Dragon TB Driving Me Crazy

[TVS VERT]

Long story short love the dragon tb, the throttle response, power it makes and drivability.....but the high idle issue is driving me insane ive tried almost everything recommended online the only way the idle drops below 1200rpm is if i push the throttle linkage backwards to close it drops to 1000rpm. Its almost as if the return spring isnt strong enough

Do you guys recommend anything?? Ive tried contacting Stefan several times but no returned calls.

Any help or input would be awesome.

 

[346CamaroSS]

Lol heres another one guys.

These things dont work right out of the box period.

You gotta search around for fixes. Long story short you need to make sure your tps voltage is right, and you will need to mess around in some idle tables to get it dialed in right.

My experiece with it... Well it was on the car a whole week before i had enough and put the stock set up back on

Sent from my SPH-D710 using Tapatalk 2

 

[foxman92]

i have added another return spring to mine, put one end on the throttle cable/ cruise cable bracket, and other end on bottom of TB.. still high idle, ive adjusted it as i was told to.. IM more sick of the stock pcv system and the Idle air control valve being on bottome of TB.. the pcv is letting oil by, and its collecting into the tb/plenum.. it filled the iac and wouldnt idle!!! so i have a few things to fix.. but this tb is starting to annoy me..

 

[cobracide]

Listen - a throttle body is not just a drop in mod. If you all found that out afterwards, you didn't do your reasearch.

http://www.svtperformance.com/forum...hrottle-body-tune-questions.html#post11793326

 

[KINGCOBRA86]

I set my tps at 960 with a return spring from a carb kit also unplugged the iac and adj the screw to we're I wanted the idle, then unplugged the neg battery cable and turnd on the headlights over night and put the cable back on started up the car , gave it 40miles now it runs great!

 

[04sleeper]

You MUST properly set the throttle stop, TP sensor and ISC Integrator.

If your throttle body doesn't stick when the car is shut off, then its not the throttle body.

Anyone that uses a return spring to try to fix this is only causing issues and not fixing the root of the problem.


There is not one aftermarket single blade throttle body out there that will close and seal exactly like the factory twin bore throttle body. The factory twin bore throttle body has round blades and the singles have oval. By nature the single will never seal the same way a twin bore will.

Hold a stock throttle body up to the light and see how much light shines through around the blades. Now do the same with the aftermarket. You will see what I am talking about.

The IAC valve controls the amount of air bypassing the throttle body so the car can idle. Since the stock throttle body seals very well, the IAC valve needs to flow a certain amount of air to keep the idle correct. If you leave the tune set with the factory values, the IAC valve assumes you have the stock throttle body that seals perfectly. Remember the aftermarket single blade by nature will never seal the same and air will get around the blade and housing causing a high idle. The ECU is doing EXACTLY as it is commanded to do causing the high idle. Adding an extra spring only fights what the IAC valve is trying to control. By adding the extra spring you only mask the problem, you do not fix it!

If you do not properly set the set screw, set the TP sensor, and Idle air integrator in the tune, you will never have it correct.

Here is the proper procedure for installing single blade throttle bodys:
1. Warm up car
2. Turn engine off and REMOVE THE KEY
3. Disconnect negative lead from battery and turn head lights on( this removes the capacitive charge in the system)
4. Connect negative lead to battery
5. Back off the stop screw on the throttle body
6. Start car
7.While grasping the throttle lever with your hand, give it a small amount of throttle and let off SLOWLY.
8. Adjust the stop screw to just meet the lever and give it another 1/8-1/4 turn and, then lock it down.
9. Turn ignition off.
10. Turn key to "ON" position and check TPS voltage. Set to .980 Volts with a Digital Multimeter (Fluke Meters are the most accurate)
11. Turn key off.
12. Repeat steps 1-4 to reset ECU.
13. Turn off Adaptive Learning in your tune so you can make the proper adjustments without the ECU making them for you. (Your tuner should know how to do this)
14. Datalog ISC duty cycle: this value tells you how much the IAC valve is having to stay open in order to control idle. ideally you want to be around 35%.
15. Datalog Idle air integrator- this is a value that correlates with the idle air neutral table values in your tune. They should be fairly close to zero. If it’s negative then you need to take air out of the ISC tables, if it’s positive then you need to add air into the tables. It’ll never be exactly zero. Allow the car to be at operating temp and idling for a few minutes before making a decision on this. In layman's terms- the integrator could be telling your ecu that more air is coming in than what is actually coming in- causing your high idle.
16. Turn on Adaptive Learning in your tune and drive car as you normally would so that the ECU can relearn again.

