98ZJ 4.6L Stroker Build

[SilverXJ]

It looks like you are still using a stock throttle body. Personally I would use this as a chance to upgrade to a 63mm or larger. It will definitely help the stroker.

[purple_jeep]

SilverXJ Trust me that is on the list of things to do (68mm) just not yet

Some new toys arrived, hope FlyinRyan can really wake up my engine

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Rental AFR (http://www.safrtool.com) but I got it for free to test their new 0-5V output for datalogging.

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Plan to use the X3 to datalog and to flash the files FlyinRyan will send me.

Waiting for the analog cable to be able to connect the two together and I should be good to go!

Cheers

Chris

[purple_jeep]

Well i have the AFR and X3 connected and talking nicely for tuning with FlyinRyan but every 7-8 mins on average (I have one file at 15mins) the x3 reports a lost connections with the ECU?

Any thoughts? I have sprayed the connectors with contact cleaner on both the OBD2 and the ecu.

Cheers

Chris

[purple_jeep]

Some progress updates:

Sticking throttle:

I pulled off the throttle body to have a look at replacing the bearings but after getting it apart they seemed to be a very difficult part to change as the bearing can not be pressed out from inside the throttle body as it sits in a cavity. Instead I cleaned and re lubricated with white lithium grease the existing needle bearings and put it back together. This seems to have fixed my sticking throttle which is nice!

Bearing from inside the throttle body:

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Bearing from the TPS mount side:

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I also changed the spark plugs to NGK BKR7E per FlyinRyan. Old spark plugs seemed fine, insulator was white with a slight bit of tan/pink coloration. New plugs the electrode is pulled back I assume this is how they pull more heat from the combustion chamber?

Image29.jpg

Cheers

Chris

[purple_jeep]

Now for the exciting information

Finally got to take the jeep to a local Dyno tune shop where I was able to have two back to back pulls on a Mustang Dyno. They ended up pulling in 2nd as in 3rd with overdrive off it would down shift to 2nd. They did comment that in the lower gears it is possible for the torque converter not to lock?

Dyno ready for my Jeep!

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Jeep on the Dyno

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Results (solid is one pull, dashed is the other):

Dyno 12-11-14.jpg

When looking at these results they do seem to confirm that I am not much better than stock power atm (if better at all) maybe a flatter response? I know you can not compare a dyno chart from one dyno to a chart from another but the numbers I see thrown around for a Jeep stroker do seem higher than what I see here.

After chatting with FlyinRyan he is of the opinion and I agree that my stock intake is most likely holding me back from reaching the full potential of this build so once I upgrade the intake I will dyno it again to see how it performs.

Any other comments on this result?

Cheers

Chris

[SilverXJ]

I pulled off the throttle body to have a look at replacing the bearings but after getting it apart they seemed to be a very difficult part to change as the bearing can not be pressed out from inside the throttle body as it sits in a cavity.

You must have thought I was joking about needing a special tool to pull the bearings. I tried a few other home brew methods and nothing produced any results.

Finally got to take the jeep to a local Dyno tune shop where I was able to have two back to back pulls on a Mustang Dyno. They ended up pulling in 2nd as in 3rd with overdrive off it would down shift to 2nd. They did comment that in the lower gears it is possible for the torque converter not to lock?

That is typically what happens when you floor it. Down shifts to second, then upshifts into 3rd.

After chatting with FlyinRyan he is of the opinion and I agree that my stock intake is most likely holding me back from reaching the full potential of this build so once I upgrade the intake I will dyno it again to see how it performs.

That stock throttle body isn't helping you.

[purple_jeep]

Good thing I just ordered a 68mm throttle body from eBay for $44 then

Now to find a 99+ manifold and build a CAI from 4" stainless steel tube, will have a bung for mounting the IAT if I decide to relocate it from the manifold.

Cheers

Chris

[jsawduste]

Offer this up for you. Agreed no two dynos are the same but the curves themselves should be pretty close and comparable.

http://www.jeepstrokers.com/forum/viewt ... hilit=dyno

This was a pull on my personal stroker with the OBD1 SBEC controller. 4th gear which is 1 to 1 ratio wise. Rest of the specs are in the link.

Since that set of pulls the crank sensor has been moved and the IAT relocated to the CAI. Also have much lighter wheels, steel beadlocks in the picture vs aluminum BL`s now. Also a change to 5.38 gears. Mention this as the spool up rate is a bit faster now.

The crank sensor mod added aprox 4-5 degrees of timing and raised the rev limter to 5500. Both according to my overly large but fairly sensitive butt were improvements. The IAT may have added a bit of timing and perhaps some fuel.

Additionally the OBD1 ECM is maintaining a 14.1~ish AFR throughout the run. The run itself is completed before the SBEC has a chance to richen the mixture. The "lag" time I`ve learned is not only the capability (speed of) of the ECM to process data but is also an emissions related to delay adding fuel until an engine speed/time threshold has been achieved.

