62mm throttlebody idle problems

Discussion in 'Mustang Chit Chat' started by theRedStorm, Jun 22, 2019.

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  1. theRedStorm

    theRedStorm forum member

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    So I actually bought this throttlebody for really really cheap. I didn't know what brand it was. I'm thinking it's for a gt500 but not 100% sure. What adapter plate do I need? Would this be a direct bolt on with the adapter plate? I got it for really Cheap so if it doesn't workout, I'm not too upset. I'll probably end up selling it
     
  2. theRedStorm

    theRedStorm forum member

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    If anyone wants it, 100 bucks and it's yours. Just throwing that out there lol
     
    Last edited: Jun 24, 2019
  3. theRedStorm

    theRedStorm forum member

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  4. GlassTop09

    GlassTop09 Junior Member

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    The whole idea of a larger TB is to increase air volume delivery to cylinders by decreasing the deltaP (pressure drop) from filter to cylinder at full open vs the stock TB. When a larger TB is calibrated to same TPS voltage as stock, the larger TB will increase throttle response due having a larger flowing surface area available per angle of butterfly open vs stock. The trick is to tune fuel mapping to take advantage of the extra air volume per blade angle swing so the ECU doesn’t pull spark timing due to momentarily leaning out so the torque shows up. Now you can readjust a stock TB pedal swing rate to open faster to compensate but you can’t make up for the area of the larger TB at WOT to flow more air volume due to lower deltaP, especially when in NA or using a TVS SC as air is being drawn thru as already mentioned. You do this by increasing flow area thru the TB...the same as you do by increasing flow area of the air filter & increasing flow area of MAF housing/air tube....what matters to an engine is how much air volume (thus mass thus weight) per sec is flowing to properly meter fuel, not how fast (velocity) the air is moving (which is created by a reduction in area...a restriction). The only thing that a smaller TB does better than a larger TB is air flow control due to the smaller butterfly/bore radius vs a larger TB but this comes w/ a cost at the upper end.
     
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  5. RocketcarX

    RocketcarX 95% of my weight is fuel

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    All them words and you didn't say a thing relevant
     
  6. Pentalab

    Pentalab forum member

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    Actually, he just nailed it. Superb explanation.
     
  7. Dino Dino Bambino

    Dino Dino Bambino I have a red car

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    Such a lovely way with words! ;)

    What he said was essentially that there are benefits to a larger TB in most situations as long as the air-fuel mapping is correct.
    On a N/A 4.6, there's little to gain unless the engine's ability to draw more air at higher rpm is increased by adding higher flowing heads, performance cams, a higher flowing intake manifold, and headers.
     
    Last edited: Jun 25, 2019
  8. eighty6gt

    eighty6gt forum member

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    throttle bodies are great for making aftermarket manufacturers tons and tons of money while adding max 15 hp on a blown application

    I have a VMP twin 67!
     
  9. Dino Dino Bambino

    Dino Dino Bambino I have a red car

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    Larger throttle bodies did add significant HP gains back in the days when the stock TB's were inadequately sized e.g. single 60mm TB on '87-'95 pushrod 5.0.
    Our 4.6 3Vs came with dual 55mm TBs (equivalent to single 78mm) which are already generously sized. Even a stock '11-'17 Coyote 5.0 "only" comes with a single 80mm TB, and that engine has 7.5% more displacement and a 7000rpm capability.
     
  10. Pentalab

    Pentalab forum member

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    I swapped from oem twin 55mm to FRPP twin 62mm.... on my 2010 auto with M90 ( 5.8 psi boost). I couldn't tell any difference on the butt dyno.....and ditto after VMP re-tuned the entire setup. Boost didn't change either.

    What did make a huge difference was the ceramic LT's and hi-flow catted H. Then it all came together. Remove all the restrictions on both intake...and exhaust.... then it all plays nicely. Again, Boost remained [email protected] 5.8 psi.
     