I would also like to add that due to the nature of single blade throttle bodies being oval, the cam eccentric needs a different profile than stock to make the car respond the same. Most do not have the proper cam eccentric geometry. Accufab, for example has a cam eccentric from a 2000 Cobra R. Which causes the cruise control to "Hessitate" when engaging.

Also, this is why most people "Feel" like the single blade throttle body gives them more "Throttle Response" It's all relative to the cam eccentric.

Given the same amount of flow, a twin bore throttle body will make the same amount of power as the single blade yet it will provide a much more stable foundation due to the shaft having a support in the middle between the blades as opposed to the single having no support in the middle.

On High HP applications a single blade can actually "Bend" upon closing. This is one of the resaons you see OEM's choose large twin bore throttle bodies over single. "A La Ford GT", "GT 500", etc....

Hope this helps.

 

[03cobra#694]

Excellent info Kevin, and saved...

 

[moddedmystic]

Follow these steps......

1) install TB and plenum
2) rotate the TPS CW(opposite throttle movement) then snug the screws
3) plug IAC in (DO NOT SCREW IT ON, LEAVE IT OFF)
4) duct tape over the IAC holes on the plenum
5) have someone start the car(DO NOT TOUCH THE GAS PEDLE) if it won't start, turn the butter fly stop screw in a bit, try to start again(repeat till running)
6) adjust the stop screw till you get the idle to 700-750RPM
7) let the car idle for 5-10 min's
8) turn car off
9) remove duct tape, install IAC
10) turn key to "on position" (do not start car)
11) set TPS to about .98V, tighten the TPS
11a)On mine I actually had to open up the holes in the TPS with a drill bit so I could rotate it far enough to get the .98 volts
12) start car(DO NOT TOUCH THE GAS !!!!!!!!)
13) just let the car idle, let the computer "LEARN" for 10min's
14) turn car off
15) done



I had to do it with my dragon set up and it worked great!
Throttle was sticky,either from the high vacuum and/or all that pressure on the front side of that massive throttle blade. Plus it had that hanging idle that we all love so much. I know it works. I've done it to many types of different t/b's with those same symptoms and when I was done(just like with my dragon)they ran great. Only other thing I can add is you might have to do it a couple of times to get it to work.

~Mark

Maybe we should make this a "Sticky" and add it to the tech section :beer:

 

[Bdubbs]

Makes me wonder if the extra hp on different tb's is even worth it. Any idle issues with the twin bbk? When I go twinscrew I may stick with the stocker or bbk I guess.

 

[04sleeper]

Follow these steps......

13) just let the car idle, let the computer "LEARN" for 10min's

Maybe we should make this a "Sticky" and add it to the tech section :beer:

The cars ECU will only "Learn" error. The tune needs to be adjusted accordingly in order to be calibrated correctly.

Duct Taping the holes for the IAC does nothing!

You are correct about setting the TPS.

 

[suaveflooder]

You MUST properly set the throttle stop, TP sensor and ISC Integrator.

If your throttle body doesn't stick when the car is shut off, then its not the throttle body.

Anyone that uses a return spring to try to fix this is only causing issues and not fixing the root of the problem.


There is not one aftermarket single blade throttle body out there that will close and seal exactly like the factory twin bore throttle body. The factory twin bore throttle body has round blades and the singles have oval. By nature the single will never seal the same way a twin bore will.

Hold a stock throttle body up to the light and see how much light shines through around the blades. Now do the same with the aftermarket. You will see what I am talking about.