The curves your showing are comparatively similar in shape to my results.

This combination of parts I`ve found to be pretty user friendly with decent gearing. Changing the cam timing and/or the cam itself different applications.

In the final stages of converting to JTEC and am looking forward to seeing what the revised calibrations and ECM processing speed will be have on the numbers.

IIRC your running the Mopar "Purple Stripe" stick ? Also curious what the larger TB does for both the curve and numbers.

[jeepxj3]

Is that with stock TB?

[purple_jeep]

Hi jsawduste,

Thanks for the information, very nice to see another Dyno result actually two with yours and the one from the magazine! Both are similar shapes to mine but my numbers are low (of course different dyno's).

Timing and everything else is programmed into the ECU by FlyinRyan based on data logging I have been doing but I will be moving the IAT to allow for more accurate intake temperature readings.

I am running the Comp Cams High Energy™, 252H: Cam & Lifters CL68-200-4 which FlyinRyan believes is a little to small of a cam for my engine but ahh well can always change it later if I feel like some torture :p

Yup now to find a 99+ intake manifold and buy or build the adapter for the 68mm throttle body. Already asked Dott on here about his throttle body adapter just have to wait to receive the throttle body to check its bolt pattern.

JeepXJ3,

Yup stock TB, stock intake manifold (1998), stock air tube and air box standard filter.

Questions for all, the 5.2 and 5.9 use the same intake tube and air box right? is the difference in the Throttle body for those applications? They have much larger displacements so should require more air then I would ever need right? So the air box and air tube should be able to handle the volume?

Just curious, I do plan on building a CAI with cone filter from 4" SS.

Cheers

Chris

[SilverXJ]

Questions for all, the 5.2 and 5.9 use the same intake tube and air box right? is the difference in the Throttle body for those applications? They have much larger displacements so should require more air then I would ever need right? So the air box and air tube should be able to handle the volume?

Hardware wise the only difference is the engine bottom end. The injectors are the same as well, but different PCM tune. Of course a few accessories are a bit different like the e-fan and some of the AC lines, and the engine mounts (IIRC, but it might only be one mount). Same intake tube, same intake manifold, same throttle body.

[jsawduste]

Hi jsawduste,

Thanks for the information, very nice to see another Dyno result actually two with yours and the one from the magazine! Both are similar shapes to mine but my numbers are low (of course different dyno's).

Timing and everything else is programmed into the ECU by FlyinRyan based on data logging I have been doing but I will be moving the IAT to allow for more accurate intake temperature readings.

I am running the Comp Cams High Energy™, 252H: Cam & Lifters CL68-200-4 which FlyinRyan believes is a little to small of a cam for my engine but ahh well can always change it later if I feel like some torture :p

Yup now to find a 99+ intake manifold and buy or build the adapter for the 68mm throttle body. Already asked Dott on here about his throttle body adapter just have to wait to receive the throttle body to check its bolt pattern.

Purple Chris......Not to be confused with Silver Chris.
After I posted up I did go back and look at the cam. Indeed a bit on the mild side. A few more degrees of duration and opening up the LSA might be in your favor.

Wonder just how much more air that engine can flow. Even if you add the TB, manifold and open up the exhaust the limiting factor may still be the camshaft. Not that the aren't not gains to be had but I strongly suspect what without putting more stick in it the gains may be modest. In fact your current setup may in be pretty well matched as is. Perhaps retarding the cam a couple degrees might be worthwhile as a no cost option.

The data logging and ability to optimize the cal is in your favor. Something I`ve been ban aiding with mixed results.

Keep us posted as what happens next.

[purple_jeep]

Well you guys are a bad influence on me :p

Just bought a used 2003 WJ header with stock throttle body and mounting bracket for the cables from ebay for another $40.

Having an extra stock throttle body and the mount for the cables means I can rig up the 68mm throttle body completely before removing my stock setup swapping over the attachment plate from the butterfly valve etc.

jsawduste,
FlyinRyan says he sees my intake going into low pressure when I am at high RPM indicating I am not getting enough air to the intake manifold. I hope to feel some difference and I will dyno again after the intake mods in mid Jan.

Cheers

Chris

[jsawduste]

Look forward to the pulls.

Will be doing the same as things come together on my junk.

May have some pulls to share on the Ultra4 engine that is in the final stages of completion. MAYBE with the Edlebrock head for comparison. That is set up a bit more radical but not overly so. Again, the numbers are not as important as the curves.

[purple_jeep]

Slowly getting everything collected for the intake upgrade which will happen late Jan I think. Still need to figure out a CAI what size tube do people recommend? 3.5"?

99+ Intake with spare TB and sensors from ebay $40

IMG_20141222_112416.jpg

4.7L Dodge 68mm TB (butterfly is removed because I was going to pull the shaft but I need long nose circlip pliers)

IMG_20141222_112424.jpg

Adapter from user Dott on here

IMG_20141222_215635.jpg

Cheers

Chris