DODGE RAM FORUM banner

3.7 performance mod list

57K views 29 replies 18 participants last post by  natehate 
#1 · (Edited)
Maybe this should get a sticky to make it easier to find. There are a good amount of mods that you can get for the 3.7 here is a list:

-Tuner either from hemifever for earlier years of the 3.7 or now hypertech has a tuner for 07-10 3.7's. As for the Jet chip I dyno'd one as I had it before there were tunes available and it showed gains only above 4k rpm on the dyno.
-Ported fastman throttle body, more air in just like the intake should help with power.
-Cold air intake, there are a lot of choices as you can easily make a 4.7 or 5.7 intake fit as long as the throttle body and air filter locations are the same as on your truck. I used a spectre intake for a hemi on my 3.7 and just had to use a big coupler from home depot to get the throttle body and intake tube lined up.
-Electric fan conversion. For this you remove the clutch fan that cools the engine and replace it with a electric fan and controller that tells it to turn on and off when needed. This can be done for as little as $100 with a ford taurus 3.8 fan, wiring, and a cheap controller. You can also buy the black magic 180 kit, but that costs a bit more. This was the only mod on my truck to increase my mpg, went up 1.5 mpg.
-Exhaust, there are shorty headers from jba which I posted about in the exhaust section. Pair them with a magnaflow y-pipe and muffler and you'll have some more grunt.
-Underdrive pulley, both ASP and ATI have underdrive pulleys that fit the 3.7. I'm not 100% on which years they fit, but I have the ASP on my 04 and it gave it some more grunt.
-Regearing, you can regear the rear end to give you more grunt and help alleviate loss of power from bigger tires, I went from 3.55 to 4.10 in my truck. If you do this the most important thing is to find a good installer who works on dodge 9.25 rears often.
-180 thermostat, not really sure what performance this gives but it was recommended with my tuning so I replaced the oem with a stant 45358. All I had to do was drill a bleed hole in it to match the stock t-stat and put it in.
-Cams, you can get stock cams reground and should be able to get more power from the truck. It will require running lash caps and can be quite expensive especially if you can't do the install yourself. I talked to both Crower and Crane about doing regrinds, but decided against it just because it was going to cost so much for the cams, then regrind, then install and I wasn't even sure if I would get good enough power to make the investment worth it.

If anyone knows of any others post them up.
 
See less See more
#2 ·
Good list, thanks for posting that and now that I know there is a tuner available, that may just change my perspective on things lol! :D

- Cajun
 
#3 ·
electric fan ?

Maybe this should get a sticky to make it easier to find. There are a good amount of mods that you can get for the 3.7 here is a list:

-Tuner either from hemifever for earlier years of the 3.7 or now hypertech has a tuner for 07-10 3.7's. As for the Jet chip I dyno'd one as I had it before there were tunes available and it showed gains only above 4k rpm on the dyno.
-Ported fastman throttle body, more air in just like the intake should help with power.
-Cold air intake, there are a lot of choices as you can easily make a 4.7 or 5.7 intake fit as long as the throttle body and air filter locations are the same as on your truck. I used a spectre intake for a hemi on my 3.7 and just had to use a big coupler from home depot to get the throttle body and intake tube lined up.
-Electric fan conversion. For this you remove the clutch fan that cools the engine and replace it with a electric fan and controller that tells it to turn on and off when needed. This can be done for as little as $100 with a ford taurus 3.8 fan, wiring, and a cheap controller. You can also buy the black magic 180 kit, but that costs a bit more. This was the only mod on my truck to increase my mpg, went up 1.5 mpg.
-Exhaust, there are shorty headers from jba which I posted about in the exhaust section. Pair them with a magnaflow y-pipe and muffler and you'll have some more grunt.
-Underdrive pulley, both ASP and ATI have underdrive pulleys that fit the 3.7. I'm not 100% on which years they fit, but I have the ASP on my 04 and it gave it some more grunt.
-Regearing, you can regear the rear end to give you more grunt and help alleviate loss of power from bigger tires, I went from 3.55 to 4.10 in my truck. If you do this the most important thing is to find a good installer who works on dodge 9.25 rears often.
-180 thermostat, not really sure what performance this gives but it was recommended with my tuning so I replaced the oem with a stant 45358. All I had to do was drill a bleed hole in it to match the stock t-stat and put it in.
-Cams, you can get stock cams reground and should be able to get more power from the truck. It will require running lash caps and can be quite expensive especially if you can't do the install yourself. I talked to both Crower and Crane about doing regrinds, but decided against it just because it was going to cost so much for the cams, then regrind, then install and I wasn't even sure if I would get good enough power to make the investment worth it.

