JET THERMOSTAT YES or NO ?

[quicksand97]

I have a 97 2.5L wrangler with many mods under hood, she is pretty fast. Mods from cold air intake, bigger throttle body and spacer, hot coil, wires, catback etc, etc. Anyway I was thinking of dropping in a jet 180 degree stat. I have heard by keeping things cooler it also helps the air/fuel charge. True or not ? What are the pros and cons. O by the way anyone know temp on factory stat ? Thanks and happy wheeling.

 

[JPNinPA]

Short answer: No



Longer version:
I could only outline CONs. Your Jeeps PCM uses engine temp as well as other measures to control when the system goes into closed loop, then controlling air fuel ratios based on O2 ratios and these readings. In short you will see less mpg, power and may harm your CAT in the process. Unless you have a supercharger on there it will not make a difference. You want to have a 195* thermo in there.

Second changing the thermo while easy opens you to other possible issues. Not all 180 or even 195* thermos are exact. Some open early or late, causing issues like the above. Some fail early like within weeks.

Why do you suppose these modifications are not factory direct options? Not take away from what you are trying to do, but how much forum research have you done on the mods you chose? I went through the same when I first bought my jeep. How to make it more efficient.
Many will agree the TB spacer does nothing for fuel injected engines.
The CAI will be relearned by the PCM within 500 mi. Unless the air in and out are both improved there is no gain. Someone has a research thread on this showing the stock air box shows lo restrictions worse than the best CAI even with supercharger or turbo.
The larger TB will give more throttle response, but that is it.
Again I went through the same things and learned. The best improvement for HP is a bigger engine.

 

[quicksand97]

Thanks I understand that bigger cubics is best for more horse. Also I have heard many times that the engines computer learns any new changes and yes it does. But at the same time with all my mods on my Lil 4 banger this thing continues to scream down the road since its been modified. I know not one modification by itself will do much, but when they all run in sync and are fine tuned they work great. Just liked cold air intakes. Mine is home brewed factory box with a K&N filter with cold air beening ramed in from outside. It is designed so that cold air presure is build up in there and ready for use. I actually performed better than a AEM system with cone filter. Just one example of how can the same mod be made to fit all engines and give the same results. I know its all a balance with just the right amount of air/ fuel / spark. My lil power plant is so sensitive, it I make one small change I can gain or lose power or MPGs / torque. So yes its displacement is not strong enough to suck in large amounts of air without raming it in. Not arguing with you just talking from what I have experienced through trail and error. Currently I am super happy with my 2.5L power plant. Is it a 4.0L no and never will be but she sure is fast with its current balance of power to wieght ratio. I think I am gonna stay with the factory stat. Thanks and Happy Wheeling.

 

[JohnnyO]

The Jet 180* t-stat is meant to work in conjunction with their Stage II chip. My understanding is that the Stage II also requires 91 octane ga$. The chip should account for the lower temps as far as the computer is concerned, but (in my opinion) if your engine is predisposed to run at say, 210*, it's going to run at 210*, and whether the t-stat opens at 180* or 195* isn't going to matter.

Funny, I was just doing some Googling on this last night. It seems the way to go is to do the intake and exhaust mods (I have an Airaid intake and just installed a Banks cat-back, no header yet) and just use the Stage I chip which will work with the stock t-stat and 87 octane gas.

Further, engines are more efficient at higher temps and and I might WANT some thermal expansion on my 157,000 mile motor. Unless overheating is an issue I wouldn't use a lower temp t-stat.

 

[JPNinPA]

Keep reading about chips you will find nothing better than Lay's. The aftermarket chips do not do a thing and sometimes cause damage.

You'll also find the high temps are an emission thing and less of an efficiency. The O2's, Temp sensor, MAP sensor and others feed the PCM that keeps the air fuel mix in the correct zones. This and attention from the part between the seat and pedal make a difference.

