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View Full Version : TTP tunes another Evo X GSR - AEM intake ALERT!


TTP Engineering
12-04-2008, 10:18 PM
We had the opportunity this week to tune another few 2008 Evo X's in house on the Mustang Dyno AWD-500.

http://i4.photobucket.com/albums/y117/dsm95hybrid/GSR5sp_EvoX_zchip_dyno.jpg

This particular car came in already equipped with the AEM intake system.

The first pull on the dyno we aborted due to excessive boost (in our opinion) on a stock BCS (boost control solenoid) vehicle. (or so we thought)

The boost spike we aborted upon rolling into the throttle was 25.8psi before we let out which we assumed was a result of a problem with the Evo X's boost control system.

We soon learned that along with the AEM intake system's cone filter and airbox, enlarged intake pipe, there was also something very interesting.

We found that the boost control line from the stock BCS which is SUPPOSED to tee both of the outputs from the dual solenoids into a single line back into the intake snorkel was in fact modified by the AEM intake kit.

AEM uses TWO BCS inputs into their intake pipe in conjunction with large hoses designed to increase vacuum onto the smaller BCS lines. The stock BCS lines have the tee removed and not only are they connected individually, they also are connected to AEM's MUCH LARGER intake lines to "suck" the boost control signal to the wastegate away from the dual BCS's, decreasing the signal to the wastegate and increasing boost tremendously.

As previously stated, we aborted the pull due to the boost spike so it could have very well kept climbing.

AEM claims +17whp and +17wtq according to their ad, with the addition of 6psi of boost from their BCS vacuum hosing alone sold with their intake, this is concerning.

http://i4.photobucket.com/albums/y117/dsm95hybrid/Untitled-3copy.jpg

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OK, so being that we had deemed 25.8psi and climbing to be excessive, we proceeded to cap one of the two lines to the AEM intake-BCS solenoid lines so that only ONE BCS solenoid was being forced to allow additional boost through.

Here is the result;

http://i4.photobucket.com/albums/y117/dsm95hybrid/Z_AEM_LOG_NO_ZCHIP.jpg

As you can see, there is still a peak of 23.8psi which is a few psi more than stock, but not so much as to max out any 25psi boost gauge on the market.

The AFR still appeared well into the rich side of things at 10.3 AFR or so, however the ignition timing appeared to be a bit on the high side with the AEM intake.

http://i4.photobucket.com/albums/y117/dsm95hybrid/aem_timingcopy.jpg

TTP Engineering
12-05-2008, 06:54 PM
Here are the dyno results of the AEM with boost hike by the AEM boost hoses included with the AEM intake.
http://i4.photobucket.com/albums/y117/dsm95hybrid/Z_AEM.jpg

After the disappointment we had with the AEM intake raising the boost without a boost controller or ANYTHING we decided with our customer that the AEM he bought elsewhere was coming off and the stock intake was going back on.

This is especially concerning for anyone considering a mail in reflash of some kind. With a tuner adjusting the boost control tables higher, on top of the AEM intake raising the boost to 26psi or so, that is a recipe for a certain unhappy result.

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Moving on, we swapped out the intake after working with the aftermarket boost hoses for a little while and deciding against continuing along that path.

Our final ZChip tune datalog on the car is shown here:
http://i4.photobucket.com/albums/y117/dsm95hybrid/Z_zchip_tuned333.jpg

Here are the dyno results with Forge UNOS boost controller and ZChip tuning on the STOCK INTAKE, not the AEM.

http://i4.photobucket.com/albums/y117/dsm95hybrid/ZAHRADKA_TUNED.jpg

And finally, the graph overlay of the AEM intake and 23.8psi to the STOCK intake at 25psi peak tapering down on a Forge UNOS MBC.
http://i4.photobucket.com/albums/y117/dsm95hybrid/zchip_Z_graph.jpg