Dyno Test - What's wrong ?

[A Satria]

Guys,
Something wrong with DYNO TEST Results ?

Current Spec :
97 XJ 4-door
Engine Stroked to 4.5L using Crankshaft
Existing ECU connected to UNICHIP Programmable Engine Control Unit (http://www.dastek.co.za/)

The UNICHIPgives the properly trained technician full control over the timing and mixture functions of most electronicallycontrolled vehicles. Not only can mixtures and timing be set, but also it can be set under various load and RPM conditions. This gives one the ability to optimise the vehicle for economy under light load conditions and set it up for optimum performance under full-throttle conditions.
TheUNICHIPis much more than just a "chip". In actual fact it is a fully functioning computer which is added to the vehicle’s existing engine control unit (ECU). Apart from controlling general timing and mixtures it can do idling control, drive extra injectors, take full control over timing functions, eliminate road speed governors etc. It can be accurately described as a "Piggyback" computer.
TheUNICHIPgets wired into the existing ECU harness. If it is removed the vehicle is back to standard. Unlike other after-market units if theUNICHIPis programmed with zeros the vehicle will be standard. Only areas where the vehicle isn’t perfect need to be altered.
The main difference between other after-market "chips" and the UNICHIPis that with the UNICHIPevery individual vehicle is optimised. It is not just a chip that was made on one particular vehicle and then gets used on other similar vehicles.

Transmission - Automatic, Standard AW-4, No Modifications
T-Case - NP-231, Standard, No Modifications
Camshaft - Standard at this moment
Intake - Standard at this moment
Heads - Standard at this moment
Throttle Body enlarge to 60mm
Injector - Enlarge 46% from standard (pulse can be programmed thru UNICHIP)
Ignition - Standard (timing can be programmed thru UNICHIP)
No - Header yet (planned on Clifford 3-Y)
Exhaust - Standard (Planned on Flow-Master)
Piston - Standard, Not over-bored
Air Filter (K&N)
Fuel 87 Octane (i know, but this is what we have in Indonesia for standard)
Tires 255x55x18
Wheel 8.5x18 inch
Average outside temp 90-100 Degree Fahrenheit
Humidity - 83%, barometer pressure around 30.00 inch
Average engine water temp during DYNO TEST - 105 Degree (on dashboard engine temp gauge)
Tires pressure during test 32-PSI

Dyno Test using :
Dyno Dynamics (http://www.dyno.com.au/specs/specs_450_SA.htm)

Questions :
- DR. DYNO
- TealCherokee
- StreetPirate
- 5-90
- All others into engine & performance

1. What is the STANDARD HP and Torque on Flywheel for this engine ?
2. What is the STANDARD HP and Torque on Rear Wheel for this engine ?
3. I brought my XJ into my Friends DYNO SHOP, they purchased the equip a year ago, and the following are the results.
4. 
5. 
6. 
7. Why is my OUTPUT on the TEST are still below numbers that all of you suggest for standard XJ ?
8. Did I do something wrong here ?, However the performance of the engine when tested against other cherokee is very impressive. But then again, why is my number are still lower than what you guys mentioned ?
9. What suggestion should I do when I plan to DYNO TEST the XJ Again ?
10. What results do you want to see (or other spec of dyno test ???)

Regards,

-Andhi (Jakarta, INDONESIA)

 

[5-90]

First and foremost, I think most manufacturer's rate their engines by FLYWHEEL output, and a chassis dyno measures REAR WHEEL output. Therefore, parasitic drag within the drivetrain and drivetrain losses are a significant factor. I don't recall the figures for the actual losses, but they are higher for automatics than for standards, because the automatics are fluid-operated, and always require running the pump. Hydraulic pumps are hungry. There is also a small oil pump in the transfer case, but that's more for lubrication than operation.

Also, temperature and humidity play a part - as those go up, power will decrease slightly (due to less dense, or just less, oxygen.) I don't know what the test conditions are for release specifications, but I'd be mildly surprised if they weren't at or near STP (68* Fahrenheit @ 29.92" Hg atmospheric pressure.) You're fairly close to seal level, as I recall - but that 30*F increase in temperature could be at issue. The 83% humidity doesn't help much, either.

I don't recall the "standard" numbers for the 242 - and anything I'd be likely to come up with at the moment would be run through Dyno2000, which is a little bit "optomistic" in its estimates (however, it's pretty close as far as the relationship between crankshaft speed and relative power output.)

I'd have to run the compression numbers, but I don't think running 87 octane should be a huge issue for you - the 242 starts with agreeably low compression, and while using the 258 crankshaft increases it somewhat, I don't think offhand that it's enough to be a problem (but I'd have to run the numbers.)