If anyone knows of any others post them up.
I was wondering what kinda wiring and controller i would need for the electric fan? thats about the only thing i havent done and never even thought about it. thanks
 
#4 ·
Maybe this should get a sticky to make it easier to find. There are a good amount of mods that you can get for the 3.7 here is a list:

-Tuner either from hemifever for earlier years of the 3.7 or now hypertech has a tuner for 07-10 3.7's. As for the Jet chip I dyno'd one as I had it before there were tunes available and it showed gains only above 4k rpm on the dyno.
-Ported fastman throttle body, more air in just like the intake should help with power.
-Cold air intake, there are a lot of choices as you can easily make a 4.7 or 5.7 intake fit as long as the throttle body and air filter locations are the same as on your truck. I used a spectre intake for a hemi on my 3.7 and just had to use a big coupler from home depot to get the throttle body and intake tube lined up.
-Electric fan conversion. For this you remove the clutch fan that cools the engine and replace it with a electric fan and controller that tells it to turn on and off when needed. This can be done for as little as $100 with a ford taurus 3.8 fan, wiring, and a cheap controller. You can also buy the black magic 180 kit, but that costs a bit more. This was the only mod on my truck to increase my mpg, went up 1.5 mpg.
-Exhaust, there are shorty headers from jba which I posted about in the exhaust section. Pair them with a magnaflow y-pipe and muffler and you'll have some more grunt.
-Underdrive pulley, both ASP and ATI have underdrive pulleys that fit the 3.7. I'm not 100% on which years they fit, but I have the ASP on my 04 and it gave it some more grunt.
-Regearing, you can regear the rear end to give you more grunt and help alleviate loss of power from bigger tires, I went from 3.55 to 4.10 in my truck. If you do this the most important thing is to find a good installer who works on dodge 9.25 rears often.
-180 thermostat, not really sure what performance this gives but it was recommended with my tuning so I replaced the oem with a stant 45358. All I had to do was drill a bleed hole in it to match the stock t-stat and put it in.
-Cams, you can get stock cams reground and should be able to get more power from the truck. It will require running lash caps and can be quite expensive especially if you can't do the install yourself. I talked to both Crower and Crane about doing regrinds, but decided against it just because it was going to cost so much for the cams, then regrind, then install and I wasn't even sure if I would get good enough power to make the investment worth it.

If anyone knows of any others post them up.
oy yea another thing what do i do with the clutch fan on it? just take it off and the cover.
 
#7 ·
The fan is bolted on to the pulley, you can make a spanner to hold it and get an extra pair of hands to help you. The pulley is attached to the water pump and will nut come off once the fan is removed. I put a couple of bolts through the holes in the pulley, wedged a pry bar there and had someone hold it, put a pipe wrench on the nut, smacked it w/ a mallet and it broke free. There are threads on it on dodge forum and dodge talk, maybe here too I haven't searched.
 
#9 ·
No problem, not many people give the 3.7 any credit. Since I can't edit the OP I'd like to mention that the 4th gen 3.7 rams already have the clutch fan eliminated w/ an e-fan used for cooling the motor. Flex a lite also makes a kit specifically for the ram now, part #183, so if you have a 3rd gen 3.7 it's an option as well as the junkyard fan.
 