 

[quicksand97]

Keep reading about chips you will find nothing better than Lay's. The aftermarket chips do not do a thing and sometimes cause damage.

You'll also find the high temps are an emission thing and less of an efficiency. The O2's, Temp sensor, MAP sensor and others feed the PCM that keeps the air fuel mix in the correct zones. This and attention from the part between the seat and pedal make a difference.

Yea I am trying to stay away from any chips. Do you or anyone know anything about IAT relocation in order to pickup cooler air temps for more HP. Is this a myth or true. I know its probably a old topic thats been tossed around a thousand times. I read 50% yes and 50% no. What your take?

 

[Skulljeep683]

I just did the jet swap stage 2 with the 180* thermostaat and its working great! Ive got a full k&n intake, over sized tb, poweraid spacer, header back exhaust with dual turndowns before the rear axle, my motor is a 00 2.5L and it gained some mpgs when you drive nice and when hotroding it takes off, i couldnt be happier! Happy wheeling.

 

[quicksand97]

I just did the jet swap stage 2 with the 180* thermostaat and its working great! Ive got a full k&n intake, over sized tb, poweraid spacer, header back exhaust with dual turndowns before the rear axle, my motor is a 00 2.5L and it gained some mpgs when you drive nice and when hotroding it takes off, i couldnt be happier! Happy wheeling.

Man thats great, I like to hear when someones rig is running good, faster, stronger, especially on a 2.5L. It Lets me know that I am not the only one out there with a fast 2.5L, or that my 4 banger can be made to be even that much better.

 

[Utah_jeepster]

one of the best mods for the 2.5L is getting a electric fan. Reducing the torque required to turn a clutch fan adds that back to the fly wheel.

 

[quicksand97]

one of the best mods for the 2.5L is getting a electric fan. Reducing the torque required to turn a clutch fan adds that back to the fly wheel.

So I have heard, that is one mod I am tossing back and forth. My concern is how dependable is a new flex-a-lite. I am leaning on getting one done. That is the only mod I dont have. My current stock fan has been trimmed and cut, and it does wind up alot faster and still cools fine. It is tad lighter than before and with the holes cut in it does spin easier. But I am sure it does not compare to e-fan. Another thing I will be doing is reducing flat spots/surfaces on front of jeep. Light round bumper instead of flat, and other little spots. Some tiny changes that add up. Yet I do not want to make the that visible. O yeah thinking of putting some air vents on back side of hood to reduce underhood temps. I got air tube under there insulated anyway. What about all those sensors getting hot, just above the exhaust manifold and possibly giving false readings. O anybody ever hear about insulating fuel rail for a tad better performance.

 

[Skulljeep683]

I put hood scoops on my jeep, one does a ram air into my k&n and the other is on the other side above my air horn, and they perfectly angled with the hood.

 

[quicksand97]

Yeah its wierd i once tried a AEM cold air intake and my homebrewed air box outperformed a cone filter setup. I dont have a hood scoop but I have removed my headlight bezels and cut some metal out just behind the right headlight. Ambient air flows into engine bay and right into my air box. The front of my factory air box is completly cut out along with about 30% of the right side of box. The right side is cut in a tapered angle from bigger to smaller. It has a aluminum sliding plate which allows me to adjust the opening size. This in turn allows me to physically adjust my air intake. Atleast before the K&N filter. Air presure seams to build up inside the box or acts like a air ram. It works so well for me its like night and day compared to a cone filter setup. Also theres a thick rubber mud flap between the air box and to the right of radiator. With this set up along with other mods my little 2.5L is really quick, spools up really fast, hits its top speeds of 70 to 75 mph, and on a headwind uphill it can hold 65 mph. Well thats with its 31in bfg muds and 4:10s. I am sure if I slapped on 32s I would lose what power I have. I guess I am getting a cold fed/ram affect. I can actually cruise at 65mph with 1/4 or less of the skinny pedal pressed down. I have a little punch from 65mph to 75mph. Slight but enough to feel and gradually pass another vehicle on highway. Well maybe I talking to much, but it works for me. I always wondered how can one aftermarket cold air intake work for all setups. Thats like one shoe size fits all. I mean some engines need more air than others and some may need more air charge/presure. Just saying not one mod works alone, they have to work in sync with one another and tuned just right. Especially on a 2.5L. Man I tell you what if I make one adjustment the wrong way wiether it be spark gap or air sliding plate, I can lose power. But yes I need some vents to let hot air out. I will be quiet now. Happy Wheeling, later.

