Topic: 62 MM throttle body

[grumpygy]

Just installed mine.  It got rid of the Whistle I had from my Cold Air Intake(ok Hot air ).  Revs Quicker.  Only change I did not like was in 5th I lose power quicker now and have to down shift.


  But I can now pass easier by just dropping it down to 4th and off she goes.   Also going up thru the gears it really does rev quick.

[quicksand]

I know this is a older post, but I have a question when you bump up to a bigger throttle body did your MPG decrese. Mine has and my thought is maybe I need to go with a bigger gap on my plugs. Currently running accel 42,000 volt coil, accel wires, and NGK plugs gapped at .042. Do you think a bigger gap will help in MPG, since I got a bigger throttle body then before.

[quicksand]

This question is for Mr bounty hunter, I have bump up from a stock 4.0L TB to a bigger bore and I love the response and HP gain. The only thing I noticed is I am getting less MPG. I did not purchase it from you. I do have cold air intake, TBS, accel coil 42,000 volt, accel wires and NGKs gapped at .042. I need your expert opinion, since I went with a bigger bore do you think I need to increase my plug gap to compensate for the increased air intake?  Thanks

[quicksand]

You know maybe I am just on the pedal harder because I like the way it feels, just thought about it I have been reving it up pretty high on take off. Maybe I need to change my driving habits. But the question remains should I open my plug gaps wider?

[Bounty Hunter]

You'll just have to experiment with plug gap and see what your gains are.  You can safely open the gap up if you have a hotter coil.

A larger throttle body will generally improve your MPG if you can keep your foot out of it.  Your results are typical as it's tough to drive conservatively with the large increase in power and throttle response.

Did you jump up to a 62mm TB?

[grumpygy]

I'm Running the  Screaming demon coil so have been running a .060.  But do not have enough mile on the throttle body to determine if my milage went down.

  But would say I think it may have but that may be my driving style doing it.

[quicksand]

Wow .060. Well maybe I will try to go with a bigger gap. My coil puts out 42,000 volts and I believe screaming demon puts out 45,000 volts. I like my power increase so much that I am willing to take the lost MPG, but only if I have to. But I have noticed I have been reving it up pretty high on take off and just driving faster wherever I go. It feels so good. Maybe its driving habits. I will try regapping with my accel coil and wires and see if it makes any changes. Hope she supports it if not maybe I will get the scremin demon setup. Thanks.

[quicksand]

Yes and no. Its 62mm on top side and tapers down to 60mm just above the throttle plate and on the bottom it measures exactly 57mm. She feels real good on take off and on through high end. I admit I have been driving it real hard, I speed every where I go. My driving habits are the same as with the regular 4.0L TB. Just sucking up more gas because I am going faster. Do I need to drive like la de da da or maybe if I gap bigger I can keep my driving habits, and continue to drive fast and keep my old MPG that would be nice. Well we will see what happens after testing different gaps. Thanks a bunch and we will try to keep you posted. Happy Wheeling.

[grumpygy]

Just have to ask what is your MPG.

[quicksand]

Well before with the regular 4.0L TB it was 12 to 13 MPG, which then I could get about 50 miles to 1/4 tank, and now with the bigger TB bored 62 over 57mm I am barely getting 40 miles to 1/4 tank. I know thats not the way to calculate MPG but it is less than before. But like I said before I am driving like a bat out of H---. I am a daily driver and right now I think I am on the auto bahn. WOOOOOOO ! I do have a stock 4.0L TB back on the self so worst case I have the option of going back to the previous setup. But darn she feels so quick right now. Power to spare. Makes we want to get a giant sticker that say 2.5L FAST

[chardrc]

Doesn't the stock 4.0l tb taper down to 57mm?

[quicksand]

No, it tapers down to 55mm. But I tell you what every bit makes a difference. In my case it was hard to believe what I felt with only 2mm bigger on bottom side. Remember you should bore intake manifold to macth.

[quicksand]

Well just regapped my NGKs from .042 to .045. First impression crawling real smooth also right now that little bucking I had is gone. When I slightly step on the pedal it dosnt jerk, its real smooth and more controled. At first it seams like I lost torque, but when I step further on pedal its still there just smoother. Instant take off still good and responsive, seems to shift easier to. While intering freeway no problem hits 70MPH easy. I did notice I lost just a little punch when cruising at 60 trying to get back up to 70 mph. Still climbs to 70 but its more of a gradual pickup, steady and smooth. You just dont feel the punch. But it holds on headwind going uphill maybe reduced to 65mph then up again. As far as mileage to early to tell. But like I said the most noticible was no bucking while crawling and super smooth and responsive. We will see what happens with the MPG. I depends, just might have to drop the gap down to .044. Time will tell. All mods must run in sync to the perfect macth. Will keep you posted.

[sharpxmen]

try 0.0435 and see if it's better (1/2 way between the 2)

[quicksand]

Yep your probably right, I am gonna take it for a few more runs see how she does and how I feel about it. right now I kinda miss that punch/torque. But I agree and predict I will end up with something in the middle as far as the plug gaps go. Its amazing how just a hair adjustment on gapping plugs makes a difference you can feel. Then again with my 4 banger its always been so sensitive to small changes. Yep the quest for more power and decent MPG. I guess thats a hard balance to find. Thats like for example my cold air intake. Its homebrewed box with k&N yet it yeilds better results compared to a AEM setup. I make one adjustment on that and it changes charateristics. My air intake box has a adjustable slide to fine tune its cold air intake coming in from the removed headlight bezels. Its air is ramed in there of course depending how fast I am going. Yes I now only a certain amount of air can go past the filter but its readitly available, and under presure ready to be used as its crammed in there. Maybe It dont make any sense, but it works great. Well dont mean to get off subject I talking to much. Will let you know what happens with my plug/ gapping/MPG.