The question here should not be one of reliability or durability, but simply what type of power band you, as an individual driver, prefer. Roots and Twin Screws are very different beasts from centrifugals. I have no doubt that both the URD and TRD set ups are very well R&Ded and will make their respective owners very happy, but it really is an apples to oranges comparison. The rotrex in the URD should make more peak power than the roots TRD, and it should have more potential on the top end (read max HP and TQ). The TRD however, being a PD charger, will be better on the lower end until the centri catches and passes it in the mid to upper RPM levels. The centris power delivery is much more linear than the fat, almost constant torque curve of a PD. Yes, I understand that a centris low end can be improved by smaller pulleys or larger gears, but, IMHO, you cannot beat a PD charger for low end muscle. One the other hand, the only thing that beats a centri for peak numbers is a turbo and mucho $$$$. I have never worked with or driven in a rotrex charged car, but I have a lot of experience with paxton, procharger and vortech centris and magnusson and kenne bell PDs in Corvettes. The centris are awesome quarter milers and will walk most maggies all day on the track, but it is a different story on the streets...I prefer my power down low and don't care much about top end, so I will be going with the TRD set up at some point, but I can't wait for anything URD might come out with to make it better.
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2007 FJ, 6 Speed, Black Diamond, 3" Rough Country, 17x9 Polished DC-1s, 33x12.5 MTZs, FlowMaster Super 40, TRD CAI, URD Short Shifter
If URD made their SC compatible with the TRD CAI/Safari snorkel, I'd be all over it. I was actually told that the URD setup was better for your engine than the TRD. I can't remember why....maybe more efficient cooling or something. Anyhow. Looks like I'm going with the TRD unless someone comes out with a better one that works with the CAI. The supercharger isn't very high on my list of mods at this point. Don't get me wrong, I can't wait to have one someday, but other things need attention first. Its not like the FJ is underpowered to begin with. All the extra weight I'm running has slowed things down a bit though.
If URD made their SC compatible with the TRD CAI/Safari snorkel, I'd be all over it. I was actually told that the URD setup was better for your engine than the TRD. * All the extra weight I'm running has slowed things down a bit though.
Another very cold day in Colorado...
Custom intake routing for the URD is not a challenge to do, the one wire set on the sensor needs to be cut and extended to turn the intake tube 180 deg over to the fender side. BOV routing can be redone. Have a custom intake tube fabbed up and adapt to your snorkel kit with sheet steel. Aluminum if you have a tig guy around would make it go smoother. Its only $$$ ha-ha
* The oil cooler was the lowest point during the fill and start up*
Had it hanging upside down, twice it has been flipped over and put back while running. but In the pictures it looks bad. when it gets flipped over and corrected right, to be the lowest point it might have to be lowered a few inches in placement of the oil cooler. Needed the 90deg fittings.
But its flowing and maintaining an even temperature across now.
* Yes that control box is in the engine compartment*
Because I tapped them in per the instructions and then caught the mistake of pushing the wires through instead of the vac line out. Cutting; looking forward to that.. In the last pic it moved up to the AFE for a better mistake for now.
The AFE mod box just made sense for this application, It was full assembled out side the FJ and serviceable in the engine compartment. The room that bumper takes up in useful space is unreal. Pretty good for flying blind on making conversions for the install. Thanks I enjoyed putting my spin on a already well thought out Supercharger application. Again I forgot to drive the vehicle before a monster mod, SO I guess I'm spoiled. They aren't all this fast??
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Master pro rally mechanic owns tune store.
National champ two car pro team in 04.
How do you make a small fortune in Racing?
Start with a large one....
The question here should not be one of reliability or durability, but simply what type of power band you, as an individual driver, prefer. Roots and Twin Screws are very different beasts from centrifugals. I have no doubt that both the URD and TRD set ups are very well R&Ded and will make their respective owners very happy, but it really is an apples to oranges comparison. The rotrex in the URD should make more peak power than the roots TRD, and it should have more potential on the top end (read max HP and TQ). The TRD however, being a PD charger, will be better on the lower end until the centri catches and passes it in the mid to upper RPM levels. The centris power delivery is much more linear than the fat, almost constant torque curve of a PD. Yes, I understand that a centris low end can be improved by smaller pulleys or larger gears, but, IMHO, you cannot beat a PD charger for low end muscle. One the other hand, the only thing that beats a centri for peak numbers is a turbo and mucho $$$$. I have never worked with or driven in a rotrex charged car, but I have a lot of experience with paxton, procharger and vortech centris and magnusson and kenne bell PDs in Corvettes. The centris are awesome quarter milers and will walk most maggies all day on the track, but it is a different story on the streets...I prefer my power down low and don't care much about top end, so I will be going with the TRD set up at some point, but I can't wait for anything URD might come out with to make it better.
I here what you are saying allot that people prefer the TRD because of its low end grunt. I have had both S/C I had the TRD on my 3.4 Tacoma and the URD on my FJC. The TRD S/C didn't seem to have allot of low end grunt. IMO it took for ever to get going then once it did it let out power near the end of the power band. It also would ping like crazy and wasn't really all that impressive.
When URD first called me and asked me if I wanted an S/C on my FJC I told them no. I hated having to constantly tune my TRD one and it sounded horrible. They told me they would take care of any issues I had with there charger. So I let them barrow my FJC for about a month and when I got it back it was a differnt FJC. At first I will be honest it wasn't that impressive I guess the computer had to recalibrate for it. Once it broke in about 5-7k into the FJ it was fun to drive.
Mine does pull harder at higher RPM's then lower but I don't know if I would want the same power at 1k as I have at 4k I think I would start breaking parts. Where I really feel the difference is on the freeway, there is very little lag and you can feel the car pulling hard. Same for steep climbs it pulls nice and hard.
What made it even better was when I re-geared the axles I was running 35in tires with stock gears and the S/C and it felt fine but I wanted more low end o the trails so I went to 4:56 gears and now it's a little rocket. I didn't know a 5000lb SUV could feel so alive.
I guess what I'm saying is don't get the TRD expecting it to be a torq monster. I have driven both in a FJ and owned both on different vehicles. I can honestly say I'm way happier with the URD.
Where in the world are dyno graphs of both of these so we can compare? Everything is just hear-say untill we see some dam plotted power graphs...
IF the TRD has more Grunt down low, well fine, but how much and when does the URD pass it up, 500 rpm later 3000 rpm later.. I just want some dam facts on this and Im sure others do to.
There are no "facts" per say.. Tuning plays a major part of any forced inducted setup and you can alter the VE, timing, etc. to change how power comes on and when.
It's a general roots/twinscrew vs. cent. conversation.
Many other factors come into play comparing one unit to the next. Something else to consider is heat. The Rotrex unit will not generate as much useless energy as it is much more efficient than a twin screw blower.
I know this is an old thread but I'm ready to buy a supercharger unit for my 08 FJ seriously considering URD Mk3 Supercharger kit vs. TRD supercharger. I like the marketing info on the URD site but my main concern is that there are not many details on the URD website and as far as I can tell no one around our area (Miami, FL) has or seen one or even heard of URD. I don't want to get stuck with a $5000 anchor. I also want to make sure the unit will work with safari snorkel and TRD catback exhaust. Has anyone here experienced or seen a URD unit? any issues I should look for? Is this something my experienced mechanic should be capable of installing without issues (he's not a speed shop but works on many exotics and foreign cars/trucks incl. Toyota) I've contacted URD for installation instructions and some photos but no luck yet so I'm in limbo asking here for any advice or info. Should I stay the "safe" route and go with TRD or go for more power and hope it works out with URD?
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