate a bunch of crap i read on the internet like some here. If i didn't get to see it in person, i normally just keep it to myself.
    Last edited: Aug 3, 2013
  16. Noobz347

    Noobz347 Stangnet Facilities Maint Tech... Er... Janitor Admin Dude

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    I've seen you post that link before and that's got NOTHING to do with whether or not that combo was tuned or what was used to tune it. I guarantee that more than just a mass air meter was installed.

    Yes... 80HP between runs with digital tuning the only change. If you have issue with that, you need to seriously consider un-assing your couch, turn the speed channel off, and go down and watch the differences before and after dyno.

    Dyno's have been around since before you were born. The first commercially available that I'm aware of was in the 1920's.


    Air/Fuel ratios don't just magically fall into the sweet spot. A9L computers don't magically adapt to oversize injectors. Injector slopes between 19's and 42+ lb injectors are OUTSIDE of the EEC IVs ability to adapt. Someone with very SPECIFIC set of fuel based values, and flow-bench "might" be able create a meter that fluctuates enough to 'fool' the computer into thinking they're 19 lb injectors but that is most certainly the LONG and EXPENSIVE way around the issue. Particularly when there are SO MANY great mass air meters (some of them OEM) that have a standardized transfer function. Even then and "IF" that magic meter could be obtained, how many trips back and forth to the facility with the flow-bench for tweaking are the fuel tables are brought into tune???

    Either way, that is still digital tuning. It doesn't matter which way you look at it. You either modify the transfer curve of the meter to make up for an unmodified EEC and injectors --or-- you modify the transfer function of the EEC to make up for an unmodified set of injectors and mass air meter. Most do both... A larger meter is run with a set transfer curve, larger injectors are installed, and a transfer function is inserted into the EEC so that AFR is correct at all power levels.

    Short notes: Stop preaching about things that you don't understand. When you've digitally tuned a car (correctly, I might add) then you can come in and tell everyone how useless it is.

    And just for the sake of argument... I've tuned with and without a dyno. I've tuned right on the street with a wideband AFR meter, a laptop, and/or an Anderson PMS. So the dyno statement that you made hasn't anything to do with anything.

    Turn your own wrenches sometime instead of regurgitating garbage that you half-heard and thought made sense.
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  17. 2000xp8

    2000xp8 Mustang Master

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    Got it, your an expert tuner, you know so much better than people with 1000 times the experience.
    80hp, lol.

    Good luck, i'll leave you to your arrogance and unsubscribe.
  18. Noobz347

    Noobz347 Stangnet Facilities Maint Tech... Er... Janitor Admin Dude

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    Good plan. :nice:
  19. f8tlfiveo

    f8tlfiveo My wife likes my spool and blow-off valve.

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    I love this.. Keep typing so I don't have to. My car was street tuned with a wideband and data logs with 42lb injectors and it ran great, prob as close to stock as you can get. Peak hp doesn't mean anything to me. I wanna enjoy part throttle drive ability also. Wasn't gonna happen without a tune either.
  20. Noobz347

    Noobz347 Stangnet Facilities Maint Tech... Er... Janitor Admin Dude

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    Thing is... At one time, I was also in the camp that believed that some store bought mass air meter was the ticket to supporting injectors large enough to power my new engine combo. Sure... I'd seen references to tuning and that sort of thing but a meter calibrated to run 42#. SWEET!

    ...and then I tried running it. LOL

    So here I am... Brand new engine, Super charger sitting on top, 8 Green top injectors and SHINEY new mass air meter straight from PMAS that was SPECIFICALLY calibrated for 42# injectors and an A9L.

    What could possibly go wrong???? :shrug:

    Putting it into practice, that's what. :bang:

    It wasn't until then that I began looking into and realizing just how much a difference there was between fuel injectors. I'd not idea that the EEC was responsible for the minimum injector pulse width and the minimum on a larger injector shot out a LOT more fuel than a 19 lb injector until it's been taught how low a slow a larger injector has to pulse in order to provide the same gas.

    Those injectors just BELCHED fuel into the combustion chambers while being operated by by and EEC that thought it was half it's size.

    THEN came injector slopes. WTF is this?!?! Why can't it just follow the same slope? Ohhhhhh.... because a 2% tweak on a 19 lb injectors is like a 20% tweak in pulse width on a 42??? :sigh:

    But the list goes on... So I cart the thing down to dyno tuner that's several hours away and low and behold... SUCCESS! It was about a year later that I started looking to why things are the way that they are. I bought a wideband, started with an Anderson (reported to be the most user friendly) then looked into first duplicating the data on the custom chip I had burned then duplicating data coming from the PMS.

    To those that can make a TwEECer do what it's supposed to do? My hats off to ya. I still can't make heads or tails out of the way that data is arranged in their software.

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