The IAC valve controls the amount of air bypassing the throttle body so the car can idle. Since the stock throttle body seals very well, the IAC valve needs to flow a certain amount of air to keep the idle correct. If you leave the tune set with the factory values, the IAC valve assumes you have the stock throttle body that seals perfectly. Remember the aftermarket single blade by nature will never seal the same and air will get around the blade and housing causing a high idle. The ECU is doing EXACTLY as it is commanded to do causing the high idle. Adding an extra spring only fights what the IAC valve is trying to control. By adding the extra spring you only mask the problem, you do not fix it!

If you do not properly set the set screw, set the TP sensor, and Idle air integrator in the tune, you will never have it correct.

Here is the proper procedure for installing single blade throttle bodys:
1. Warm up car
2. Turn engine off and REMOVE THE KEY
3. Disconnect negative lead from battery and turn head lights on( this removes the capacitive charge in the system)
4. Connect negative lead to battery
5. Back off the stop screw on the throttle body
6. Start car
7.While grasping the throttle lever with your hand, give it a small amount of throttle and let off SLOWLY.
8. Adjust the stop screw to just meet the lever and give it another 1/8-1/4 turn and, then lock it down.
9. Turn ignition off.
10. Turn key to "ON" position and check TPS voltage. Set to .980 Volts with a Digital Multimeter (Fluke Meters are the most accurate)
11. Turn key off.
12. Repeat steps 1-4 to reset ECU.
13. Turn off Adaptive Learning in your tune so you can make the proper adjustments without the ECU making them for you. (Your tuner should know how to do this)
14. Datalog ISC duty cycle: this value tells you how much the IAC valve is having to stay open in order to control idle. ideally you want to be around 35%.
15. Datalog Idle air integrator- this is a value that correlates with the idle air neutral table values in your tune. They should be fairly close to zero. If it’s negative then you need to take air out of the ISC tables, if it’s positive then you need to add air into the tables. It’ll never be exactly zero. Allow the car to be at operating temp and idling for a few minutes before making a decision on this. In layman's terms- the integrator could be telling your ecu that more air is coming in than what is actually coming in- causing your high idle.
16. Turn on Adaptive Learning in your tune and drive car as you normally would so that the ECU can relearn again.

I would also like to add that due to the nature of single blade throttle bodies being oval, the cam eccentric needs a different profile than stock to make the car respond the same. Most do not have the proper cam eccentric geometry. Accufab, for example has a cam eccentric from a 2000 Cobra R. Which causes the cruise control to "Hessitate" when engaging.

Also, this is why most people "Feel" like the single blade throttle body gives them more "Throttle Response" It's all relative to the cam eccentric.

Given the same amount of flow, a twin bore throttle body will make the same amount of power as the single blade yet it will provide a much more stable foundation due to the shaft having a support in the middle between the blades as opposed to the single having no support in the middle.

On High HP applications a single blade can actually "Bend" upon closing. This is one of the resaons you see OEM's choose large twin bore throttle bodies over single. "A La Ford GT", "GT 500", etc....

Hope this helps.

Great write up! Nicely done Kevin!

 

[03COBRA-88]

Alittle off topic but would these ford racing throttle bodys work on our cars? They say they use the same linkage and throttle cable connection that are on an 03/04 cobra. It's a 65mm just the the BBk made for our cars.

COBRA JET 65MM MECHANICAL THROTTLE BODY | Part Details for M-9926-CJ65M* | Ford Racing Performance Parts

 

[asierra1]

Hmm saving this thread


Sent from my iPhone while killing America's enemies with pure awesomeness

 

[moddedmystic]

The cars ECU will only "Learn" error. The tune needs to be adjusted accordingly in order to be calibrated correctly.

Duct Taping the holes for the IAC does nothing!

You are correct about setting the TPS.

Its worked for me and many others with out any "learn error" or ill side affects. You dont need to change the tune at all.
And yes the duct tape DOES do something ,it plugs the holes in the top of the throttle body elbo when the car is running. Otherwise you'd have a huge vacuum leak,lol.
On a side note (for Bdubbs), I had the BBK twin 65 on my heaton before the dragon and had to go through the same process to get it to idle properly.

 

[Fox-4]

Kevin, should those instructions apply to any single blade TB for 03/04 cobra?