While I'm about it, have you thought about what I'd PM'ed to you? I know one thing I was looking for was a fairly concrete goal, so we could see if you were heading in the right direction and to make sure it was attainable.

I'll also be digging into the "Unichip" over the next couple days, just to get information on it. I've not heard of it before now - which doesn't mean that it's not any good, only that it's escaped my notice until now...

5-90

 

[A Satria]

While I'm about it, have you thought about what I'd PM'ed to you? I know one thing I was looking for was a fairly concrete goal, so we could see if you were heading in the right direction and to make sure it was attainable.

I'll also be digging into the "Unichip" over the next couple days, just to get information on it. I've not heard of it before now - which doesn't mean that it's not any good, only that it's escaped my notice until now...

5-90

Yes 5-90, I am working on it to give you a detail spec. I'll sent it to you as soon as I finished.

UNICHIP, yes it is does its job, as you can program timing and injector. We have use it for quite sometimes on different car. I still have "HALTECH" ECU which can run as MASTER ECU by itself. However on this engine, I do not think it is worth it, because that means I need to take out the existing ECU, and re-wiring the HALTECH to be able to communicate with the TCU. That's would be lots of candles to burn at night...

Like I said, this is my first time playing around 242, and I just would like to hae a good performance 242 for week-end.

 

[5-90]

I didn't see a manual download on the linked site - so I emailed and asked for one.

No hurry on your plan - I mainly asked because I hadn't gotten a "workin' on it" response from you before now. Now that you have said so, I'll just shut up and wait...:wow:

Once we know more about what you're trying to do, we'll be able to give you more help - it's just figuring out what your plans are (I'm psychotic, not psychic...) is a problem - once we know that, then we can all move in the same direction! :lecture:

5-90

 

[A Satria]

I didn't see a manual download on the linked site - so I emailed and asked for one.

No hurry on your plan - I mainly asked because I hadn't gotten a "workin' on it" response from you before now. Now that you have said so, I'll just shut up and wait...:wow:

Once we know more about what you're trying to do, we'll be able to give you more help - it's just figuring out what your plans are (I'm psychotic, not psychic...) is a problem - once we know that, then we can all move in the same direction! :lecture:

5-90

Thanks, ans no problem at all...
The most difficult part about this forum is "LANGUAGE" as I need to translate your words (and thinking) into my language and translate my langage (and thinking) into english...., sometimes the results can be 180 degree apart...:doh:

 

[tealcherokee]

what year is your jeep?

 

[A Satria]

what year is your jeep?

1997 XJ, 4 Door, Right Hand Drive.

Test was performed 2 wheel rear drive.

Maybe something wrong within the auto or converter or slippage, or ???

 

[A Satria]

1. Does test performed in 2nd gear or 3rd gear (which is 1:1) ratio will give same value or it would be different ?
2. How about my 255x55x18 tires ?
3. :doh:

 

[5-90]

Chassis dyno tests should always be done in "direct drive," or 1:1. For the AW4, that's third/drive, and for 5-speeds, that's fourth. Otherwise, you get skewed results.

Tyre size is going to have an effect on the readings as well - there should, I think, be a means to compensate for that in the Dyno drivers/software. Likewise final drive or "axle" ratio - should be 3.55:1 for you.

It would probably be best to override the torque converter clutch and force it to lock for the duration of the test - that way, you won't have any "slip" in the converter. I don't know offhand how much slip there is, but I'm inclined to think a 5-10% loss is not uncommon without the clutch being locked (the clutch is a direct mechanical coupling, and the torque converter is a fluid coupler. They introduced the clutch - either electrically or hydraulically operated - in an effort to increase fuel efficiency and reduce transmission operating temperatures at cruise speeds.)

Just curious - do you translate into English on your own, or do you use an online translator? I don't have any trouble at all understanding what you're asking, and I've noticed that online translators seem to "lose something in translation..."

5-90

 

[jeepinwi]

I see that your injectors were running 46% more than stock. You have very little done to allow a lot more air through the engine. I'd guess you're running quite rich with the injectors set the way they are. Stock hp/tq ratings for your Jeep are 190 hp/225 tq. I think you'd expect roughly a 25% loss in power through the drivetrain. Also, the large tires and rims are robbing some power from you.

 

[A Satria]

UNICHIP PiggyBack ECU

Existing ECU connected to UNICHIP Programmable Engine Control Unit (http://www.dastek.co.za/)

http://www.dastek.co.za/
The UNICHIPgives the properly trained technician full control over the timing and mixture functions of most electronicallycontrolled vehicles. Not only can mixtures and timing be set, but also it can be set under various load and RPM conditions. This gives one the ability to optimise the vehicle for economy under light load conditions and set it up for optimum performance under full-throttle conditions.

