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C&L Plenum, Inlet Tube, & 80mm Mass Air Meter
Product Review
February 2004

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Our 99 yellow GT coupe (a.k.a. Project BrightMare) was in dire need of some additional airflow on it's factory 2-valve 4.6 engine. So after some research we contacted C&L Performance out of Huntsville, AL to order a completely new intake tract from Plenum to Filter. After studying other people's dyno results it appeared C&L had the greatest response in power gains. We also decided to go with the Accufab throttlebody as Lee Bender with C&L suggested for us.

Quick Links: Installation / Dyno Results / Cost Breakdown / Conclusion

So we ended up with boxes a few days later containing the following components ready for dyno testing:
  -C&L 80mm Mass Air Flow kit (includes conical K&N filter)
  -C&L TrueFlow Inlet Tube
  -C&L TrueFlow Intake Plenum
  -Accufab 75mm throttlebody
  (also tested the Accufab 70mm)
  -Pro-M Remote Optimizer (for tuning air/fuel ratio)

CnL components CnL components Project BrightMare on the Dynojet 248C

Just for a recap, our test car had a few minor power bolt-ons already in place before the testing. BrightMare has a 3.73 rear gear, aluminum driveshaft, MAC Prochamber, Flowmaster mufflers, Steeda underdrive pulleys, and a MAC "cold air" kit that we took off to replace with the new C&L pieces. We also have a 100-shot Nitrous Works kit on the car but due to some problems yet to be determined, we could not get full potential out of the nitrous on the dyno, so are not going to report on that for this article until we locate the problem.

If you are planning on getting any part of this setup for your Mustang, we suggest buying multiple pieces together when you can. Most dealers offer discounts for buying more than 1 of these items together. The prices below are manufacturer LIST prices for a 99 GT at the time of this writing, although the dealer links we've provided below contain much better values. Since prices change regularly, we won't list the advertised pricing.

  • C&L 80mm MAF kit: LIST $269
  • C&L TrueFlow Intake Tube: LIST $149
  • Accufab 75mm Throttlebody : LIST $235
  • C&L TrueFlow Intake Plenum : LIST $199
  • Pro-M Remote Optimizer: LIST $169 (Pro-M Website)
  • Grand Total for our setup: about $930 after savings.

RPMoutlet.com (great deals on buying part combos above)
Ronnie Diaz Motorsports (great online combo pricing)
www.cnlperformance.com (lots of good technical data about the C&L flow capabilities)
Custom Performance (Charlotte NC Mustang specialty shop) 704-454-5220

Installing these components is a simple bolt-on process, but we highly recommend you have the car tuned immediately after the installation. Replacing any intake components can easily cause the air/fuel ratio to change. If the A/F ratio goes too lean, you can damage your engine internally. If it goes too rich, your performance will suffer and you may not see power gains from your new purchase.

First of all, we want to point out that we were removing our MAC "cold air" kit from the car to replace with all new components. The 90 degree bend in the MAC kit was contributing to a rich A/F condition which was hurting our performance. We could simply have added the Remote Optimizer to tune what we had, but it was time to upgrade to a larger MAF meter and C&L had everything we needed to do the job from plenum to filter.

Removal of Parts:
First we began by removing the MAC filter from the fender, then the intake tubes and factory MAF. Don't forget to unplug the IAT sensor from the intake tube for use with the new tube. We then moved to the factory throttlebody and plenum. You can leave the throttlebody attached to the plenum and remove it as one unit. This is pretty straightforward, but in general just remember that whatever you disconnect, must be reconnected to the new parts in the same location. So we started by pulling off all rubber hoses and wiring harnesses.
Unplug Throttle Position Sensor wiring plug Removing black rubber hose from plenum Remove throttle cable spring

The (usually rusty) EGR module on the driver's side of the plenum must be disconnected by unbolting 2 long bolts.
Removing 2 bolts from EGR Removing the IAC wiring connection

There are 5 bolts to remove that are holding the plenum down. Once these bolts are out, and all your cables, brackets, and accessories are pulled from the factory piece, you should be able to simply lift up and pull the unit off the engine. We must remind you to be very careful not to drop anything into the intake or you'll be paying for it severely later on. The Throttle Position Sensor (TPS) and Idle Air Control (IAC) valve can be removed after the unit is off the car. It's much easier than doing it under the hood.
Removing Idle Air Bypass tube Removing the Idle Air Control Valve- 2 screws

Transfer of components to new parts:
The new 80mm Mass Air Flow meter is just an aluminum shell and requires that you move the electronics from the factory MAF to the new unit. This requires a special star bit which C&L kindly includes with your purchase. There are 2 screws to remove and reinstall. This is a good point to install the IAT sensor from the old tube into the lower end of the new C&L tube. You may need to put a small amount of lubricant on the rubber grommet to get it in the pre-drilled hole easily. Once you have this transferred over, you're ready to begin installing the new system.
IAT sensor on new intake tube Installing electronics from factory MAF to new MAF

Special Notes for Nitrous users:
C&L provides a special "bung" on their intake tube to place your spray nozzle. You can drill this out and thread it depending on the brand of nitrous kit you have.Without this, you would need to find another method to hold it in place. You can also still mount a throttle activated microswitch to work with the new Accufab throttlebody without any issues.

photo after drilling and tapping nitrous port after installing throttle activated microswitch Nitrous Works nozzle installed into special port

