4bangerjp.com
General Forums => The Mess Hall => Topic started by: kenandtj on June 21, 2007, 09:10:22 PM
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i went to a local salvage yard yesterday and i found a tb for sale they wanted 75.00 for it.i know i can find them cheaper but my real question is do they really make a difference? i have read a lot of things saying they dont really do anything.....but then i find some that say do it it's worth it.. whats the opinion round here? thanks
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I use a 62mm TB which is slightly larger than the 4.0 version. I don't think the 62mm or 4.0TB hurt performance on a 2.5 and they probably help slightly at mid-rpms and WOT. I don't have any real, immediate reference though since I made the change a while back.
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They are worth it, but you want to ensure your intake manifold opening is as large as the TB, and throw on an airtube and conical K&M filter to get the most benefit from the larger TB.
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i do have the intake and that it self was a huge improvement....makes alot more noise, but still more performance. so worth it....any one else? i sold my brush guard so i am thinking of doing this or shocks next, so any help would be great...my next investment is going to be the jet chip----hopfully!
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I have the 4.0 tb with tbs and noticed a decent increase in both take off speed & highway top end. Shop around on ebay you usually can pick them up for $40-50 on a good day.
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I thought it was a noticable difference, but $75 is too much.
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I got my TB from a salvage yard in town for $25-30 dollars. Coupled with the TB spacer from eBay ($10-20?) it was well worth the money.
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I got my TB from a salvage yard in town for $25-30 dollars. Coupled with the TB spacer from eBay ($10-20?) it was well worth the money.
x2
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I didn't notice much of a gain with my TB/Spacer/ported intake plenum with a AEM conical filter/aluminum tube. Then again i barely ever REV the motor up high, so maybe thats why i didn't notice much of a difference. But once i put a header/2.5" exhaust on it definately made a difference. I wouldn't spend $75 on it thats for sure.
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Unless your air tube setup is long and routed to an actual cold air source, all you're doing is sucking in warm engine heat which will drop power. So choose your CIA's carefully. 1+1=-2 in this case.
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There is basically no difference in inlets temps between a "ram style" intake and the stock set-up (i didn't notice temp changes when i switched to the ram style from my stock set-up with a WIX filter). I didnt see much of a gain from the intake, i did the 4.0/spacer/intake plenum portmatch first, and didn't notice anything, so i then did the "ram" style intake hoping maybe that would help some, but i still noticed barely anything. The jeep already has decenly hot intake temps just because of the fact that the intake/exhaust flow right by each other on the head.
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I´m also getting ready to do this swap. Does anyone know of a dyno test of the 4.0 TB upgrade?
My concern is that the extra throttle response is simply due to a larger air opening per peddal travel distance, making one think there is more power but it may be just a touchier throttle. Has anyone felt the throttle was harder to control off road, making you feel like you need a hand throttle?
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I´m also getting ready to do this swap. Does anyone know of a dyno test of the 4.0 TB upgrade?
My concern is that the extra throttle response is simply due to a larger air opening per peddal travel distance, making one think there is more power but it may be just a touchier throttle. Has anyone felt the throttle was harder to control off road, making you feel like you need a hand throttle?
i would be very interested in that test. You guys are a great source of info.Thanks to everyone that answered..ken
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I´m also getting ready to do this swap. Does anyone know of a dyno test of the 4.0 TB upgrade?
My concern is that the extra throttle response is simply due to a larger air opening per peddal travel distance, making one think there is more power but it may be just a touchier throttle. Has anyone felt the throttle was harder to control off road, making you feel like you need a hand throttle?
Well, I'm able to lug my engine below 500rpm and not have it die. It's a lot easier to catch when it is hinting of dying, though. Offroad, the smoother throttle is great when having to start from a dead stop on an obstacle. You're not jjumping on the throttle as much. The other thing is at higher RPM's the engine is smothered a bit. But then if all you did was put a 4.0L TB on an otherwise stock Jeep, you'll probably see a decrease in performance.
As for a dyno print out, I doubt anyone has one. Dyno numbers change from dyno to dyno also. BUT I do know the person how told me about this swap, did test his on a emission tester which showed air flow. He lives in CO where the air is thin and from his tests, he said his engine was breathing at sea-level.
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I got my 4.0L TB from a salvage yarfd for about $30, and a TBS (62mm) from eBay for something similar to that (dont remember exactly how much it was). When I installed both, the idle RPM's would not come down from 1,500, so after a couple of days of this (I figured that the computer had not adjusted before that), I took off the TB and left only the spacer. Maybe my TB had some problems (I used the sensors from my 2.5L TB, so I know it was not that). In any case, for me, it did not work. And I would not advise you to pay $75 for that, as they can be found cheaper on eBay or by looking in a salvage yard.
