Steeda Delete Plugs - My Impression
04-23-2010, 09:17 PM
#1
2nd Gear Member
Thread Starter
Join Date: Feb 2010
Location: Virginia
Posts: 464
Steeda Delete Plugs - My Impression
Well, it's been 10 days since installation of my Steeda Delete Plugs, and I want to share some impressions of installation and performance. There is other stuff out there, but not one particular thread that hits "on point" to the pros and cons I experienced. I hope this helps someone else.
For those who are unfamiliar, there are butterflies within the intakes of the 2009 and 2010 models (they are located within plates just below the intake in earlier models). These butterflies stay closed until about 3000 RPM, at which time they open and allow more air into the intake. The idea here, they stay closed at lower RPMs to increase torque and open up at 3000 RPM when the extra airflow is needed.
Problem is, at the point in which they open, the air/fuel tables, timing, etc. must adjust . . . and this split second adjustment is what causes the infamous 3000 RPM "flat spot." For me, the problem was even worse -- I have 4.10 rear end gears and when really cold and in first gear, the flat spot was having the same effect as lightly feathering the throttle, and it actually was enough to make the car surge/buck.
By removing the butterflies (at which time you must install these plugs in small holes in which the butterflies were located), you increase airflow and allow for the tune to be simplified, i.e. the air/fuel, timing, etc doesn't need to adjust for their opening at 3000 RPM. The flat spot is eliminated, and Steeda advertises you gain "up to" 10 HP. In reality, I've read they're only worth about 4 RWHP, and only in the upper RPM where the airflow is truly needed. But, at a cost of only about $60, that actually represents a good $-to-HP ratio. Obviously, the car must be re-tuned to adjust for this modification.
Installation: There's several threads out there (not necessarily in this forum) that discuss installation. It's truly not difficult. It took me 3 hours, but only because I really took my time, as it was a beautiful day out. Further, I also installed a JLT CAI at the same time, so I took the time to make sure both were done with care and cleanly.
For reference, there is an actuator on the back of the intake that is connected to long rods, a.k.a. "jackshafts," on either side of the intake. When the computer sends a signal to the actuator at about 3000 RPM, it turns the jackshafts. The jackshafts open and close the butterflies.
Steeda's instructions are decent. However, of issue, when you follow Steeda's instructions, you literally remove not only the butterflies in the intake, but the two "jackshafts" that hold and turn them. The Steeda Delete Plugs seal the necessary areas where the butterflies were, but they leave one hole on the back of each side of the intake where the jackshafts normally exit (and connect indirectly to the actuator). It was these holes that end up leaking on some folks and causing performance issues and the occasional CEL. With the factory setup, the jackshafts have plastic bases that adequately seal the holes.
Some folks used sealant in these holes, but I've read of mixed success. However, Chris Rose at Tillman wrote of a brilliant idea on another forum: Cut the rods off the jackshafts (so that the Delete Plugs can still be installed) and reinstall only the jackshaft's plastic base. In that way, you have completely removed the butterflies, but sealed all holes in the intake. THIS IS THE CLEANEST WAY TO ENSURE YOU HAVE NO LEAKS. In my case, I bought some extra (uncut) jackshafts from a member of another Mustang forum so that I could reinstall them and return the car to stock, if necessary.
Performance: Some have complained that making this modification costs low end torque, while others have said a good tune will keep the torque while still giving you all the HP gains at higher RPMs that the plugs are supposed to give.
In reality, it did cost some torque, but I love it. You see, I had Tillman Performance tunes before this change. And before the plugs, I found the '93 Tillman All Out' tune to be too jumpy, i.e. I couldn't drive it slow. I generally used the '93 Road Race' tune, and even it was tough. I was either "all on" or "all off." My wife complained that she couldn't drive it, i.e. it lost driveability because the throttle was so touchy.
Now, with the plugs, the entire power band is so much smoother. There are no flat spots or jumpy areas. The car is not twitchy, even with the 'All Out' tune. I can now drive it slow, fast, or somewhere in between. And, when you get on it, it still feels like a rocket just as it did with the tune alone. Simplified, the power has been spread throughout the band so much nicer.
Keep in mind, I did install the JLT CAI at the same time. However, in going from a tune alone to the tune with the CAI and plugs, I attribute the newly found smoothness to the plugs. Also note, my 4.10 rear end gear undoubtedly compensates for any loss of torque in a way 3.31, 3.55 or 3.73 gears won't.
In short, I highly recommend this modification. The only downside -- you'll have to take the 1-2 hours to put it back before taking the car to the dealer for warranty work. If you try to install the stock tune with these plugs in place, it won't be pretty.
For those who are unfamiliar, there are butterflies within the intakes of the 2009 and 2010 models (they are located within plates just below the intake in earlier models). These butterflies stay closed until about 3000 RPM, at which time they open and allow more air into the intake. The idea here, they stay closed at lower RPMs to increase torque and open up at 3000 RPM when the extra airflow is needed.
Problem is, at the point in which they open, the air/fuel tables, timing, etc. must adjust . . . and this split second adjustment is what causes the infamous 3000 RPM "flat spot." For me, the problem was even worse -- I have 4.10 rear end gears and when really cold and in first gear, the flat spot was having the same effect as lightly feathering the throttle, and it actually was enough to make the car surge/buck.
By removing the butterflies (at which time you must install these plugs in small holes in which the butterflies were located), you increase airflow and allow for the tune to be simplified, i.e. the air/fuel, timing, etc doesn't need to adjust for their opening at 3000 RPM. The flat spot is eliminated, and Steeda advertises you gain "up to" 10 HP. In reality, I've read they're only worth about 4 RWHP, and only in the upper RPM where the airflow is truly needed. But, at a cost of only about $60, that actually represents a good $-to-HP ratio. Obviously, the car must be re-tuned to adjust for this modification.