TheUNICHIPis much more than just a "chip". In actual fact it is a fully functioning computer which is added to the vehicle’s existing engine control unit (ECU). Apart from controlling general timing and mixtures it can do idling control, drive extra injectors, take full control over timing functions, eliminate road speed governors etc. It can be accurately described as a "Piggyback" computer.

TheUNICHIPgets wired into the existing ECU harness. If it is removed the vehicle is back to standard. Unlike other after-market units if theUNICHIPis programmed with zeros the vehicle will be standard. Only areas where the vehicle isn’t perfect need to be altered.

The main difference between other after-market "chips" and the UNICHIPis that with the UNICHIPevery individual vehicle is optimised. It is not just a chip that was made on one particular vehicle and then gets used on other similar vehicles.

 

[A Satria]

Chassis dyno tests should always be done in "direct drive," or 1:1. For the AW4, that's third/drive, and for 5-speeds, that's fourth. Otherwise, you get skewed results.

Tyre size is going to have an effect on the readings as well - there should, I think, be a means to compensate for that in the Dyno drivers/software. Likewise final drive or "axle" ratio - should be 3.55:1 for you.

It would probably be best to override the torque converter clutch and force it to lock for the duration of the test - that way, you won't have any "slip" in the converter. I don't know offhand how much slip there is, but I'm inclined to think a 5-10% loss is not uncommon without the clutch being locked (the clutch is a direct mechanical coupling, and the torque converter is a fluid coupler. They introduced the clutch - either electrically or hydraulically operated - in an effort to increase fuel efficiency and reduce transmission operating temperatures at cruise speeds.)

Just curious - do you translate into English on your own, or do you use an online translator? I don't have any trouble at all understanding what you're asking, and I've noticed that online translators seem to "lose something in translation..."

5-90

• I'll re-confirm whether the test was performed on 3rd Gear. and any other test conditions.
• I do not know the Final Gear, as I have not done anything to the Differential yet, and I assume it is a standard final gear coming from factory
• How would I be able to override the torque converter clutch and force it to lock for the duration of the test - on 3rd gear I assume ?
• Translator, No, I came to us and went to school in 1985 to 1990 in Colorado, then moved to California. then in 1991, I went back to Jakarta, INDONESIA. So english is not my primary language :worship:
• But, still, seems my number is so low, eventhough the performance ON-STREET are very impressive.

 

[A Satria]

I see that your injectors were running 46% more than stock. You have very little done to allow a lot more air through the engine. I'd guess you're running quite rich with the injectors set the way they are. Stock hp/tq ratings for your Jeep are 190 hp/225 tq. I think you'd expect roughly a 25% loss in power through the drivetrain. Also, the large tires and rims are robbing some power from you.

Yeah,... but the numbers seems so low....

• 190HP/225TQ is on the Flywheel Right ?, Assuming say most 25% losses (auto, tires, conv slippage, drive train, etc)tThat means about 142HP. The number still more than what I've achied with all of the mods...
• I'm using Large Free Flow K&N Air Filter
• TB Overbored to 60mm

I (or the dyno shop) must have done SOMETHING very wrong here...Hasta

 

[tealcherokee]

i can guarentee the dyno shop messed up btw....if the dyno was run w/ the jeep in overdrive, about .753:1 gear ratio.....your horse power should be more along the lines of (135.3/.753) 179.7 if i did that right + the 20% or so drivetrain loss, 215.6 at the crank, granted these are just estimates

still seems low though

 

[5-90]

• I'll re-confirm whether the test was performed on 3rd Gear. and any other test conditions.
• I do not know the Final Gear, as I have not done anything to the Differential yet, and I assume it is a standard final gear coming from factory
• How would I be able to override the torque converter clutch and force it to lock for the duration of the test - on 3rd gear I assume ?
• Translator, No, I came to us and went to school in 1985 to 1990 in Colorado, then moved to California. then in 1991, I went back to Jakarta, INDONESIA. So english is not my primary language :worship:
• But, still, seems my number is so low, eventhough the performance ON-STREET are very impressive.

I'd figured it wasn't your primary language, I was just wondering how you were translating. By the way - what is the primary langauge in Indonesia, anyhow? Just wondering...

The final drive (rear axle) should be 3.55:1, if it hasn't been changed by a previous owner. As I recall, most of the early and all of the late AW4's got 3.55:1 gears in the axles.

