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How to solve drivability and belt slip issues on a supercharged 2001 Cobra

11K views 16 replies 1 participant last post by  cobraracer46 
#1 · (Edited)
My 2001 Vortech supercharged Cobra has been experiencing some random stalling and surge issues along with belt slip problems so I'm going to resolve these issues once and for all so I can get busy with fiddling with the SCT pro racer package I loaded into the PCM.

Old set up:
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A pile of new 8 rib conversion parts and Maf components to solve the surge, stalling and belt slip problems. I sourced all of the 8 rib parts individually and used some custom spacers to save some money by avoiding the overpriced 8 rib "kits" out on the market. With the money I saved by selecting the 8 rib parts myself, I was able to put into an upgraded ATI overdrive damper and a premium Gates fleet runner belt. For sure it took some work to calculate the proper bolt lengths and figure out the right pulleys to use, but the effort was well worth it. For those of you not willing to perform some calculations and do a bit research, then you can just go ahead and purchase a "kit."

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Stay tuned as I go to work on installing all the upgrades on a 01 Cobra.
 
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#2 ·
Getting started on modifying the coolant crossover in order to clear a new and wider 8 rib alternator pulley
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#3 ·
New OEM ford F65Z10344AA 8 rib alternator pulley shaft is longer than the original one.

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Off to the machine shop to mill down the shaft to match the dimension of the original.
 
#4 ·
Finished modifying the coolant crossover so it clears the wider 8 rib alternator pulley.

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I like the glossy finish on the Rustoleium High temp engine paint.
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#5 ·
Getting ready to swap the damper and this will require a flywheel locking tool.

OTC has a rather pricy tool to do the job


However, I didn't feel like spending a hundred bucks on a tool so I fabbed up my own locking tool with some left over scrap for nothing.

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#6 ·
Installing the new ATI damper hub with a Snap On special tool
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Bearing overheated on the cheap plastic Vortech idler because plastic acts as an insulator rather than a heat sink as it would with a steel idler. A new wider steel idler pulley will eliminate this problem.
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Getting ready to swap out the old 6 rib blower pulley for a New 2.87 Vortech 8 rib Pulley. Notice all the belt dust from the slipping 6 rib drive system.

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#7 ·
While installing the new ATI damper hub, I made sure to add a bead of black silicone to the keyway and the back of the damper washer. If you forget to do this, then result will be an oil leak.
 
#9 ·
I got some more work done. Using a sanding disc to clearance the timing cover for the new ATI 12% overdrive damper
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On a side note, the home made flywheel locking tool worked great for trolling the damper bolt.
 
#10 ·
The stock 2001 Cobra water pump is to short to work with the new wider Fort truck pulley so it was a perfect opportunity to upgrade to a new "long style" Stewart water pump.

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#11 ·
The ATI damper is in and getting started on swapping out the stock Cobra power steering pulley for the 8 rib OEM Ford F65E3A733CA pulley
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Stewart water pump and a wider truck OEM F6TZ8509AA water pump pulley.
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#12 ·
Installed the rest of the 8 rib pulleys and the new Gates "fleet runner" 8 rib belt. Also installed a new OEM Ford tensioner. I sourced the spacers rather inexpensively from a Nascar race supplier. I used five .280 spacers to move out the Vortech bracket out and all of the idler pulleys get a .140 shim. The new 8 rib A/C, water pump and power steering pullies install without any modifications. As mentioned earlier, the 8 rib alternator pulley shaft needs to be machined down.
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Another shot showing the new 8 rib idler and wider tensioner pulley. In order to fit a wider pulley on the factory cobra belt tensioner, A custom .280 spacer and pilot along with a .140 shim for the new pulley was needed. Some people reuse the 6 rib idlers or swap over to a 3 bolt belt tensioner, but I did not like either one of those methods so I figured out a way to replace all of the pulleys with the wider truck versions and everything came out great.
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As an added bonus, I solved an oil leak that has bothered me for ever. It turns out that some of the bolts for the Votech blower bracket that go into the timing cover will leak oil unless you silicon them in. One final note on the Vortech bracket, You will need longer bolts and here I got a little creative and sourced some nice new shoulder bolts from land Rover and Ford that had the sizes I needed. I wanted to avoid using cheap hardware store bolts.

The alternator case does not need to be clearanced if you use a 2.87 pulley, but the right Vortech alternator mounting boss will require some grinding to clear the wider blower idler pulley.
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#13 · (Edited)
New hoses with AN 16 fittings hooked up
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Modified coolant crossover clears the wider 8 rib pulley with ease. I also installed new ARP 12 point stainless steel alternator bolts
I'm thinking about polishing the Alternator to bling up the engine compartment some more, so I might pull the alternator and go to work on it with a sanding disc and some sand paper.
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#14 ·
Decided to polish the Alternator and I got it done in an evening with a sanding disc, 400, 2000 and some aluminum polishing paste.
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Now that the 8 rib conversion is done, I'm goint to start work on the power pipe and MAF ducting to take care of the random stalling and surge issues. I believe that the stalling issue is being caused by a sharp 90 bend after the maf, no screen on the lighting maf and a blow off discharge valve that is too close to the MAF, thus resulting in MAF issues.

