Topic: Need advice from people experinced in increasing engine performance

[countryboy15]

First Off I am a 16 year old and a newbie to the performance part of cars. I am trying to increase the HP on my 2.5L jeep, but I am Not real sure what to do, and I know engine swap is pretty much out of the question for me. I just want to increase performance at the low amount of RPMs, which is the rpm range Like to keep my jeep in driving, especially in the mud. I have a list(half the stuff I most likely am not going to do) but is there anything else I can do to increase the horse power on a engine?


THE LIST(THAT ACCUMALATED OFF OF A GOOGLE SEARCH):

-changing the ROM chip in the engine control unit (ECU) to a performance one= not sure
-Make everything lighter
-Increase the compression ratio
-Change the heads and cams
-Increase displacement
-change to performance Air filter
-change to performance Intake piping
-change to performance Intake manifold
-change to High performance exhaust system
-get and install a Intercooler
-get and install a Turbo charger
-change Engine head with multiple valves
-change to synthetic motor oil
- change Throttle Body Spacers =what type,etc
-change to performance Spark Plugs, Wires, Distributor

WHat AM I FORGETTING(IF ANYTHING)? THANKS FOR THE HELP.
ALSO IF SOMETHING DOESN'T WORK ON THE LIST LET ME KNOW, SO NO ONE ELSE WASTES THEIR MONEY ON IT.

some of Stuff that I found on the internet that I think is good but not sure. Need advice people's advice.

Things You'll Need:
Air filter
Intake piping
Intake manifold
High performance exhaust system
Engine head with multiple valves
ROM chip




Step 1
Increase the size of your car's air filter or reduce the size of its intake piping. This allows air to enter the engine more freely, which lets the pistons work more efficiently and increases the engine's horsepower.
Step 2
Replace your intake manifold with one made of smoother material, or simply polish it to buff out any imperfections. That will lower the air's resistance as it moves into the engine's pistons and increase its effective horsepower.
Step 3
Add a high-performance exhaust system to your car. The engine's exhaust must exit as freely as possible, or else it causes the car to lose horsepower. The inclusion of a header, a free-flowing muffler or a larger tail pipe--all components of a high-performance exhaust system--will reduce the air resistance out of your engine and help exhaust to escape.

.....skipped....

Step 6
Switch the engine's head with one that has multiple intake values and exhaust valves. Most standard engines only have one of each. With multiple valves, the engine's airflow will increase and the horsepower will improve.
Step 7
Exchange the ROM chip in the engine control unit of the car. However, this technique is only applicable to late-model cars, and it isn't always guaranteed to increase the horsepower. Check the chip carefully before you purchase it and get an independent opinion on its quality, if possible.

......skipped..... to some stuff

some more stuff found on internet

3 : change Spark Plugs, Wires, Distributor - Many people like to slap cheap plugs into the engine and call it that. I personally noticed a 6HP gain on my 6.0l V8 in my truck just by adding my Bosch Platinum +4's. So run some good plugs, helps with the combustion process. The better the combustion, the more power the combustion will produce. Low resistance wires combined with new plugs and a new distributor cap is a great way to get complete combustion in the cylinders!

4 : Throttle Body Spacers - While there has been much controversy over these, I'll add them for the guys that swear by the "seat-o-my-pants" dyno's showing gains. Throttle body spacers (considering the helix/spiraled designs) claim to atomize fuel better allowing for better mixture rates that lead to more power.
^
llll
does this really work because I have the free parts need to do this

5 : Synthetic Motor Oils - Less Friction, More power. Simply put of course. Synthetics are designed to strict standards and are man made. A good idea to compare, think of a lab with a bunch of people designing the oil as your synthetics like Mobil 1 or Royal Purple.. Think of your "Coastal" el-cheapo conventional motor oil being refined from a barrel of oil.




re gear to 4.88

I not real sure on how to this, could someone explain this to me.
  
Need advice on what to do or not to do. Aslo if something doesn't work or isn't on here plese let me know so I possibly don't make a mistake mod to my jeep.

[sharpxmen]

i'll answer what i know about your list

-changing the ROM chip in the engine control unit (ECU) to a performance one= not sure
 * not likely if your Jeep is a YJ (like the one in your profile pic) - unavailable for YJ mpfi as far as I know
 ** there are other options to lower your AFR (increase your fuel delivery) which is mostly what a chip does (ignition advance too actually).

-Make everything lighter
 *yes

-Increase the compression ratio
 *yes

-Change the heads and cams
 *i didn't see a perf head for the 2.5L so it's not likely you'll find one, a cam yes i think there were a couple of brands available (besides Mopar)
 ** you will need to make a perf head yourself, most likely by polishing and porting at least intake runs and valves (if not exhaust as well).

-Increase displacement
 *good luck with that, let me know if you find anything as i am also interested.

-change to performance Air filter
 *yes
-change to performance Intake piping
 *yes
 ** the 2 above make sure you are combining it with a cold air intake or snorkle, hot air under the hood will hurt your power as much if not more than what you are gaining with the high flow filter

-change to performance Intake manifold
 *you'll have to make one as i don't think there are any available for the 2.5
 **if you do end up making one you'll need to carefully match the manifold piping with the cyl head intake runs to make sure they flow smooth.