#10 ·
The clutch fan does come off, some people keep the shroud on to direct airflow or mount the e-fan in. You can mount the fan to the radiator and pull the shroud if you like.
Just want to comment that you really should have a shroud around the fan, it makes a drastic difference.

Sound like a great list to wake up the 3.7L. Only thing I'd add is headwork...
 
#26 ·
3.21 ratio

Just one question. It shows you going up to higher gears but I read somewhere else that for best MPG you should go to 3.21 gears. Does anyone know about this or which is better as far as mpgs go?
I believe you'd be going the wrong way with the 3.21. That's 10 % lower than 3.55, if that's what's in your Ram. You'd need a lot more throttle to maintain your driving style and most likely never see the "eco on" light up unless you're going downhill or coasting. It's been said that gas mileage is maximized at rpm's where torgue is at it's max. If true, you'd have to drive faster, but then increased wind resistance would drag your mileage back down. It's a no-win situation. I do believe that factory engineers knew what was the best all around choice for your particular model and tranny. My favorite saying is always "if it ain't broke, don't fix it"
 
#16 ·
If you currently have 3.55 I wouldn't go to 3.21. It's a heavy truck with a small engine, you need some gearing advantage. Your hwy mpg probably wouldn't change anyway. What I said above is "typically" true, but in your case the engine would probably be lugging at such a low rpm that it wouldn't help, and may hurt hwy mpg.

3.55 Is probably the best hwy mpg gearing for your truck.
 
#17 · (Edited)
Awesome thanks, one more thing, the 180t-stat mod, I live in west texas where we get hotter than hell during the summer so in my previous car I pretty much ran a cooler summer t-stat all year round. so would that be a good mod for me to do? our winters are pretty mild, we hardly ever get below freezing.

I am looking at doing the electric fan as soon as I can. I keep my cars for a long time, my last car I had for 14 years, so I am looking to do it slow but plan on modding the truck for what I need, which is commuting with some light city driving and every now and then hauling a bed load of junk to the landfill.
 
#21 ·
Howdy Guys ,new to the Forum(best one I've ever seen) have a love hate relation with my 06 3.7 Dakota,what I really dislike is that the Guys with the V-8s claim as good or better gas mileage then my truck gets,I would like to to help things a little bit(already have CAI installed{super turbo muffler didn't help a thing,it finally rusted off} what do you recommend? E fan? or underdrive pulleys?,looking for bang for the buck ,mpg improvement desirable too,I see a brand new E-fan from Dorman for about 160$ for a 2010 ram V-6,will that work-hello and thanx-Kevin
 
#22 ·
Use supper unleaded. You will get 1-2 more miles per gallon. No a good bang for your buck in millage but the added response you will have will be well worth the price. After a few tanks if you think there is no difference in power go back to the cheaper plain unleaded. Before the tank is empty your going to be hardly able to wait to filler up with premium. So you can have the power back at higher speeds. I just can't figure out why this is not on your list of modification for this six banger.
 
#23 ·
Well that's a pretty good list of things to start with. I swapped my gear set out and managed to find a set of 373's.I was gonna do the 410 deal but had some concerns about high rpm for hwy driving. What I would like to know is anyone here tried a supercharger or turbo setup yet? Just wondering how much more grunt could be gained from trying this out?
 
#29 ·
To change out that Y pipe, from factory, it looks like I need to change everything from the Cats. to the muffler to replace it. Should I cut the existing pipes from the cats and install sleeves? Or just go all the way up to the factory headers? How legal is it going to be without the cats? I live in Az. I think those are required.
 
#30 ·
has anyone done the cam regrind?
or switched out their pistons and added a turbo?
i was looking at the keith black piston kits, but they are just stock replacements they say? will they hold up to boost?

(yes yes i know it's cheaper to but a v8 truck, but its long since paid for and in immaculate shape)
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top