Here is the stock Vortech intake tubing with the sharp bend after the maf that can cause drivability problems.
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The coyote control pack instructions warns against sharp bends in the MAF ducting:

"1) Flow Profile: the MAF sensor should be located on a straight section of zip tube where the flow profile is generally uniform. If the sensor cannot be located on a straight section put the sensor on the outside radius of the zip tube so the sensor is located in the higher flow velocity area.
2) Flow Area: Keep the cross sectional area of the MAF sensor tube as close as possible to the cross sectional area of the original induction system.
3) Flow quality: minimize flow direction changes and maintain smooth tubing to minimize air flow disturbances and turbulence.
4) Flow pulsation: install sensor at least 6 to 8 inches upstream of the throttle body.
5) Transient performance: installing the sensor too far upstream of the throttle body (>24 inches) will result in transient lean/rich spikes due to the additional amount of time required for the measured air flow to travel from the MAF sensor to the intake manifold.
6) MAF sensor contamination: A) install sensor in upper half of cross sectional area to minimize possibility of condensation coming in contact with the MAF sensor element. In other words, if a clock is superimposed on a cross section of the zip tube, the sensor should be installed somewhere equal to or above the 9:00 and 3:00 positions. Most OEM applications have the sensor located at the 9:00 or 3:00 location. B) Sensor must be installed downstream of air filter and upstream of blow-by inlet. Ideally, sensor should be located 3 diameters upstream of the blow-by inlet."

http://www.jegs.com/InstallationInstructions/300/397/397-M-6017-A504V.pdf
 
#15 ·
I started work on improving the MAF ducting by fabricating a screen that goes after the air filter. The job of the screen is to straighten the air flow going into the MAF in order to eliminate erratic readings. Next, I added a four inch extension and a smooth 45 degree duct to further eliminate the possibility of turbulant air going into the MAF. Since the MAF is further down than before, I used A Diablo sport MAFIA to extend the MAF harness.

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In the engine compartment, I relocated the Maxflow blow off inlet on my home made power pipe by angling it as close as possible to the blower inlet in an effort to eliminate the possibility of any MAF wash issues.

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Final Upgrade was done on the ATI damper. It turns out that after I washed down the motor, the black oxide 12 point damper bolts rusted.
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I ordered some ARP stainless 12 point bolts to replace the rusted originals and at $25 for a set of six bolts I think it's a no brainer to do this upgrade
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New bolts installed on the damper
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It's interesting that the ATI damper for the Dodge Hellcat comes standard with ARP stainless steel bolts.


Hopefully I can find some time to drive the car in the next couple of days and give a report on how the modifications helped or didn't help in resolving the belt slip, stalling, hard start-long crank and random surge issues.
 
#16 · (Edited)
I took out the car for a night out on the town and results were fantastic. The hard starting, surging and random stalling issues were eliminated and now the car idles nice and smooth. The belt slip problem has also been solved and thanks to the ATI 12% overdrive damper, the car feels stronger down low as the boost kicks in sooner than it did with the stock damper so mission accomplished on all fronts. Finally, it was very rewarding to create my own 8 rib kit and design/ fabricate a power pipe that looks good and works great.

With the drivability and belt slip issues solved, I can now dig into my macbook pro and start playing around with the pro racer software and dial in the maf transfer function. Yep, many people say that you can't use the pro racer software on a mac, but that is not true since I have a Macbook pro with windows software loaded on it and it runs the PRP software just fine and I had no issues with it when I load a base tune into the PCM of my 01 Cobra.

Final take away: The 8 rib conversion kits out on the market are insanely over priced, but they might still be an option for those of you who enjoy wasting money and are unwilling to put in the time and effort to run some calculations and figure it out on your own to up with a home brewed 8 rib conversion kit. I also like the fact that except for the ATI Damper, all of the 8 pulleys are stock Ford Super duty pick up truck parts so I ever need new ones, I can go to the dealer or the local parts store rather deal with shady on line vendors who spam the various Mustang forums.
 
#17 ·
Decided to install some upgrades the front end accessory drive in the form of a new billet belt tensioner and a Dayco Gold Label heavy duty belt. Since Thump Racing discontinued their single bolt tensioner for the 2001-2004 mustang 4.6, a billet tensioner from ARS was the only choice.
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ARS said that their tensioner would fit behind a Vortech bracket, but that was not the case as the photo below showed
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So I modified the Vortech bracket to make it fit
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New Tensioner installed
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I was happy to find a heavy duty belt in black rather than green!
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With the new belt and tensioner, the car picked up some extra boost down low as 5 pounds of boost is available at just over 3000 RPM's so overall even with an 8 rib conversion there is still some rome for improvement by going to a billet tensioner.
 
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