    Last edited: Jun 25, 2019
  11. RocketcarX

    RocketcarX 95% of my weight is fuel

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    I expect you to agree, none the less the actual question here is how to make the TB work...which was answered simply already.
    Get a tune revision for the specific throttle body
     
  12. Dino Dino Bambino

    Dino Dino Bambino I have a red car

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    This is one mod that I'll give a miss. It just isn't worth spending $300+ (Ford Performance version $600+) for a 2-3hp gain.
     
  13. Pentalab

    Pentalab forum member

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    Agreed....and maybe 5-7 hp gain if a blower is used. The 5-7 hp gain came from JDM engineering... where I bought the FRPP twin 62mm on sale years ago. Most tuners will tell you that a twin 62mm on a NA car will show no improvement on a dyno...or within dyno testing tolerances.
     
  14. eighty6gt

    eighty6gt forum member

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    hold on you guys I thought granatelli just said it was good
     
  15. Dino Dino Bambino

    Dino Dino Bambino I have a red car

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    Granatelli has to sell throttle bodies so of course they'll say they're good.
    On an HCI NA 4.6 there's almost no HP gain from a dual 62mm TB until you hit 5000rpm, and the difference only becomes significant from 6500rpm upwards. Unless the engine has a 7000+rpm capability, or you've built a 323ci stroker (15% more displacement), a larger TB is rather pointless.
     
    Last edited: Jun 27, 2019
  16. Pentalab

    Pentalab forum member

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    The FRPP twin 62mm is the real deal. Acufab makes both the oem twin 55mm..and also the FRPP twin 62mm.

    All the other twin 62mm TB's re-use the guts from the oem twin 55mm tb... like gears / motor/ spring etc.... which is why they cost less. You re-use parts from your oem twin 55m.... rendering the 55mm tb useless. Then they have you tweak the TPS to read the same as oem.
     
  17. Badd GT

    Badd GT forum member

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    Your factory throttle body is all you need NA. I had a 385 rwhp NA motor and it made absolutely NO difference putting a 62 mm throttlebody on it. And by the way the ford racing intake lost horsepower and torque thruout the curve until 6700 rpm where it matched the factory setup with delete plates. All that Throttlebody and Ford racing intake is only beneficial if you have forced induction
     
  18. Dino Dino Bambino

    Dino Dino Bambino I have a red car

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    Even then, that only applies to a turbo or centrifugal supercharger set up.
     
  19. Granatelli

    Granatelli forum member

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    Several companies can sell you the adapter plate – have you tried American Muscle. You will need that part to make the GT500 fit – but it’s easy



    Actually you are incorrect. You are on the right track but still not correct when you continue to say only forced induction will benefit. While you hedge by saying the N/A motor has little to gain (acknowledging there is a gain to be had) factually the gain is everywhere but more so at the top end when the engine really needs to increase air flow. Clearly the stock throttle body or even something a bit smaller and anything larger than stock would move (flow) enough air at say 3500 rpm (so half the RPM peak) It’s at the higher RPMs where the engine needs the most air because “RPMs are horsepower and horsepower need air to make it” at 300hp the 4.6 is producing 1.06hp per cubic in. It was not long ago that was considered GREAT. Example a 5.0 Mustang from 88-93 only made .75 hp per c.i.. Then 94-95 it went down to .67hp per c.i. then 96-98 it made .86 and then 99-2004 it made .99. When the first 305 hp Cobras came out everyone freaked out because Ford made 1.08hp per cubic inch with 32 valves. I agree adding higher flowing heads, performance cams, a higher flowing intake manifold, and headers all result in a power increase as well. Side Question – Why would you want any of those things if you still run a stock TB which can barely support the stock HP numbers.



    Define tons of money. Speed and HP are never free. Speed can come from dropping weight and that could be free but HP costs money.



    Now you are proving the point. A 88-93 Mustang only made 225 hp. naturally it did not need a bigger TB. AND DON’T FORGET 225 was a wishful HP number. That was SAE with no cats and no accessories drag it down. I owned Paxton back then and we flowed every TB on the market stock good for 400cfm at 15” H20. That sucks. Going to a 65mm TB increased air flow to 435cfm at the same 15” H20. But the trick was the motor only needed 360cfm. And at 360cfm (from the 65mm) the flow restriction dropped to 360cfm at 7” H20. That is where the power came from. The motor did not have to work so hard to suck the air through.



