its not hard to find new/old posts around the net that say doing one thing dont do much, if anything.
one guy suggests puting in a 6 inch tb !!but notes that that alone will make no difference.
spending money and thinking it matters really matters huh?

i think ill invent a small module that will go in seriers with the throttle sensor and provide a continuous adjustable boosted output voltage. that will tell the pcm that the throttle is pushed harder and the pcm will respond accordingly going faster with the same throttle position as b4. it will feel like a big jump in power. thats just about what a bigger tb does, if anything in a normal motor at normal rpms.

 

Well, budget is not a concern. If I was gonna motor swap, turbo, nitrous, supercharge etc. I would not do that in my 3.7 liter. I would sell it and get an alpha and go from there. I am looking @ some grand Cherokee srt8s if I was gonna get really serious. Just trying to squeeze out as much from my 3.7 that's all!

 

So you want to improve the performance of the 3.7 but not to much of an improvement right?

So basically things that improve horsepower on the cheap...

Tune
Exhaust
better gas
air flow upgrades

 

has anyone actually dyno run there H3? My buddy at FSR Motorsports laughed when I mentioned tunning the 07' I just bought. He did mention the air intakes are a great way to spend money and get nothing (VERY little) in return. The exhaust is possibly the only restriction to remove for a normal use vehicle. Please anyone, correct me if I'm wrong, but really besides a tune up and maintenance care, their ain't alot to do with the 3.7. I'm having mine dyno tuned in about three weeks. If anyone i interested I can post the actual dyno results. I put in new plugs and the p.o. had a flowmaster welded on. Other than that I changed the oil and shes good to go. If she make even 230horse I'll be shocked - lol.

 

I would pass a brick if I got 232 on a dyno. Thats only about a 5% loss from the flywheel numbers. I would be surprised if you got 185 from a stock tune and probably closer to 165. If you run it on a dyno, make sure to get the pressure and temp calibration factors on the print out. Nobody would EVER spin the altitude dial to show bigger numbers. (would they???)

 

You "buddy" at FSR is daft. The I5s have a robust response to intakes, if he ever actually worked on one he might have a clue. Maybe you should re-read post #2 and consider yourself corrected. Here's a tidbit for your buddy, 10HP from nothin but an intake.


I've pulled 202 with my 07 on 33s at 40PSI, but it has a bunch more than just an intake. Considering a bone stock 3.7L H3 pulls about 173-175, I'd say picking up 100% reliable 25HP & TQ ain't bad.

As to H3 I5 exhaust, by itself, does virtually nothing except provide some sound. You can make some HP with a gutted Mini-Cat or with a header, but that's a different story. A better flowing exhaust works well with other mods, but the proven biggest bang for the buck is a PCM Tune and an intake, followed closely by an Efan conversion.

 

to get the gain at 5000 rpm you will need to downshift to a gear that will keep the motor spinning !. mpg about 4.7! the gain at 5000,red line aint tooo useful except at the drag strip.
the curves start at 3000, high above any rpm i would run steady. the facts are the facts

 

Did you ever pass a RV pulling a boat on a 2 lane highway? Ever climb a 400' sand dune? Merge onto a crowded expressway with a short ramp (whole bunch of those in Urban America)?

Apparently you never depress the skinny pedal.

 

At a quick glance, your 10 hp gain seems to be simply a very short-lived blip on the overall curve. At 4500 rpm and 4850 rpm, the hp gain appears to be next to nothing.
Now the torque curve is increased throughout and looks to be a much more even and noticable gain, especially at normal rpm range encounter in everyday driving. It's also the one that you actually feel in the 'seat of the pants'.

That's the one you should be using as an example of perfomance benefits of adding an intake.

 

Obviously the OE engineers weren't so narrow sighted as to make the factory intake tube too narrow or restrictive by mistake and choke out an otherwise good design.

It's pretty well accepted that the gains of adding intake and exhaust mods alone is very minimal on most factory motors made today without adding fuel, spark, and duration into the equation.

But the part of the equation that is nearly always overlooked in these discussions is durability and longevity.
Hell, with the right mods you can get a lawn-mower engined mini-bike to run like it's hair is on fire...for a short while anyway.

These inline motors are designed with longevity in mind from the factory,and have also been tested at great length to provide maximum performance.

If it was simply as easy as adding a new filter or intake tube to get 10 free horsepower throughout the entire horsepower curve, the factory would have likely done that rather than bore the engine from 3.5 to 3.7.