ADM Performance upgrade

This was the trucks first modifications. It included ADM's electric fan kit, underdrive pulleys, tune, CAI and 4" MAF.

I ordered the parts and a couple days later they showed up. Once I received the parts, I sent the ECM/TCM module back for programming (next day air). They programmed and shipped back the modules the same day they received them. They shipped them back next day air as well. So out on a Tuesday and back on Thursday.


This is ADM's Electrical fan (E-fan) kit. All first rate components in a OEM type package.

Installation was a snap and can be accomplished in about 3 hours. The toughest part was finding the correct wire for fan control. The original instructions were vague and somewhat incorrect. This has been rectified.

Installation instructions can be found here.

This is something GM should have done from the factory. This kit looks so good that most dealers would not realize its aftermarket. Highly recommended.

The balancer pulley on the bottom is the underdrive pulley. It's smaller in size than the original pulley and is worth a few horsepower.

Some people worry about not driving the alternator well but I am running E-fans and I honestly cant tell any loss in charging.

Between the electrical fans and underdrive pulley I CAN tell the difference in the way the truck revs.

ADM sells a kit that includes belts, new balancer bolt and balancer.

Instructions can be found here. This is a modification that you might want to have professionally installed.

Compare the new underdrive next to the original.

This is the ADM 4" (100mm) intake system. ADM stands firm that the optional 4" MAF sensor which is larger than the OEM has definite performance gains.

Other vendors say there are no gains to be had on normally aspirated engines since the limiting factor is size of the throttle body. larger view

Installation was simple although the MAF adapter cable supplied by ADM can be a little finicky and caused issues at first. I know of one other installer that had similar problems in this area.

I also received a few comments from forum members about this being an "ugly" intake. Personally, I like it and think the 4" MAF makes it look stealth.


One thing you might consider is asking Andy NOT to put stickers on the back of your modules. I personally would rather not take it to the dealer with a bunch of ADM performance stuff stuck to the back.. Just my opinion though :)


Well the first issue came when I pulled it out on the street for the first time. Although it became instantly extra fun to drive, something was not right. Under low throttle conditions it jerked into second gear in a neck snapping manner. A quick call to Andy and I was back to checking the connection to the MAF sensor. For starts the "key" on the connector should have been removed before it shipped and wasn't. The result of this was a connector that was plugged in backwards. I had to bend the pins back straight and try again. This took several attempts but I finally got it right.

The next drive and everything seemed right. It was much more spirited and I found myself saying "Whoa" a few times :) Shifts were much improved and it was an all new truck.

So I plugged in the G-Tech and headed for a desolate strip of asphalt. The first run yielded a 13.676 (see here) but had very audible detonation. So I decided to stop testing until this could be resolved. My options at this point would be to return my ECM to ADM or wait for the HPtuner software which had already been shipped. Andy knew I had this on order so he suggested I wait for the HPtuner delivery. Once it arrived, I made another run and sent Andy the log file. I also "READ the vehicle and sent him the file for him to modify.

After review, Andy said he felt the problem was causes by a change in a new K&N filter he was using (flowed better) and that he would make some modifications to the tune and email it back. So the following day I had a new tune sent to me via email. The electronic delivery of tunes is cool stuff. I am liking this.

Tune #2 Arrives. I write the new tune file to the truck and head out for my testing spot. Did not notice any detonation that time but the performance was way down. Andy told me when he transferred the file from his notebook to the memory stick, he accidentally sent me the wrong file. Scan file for those with Hptuners

Tune #3 Back to the asphalt with the G-Tech. Audible detonation is back and performance is down about 1/10 even though the ambient temperature is lower by about 25 degrees from the first test. Stop testing and wait for the next tune. Sent Andy the Hptuner log for evaluation. Scan file for those with Hptuners

Tune #4 Write the tune and back testing. Results about the same. Detonation again. One good run at 13.61 click here and the rest were all 13.7 to 13.8 range. Sent the results to Andy for review. Andy replied telling me he had sent me Pedro's race file by mistake. Scan file for those with Hptuners

While waiting I decided to start learning a little about Hptuners and discovered a couple things about the four ADM tunes that I really did not care for. One was the max knock retard tables had been modified which is something used to pull timing if needed. Bad fuel, etc. Also all torque management has been removed which can prove to be fatal to the transmission. Or that's the general opinion anyway.

Tune #5 shows up in my inbox. So the first thing on the agenda is check the tables for torque management. As with the previous four tunes, this one has zero torque management. For those interested, here are the torque management tables from each tune.

The results on the left are the truck as delivered and comparison runs with other vendors. These are the best results from multiple runs including 5 different tunes sent from ADM.

Complete Results including corrected ET You can see the results here in pdf including the corrected times.

The actual comparision chart between vendors can be found on the Results and Comparisons Page

How ADM Rates !


Service & Availability
Fit & Finish
Delivery Time
Quality & Performance

5 stars - Was going to knock off 1/2 star since ADM has long weekends. Shop is closed on Fridays and not available on weekends when most amateurs "play". Have to give credit though as I did get email responses on weekends. So far on this TBSS project ADM has been available for support better than anyone.
5 stars - Finish was excellent on all pieces and installed CAI looked great. 4" MAF connector was a hassle as noted above.
5 stars - Nothing could have been better unless he got on a plane and flew it to me. Parts arrival was fast and ECM/TCM turnaround was perfect.
3 stars - Truck "Ran" very well but had large amounts of knock. After 5 attempts at them giving retunes, I gave up. Rating of 3 is based on quality. No TM and knock.