I can't keep flange bolt nuts on mine. I have tried lock washers and double nuts. I am sick of pulling them out of the belly pan. I am also not happy that Bob would not answer my emails or return my calls. The only way to get out of the drone at highway speeds was to run high RPM in 3 rd and sometimes 4 th. Hennessey ordered the Heffner with baffles. I was curious if the baffles are removable? I would like to dyno with and without.
IDA exhaust problem
- Thread starter kosupply
- Start date
BlackICE
GT Owner
The Heffner baffles are removable. They sandwich between the cat and exhaust flanges. They are Vortex baffles.
KO, there must be more to this story? Bob Ida has done a lot of work on several GT's including installing his exhaust design and other upgrades on my GT. I have nothing but good things to say about my dealings with him. PD
analogdesigner
GT Owner
belleville washers
Since I used to own this exhaust, I would try the following;
Place a belleville washer (load rating should be about 2,000 lbs.) under the heads of all six fasteners. Then, place a large diameter (about 1.0" O.D.), thick, hardened washer between the belleville washer and top of the exhaust flange. This hardened washer should be just large enough to prevent the belleville washer from marring the top surface of your exhaust flange. For the bottom side, use a flanged nut. This type has an integral thick washer as part of the nut to spread the clamping force over a larger area. If a flanged nut is not available, try another large, hardened washer between the nut and cat flange. The use of a washer on the bottom side is less critical due to the cat flange's thicker material. Use new, quality fasteners with a thread lube with a low friction coefficient, suck as ARP thread lube or a known anti-sieze. Ideally, the fastener and the nut could be different materials to minimize galling between the thread interface. There will be a tradoff between ultimate clamping force and flange distortion. I know this is a subjective, seat-of-the-pants engineering approach, however, I expect you will have much better results. I would stay away from high tensile strength fasteners, such as Grade 8. A 300 series stainless steel or grade 5 hardness is probably better, since their high tensile strength is not a goal for your situation, as it will not stretch as much.
I have just completed my new GTsaver "Classic" Exhaust system. I am trying to do my best at creating a structurally sound and good looking fastener setup. Since there is a high level of vibration, safety wire can help with keeping the pieces together, however I am not a real fan of this technique.
Perhaps Bill, Kendall or others can suggest something.
Good luck,
Jay
www.gtsaver.com
http://www.fordgtforum.com/forums/forumdisplay.php?f=34
kosupply,
Since I used to own this exhaust, I would try the following;
Place a belleville washer (load rating should be about 2,000 lbs.) under the heads of all six fasteners. Then, place a large diameter (about 1.0" O.D.), thick, hardened washer between the belleville washer and top of the exhaust flange. This hardened washer should be just large enough to prevent the belleville washer from marring the top surface of your exhaust flange. For the bottom side, use a flanged nut. This type has an integral thick washer as part of the nut to spread the clamping force over a larger area. If a flanged nut is not available, try another large, hardened washer between the nut and cat flange. The use of a washer on the bottom side is less critical due to the cat flange's thicker material. Use new, quality fasteners with a thread lube with a low friction coefficient, suck as ARP thread lube or a known anti-sieze. Ideally, the fastener and the nut could be different materials to minimize galling between the thread interface. There will be a tradoff between ultimate clamping force and flange distortion. I know this is a subjective, seat-of-the-pants engineering approach, however, I expect you will have much better results. I would stay away from high tensile strength fasteners, such as Grade 8. A 300 series stainless steel or grade 5 hardness is probably better, since their high tensile strength is not a goal for your situation, as it will not stretch as much.
I have just completed my new GTsaver "Classic" Exhaust system. I am trying to do my best at creating a structurally sound and good looking fastener setup. Since there is a high level of vibration, safety wire can help with keeping the pieces together, however I am not a real fan of this technique.
Perhaps Bill, Kendall or others can suggest something.
Good luck,
Jay
www.gtsaver.com
http://www.fordgtforum.com/forums/forumdisplay.php?f=34
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are they baffles or cones? As far as fasteners go, try smashing the nuts with a hammer before installing them, creating an interference fit.
Ida exhaust
I haven't had any problems with my Ida exhaust. I tightened the flange & bracket nuts once & I check them occasionally. They have been tight since then. I am not experiencing the drone you mentioned but revel in the awesome sound at full throttle & the great crackling & popping when letting off the gas. Very cool! I'm sorry you had the problems. Best of luck.
Ed
I haven't had any problems with my Ida exhaust. I tightened the flange & bracket nuts once & I check them occasionally. They have been tight since then. I am not experiencing the drone you mentioned but revel in the awesome sound at full throttle & the great crackling & popping when letting off the gas. Very cool! I'm sorry you had the problems. Best of luck.