-change to High performance exhaust system
 *yes

-get and install a Intercooler
-get and install a Turbo charger
 * yes, not in that order or at least both at the same time :)

-change Engine head with multiple valves
 *good luck here too, not likely to find one.

-change to synthetic motor oil
 *yes

- change Throttle Body Spacers =what type,etc
 *for t/b from lower to higher flow 2.5L < 4.0L < 4.0L bored out (60mm) < 62mm < 64mm
 ** not sure about spacers, some say the helix type gives more low end, personally i cannot certify that.
 ***when you put a t/b larger than the stock 4.0L you'll have to increase the opening in the intake manifold to match your t/b

-change to performance Spark Plugs, Wires, Distributor
 *yes, but don't expect too much of a boost from this


what you missed (i think, didn't read your post to the end)
 - re-gearing will give you more umph
 - electric fan combined with a good controller - will save you a couple of ponies i believe.

in your "step 1" - if you reduce the size of your intake piping you will increase the pressure loss, so you only want to go bigger there. for the size of the stock engine with the rpm at which it makes max power the 2.5'' smooth tubing is considered to have minimal pressure drop, the 3'' will be negligible - the difference between the 2.5 and 3 would be also negligible or minimal. If go to 2'' intake tubing the pressure drop is significant (i posted the numbers in another thread here once, i can't remember which one though)


that's as far down i got in your post, i'll read some more later.

[dwtaylorpdx]

Just as a benchmark for you, my engine was a little over $2000 to build up.
This included:
Balance and Blueprint the engine.
Bore .030
Internal parts like pistons rings bearings.
4 Cut Valve job
Cut teh head .010
Mild Head work.
Hesco Cam.
Cam and crank degreed in.

Dave

[sharpxmen]

some more stuff found on internet

3 : change Spark Plugs, Wires, Distributor - Many people like to slap cheap plugs into the engine and call it that. I personally noticed a 6HP gain on my 6.0l V8 in my truck just by adding my Bosch Platinum +4's. So run some good plugs, helps with the combustion process. The better the combustion, the more power the combustion will produce. Low resistance wires combined with new plugs and a new distributor cap is a great way to get complete combustion in the cylinders!

depends on what he was using before - if you compare crappy spark plugs that have 100k miles on them with brand new platinum or iridium maybe, otherwise i doubt it. Modern vehicles have fairly good ignition systems as long as all the parts/components are in good shape - if you compare a performance ignition with your old beat-up ignition parts (distributor, rotor, wires and plugs) you will notice a significant difference, compare oem and performance both brand new, the latter will be better but it won't give you any major power increase

re gear to 4.88

I not real sure on how to this, could someone explain this to me.
   
Need advice on what to do or not to do. Aslo if something doesn't work or isn't on here plese let me know so I possibly don't make a mistake mod to my jeep.

this is not that easy to do and something that you should take on after watching someone else doing it - i'm not saying you can't do it, but i would do some research first. Give this a read http://www.pirate4x4.com/tech/billavista/PDFs/Yukon%20Gear%20Ring%20and%20Pinion%20installation%20instructions.pdf - it explains step by step how to install a ring and pinion in an axle - if you're comfortable doing it then by all means go ahead, if not i would look for some axles that have already been re-geared or find a shop to do it for you.

Step 2
Replace your intake manifold with one made of smoother material, or simply polish it to buff out any imperfections. That will lower the air's resistance as it moves into the engine's pistons and increase its effective horsepower.

you can polish the cyl head intake runs and valves (said it in my prev post) but with the stock intake manifold would be nearly impossible to polish the all of the inside as they are small in diameter and hard to reach - you would probably be better off making a custom intake that is already smooth inside and not cast as the stock one. The less sharp bends and turns you have the less pressure drop/loss and better flow like you mentioned - mandrel bent aluminum or stainless works best. Keep in mind that size also matters, so the bigger the better unless you use a turbo but that's a different scenario (there is a tradeoff in the plenum size as there is more volume where the air would be compressed into - to compare it's something like an air compressor with a tank, the bigger the tank the longer it takes to reach a certain pressure).

[Torch_Ind]

I have done a 64mm tb and header. increased top end didn't feel a gain for bottom. picks up rpm faster and better throttle response.
p.s ported out my intake and gasket matched the intake to head.

re-geared to 4.88's  Loves it!!! got 5th gear back no probs with 33's. that said gives you more transmission ranges to work with!!

have a accel high vibration performance coil. don't feel it did anything but I went to the round old school style with bolt on connections was a huge plus for me cause I had a lot of problems with the coil connectors for some reason. I have even replace the entire connector a few times. don't regret this change!!! was worth it for the bolt on connections for me.
 
Just picked up a IHI turbo,inter-cooler, boost gauge, boost controller and currently building a manifold for it. so I can update you on that later. and I have a spare engine I plan to rebuild and may build it for higher boost later on but that's far off at this time.