The torque converter clutch is supposed to lock when cruising in 3d or 4th - but you can "force" it to with a switch.

The torque converter clutch is controlled hydraulically, with pressure being allowed to pass by a solenoid in the transmission itself, with the solenoid given power by the transmission control unit. On the transmission control unit (should be the same for LHD and RHD,) there is a 20 gage Dark Blue wire with White tracer which the TCU uses to provide power to the lockup solenoid. It should be fairly simple to wire up a SPDT (Single Pole Double Throw) switch that goes to the wire - with one side of the switch going to the TCU and the other side going to a +12VDC source. Flipping it toward the TCU is normal operating, flipping it the other way forces it to lock. Secure the switch somewhere, and make sure you can't access the switch normally, or that it can't be accidentally switched to "override" by something hitting it - it may be a good idea to use a keyswitch for this - so you need a key to switch modes on it. Check local electronics houses for something like that.

The TCU plug is a two-row x 13-pin connector. With the retaining latch held at the TOP, and looking INTO the wiring, pin 11 will be in the TOP row, third from the right. Verify by wire colour.

The FSM isn't exactly clear on where the TCU is - there's a drawing of it, but there's not much in relation to it to locate the thing. However, it's got a single plug, and it enters into the bottom of the box - looks like it may be near/on the firewall.

All wiring data is from a 1997FSM.

5-90

 

[Fred]

STP is O degree C, or 32 degrees Fahrenheit. The pressure is correct.

If his intake air is 62 degrees C, as shown in the print out, that is a considerable loss of density.

Fred

 

[5-90]

Ah - I must have gotten my physics confused with my metrology - 68*f is considered the "standard" when doing precision measurement (down to millionths of an inch!)

I'll have to look it up to confirm for myself, but that does sound right.

5-90

 

[A Satria]

I'd figured it wasn't your primary language, I was just wondering how you were translating. By the way - what is the primary langauge in Indonesia, anyhow? Just wondering...

The final drive (rear axle) should be 3.55:1, if it hasn't been changed by a previous owner. As I recall, most of the early and all of the late AW4's got 3.55:1 gears in the axles.

5-90

Language : BAHASA (language) INDONESIAN(indonesia).
Located just north of Australia, South of Singapore and Malaysia.
2 Years ago, one of our 13.000 island was hit by TSUNAMI Disaster.
Bali is one of the best Island like Hawaii....

I have a best friend from us (an American from TEXAS) who stayed in Indonesia for 2 years, setting up ROCK-CRAWLING event and fabricating Rock Crawling buggy. www.fabfours.com. Now they are back in Colorado, setting up fabrication shop for Bumpers, Diff Cover, etc. Such a great guy. I just love american who like to travel.

So, Why dont you come over and visit Indonesia for a change ?. Accomodation and transportation are free for you guys...., ask them how I treat people who just loves Jeep (Speed, Rock, Adventure or just performance....)


-Andhi-

 

[A Satria]

i can guarentee the dyno shop messed up btw....if the dyno was run w/ the jeep in overdrive, about .753:1 gear ratio.....your horse power should be more along the lines of (135.3/.753) 179.7 if i did that right + the 20% or so drivetrain loss, 215.6 at the crank, granted these are just estimates

still seems low though

Yeah,... even in OVERDRIVE Mode i should have gotten (135.3/.753) 179.7.... BUT now. my own test only shows 135HP.
Where have my money that I've been investing gone to....?:doh:

 

[Dr. Dyno]

There's nothing wrong with your dyno test results (says the Dyno Doctor ).
The Dyno Dynamics dyno is a load bearing dyno that reads HP/TQ at the wheels (not the flywheel), therefore the drivetrain losses are higher than what you would expect on a Dynojet (~32% for a RWD automatic). The results are usually very accurate and the numbers are corrected for atmospheric conditions.
Your rear wheel numbers were 135hp @ 3950rpm and 205lbft @ 3000rpm. Flywheel numbers would be ~198hp/301lbft. The air/fuel ratio was just about perfect during the dyno test. It's hardly a surprise that your peak HP and peak HP rpm are so low given that the engine is choked off by the:
Stock airbox
Stock exhaust manifold
Stock exhaust system
Stock head
Stock camshaft
60mm TB
As I told you previously you'll need to replace all the bolt-on items (free-flow cold air cone intake, 62mm TB, header, 2.5" downpipe, 2.5" exhaust, ported head, CompCams 68-231-4 camshaft). Then you can start making some real power (260-270 flywheel HP should be easily attainable).
With all these items added, you can use the Unichip to dial in the fuel/timing curves to get the best results.