Magnuson Tune

I decided to post an update to my Magnuson SC install. I recently had a custom tune done on it that has tweaked the low end torque slightly over what I was getting from the generic Magnuson/Diablo tune by adjusting the engine timing and also made some adjustments to the air/fuel ratio during wide open throttle, idle, normal acceleration, and cruising. I went with a custom tune because I think Magnuson's generic tune is done on a smaller Jeep. I wanted the tune specific to my Jeep.

According to the person that did my tune, I'm starting to get boost at about 1600 rpm based upon data logs with a maximum boost of 6.3 psi. I estimated that I'm getting about 100 hp/91 tq more than I was getting when it was stock. My mileage may have gone back to what I was seeing when it was stock too, which would be a gain of about 2 mpg. I lost 2 mpg with the standard Magnuson/Diablo tune. I'll know more about the mpg after I run a few more tanks of fuel through it. The auto still likes to hold the gear longer like it did with the Magnuson/Diablo tune, but I'm at the point now where I manually shift it. The catch can that I installed also seems to have cleaned up the air fuel mixture for a more consistent smooth running engine. I also installed a PLX gauge to monitor the air/fuel ratio and boost. https://plxdevices.com/product_info....DBDSMAFR_DM6G4

My dyno chart looks pretty ugly because we couldn't keep the auto tranny from shifting, but with 40" tires and 5.13 gears, my Jeep is producing roughly 270 hp/250 tq at the wheels. I was told that my Jeep would produce larger hp/tq numbers if I was running smaller tires and if we could keep the transmission from shifting on the dyno, but at least I have numbers now instead of speculating what I have based upon other dyno charts that I've seen.

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I guess going with a custom was the rite thing to do after all. Thats why i went with my own custom tune my jeep never ran rite with ripps canned tune

Do you have a dyno chart?

What is the difference specificly vs the mag tune? Do you have the surging issue at crusing speed?

Your power numbers seem right for a jeep set up like yours. Sweet Pea did better, but she was on 32s. with 4.10.

what was the expense of the custom tune, and is it worth it?

Would love any info on what exactly the tuner did. If mileage went up then it sounds like your leaner now. Seems like the S/C manufacturers' tunes are rich to avoid the risk of leaning out. How did your tuner conclude that you're getting boost at 1,600 rpm? I've been told by Magnuson that the bypass won't close unless the intake is at zero BAR which is WOT. Is he/she saying that at WOT boost comes on at 1,600? Great info.

There's a chance (small) that I'll keep my 3.6 on a stand with the S/C and tear it down to the rotating assembly and see how it looks after living half its life under forced induction. Then put it back together with any and all improvements I can and experiment with electromechanical bypass control on the S/C and a custom tune. All toward the end of finding a used 6-speed JK to build as light a truck as I can and have it be capable off road.

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Originally Posted by JeepLab

Do you have a dyno chart?

What is the difference specificly vs the mag tune? Do you have the surging issue at crusing speed?

Your power numbers seem right for a jeep set up like yours. Sweet Pea did better, but she was on 32s. with 4.10.

what was the expense of the custom tune, and is it worth it?

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I'm still trying to get my hands on the dyno chart. I saw the graph on the dyno, but the technician hasn't pulled it off and emailed it to me yet. The guy doing the tune started with the Magnuson tune and made adjustments to the fuel maps and timing. I don't have any surging issues that I can detect. I haven't tried the cruise control, so surging could be a problem with cruise, but it isn't tested under that condition yet. It cost me $450 for the custom tune. I have to drive it more to see if the tune was worth the money. I've only used half a tank of gas since I had the new tune, so I have to give it a little time.

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Originally Posted by gbaumann

Would love any info on what exactly the tuner did. If mileage went up then it sounds like your leaner now. Seems like the S/C manufacturers' tunes are rich to avoid the risk of leaning out. How did your tuner conclude that you're getting boost at 1,600 rpm? I've been told by Magnuson that the bypass won't close unless the intake is at zero BAR which is WOT. Is he/she saying that at WOT boost comes on at 1,600? Great info.

There's a chance (small) that I'll keep my 3.6 on a stand with the S/C and tear it down to the rotating assembly and see how it looks after living half its life under forced induction. Then put it back together with any and all improvements I can and experiment with electromechanical bypass control on the S/C and a custom tune. All toward the end of finding a used 6-speed JK to build as light a truck as I can and have it be capable off road.

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I don't have exact details on what the tuner did. He had my Diablo Trinity connected to the OBDII port and simultaneously connected to his laptop that was running Diablo software. We took my jeep for a drive in stop and go traffic and did some WOT in some areas that had no traffic. We put it on the dyno for three pulls to get more data logging while he still had the Diablo Trinity and his laptop connected to my jeep. After the dyno pulls and some tuning adjustments, we took the jeep for another road test to make sure there wasn't any engine knocking or stuttering at idle, WOT, or cruising.

I have an air fuel ratio gauge installed, so I can see the numbers as well as the boost. He did lean out the WOT fuel map by about 6% and fine tuned the other settings because Magnuson's tune was running a little rich. He said the company was being over cautious because their tune had to work on every jeep. It made sense to me because Magnuson has told me that their tune also works without modification with their high altitude pulley that adds another 2 psi boost.

My WOT AFR is about 12 and normal cruising is about 14.6. The AFR is not a steady number, so it varies a bit with each cylinder combustion/exhaust cycle. The tuner determined that I was getting boost at 1600 rpm from the data logging. Using my boost gauge, I can see boost even driving on the interstate if I'm going up an incline or running against a headwind. I've had as much as 5 psi boost in a bad headwind on the highway and I definitely wasn't running WOT.

bo9roadking: Thanks for posting this. I'm encouraged by the information you've provided. The sprintex canned tune I'm running is pretty good, but I feel like it could be better. I may consider getting a professional tune this spring or summer. If you don't mind, could you post your tuner's info? Also, did you weld in a separate bung for your PLX gauge, or did you replace your original O2 sensor and wire the PLX provided sensor to your jeep's computer? After reading your initial post I looked at the link you provided and it seems as though you can replace the original sensor, but I wasn't sure if that's the route you took. Thanks again and congrats on the progress you've made with the magnacharger.

rumor mill started spinning today..... word is Magnuson has solved the tune.

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Originally Posted by FLIPmeOVER

rumor mill started spinning today..... word is Magnuson has solved the tune.

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Where did you hear that? I emailed Magnuson today and was told they don't currently have a new tune. They had sent me a tune back in November and they told me in today's email that the November tune is the latest one.

Maybe they have something, but they are still testing it? It would be nice to get the transmission to shift better. Even my custom tune still has the auto transmission issues. If Magnuson has it resolved, I'll go back to using their tune to get better shifts.

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Originally Posted by FLIPmeOVER

rumor mill started spinning today..... word is Magnuson has solved the tune.

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Its not a rumor, Im not sure about weather or not the testing phase is complete, but I just sent sweet pea's VIN back to MAG and am expecting a new tune from them any day.

SP is a manual trans, and they know that (i think) so I'm not sure if its auto shifting they are correcting. We will see when the email comes in and Ill post the differences once installed.