Installation: There's several threads out there (not necessarily in this forum) that discuss installation. It's truly not difficult. It took me 3 hours, but only because I really took my time, as it was a beautiful day out. Further, I also installed a JLT CAI at the same time, so I took the time to make sure both were done with care and cleanly.
For reference, there is an actuator on the back of the intake that is connected to long rods, a.k.a. "jackshafts," on either side of the intake. When the computer sends a signal to the actuator at about 3000 RPM, it turns the jackshafts. The jackshafts open and close the butterflies.
Steeda's instructions are decent. However, of issue, when you follow Steeda's instructions, you literally remove not only the butterflies in the intake, but the two "jackshafts" that hold and turn them. The Steeda Delete Plugs seal the necessary areas where the butterflies were, but they leave one hole on the back of each side of the intake where the jackshafts normally exit (and connect indirectly to the actuator). It was these holes that end up leaking on some folks and causing performance issues and the occasional CEL. With the factory setup, the jackshafts have plastic bases that adequately seal the holes.
Some folks used sealant in these holes, but I've read of mixed success. However, Chris Rose at Tillman wrote of a brilliant idea on another forum: Cut the rods off the jackshafts (so that the Delete Plugs can still be installed) and reinstall only the jackshaft's plastic base. In that way, you have completely removed the butterflies, but sealed all holes in the intake. THIS IS THE CLEANEST WAY TO ENSURE YOU HAVE NO LEAKS. In my case, I bought some extra (uncut) jackshafts from a member of another Mustang forum so that I could reinstall them and return the car to stock, if necessary.
Performance: Some have complained that making this modification costs low end torque, while others have said a good tune will keep the torque while still giving you all the HP gains at higher RPMs that the plugs are supposed to give.
In reality, it did cost some torque, but I love it. You see, I had Tillman Performance tunes before this change. And before the plugs, I found the '93 Tillman All Out' tune to be too jumpy, i.e. I couldn't drive it slow. I generally used the '93 Road Race' tune, and even it was tough. I was either "all on" or "all off." My wife complained that she couldn't drive it, i.e. it lost driveability because the throttle was so touchy.
Now, with the plugs, the entire power band is so much smoother. There are no flat spots or jumpy areas. The car is not twitchy, even with the 'All Out' tune. I can now drive it slow, fast, or somewhere in between. And, when you get on it, it still feels like a rocket just as it did with the tune alone. Simplified, the power has been spread throughout the band so much nicer.
Keep in mind, I did install the JLT CAI at the same time. However, in going from a tune alone to the tune with the CAI and plugs, I attribute the newly found smoothness to the plugs. Also note, my 4.10 rear end gear undoubtedly compensates for any loss of torque in a way 3.31, 3.55 or 3.73 gears won't.
In short, I highly recommend this modification. The only downside -- you'll have to take the 1-2 hours to put it back before taking the car to the dealer for warranty work. If you try to install the stock tune with these plugs in place, it won't be pretty.
Last edited by cidsamuth; 04-23-2010 at 09:22 PM.
04-23-2010, 11:18 PM
#2
Awesome write up! I am really glad to see that everything worked out for you. I was hoping that the car was going to get better for you. I know you were really bothered (as I would be, too) by the surging problem, and I'm glad to see things panning out for you! Call me if you need absolutely anything else! Updates, etc.
04-24-2010, 07:26 AM
#4
2nd Gear Member
Thread Starter
Join Date: Feb 2010
Location: Virginia
Posts: 464
Thanks, both.
Chris, I know you're on vacation. I talked with Chris Tillman about a fast idle when cold with this tune (particularly if the air conditioning/defrost was on), but no worries -- the car must have just needed to "adapt."
When the new tune was installed, after two cold startups, and then two other cold startups with the defrost on, the idle adjusted to normal. This was in addition to the normal procedure of letting the the car idle at operating temperature with and without the air conditioning on.
I didn't realize the idle needed to set for open loop, but I guess it did . . .
Chris, I know you're on vacation. I talked with Chris Tillman about a fast idle when cold with this tune (particularly if the air conditioning/defrost was on), but no worries -- the car must have just needed to "adapt."
When the new tune was installed, after two cold startups, and then two other cold startups with the defrost on, the idle adjusted to normal. This was in addition to the normal procedure of letting the the car idle at operating temperature with and without the air conditioning on.
I didn't realize the idle needed to set for open loop, but I guess it did . . .
04-24-2010, 11:33 AM
#8
Thanks, both.
Chris, I know you're on vacation. I talked with Chris Tillman about a fast idle when cold with this tune (particularly if the air conditioning/defrost was on), but no worries -- the car must have just needed to "adapt."
When the new tune was installed, after two cold startups, and then two other cold startups with the defrost on, the idle adjusted to normal. This was in addition to the normal procedure of letting the the car idle at operating temperature with and without the air conditioning on.
I didn't realize the idle needed to set for open loop, but I guess it did . . .
Chris, I know you're on vacation. I talked with Chris Tillman about a fast idle when cold with this tune (particularly if the air conditioning/defrost was on), but no worries -- the car must have just needed to "adapt."
When the new tune was installed, after two cold startups, and then two other cold startups with the defrost on, the idle adjusted to normal. This was in addition to the normal procedure of letting the the car idle at operating temperature with and without the air conditioning on.
I didn't realize the idle needed to set for open loop, but I guess it did . . .
I'm not on vacation, I'm with a new company. Idle is absolutely adaptive. It enters closed loop very quickly, but yes idle needs to be learned no matter what the current fueling state is. Give me a call, my contact info is in my signature if you need anything!