 

[TVS VERT]

Got the dragon figured out now idling at 850-900 which is awesome compared to 1200rpm, thanks for all the help guys as i tried several emails and at least 8 calls to Stephan at dragon and still never recieved a call back or an email response glad my car came with the throttle body as i would nevr buy anything from that wanker

 

[mdrc347]

My fix for the dragon TB

Everyone seems to dodge the issue on this, but the fact is the dragon has more problems than most. I followed the steps that others have posted above perfectly, and it still didn't work right. It was better, but not good enough for me. I wanted a stock type feel and idle. I have talked to others that have had no luck with the above procedure as well, and have done as I did below. I really think that this boils down to how picky you are, and I am anal retentive. There is no reason that this TB should not work like stock after installed, especially considering the price that these things sell for. If it isn't going to work right out of the box, then it should be priced at half of it's current price. That's just my opinion. I don't have a problem making the above adjustments, but mine still did not work right after this. I had to do much more. Here is what I went through.

I finally talked to a knowledgeable tuner that told me the right fix. I had to remove the blade from the tb. Mark it with eraseable marker. Reinstall it in the tb, and open and close it a few times. Then, I had to remove it again and use emory paper to sand down the high spots where the eraseable marker had worn off. This is a huge pain in the butt, and I ruined the first blade because I removed to much.

Steffan is not the greatest about handling this issue. I had a lot of trouble getting him to return my calls and emails, and he refused to return my money and take the tb back. But, he did eventually work with me enough to fix the problem. It only took about 3 months. He did send me a new blade for free.

If you shine a flashlight through the back of the throttle blade and look closely at it, the problem is easy to see. The throttle blade is not machined to perfectly fit the bore. It has high and low spots around the outside edge. I HAVE seen other tb's for these cars that are NOT like this. At least not as bad.

This is what I did to eventually fix the problem 100%. I first did as I stated above with the eraseable marker and emory paper being more careful to not remove to much material. After doing this process 10-12 times which took over 2 hrs, It finally fit the bore properly. I reinstalled the tb on the car. It was better, but still not perfect. After looking at the tb even more closely, I was able to determine why. The throttle blade comes with a sharp edges around the outside on both the front and rear sides of the blade. After my procedure to make the blade fit properly and more tightly, this sharp edge seemed to catch just slightly on the tb bore when moved near the closed position.

Back off came the tb and out comes the blade again. This time I sanded down the sharp outside edges on both the back and front of the blade to give it a slightly beveled or rounded finish. You must do this by hand and not with any type of air tool, or you risk damaging the blade by removing to much material. All you need to to is remove the sharp edge, nothing more. Just make it a little rounded. After reinstalling the blade and the tb, it finally worked like a charm. And besides the gain in power and throttle response, I finally could not tell that the TB was different than stock. No additional springs were required, either. And, I then did the above posted procedure all over again to make sure that it was properly adjusted.

The last problem that I had with it, was that the idle stop screw would move under engine vibration. So, I removed the screw and used a hammer and chisel to "ding" the threads ever so slightly. This makes it so the screw will not move once set. I then repeated the above procedure again, and haven't had an issue since. Thinking back on it, I could have probably also applied teflon or something to the screw to achieve the same result.

Say what you want, but for the price of these things, that is the what the end result should be. I am sick of people saying that you have to sacrifice having a nice driveable car to modify it. In my opinion, my tb is the way it should have come out of the box. All that is required is for them to make the blade fit the bore better and round the edges of the blade, which should be done by the manufacture. And to machine the throttle stop screw in a fashion that would make it not move once set. The dragon is a good general design tb, but requires a lot of dinking around to get it to work the way it should.

Just my 2 cents. And if Steffan, or anyone else from dragon reads this, I suggest you incorporate this in to the manufacturing of these TBs if you want happier customers. I probably had a good day of time total in messing with it from start to finish. Maybe this will save some others some time and headache.

 

[suaveflooder]

Everyone seems to dodge the issue on this, but the fact is the dragon has more problems than most. I followed the steps that others have posted above perfectly, and it still didn't work right. It was better, but not good enough for me. I wanted a stock type feel and idle. I have talked to others that have had no luck with the above procedure as well, and have done as I did below. I really think that this boils down to how picky you are, and I am anal retentive. There is no reason that this TB should not work like stock after installed, especially considering the price that these things sell for. If it isn't going to work right out of the box, then it should be priced at half of it's current price. That's just my opinion. I don't have a problem making the above adjustments, but mine still did not work right after this. I had to do much more. Here is what I went through.

