the port for the IAC is tiny
Point?
Be assured though that any difficulties/noise/unpleasantness I run into will be accurately described and the solution posted.
Just the facts.
As for the trimming the TB, I
think that it really just needs to be trimmed down to the first groove cut into the top. The "stop ring" for the air tube is taller than stock as well. Will be cutting the 90 elbow down to the minimum I can get away with. As I do not have, or have access to, a lathe I will have to cut the TB the hard way. The hose can run through the band saw without issue and yes, I will attemp the TB cut on the band saw as well...
Pricing. Where else can you get either a 68mm or a 70mm TB for less? For that matter, where else can you get a 70mm TB? It is an impossibility to machine the stock TB out anywhere near that far. This is a true 68mm through bore. I went to F&B not for the price but for the experience they have with supercharged engines.
I may sound like a shill for F&B but I can assure you all, I am not, Laid out near $400 to get the TB to my door.
IMO, if you increase the displacement (via bore/stroke or forced induction) the TB should be increased. Now, sprintex assured me that the stock TB would be just fine and that is what I posted originally in my SC thread.
When I bult the 4.7L back in '01 or so, I ran the stock TB for a time. After thinking about it, I replaced it with the factory 68mm (65mm after the neck down) from the 4.7L V8. At the time, Chryco had two, one for the "Magnum" engine and the "standard". The difference was 3mm with the Magnum, obviously, having the larger of the two. Made a world of difference. By my lights, if the engine is 15% larger (4.6L) or 17.5% larger (4.7L) then the flow capability of the TB needs to change as well. But, then again, that is just my opinion.
After both living with the SC for some time now and, more importantly, running the test that F&B uses, I respectfully disagree with this assessment. It is my opinion that in order to hold the cost of the kit down, they elected to recycle the stock TB. Just as they went with the "extra" injector route. With the limitations of the Chrysler PCM, you have to add in a piggyback anyway so the cost savings is in supplying one injector, not six.
Work begins in the morning. As the garage is not air conditioned (it is heated, snow you know...) the work will stop once the temperature gets up to "too bloody hot" point and then continue the next day. I do not do well in the heat so I am estimating that this will take more than two days to complete. Possibly as many as four. It all depends on how quickly I can open up the SC intake maifold to accept the TB. I am not trusting this work to the Kid so fighting my disability comes into play. He will be doing all of the heavy lifting and taking care of the discharge manifold mods. Doing the discharge manifold will be easy as it only requires the existing IAT location to be opened up and retapped to accept the AEM Sensor, the bottom side sanded smooth (the better for the insulation adhesive to grab) and the insulation applied. The exhaust manifold gets a blanket so that will not take long either. Pictures will be taken and posted.
BTW, a simple three bolt to four bolt adaptor plate plus opening up the intake manifold will put a factory TB on your Heep... Not a difficult task, the linkage is the only major issue and for that, you need to sacrifice a stock TB. I was on JU at the time I did this and the thread may still exist there or, more likely, it may be gone due to it's age. I used a piece of 1" T6 (6061) aluminium plate for the adaptor I made back then. This was soon after Dr. Dyno put a Ford TB (from the Mustang) on his stroker. I wanted to stay "All Heep" with the mod so...
If there was room under the hood, I would have done it again in lieu of the new TB. My labor is cheap... And, I still have some of that plate laying around. Doesn't everyone? Have tooling grade aluminium laying around? No? Hmm... But, alas, no room...
For those that possibly are now thinking about this, half inch plate will work just fine. As long as you can get the countersunk fasteners into it (to hold the adaptor to the manifold) you are good to go. An idea, yes? You can snag a TB for less than $50 from
www.car-part.com all day long. The other thing you have to do is to use the pintle from the 4.7L TB with the IAC stepper from the XJ. The XJ TPS will bolt on. The IAC pintel is longer on the WJ/Dodge TB so, it has to be swapped. Now that I think about it, I did cut a gaskets for the TB and the adaptor out of stock gasket material. Also laying around.
Be amazed at just how much "stuff" you get laying around after better than a half century of playing with toys.
I call it stuff and goodies. My Wife nas another name for it...