    Or in other words – You are only going to make as much power as the most restrictive part in the flow chain



    You just described a 5 cfm increase. What a person does by going to a larger TB is eliminate that part of the restriction. It’s a great add on TO THE REST OF THE STUFF YOU ARE DOING – I don’t think anyone is saying it should be the only thing you do.


    Plain and simple FACT. N/A motors and motors that run superchargers that bolt to the center on the engine valley NEED THE LARGEST TB you can run to make the most power possible. PAXTON, Vortech, Procharger and any Turbo don’t rely on the larger TB because they can force it through. For all the guys here that want to do a simple test to prove my point…grab a straw from the drawer or McDonalds, now suck through it as hard as you can. NOW blow through it as hard as you can. You will all see that you can push way more air then you can suck. It’s just that simple.



    Those guys must all be using dynojets J



    Granatelli is here giving free advice. Granatelli looks at it from an engineering standpoint FLOW IS GOOD. And again if anyone here is looking for a power gain below 5000 rpm then Mr. Bambino is correct.




    Not true. Accufab never made the stock cast TB for Ford. Also Granatelli does not make you move any guts from stock to modified – it comes complete.



    What other mods – like exhaust, no cats, etc?



    You have that dead backwards.


    I could tell you that we build 500hp N/A Coyotes all the time. We have made as much as 550. Today 700hp Coyotes are the norm at 9psi - change the TB and its 735 – RIGHT NOW.


    Let’s talk Chevy just for a moment a 427c.i. motor with a 12psi whipple makes 900 with the stock TB. Now just go to a 102mm and they gain darn near 80hp. So that proves my point and Dino’s point. HP is airflow dependent.


    To answer the 1st question again – check for vac leaks, check TPS angle and get a tune…after you purchase the adapter plate J
     
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  20. Dino Dino Bambino

    Dino Dino Bambino I have a red car

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    Thanks for educating us on a few points. :)
    According to my calculations, a 281ci engine requires 528cfm of airflow at 6500rpm and 100% VE. The stock dual 55mm TB flows 953cfm @ 28inH2O pressure drop, while the FRPP dual 62mm unit flows 1306cfm. Both seemingly flow much more air than the engine needs at 6500rpm. The difference is that the 62mm unit can flow the required 528cfm at a lower pressure drop:

    55mm TB: 528cfm @ 8.6inH2O
    62mm TB: 528cfm @ 4.6inH2O

    Basically you don't need to suck as hard through a bigger straw to draw air at the same rate. However in most circumstances, the stock TB is already a big enough straw to begin with.
     
  21. Pentalab

    Pentalab forum member

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    KB sez it's typ 1.5 cfm per crank hp. 528/1.5= 352 crank hp.

    Toss a PD blower into the mix, say 500 crank hp....X 1.5 = 750 cfm.

    Looking at VMP's old notes, he managed to get 650 rwhp from his GT-500... with just the oem twin 60mm TB. Bigger TB's only made marginal improvements. The restriction lay elsewhere. Turns out the restriction was the blower elbow. So in went the VMP designed new style blower elbow, which is oval shaped at TB end.... and D shaped at blower / elbow interface. Oval on blower input was modified to a mating D shape. Ok, then the flow rate increased a bunch. IAT's coming out of the bower (pre-ic) dropped a bunch. Now the bigger TB's do something.

    His new TVS-2650 and TVS-2650R took it to a new level.... the blower casing and elbow are now all one piece. The 2650 alone is 15.2% bigger displacement than a TVS-2300..yet flows 25% more air... due to the 170 deg twist.. vs 160 deg twist ( 2300). Add in the new combo blower / elbow integrated casing
    and then it really flows. So out came even bigger TB's...+ new design intake manifold. The rest is history.