Ed
BlackICE
GT Owner
Silverbullitt
GT Owner
If you would like to forget about this problem use Locktite Stud and Bearing mount (red). You will have to break the bolts to remove them.
BlackICE
GT Owner
Red loctite is weakened by heat. I suspect that the exhaust is hot enough to weaken the bond, so loctite won't be much help.
I too have an Ida.Horrendous drone between 1500-2500 RPM.Contacted Bob and he says its normal for a high performance exhaust????????
Since IDA did not propose a fix, the Heffner exhaust will be here next week. Champion Ford has tried different fixes to the nut problem to no avail. There was not much adjustability with the IDA and it really had to be finagled to fit. Having said this....does anyone want my IDA???
STORMCAT
GT
I've bought the Vortex cones thru Jegs. I'm going to try them on my Accufab someday... I bought my Accufab used and It did not come with bolts. I used 3/8" SS bolts, nuts & lock washers. SS stays together better due to the natural binding tendencies of S.S.
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No more to the story. I had it shipped directly to Champion Ford in Houston. I probably bought one of the early ones because it has been on my car for over a year. Champion has changed the oil every 2000 miles ( 8000 on car), EGR valve, brakes , trans cooler, door panels etc. Everytime it has been in the shop, we had to replace nuts. Service after the sale is important. I am sure Bob has satisfied a lot of people or he would not stay in business. All of the X and H pipes are similar in design and I am sure sound close to each other. I love the crackle and pop on deceleration, but the drone at highways speeds wears me out. The exhaust sounds better outside of the car than inside. I noticed that at the track when someone else was driving the car.
BlackICE
GT Owner
The drone is probably a resonance frequency of the interior, that is why you don't hear it outside the car. All confined spaces have certain frequencies that are reinforced. OEM exhaust system are designed to tune out that frequency, so whatever sound is magnified is not noticed. My guess is the resonance is around 1900-2100 Hz. I think all X and H pipe cat backs have this problem to some extent. Some people are more sensitive to it. Some people drive there GTs in a way that it isn't a problem. If it really bothers you, a stock or Borla is are the best choices. Very hard to build a notch filter without a big can.
The same problems setting up subwoofers for a stereo or home theater.
The same problems setting up subwoofers for a stereo or home theater.
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Spirit
Heritage GT Owner
The Dreaded Drone
Ice,
You are right on the money as to the resonance frequency of the interior being the "drone" culprit.
I have an Accufab unit on my GT with, NOT what I would call a "drone", but rather a sound "change". Right at 2,000 rpm there is a definite sound change that takes place in the cabin. It becomes louder, but not quite a "drone", then at about 2,100 rpm all settles down again and becomes very nice.
My suggestion is, when ever possible, one should take a ride in a GT that already has the exaust system one may be contemplating. Have the driver run it through the rpm ranges and judge for yourself if the sound is acceptable to you and your driving style.
I have noticed that mine "likes" to "cruise" right at 2,000 rpm. So where ever you normally drive, is where you should really take note of the sound level, and be certain that it is comfortable for you.
Fred
Ice,
You are right on the money as to the resonance frequency of the interior being the "drone" culprit.
I have an Accufab unit on my GT with, NOT what I would call a "drone", but rather a sound "change". Right at 2,000 rpm there is a definite sound change that takes place in the cabin. It becomes louder, but not quite a "drone", then at about 2,100 rpm all settles down again and becomes very nice.
My suggestion is, when ever possible, one should take a ride in a GT that already has the exaust system one may be contemplating. Have the driver run it through the rpm ranges and judge for yourself if the sound is acceptable to you and your driving style.
I have noticed that mine "likes" to "cruise" right at 2,000 rpm. So where ever you normally drive, is where you should really take note of the sound level, and be certain that it is comfortable for you.
Fred
Bob is the man
Lots of work on my two GTs,He is there for me all the the time,Whipple
pullys chips exhusts talks all the time with me.He knows fords like no one
i know.sorry for your bad time.
Lots of work on my two GTs,He is there for me all the the time,Whipple
pullys chips exhusts talks all the time with me.He knows fords like no one
i know.sorry for your bad time.
Bart Carter
GT Owner
For those of you having trouble with fasteners loosening: Use a castellated nut or an all-metal stop nut. These are necessary due to exhaust temperatures.
Aircraft Spruce
Aircraft Spruce
thanks for the tip....my heffner exhaust with baffles is at hennessey ready for instal.....just waiting on the rain to stop in houston!!!