By the way, JP had an article about the performance gains of putting a ram air type intake. Check it out at:
http://www.jpmagazine.com/techarticles/engine/154_0706_jeep_wrangler_tj_intake_dyno/index.html
Felipe
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Jeffy,
What other mods should be done along with the TB swap to get better performance? Exhaust upgrade or air intake ... both needed?
Thanks
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Jeffy,
What other mods should be done along with the TB swap to get better performance? Exhaust upgrade or air intake ... both needed?
Thanks
Well, the general rule of thumb is to start out back and then up front to balance it. The engine is just a large pump.
Another issue to consider is the pressure pulse wave. You don't really hear about it on Jeep forums but it's really important. The intake and the exhaust need to be a certain length to work properly...
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Jeffy,
What other mods should be done along with the TB swap to get better performance? Exhaust upgrade or air intake ... both needed?
Thanks
Well, the general rule of thumb is to start out back and then up front to balance it. The engine is just a large pump.
Another issue to consider is the pressure pulse wave. You don't really hear about it on Jeep forums but it's really important. The intake and the exhaust need to be a certain length to work properly...
jeffy can you explain further? this is the first for me..pressure pulse? :puzzled:
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Thanks Jeffy. From the discussion it sounds like it should work out for me since my cat has been removed (legal in my area and the jeep is not my daily driver) and the muffler is a higher flow type than stock, so that should take care of the outflow. Now just need to match the inflow. From your description of the benefits in your own case it sounds like they are real benefits, time to swap!
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jeffy can you explain further? this is the first for me..pressure pulse? :puzzled:
OK, I guess I'll address this here in general terms so bare with me. Your engine is a air pump. Actually make that four air pumps (#1-4) Each pump turns on (Intake) in the order of 1324. This corresponds to each cylinder in the engine. When ever one pump turns on it creates a high-pressure wave of air. Behind that high-pressure wave is also a low pressure wave. Then the next pump turns on and you get another pulse generated. Basically, you have created a sign wave.
(http://www2.uma.maine.edu/faculty/rsm/slides/chap4/f4-3a.gif)
Keep in mind that each time the pump takes in air, it may not be the wave that is initially started on that cycle but one that has already been created. Now here comes the confusing part. The wave goes both ways. The wave will bounce back as it reaches the pump and travel back out to the end then start again traveling towards the pump again.
Timing of the wave will be dependent on the length of the tube. Keep in mind that when the pump starts up the wave that arrives at the pump is already in the channel so to speak. Optimally, you want the wave to arrive at the pump right before. As the pump starts, the wave will push it's way into the pump. This helps crap the pump with the most air possible. Now, if the timing is off, and the high-pressure wave passes the pump the low-pressure wave will arrive at the pump. The air charge entering the pump won't be as strong as it should and performance will drop.
Now that only covers the intake. There is still the exhaust. In simple terms, the same thing happens but in reverse. Here are the differences though; As the pump turns on (exhaust) creates a pulse as the exhaust. So the pulse travels out the exhaust then returns like with the intake. What you want to happen is the pulse to arrive back at the pump right before the pump creates a new pulse. The pulse will then pull any remaining air from the pump.
Theres a lot more but it's a start.
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holy crap..i guess i never thought of it that way..thanks
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It is a sort of scientific "forced" intake. Almost like supercharging but more subtle.
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jeffy you may want to also note that the helmz holts resonator (sp??) theory only works for a very small bandwidth (only a couple hundred rpms), and depending on the amount of bounces you have will determine how strong the wave is. Most people don't bother with it, especially OEM producers like our stock intake manifolds. Velocities, volume, and even flow are other things that play bigger impacts. In terms of the exhaust you want to create a suction at the merge collector (as in using the smallest diameter tubing possible to create the highest velocity which will then create the best suction on the other 3 runners as it passes the merge collector). All of these theories are worthless with our jeeps though, they are extremely inefficient as is, so trying to truely engineer something would be pointless. Better off just getting a different motor.
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Does the AIS motor housing need a gasket? I have a tb I am going to install and wondered if I need a gasket before I start.
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I think the only way to properly tune your 2.5L MAP-sensor Jeep YJ/TJ for siginificantly better, normally-aspirated, engine-performance is by taking it to a shop that can analyze and tweak the air fuel ratio, supply the necesary sensor mods, and/or fuel pumps (after you open up the intake and exhaust side of the equation). See www.TurboCity.com.
