Has anyone tried this?

[318willrun]

A guy on ebay is selling 5.2/5.9 throttle bodies that he has brought from a 47mm to 50mm by boring and polishing. They are 99 bucks and 9.99 for shipping. Claims better throttle response, gas mileage, and upper rpm horsepower. Anyone try this??? His ebay user name is 1999blkdakrt

P.S. I paid 88 bucks for an aluminum throttle body spacer that was suppose to create a vortex effect. I could tell no difference.

 

[DaveBonds]

The vortex/ twist spacers don't do a damn thing, nor do the twisted air horns that go on to a throttle body or carb.

Air velocity changes completely, by the time it gets into the cylinder head runner, through the intake runner. The only time that it matters is down that far, when the air has been channeled down the runner. A set of 302 heads will make a difference in velocity on an LA, but as far as a magnum goes, you've already got the science right there.

A spacer is supposed to help keep air and fuel mixture cooler in a carburetor, but I don't know that it would do anything on a TB, unless it was TBI, but even then, I don't see it making much, if any valuable difference.

Increasing size will do nothing for you, without doing a hand full of other modifications to make use of it. On an engine that you want to produce more low end RPM torque, it can actually handicap it.

 

[318willrun]

Thanks, Davebonds. Your statements kind of matches what I had already thought. Maybe somebody else will chime in that actually tried one? My 5.2 does fine in first gear, in traffic. However, going down the highway I think it lacks some torque/power when needing to pass or pull a long grade hill. My Durango is the two wheel drive. I thought about a "Jet power tuner" that plugs in under the hood by the ECM. Perhaps I should pull the intake (my gasket underneath is bad anyway) and shorten the ports. Some say this does a lot for the 5.2/5.9 magnums...

 

[fishy68]

It might improve the top end slightly (and I mean a very slight barely noticeable diff) but I have the hardest time believing a larger throttle body will improve fuel mileage. If anything I'd think it'd hurt fuel mileage.

Also a comment on the JET piggyback chip you mentioned. I tried one and the difference was so little (barely noticeable) it wasn't worth the money IMO. Then I bought a Superchips tuner and tuned it. Nice improvement. Could tell it picked up power all the way through the RPM range. If I had a guess I'd say +20 hp. The Superchips also has more than just the all out power setting. Been a while since I messed with it but if I remember right it has a towing mode and a max perf 87 octane mode that does help fuel mpg 1-2 mpg and gives you a slight power boost. The Superchips will also read DTC's.

Is the exhaust system stock? I also added an aftermarket exhaust to mine and it picked up some power up high.

 

[318willrun]

Good info, fishy 68. I often wonder if the best bet is to pay the salvage yard 350.00 for a 360 mag. That would be a 45 more ft. lbs. of torque, and about 20 horsepower. I guess I'll see, and check more into the super chip set up you talked about....

 

[adiffrentcity]

Thanks, Davebonds. Your statements kind of matches what I had already thought. Maybe somebody else will chime in that actually tried one? My 5.2 does fine in first gear, in traffic. However, going down the highway I think it lacks some torque/power when needing to pass or pull a long grade hill. My Durango is the two wheel drive. I thought about a "Jet power tuner" that plugs in under the hood by the ECM. Perhaps I should pull the intake (my gasket underneath is bad anyway) and shorten the ports. Some say this does a lot for the 5.2/5.9 magnums...

Seems like the best option I saw when I had my truck was a combo of shortened runners and a "turtle" of a very specific shape welded in on the bottom plate. Check the Dakota-Durango forums. Also an SCT plug in tuner and an email tune from... Dang I can't remember his name... [email protected] I think... would be much more effective than one of the one size fits all types.
There are also guys on that forum that sell oversized TBs. IMO more trustworthy than some random guy from fleabay. A TB as stated already will do the most if you also have a cam, headers, and other stuff as I'm sure you know. Best of luck to you! Be sure to check out that forum too, basically a modern truck version of FABO.

 

[rumblefish360]

There is a guy on one of the truck forums, I think it was the Dodge Dakota forum, that does work on the throttle bodies. Nice work. He and I spoke at a short length. He told me that he would do the work but cautioned about just what you guys are saying.

The mod itself was worth a few ponies. A few ponies is hardly worth a notice. Something a time slip picks up but not you. The V6 would be a barley registering improvement. Even with other mods the Dakota guys were doing to there V6 engines, there really was never anybody jumping and shouting about it. Mostly a bunch of pissed of guys getting cruddy results. I think it is to much weight for the V6 to move effectively.

In a car? Probably a different story. The V8 guys seemed to like his mods. Then again, a 5.2 or better yet the 5.9 returns are a bit better and noticeable. They were normally coupled with other mods.

 

[moper]

Not a Magnum - but similar situation... When I bought my 1st gen Neon it had the usual blown head gasket & oil leak. While the head was off I did a bunch of what I called "clean up" work. That included porting the head, plus the intake manifold, the exhaust manifold, and the throttle body. There was a 2-3mm radius in front of the throttle plate. I assumed it was for throttle response as it would speed up the air as it went through the blade. I took that out and smoothed the opening to the blade's diameter so there was no restriction. I don;t have horsepower figures, I also milled the head and degreed the cams.. But I'm guessing the whole deal was worth another 30-40hp. I could run away from modified ACR and R/T Neons at will, in any gear. It also would keep up with most stock performance cars (like the V-8 Mustangs) on the highway. There was a moderate decline in idle quality but I had done a bit of work. I'm sure it's worth something though.

 

[blk00rt]

the belly pan gasket is bad, it will pool oil in the bottom of the intake and decrease performance. The Throttle body will probably not help much unless he opened up the bores near the throttle blades and has put in new blades due to the increased size. The Jet chip is not a good idea it just tricks the motor to think it is running in a really cold temperature thus adding more timing to it..but it does not work as well as having someone tune the computer with an SCT system. Exhaust work will help if you can find mopar mid length headers they are probably the best ones for your application, if not Spintech midlengths would be another alternative. As far as tuning goes Sean (AKA Hemifever is good) and so is Flying Ryan. Both have taken the magnum engines to the next level as far as programming goes. the real limiting thing is the intake it is made for a truck and runs out of power soon. The mopar 2 bbl with a fastman 52 tb will get you going, then the Harland sharp bolt on 1.7's non adjustables will be good too. If you go to Dakotart.com there are some guys there that have really worked over their motors and are still running the stock computer with a custom tune they can give you some ideas about increasing the power on them.