rev limiter question ( mines funer than yours)

[Frank]

Wont help you much trying to crawl a ledge.(8000rpm) The rev limiter is not so you wont blow it up, Its where the engine makes its peak Hp and beyond that is wasted rpms and engine wear ! Its easy to do without a muffler cause your ear is telling you when to shift not the seat of your pants. Have fun till then . FjR68

[wesley4x4]

I know all about valve float. Started in drag racing prior to Jeeping. I used to shift my small block powered Malibu at 6,000 rpm. The valvetrain uses solid lifters and high pressure valve springs.

I've looked into the mopar stage 2 cam for the 2.5L. It moves the torque curve up in RPM and would make trail performance suffer. If you don't have the gears to be happy now, adding this kit would actually make it worse.

If you were to get the kit, the rebuild on the 2.5L will cost you about $1500.00 assembled. Having the machine work done and assembling it yourself would save a ton of money. Still, I think a supercharger (even at $3K) would give much better performance tossed on a stock engine than having a custom grind cam in an N/A motor.

I have three small block Chevy's in my shed and the right bellhousing to mate it to my SM420. I'm just not ready to take the plunge in my YJ. My little 2.5L sucks on the highway, but I always make it back to camp after a run. Even though it sucks, it has a character than can not be described. Having to floor it so I can make the hills in western MA or NH still puts a smile on my face. The trail performance is pretty good (except maybe deep mud), and I think I use much less gas than a 4.0L (less load due to gearing helps).

I'm going to get my fun with a V8 though, as I've finally decided on a drivetrain for my buggy. It will include a 350 Chevy ('carbed), SM465 tranny, and either a NP203 or NP208 Tcase. The rear axle will be a 14 bolt and the front a Dana 60. These are all going into a TJ carcass.

well i didn't want to start a war just a discussion on the topic and just post my readings butttt... thats going to be one sick buggy cant wait to see the finished product

[DDewar53]

I know all about valve float. Started in drag racing prior to Jeeping. I used to shift my small block powered Malibu at 6,000 rpm. The valvetrain uses solid lifters and high pressure valve springs.

I've looked into the mopar stage 2 cam for the 2.5L. It moves the torque curve up in RPM and would make trail performance suffer. If you don't have the gears to be happy now, adding this kit would actually make it worse.

If you were to get the kit, the rebuild on the 2.5L will cost you about $1500.00 assembled. Having the machine work done and assembling it yourself would save a ton of money. Still, I think a supercharger (even at $3K) would give much better performance tossed on a stock engine than having a custom grind cam in an N/A motor.

I have three small block Chevy's in my shed and the right bellhousing to mate it to my SM420. I'm just not ready to take the plunge in my YJ. My little 2.5L sucks on the highway, but I always make it back to camp after a run. Even though it sucks, it has a character than can not be described. Having to floor it so I can make the hills in western MA or NH still puts a smile on my face. The trail performance is pretty good (except maybe deep mud), and I think I use much less gas than a 4.0L (less load due to gearing helps).

I'm going to get my fun with a V8 though, as I've finally decided on a drivetrain for my buggy. It will include a 350 Chevy ('carbed), SM465 tranny, and either a NP203 or NP208 Tcase. The rear axle will be a 14 bolt and the front a Dana 60. These are all going into a TJ carcass.

well i didn't want to start a war just a discussion on the topic and just post my readings butttt... thats going to be one sick buggy cant wait to see the finished product

The road to Hell and all that...

[schwalby]

I found the biggest gain in HP after I had the computer on the Jeep unplugged for over a month. Granted no testing what so ever was done to come to this it is purely based on my arse dyno. It seems a lot better now though.

[wesley4x4]

I found the biggest gain in HP after I had the computer on the Jeep unplugged for over a month. Granted no testing what so ever was done to come to this it is purely based on my arse dyno. It seems a lot better now though.

yeah an ECU Reset... helps your jeep relearn everything due to engine upgrades (intake, exhaust, bigger throttle body's) or driver habits,

anyone know the proper procedure to resetting the ECU on the wranglers?

i think it go's like this
step 1: drive jeep around until the engine gets nice and toasty
step 2: unplug positive terminal on battery
step 3: let stand for 15 minutes
step 4: secure positive terminal back onto battery
step 5: turn jeep on for 15 minutes (don't touch anything let it idle)
step 6: after 15 minutes or idle drops to normal turn the jeep off
step 7: wait 15 minutes then start the jeep and drive the jeep around on a long trip
step 8: return home and your done

i think it is the 15 minute rule or something like that... correct me if im wrong

[Frank]

Wrong : After you diso the GROUND cable for at least 1 min. The computer starts at its base line so how you drive it is what it learns. FjR68

[wesley4x4]

Wrong : After you diso the GROUND cable for at least 1 min. The computer starts at its base line so how you drive it is what it learns. FjR68

ohhhhh... so i guess hondas ecu's needs more care than a jeeps ecu's

thaought the reset process was the same, but thanks for the help

[Frank]

Just so you know ,I dont think they have computers in 1974s. I was talking in general. The computer has millivolt memory so even if you disco the pos. it will not be disconnected till the millivolts run out. That the reason for the neg. cable to be removed. FjR68

[Carl McFly]

yeah an ECU Reset... helps your jeep relearn everything due to engine upgrades (intake, exhaust, bigger throttle body's) or driver habits,

anyone know the proper procedure to resetting the ECU on the wranglers?

I'm not sure an ECU reset is going to do what you're looking for but I'm not sure what you're looking for either..... .....this thread's taken a few turns

Engine management settings are stored in non-volatile memory and you'd need something like that COOL PROGRAMMER THAT TIM WON to change them

[nostaw]

Engine management settings are stored in non-volatile memory and you'd need something like that COOL PROGRAMMER THAT TIM WON to change them

Carl -

Modern ECUs do "learn" from the driver and adjust over time. Resetting the computer (e.g. disconnect it from power for 10-15 mins) will clear the "learned" behavior that isn't from the factory back to a baseline (which is from the factory). Not all years do this, and I'm not sure when it started in the Jeep computers, but it was probably sometime in the mid / late '90s models.

I know my Subaru's ECU does "learn" how you drive... I've talked to the service guys at the dealer about it.

JW

[SidewaysTim]

Engine management settings are stored in non-volatile memory and you'd need something like that COOL PROGRAMMER THAT TIM WON to change them

I was also able to reset my top speed limiter to 140MPH so mine is "potentially" faster than yours.

[wesley4x4]

[Carl McFly]

AND LIKE A TRAIN WRECK, I can't stop watching it!

[Carl McFly]

Carl -

Modern ECUs do "learn" from the driver and adjust over time. Resetting the computer (e.g. disconnect it from power for 10-15 mins) will clear the "learned" behavior that isn't from the factory back to a baseline (which is from the factory). Not all years do this, and I'm not sure when it started in the Jeep computers, but it was probably sometime in the mid / late '90s models.

I know my Subaru's ECU does "learn" how you drive... I've talked to the service guys at the dealer about it.

JW

yeah, I know. It seemed like the question of an ECU reset was in the context of increasing your red line or doing something that could alter engine performance. I'm just saying that a reset won't alter engine management settings. If you have a slush box and you like to lean on the throttle then the ECU can 'learn' and alter factory shift points, hold a gear longer than factory default. But it's not going to change anything related to engine management. Like a rev limiter