 

[JPNinPA]

Show us data like this guy did.

Restrictive Intake filter/tube-some interesting objective findings - JeepsUnlimited.com Forums

 

[Skulljeep683]

my 2.5L has serious take off, when i slam it into second im chriping the 31in firestone all terrains with it launching up to 50mph before 3rd. same 4.10 gears, and ax5 trans, sport clutch, new injectors, ram air effect with k&n cold air system poweraid spacer 4.0tb and pacestter header longtube with flowmaster 40 series single inlet dual out with 2 90* turndowns before the axle. and the thermostaat at 180* and jet chip, runnin on 89 pump gas... new rear axle too cause the old one blew apart. XD plenty of pickup with that alone, cant wait to keep goin on building the motor. i can cruise in 5th gear at 65 just fine and maintain it through chicagos on ramps and inclines, i could go faster i know it, just trying to keep the tickets down for now. XD happy wheeling!

 

[quicksand97]

Man sounds nice, keep up the good work.

 

[Skulljeep683]

i plan to, but as for any header back and cold air upgrades i recommend the chip and thermostat, it really helps open up the computer to allowing the higher flow and bump up the power, also on a side note you notice more torque and better fuel economy if you keep the rpms low. so my rating is 5 stars for the stage 2.

 

[quicksand97]

i plan to, but as for any header back and cold air upgrades i recommend the chip and thermostat, it really helps open up the computer to allowing the higher flow and bump up the power, also on a side note you notice more torque and better fuel economy if you keep the rpms low. so my rating is 5 stars for the stage 2.

That is the best feedback or review I have ever heard on the stage 2 Jet chip. I am glad to hear its working well for you along with the thermostat and other mods. It gives me hope and inspiration in making my rig that much faster. Right now my next upgrade on my wish list is a E-fan. I know that building a good all around jeep is not just about power under the hood but for a 2.5L it can be a much needed focul point. There is still other areas on my rig that need upgrading and building such as gears, skids and so on. But it is fun and a passion as you well know. Happy 4 Wheeling.

 

[Skulljeep683]

That is the best feedback or review I have ever heard on the stage 2 Jet chip. I am glad to hear its working well for you along with the thermostat and other mods. It gives me hope and inspiration in making my rig that much faster. Right now my next upgrade on my wish list is a E-fan. I know that building a good all around jeep is not just about power under the hood but for a 2.5L it can be a much needed focul point. There is still other areas on my rig that need upgrading and building such as gears, skids and so on. But it is fun and a passion as you well know. Happy 4 Wheeling.

The idea after the motor is to do an ax15 swap. Cause the motor will destroy the ax5 after prolonged use, and thank you, im willing to spend the cash and do every mod i planned out when i first posted. So any feedback i can give on my current mods i surely will. Cause my jeep is proof that these things work.

 

[JPNinPA]

Butt Dyno - $529.95 : KaleCoAuto.com, Your home for the rare, unusual, and hard to find auto parts.

 

[quicksand97]

The idea after the motor is to do an ax15 swap. Cause the motor will destroy the ax5 after prolonged use, and thank you, im willing to spend the cash and do every mod i planned out when i first posted. So any feedback i can give on my current mods i surely will. Cause my jeep is proof that these things work.

Cool ! When you reach the end do it all over again. Keep up the good work, take care.