You 'should' get a retune for it, but its not going to pose any real problems if you don't, at most your idle may be a little off.281_tuner said:sorry to bring up this old thread but do you need a reflash for a bigger throttle body and ud pullies?any help would be appreciated thanks
Well do you really need a 75mm throttle body?281_tuner said:see the thing is im doing a pi swap and theres no telling when im going to get a dyno tune or another reflash,"maybe never lol" so i really dont know what to do i can get a deal on a reflashed eec but i also want the other mods,any suggestions?
the EECs adaptive strategy if he has one of Js chips might be able to read the changes in the engine parameters and adjust accordingly. My chip seemed to have been able to adjust for the changes in my TC when I put in my new trans..A reburn wouldnt hurt though.NRL said:
You 'should' get a retune for it, but its not going to pose any real problems if you don't, at most your idle may be a little off.
And just how many cfm do you think a stock or even a modified 4.6L can move?BirdofPrey97 said:You go from 425 cfm to 680 cfm.
That's not what I asked...BirdofPrey97 said:The stock cfm is 425 thats what ford says. C&L moves around 660cfm. These may not be exact numbers been a few months since I looked at it all. They all do cfm ratings.
I had C&L and hated it. I have Accufab and love it. As I said thats just my 2 cents. Read what the 3rd party said here. This is the 2nd of 2 tests. You can check their site for the first test, but the results are the same both times. Accufab wins!!
I dont want to argue with anyone, but they do make the best available product.
SCT Guy said:Whistle is a very interesting problem. It can be caused by seveal things.
The most common is the aftermarket throttle body manufacturers inabiltiy to make a quality part, this is all of them, not just one. A Ford throttle body is made the following way; There is a hole stamped in it for air flow when the blade is closed. Then the blade is closed in the bore and the hard stop is cranked open so that the blade does not stick in the bore. Then, to prevent air leaks a chemical substance called RJ is sprayed on the back of the throttle body blade to seal the blade to the bore. This ensures that the only air flow going into the engine at closed throttle is through that hole and the idle speed valve.
I can assure you that no aftermarket TB manufacturer does this. At one point BBK was spraying an epoxy paint on the back of their throttle bodies, but it flaked off (and was at best a poor solution). The problem is this, to do what I described costs money to set it all up (and RJ is a carcynogentic (I can't spell) compound that requires special handling $$) and do it right. So let's say our Accufab buddies go the extra mile and do all this and make it right. Now their throttle body will cost more than their compeition. So, you as the consumer think, why should I pay more for their throttle body, it's just a throttlebody. So you buy someone elses and they lose business. They have no choice now but to make a sub-Ford standard part to stay in that business. In addition, even if they marketed their throttle body as being better than the other guys, and it would be, can they really charge more money for it, probably not. There will always be some idiot that says his cheap *** TB has no problems. In the mean time he has no clue that his air integrator in his PCM is going nuts trying to control idle, and *****es to his tuner that it doesn't seem to idle right....But, it's just a throttle body.
So, it really comes down to you the consumer being cheap asses and buying stuff that is marginal in quality, so the people that want to do a good job have no choice but to succomb to that level to continue to sell parts. You get what you pay for, a cheap throttlebody is, well, cheap. Its your fault, not theirs.
Now, there are also some other things that can cause whistle, like how the air from the idle speed valve gets introduced into the elbow (it's not a plenum, that's at the bottom of the manifold). The ISC valve flows air at part throttle and the way the air passes through the clean air tube, where the ISC gets it's air from, and the way it's introduced after the valve can have a huge affect on whistle.
From the factory on many cars is an ISC damper, that square black box. This is designed to help some of these issues.
That's ok, I'll take Jerry's word for it..BirdofPrey97 said:Who has read comsumer reports on these TBs? Would like to know what they say......
SCT Guy said:The single biggest problem I see is the throttle body air flow not set right. This problem manifests itself in several ways;
The engine races too much at startup.
When you go to closed throttle the car doesn't slow down like it use to.
The idle could hunt some.
When you push in the cluch on a manual, the engine speed flares up (although there is some of this in a stock car, but that's another post).
I didn't even get into this, but let's say you realize that the airflow is too high so you turn the screw down. Well, without the RJ to seal the blade in the bore, you can probably go all the way down to the point where the blade sticks in the bore. Anyone ever have their TB stick when coming in from closed throttle?
I know of no aftermarket company that sets the airflow when the blade is closed, and can control that airflow to within normal Ford tolerance. I even worked with one once to help them and when the dust settled, they didn't want to take the time to do it, they didn't have a flow bench to create that much vacuum, stuff like that.
Go talk to the '03 Cobra or Lightning guys (my friends ) with the single blade throttle body and ask them how well idle is controled. It's not, not at all. The shafts are too thin (in an attempt to make them smaller to get more air flow) so the blade actually distorts under vacuum and the closed bore air flow actually changes with time as the blade/shaft take a permanent set. Total nightmare....
If all you have is whistle, you should feel lucky.