4.0L YJs and TJs at least have chips available that can ride on the ECU; no chips for the 2.5s. 2.4L TJs and 3.8JKs are MAF -- owners are lucky bas#$$ds; I've had a lot easier time tuning a MAF-controlled vehicle.
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Does the AIS motor housing need a gasket? I have a tb I am going to install and wondered if I need a gasket before I start.
Yes, it does have a gasket but if you're careful, you can reuse your old one.
I think the only way to properly tune your 2.5L MAP-sensor Jeep YJ/TJ for siginificantly better, normally-aspirated, engine-performance is by taking it to a shop that can analyze and tweak the air fuel ratio, supply the necesary sensor mods, and/or fuel pumps (after you open up the intake and exhaust side of the equation). See www.TurboCity.com.
4.0L YJs and TJs at least have chips available that can ride on the ECU; no chips for the 2.5s. 2.4L TJs and 3.8JKs are MAF -- owners are lucky bas#$$ds; I've had a lot easier time tuning a MAF-controlled vehicle.
The proper way to tune the engine would be to replace the PCM with completely new computer that allows for laptop tuning. Forget about dialing sensors and just remap the whole air/fuel curve.
Oh and you can chip a OBD-2 2.5L but not a OBD-1. Still it's better to get a dyno tune and a remap then to use a generic chip.
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Yes, it does have a gasket but if you're careful, you can reuse your old one.
So, what if I'm not careful. :'( I already checked a couple of the parts stores, and they do not show a part number. Could I use permatex if I need to?
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Or an Xacto Knife and a cereal box or a piece of gasket material from the partshouse.
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Well, it all came off like a champ. Took about 30 minutes to do the swap, and that was because I took the time to clean the old AIS motor and housing. Took out the restrictors in the air box as well and dropped in a new filter. New plugs, wires, cap and rotor and seafoamed the intake (before I changed everything) Fired right up. Sounds a little "throatier" and I can tell maybe a little difference on the low end. I have only driven about 20 miles since the swap, so the jury's still out. Even if it helps only a little I only paid $40 for the TB.
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Tell me how was the port match between the TB to TBS to Intake maniflod.
I sure like my smooth tbs & 4.0L TB great mod with The Banks Header.
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Did you reset the computer? You'll see performance increase more after you drive it more as the comp adjusts.
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Tell me how was the port match between the TB to TBS to Intake maniflod.
I sure like my smooth tbs & 4.0L TB great mod with The Banks Header.
This is the amount of overlap between the 4.0 TB and my 2.5 intake. I'm going to pull the intake and port match the TB inlet on the manifold and the ports at the head, but that will have to wait till the daytime temps drop well below the 110 mark, maybe September when it cools off.
(http://i39.photobucket.com/albums/e192/b97458/Jeep/TB_Intake.jpg)
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Did you reset the computer? You'll see performance increase more after you drive it more as the comp adjusts.
Yes, I kinda had to. I ran seafoam through the intake before I made the swap and my check engine light came on. So I reset the computer after I did the swap.
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well i did it, i picked up a 4.0 tb on ebay for 30.00 not bad considering i was going to spend 75. first off i must say it was probably the simplest thing i have done yet. it took me 30 min to swap it all out and put it back in. from what i can tell it seems a little snappier of the line. i am going to drive it today and get a base line of how it is.then tomorrow i am going to hone out the intake to match and then see how much that adds. i also have a set of headers waiting for me to free up time to put in. thanks to everyone who had something to say.....ken
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I got my 4.0L TB from a salvage yarfd for about $30, and a TBS (62mm) from eBay for something similar to that (dont remember exactly how much it was). When I installed both, the idle RPM's would not come down from 1,500, so after a couple of days of this (I figured that the computer had not adjusted before that), I took off the TB and left only the spacer. Maybe my TB had some problems (I used the sensors from my 2.5L TB, so I know it was not that). In any case, for me, it did not work. And I would not advise you to pay $75 for that, as they can be found cheaper on eBay or by looking in a salvage yard.
By the way, JP had an article about the performance gains of putting a ram air type intake. Check it out at:
http://www.jpmagazine.com/techarticles/engine/154_0706_jeep_wrangler_tj_intake_dyno/index.html
Felipe
#1 cause of high idle is a vacuum leak... It gets asked a lot here. Not only are you supposed to swap sensrs but also the IAS housing. Otherwise, you'll get a vacuum leak there too.