Topic: was: Re: 62mm Performance Throttle Body

[stan98tj]

anyone have results they'd like to post with the 62 throttle body. im real interested in this mod.  hp?mpgs?response?  this would be goin on my 2.5 which has a cold air intake and TBspacer-hope this TB wont be too much for the 4banger???

[FourbangerYJ]

anyone have results they'd like to post with the 62 throttle body. im real interested in this mod.  hp?mpgs?response?  this would be goin on my 2.5 which has a cold air intake and TBspacer-hope this TB wont be too much for the 4banger???

I just ordered one. It'll be a few weeks until I get it on. I'm curious myself. Mine is pretty much stock just a air intake tube.

I think you will need to replace your TB spacer with a 62mm one. Your stock one will act as a restrictor.

[tallrugbyguy]

works well on mine except for some small starting issues, i think thats just a tinkering issue

you will notice a way quicker throttle responce. and att he higher rmp there is some more give for sure. also a bit of a gas saver.

[FourbangerYJ]

works well on mine except for some small starting issues, i think thats just a tinkering issue

you will notice a way quicker throttle responce. and att he higher rmp there is some more give for sure. also a bit of a gas saver.

What kind of starting issues?
 How long have you been running it mileage wise?

I thought that the mileage would go down. More air in, computer adjust the fuel mixture for more fuel= less mileage.

[Jeffy]

I thought that the mileage would go down. More air in, computer adjust the fuel mixture for more fuel= less mileage.

Not necessarily.  More torque/HP will allow you to let off the throttle a bit which means you'll won't have to rev as high to maintain speed.

[FourbangerYJ]

Not necessarily.  More torque/HP will allow you to let off the throttle a bit which means you'll won't have to rev as high to maintain speed.

Gotcha, in theory that makes sence.

Is there a point where you get to much air for the size motor? Maybe causing issues with running properly at lower RPM's or idelling? (sp)

The computer should adjust for proper fuel ratio so you shouldn't be to rich or to lean. Right?

[Jeffy]

Gotcha, in theory that makes sence.

Is there a point where you get to much air for the size motor? Maybe causing issues with running properly at lower RPM's or idelling? (sp)

The computer should adjust for proper fuel ratio so you shouldn't be to rich or to lean. Right?

14.7:1 air/fuel is the optimal ratio, I believe.  Your CC would put a limit on that.  I think timing would also limit it since you can't let it burn indefinitely either.  You want a complete burn but you also want it to be done before the next stroke starts.

I think I'm going to separate this stuff from the sale.

[FourbangerYJ]

14.7:1 air/fuel is the optimal ratio, I believe.  Your CC would put a limit on that.  I think timing would also limit it since you can't let it burn indefinitely either.  You want a complete burn but you also want it to be done before the next stroke starts.

I think I'm going to separate this stuff from the sale.

I didn't want to mess up the For Sale thread, but this is good info for people who are thinking about buying or have the same questions.

[Bounty Hunter]

Thanks Jeffy, good idea on splitting threads.

It's been my experience that mileage and power gradually improve over the matter of a few weeks as the computer learns to adjust for the increase in airflow.  You will notice it right away, but you will see benefits improve over time.

I've never had a problem with all the 62mm TB's I've personally installed.  The only problems I've seen have been few and far in between and usually related to improper installation or a bad sensor.

[stan98tj]

soon as i determine if i cant keep my AEM with the 62mm and if that wont be too much air for it handle ill let ya know and more than likely ill get one. its the end of a very long and hard semester here at the academy and the jeep bug just came back to visit me. 

[TahoeYJ]

Although I don't have the 62MM TB (Plan on getting one at some point) I have installed a stock 4.0 TB and noticed a difference right away. I have no problem towing at 65-70 if I want (on flat highway anyway :) ) and definitely saw a HUGE jump in mileage and power. I can run 80 down the highway all day if I want, and if I keep my speed below 70 I can get 20 MPG out of my rig, if not then damn near that anyway. Numerous people at my buddy's shop give me crap about having a 4 banger and how slow it is, I just tell them they haven't driven it or even rode in it so they have no room to talk 

It did take my rig a week or two for it to fully learn the new TB, mileage was way up within 2 weeks and power was noticeable right away. I plan on adding a spacer sometime in the near future as well as a couple other small mods to compensate for the extra air. The best thing you can do for an engine is let it breath!

[Bounty Hunter]

I don't buy into the idea of 'too much' air, unless it is forced induction and the fuel system/computer can't keep up with it.  With normal aspiration the engine is only going to breath in the amount of air it can use.

I run a 62mm TB and matching spacer, with a TJ 4.0 airtube and conical K&N on the end.  It doesn't flow much more unless you remove the tube and filter completely.  No problems here.

[jwalls4x4]

As Jeffy said, 14.7:1 is the ideal stoichiometric air:fuel ratio for gasoline (100% burn).  However, talking to my ricer friends at work, they say this would be too lean and the ideal ratio for a car is 12:1.  The unburnt fuel helps keeps cylinder temps down to a safe level.  As one says,"Remember, it's always fastest right before it blows!"  They run wide band O2 sensors and carefully guard against lean conditions, but they all run big turbos.  I'm sure our NA engines are a slightly different story.  How far can we go with intakes, TBs, TBSs, ignition, and exhaust before fuel delivery lags and becomes unsafe?

[tallrugbyguy]

im with bounty hunter. because this is not forced induction the jeep will take in the same amount of air no?
thus larger tb and intake are just allowing for easier breathing. spacers may have a different inpacke since they allow the air to travel faster. (some stupied physics there but the same concept as headers, the longer the faster the air moves in at high rpm)

but i could be totally wrong. since its 3 am after working/ drinking at the bar.

[Jeffy]

im with bounty hunter. because this is not forced induction the jeep will take in the same amount of air no?
thus larger tb and intake are just allowing for easier breathing. spacers may have a different inpacke since they allow the air to travel faster. (some stupied physics there but the same concept as headers, the longer the faster the air moves in at high rpm)

but i could be totally wrong. since its 3 am after working/ drinking at the bar.

No.  Restrictions... well, they restrict.  So, you'd get a stronger vacuum but less CFM.  If the engine took in the same amount of air no matter what, then there would ne no need for any intake modifications.

Then you get into still like pulse waves and other tricks that can give you a bit more or less air.

Also, colder is is more dense then warmer air.  Problem with this is that many so called cold air intakes, do the direct opposite because of their poor design.

The only real way to make sure you're getting the most from your engine is to run a wide-band O2 sensor or run a diagnostic computer connected to the PCM.  Otherwise, you're just sort of hoping the PCM will adjust correctly.  Small changes like what we're doing shouldn't cause issues though.

The problem with forced induction is building up too much pressure to where the engine can't handle it.  With forced induction, you're basically increasing the compression ratio by stuffing more air into the cylinders then what the engine normally can handle.  Then you're relying on things like the connection rods, cylinder walls and heads staying intact.

If you've ever watched NHRA top Fuel or Funny cars, you'll occasionally see an engine blow up.  Usually there building so much pressure the supercharger gets blown off the engine, which is why they strap them down.  Before, they would go flying into the air though.