I finally talked to a knowledgeable tuner that told me the right fix. I had to remove the blade from the tb. Mark it with eraseable marker. Reinstall it in the tb, and open and close it a few times. Then, I had to remove it again and use emory paper to sand down the high spots where the eraseable marker had worn off. This is a huge pain in the butt, and I ruined the first blade because I removed to much.

Steffan is not the greatest about handling this issue. I had a lot of trouble getting him to return my calls and emails, and he refused to return my money and take the tb back. But, he did eventually work with me enough to fix the problem. It only took about 3 months. He did send me a new blade for free.

If you shine a flashlight through the back of the throttle blade and look closely at it, the problem is easy to see. The throttle blade is not machined to perfectly fit the bore. It has high and low spots around the outside edge. I HAVE seen other tb's for these cars that are NOT like this. At least not as bad.

This is what I did to eventually fix the problem 100%. I first did as I stated above with the eraseable marker and emory paper being more careful to not remove to much material. After doing this process 10-12 times which took over 2 hrs, It finally fit the bore properly. I reinstalled the tb on the car. It was better, but still not perfect. After looking at the tb even more closely, I was able to determine why. The throttle blade comes with a sharp edges around the outside on both the front and rear sides of the blade. After my procedure to make the blade fit properly and more tightly, this sharp edge seemed to catch just slightly on the tb bore when moved near the closed position.

Back off came the tb and out comes the blade again. This time I sanded down the sharp outside edges on both the back and front of the blade to give it a slightly beveled or rounded finish. You must do this by hand and not with any type of air tool, or you risk damaging the blade by removing to much material. All you need to to is remove the sharp edge, nothing more. Just make it a little rounded. After reinstalling the blade and the tb, it finally worked like a charm. And besides the gain in power and throttle response, I finally could not tell that the TB was different than stock. No additional springs were required, either. And, I then did the above posted procedure all over again to make sure that it was properly adjusted.

The last problem that I had with it, was that the idle stop screw would move under engine vibration. So, I removed the screw and used a hammer and chisel to "ding" the threads ever so slightly. This makes it so the screw will not move once set. I then repeated the above procedure again, and haven't had an issue since. Thinking back on it, I could have probably also applied teflon or something to the screw to achieve the same result.

Say what you want, but for the price of these things, that is the what the end result should be. I am sick of people saying that you have to sacrifice having a nice driveable car to modify it. In my opinion, my tb is the way it should have come out of the box. All that is required is for them to make the blade fit the bore better and round the edges of the blade, which should be done by the manufacture. And to machine the throttle stop screw in a fashion that would make it not move once set. The dragon is a good general design tb, but requires a lot of dinking around to get it to work the way it should.

Just my 2 cents. And if Steffan, or anyone else from dragon reads this, I suggest you incorporate this in to the manufacturing of these TBs if you want happier customers. I probably had a good day of time total in messing with it from start to finish. Maybe this will save some others some time and headache.

Interesting post! Thank you.

 

[cj428mach]

I would also like to add that due to the nature of single blade throttle bodies being oval, the cam eccentric needs a different profile than stock to make the car respond the same. Most do not have the proper cam eccentric geometry. Accufab, for example has a cam eccentric from a 2000 Cobra R. Which causes the cruise control to "Hessitate" when engaging.


Hope this helps.

Any suggestion on improving this? I'm pretty happy with my accufab. It idles great and drivability is pretty good. The only thing I don't like is the cruise operation. When the cruise is engaged it functions about like stock. Its just when initially setting the cruise it lags a little and then hits the throttle hard enough to even go into boost at times. :dw:

If the cruise part was fixed I'd say it was perfect.

 

[matt87]

stock maf with a an extender....check, stock throttle body with a port...check, stock injectors reflowed....check. my car drives what a 500 rwhp cobra should drive like, as if it were stock, and thats how i like it.