Installing the new intake:
To get started, we placed the new C&L Plenum into place and loosely screwed in the 5 new bolts that C&L provided. We then used the 4 supplied bolts and gasket to attach the new Accufab throttlebody. We tightened all bolts snugly and reconnected all hoses, brackets, and cables in the same manner they came off the stock intake. Now was a good time to test the cable spring on the throttlebody to ensure the butterfly opened and closed properly. From this vantage point, we could see the new 75mm Accufab was going to breathe much better than the factory TB.
Top view of new plenum New C&L Plenum and 75mm TB in place Looking into the Accufab 75mm TB
The next step was to put the C&L TrueFlow intake tube on the car. There is a rubber spacer that goes between the rubber boot and the mouth of the TB. Because the opening of the 75mm TB is so large, the spacer is difficult to get on but is required in order to seal the connection.We then lightly tightened the hose clamps over the rubber boot to hold it in place.
Rubber spacer between TB and rubber gasket Rubber connector over spacer Installing the CnL Trueflow intake tube
Next, was installing the new C&L 80mm MAF meter onto the end of the intake tube. Once those hose clamps were on, we connected the conical K&N air filter that is supplied with the kit. It simply mounts right onto the MAF meter with more hose clamps. C&L also provides a nice looking black heat shield that we plan to use in the hotter summer months.
inside intake tube viewing IAT sensor after installing 80mm MAF in car Installing the conical air filter
After everything was on the car, we tightened and double-checked all connections.

Installing the Pro-M Remote Optimizer:
In order to tune the combo, we chose to add Pro-M's Remote Optimizer which simply plugs into the Mass AirFlow (MAF) Meter to accurately tune the air/fuel ratio. Because of the amount of changes taking place to the breathing of the motor, it was critical to tune it on the dyno for maximum results. We definitely recommend getting a tool like this to tune your car after any intake changes. There are 2 simple dials on the box, 1 for idle control, and the other for high rpm tuning. To make an adjustment, we just needed to turn the second dial slightly until our dyno graph showed that the A/F was reading in an acceptable range.

We chose to mount the box on the fenderwell using an existing hole leftover from the old airbox location. This allows easy reach for tuning should the need arise in the future.
Photo showing placement of new Remote Optimizer for tuning Plugging in the remote optimizer Completed installation of Optimizer and new 80mm MAF
Once the Optimizer is in place, we started up the car and let it run at idle. We then turned the idle screw to the point where we had the smoothest idle. There is a built-in jack for a voltage meter so you can get the correct voltage based on the sheet provided by Pro-M. The other hi-speed screw must be adjusted based on your air/fuel ratio seen during the dyno runs. It only took a few tries, but we got the optimal A/F for the car using this new box.

Much to our advantage, we were able to pull Dale Sciranko, owner of Custom Performance, from his busy shop to help tune the new combo on our GT. His knowledge of Mustang tuning was extremely helpful that day. We made a total of 24 runs to fully test all the different angles of the new C&L setup. We would like to have spent more time, but our dyno bill was starting to grow faster than a ChiaPet on steroids. But we managed to gather a great amount of useful data that we can share with you here.

Overall Gains:
Our first set of results shows 3 runs including the best Baseline Run which is with our MAC CAI, the best run after installing the 80mm MAF kit, and then the last showing the best run after tuning with the Optimizer, 75mm throttlebody, C&L plenum, & 80mm MAF. The graph shows a big horsepower gain throughout the powerband, but from 4000 to 6000rpm it drastically increased. The end result was a peak gain of 22.6 rwhp and 28.1 rwtq ! VIEW HP GRAPH
HP Graph Overall Dyno ResultsTorque Graph Overall Dyno Results

70mm vs 75mm Throttlebody:
We also tested the 70mm vs. the 75mm Accufab throttlebody since we had heard complaints that the 75 was too large of an opening. For our testing, we proved that to be FALSE. The below graphs show 3 runs including our best run with the 70mm, our best run with the 75mm, and then the 75mm run after tuning with the Optimizer. This graph shows that when we went from the 70mm to the 75mm the horsepower and torque stayed nearly identical, but the A/F ratio dropped. Which means there was more airflow but the drop in A/F caused a rich condition but the car still produced more power. After we tuned the Optimizer to get the A/F ratio back up, the power increased beyond that of the 70mm.
HP Graph 70mm vs 75mmTorque Graph 70mm vs 75mm
We recommend the 75mm throttlebody over the 70mm if you are going to dyno tune the car (which you should).

What does all this mean you might ask? It means my right foot is directly connected to the huge smile across my face when I drive this beast! If this pony were a killer bee, we just did the equivelent of poking a stick into it's nest. Project BrightMare is now awake and is one pissed off hornet that screams all the way to 6000rpm in search of it's prey. Pressing your right foot to the floor is much harder to resist now, and gives you instant throttle response and traction breaking torque that wasn't there before.
Complete setup of Cnl intakeComplete setup of CnL intake

We are under the impression that the MAC cold air kit was the cause of our overly rich condition (11.2 A/F above 5400rpm). We were probably actually losing power because of the MAC kit, which produced an even better overall gain for our car. Going from any other intake setup to C&L may produce different gains, especially if other modifications differ from that on our car. All we can say is that C&L has hit the nail on the head. It is about time the Mustang aftermarket came to life, and C&L Performance is on the top of my watch list for future products. Our test mule only has a few basic bolt-ons but is putting nearly the same horsepower to the ground(256), that Ford claims at the flywheel(260).

If you'd like to consult with Custom Performance in NC to have this done to your Mustang, feel free to call them at 704-454-5220. They can get all the necessary parts required, and provide the expert tuning to get the results you've read above. You can also email them directly at sales@gofastfords.com.

Written by: Steve Shrader, YMR

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