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• I already have a GT500 supercharger (M122 or TVS) and/or other parts needed to complete the installation. Can I order a Phase III kit minus those items and get a discounted price?

• What is the safe limit of my stock motor?

• How hard is it to install?

• Why would I want to use one of those “junk” stock GT500 M122 blowers?

• How much power can a GT450 kit make?

• Can I run the GT450 kit with my cams, ported heads, headers, etc?

• Can I put the big aftermarket GT500 blowers on the GT450 (Whipple, Kenne Bell, etc)?

• What other supporting modifications will I need?

• Who can tune my GT450 kit?

• Why doesn’t Department Of Boost supply tunes with their kits?

• Are the GT450 kits 50 state emission legal?

• Can I put a GT450 kit on my 2005-2010 Mustang with an automatic transmission?

• Why doesn’t my shop want to install a GT450 kit?

• Can I put a blower on my high mileage car?

• How many GT450 kits are out in the world?

• How Do I Get The Stock Supercharger Pulley Swapped For The GT450 Pulley?

I already have a GT500 supercharger (M122 or TVS) and/or other parts needed to complete the installation. Can I order a Phase III kit minus those items and get a discounted price?

If you don’t need a supercharger subtract $300.
If you don’t need a GT500 throttle body Subtract $50.
If you don’t need a GT500 cold air kit subtract $75.
If you don’t need injectors subtract $175.
If you don’t need a heat exchanger subtract $40.
If you don’t need an intercooler water pump subtract $100
If you have other items you need pricing for please feel free to email us.


“What is the safe limit of my stock motor?”

The safe limit of your 4.6L 3v motor is 450rwhp and 6,000rpm’s. You’re flirting with danger running any more than that.

Some people will say that the 3v is only good or “XXpsi”. That is not the correct way of expressing the limits of the motor. Boost does not break parts, power does. Depending on a lot of factors (exhaust, inlet size, ported heads, etc) you can make 450hp with anywhere from 7-14psi. So saying that the motor is safe to XXpsi is simply not an accurate enough way to gauge safety.


“How hard is it to install?”

Installing a GT450 kit is no harder to do than any other positive displacement blower kit. And easier than some. There is a little more “hot rodding” when installing a GT450 kit but nothing that is mentally challenging. Just a little more time consuming. That’s splitting hairs though. The instructions (which can be found on this site) are very thorough and everything is explained in detail. Installing blower kits is not “hard”. They’re time consuming because there is a lot to do. But they are not “my brain hurts” hard. Most people are capable of doing a blower install for their first big project.

It will take your average home mechanic 16-18hrs to install. Basically a weekend.  If you’ve done blower kits before or are a little more advanced it takes about 10-12hrs. If you’re a “Pro” expect it to take you 9-10hrs.


“Why would I want to use one of those “junk” stock GT500 M122 blowers?”

Out there in internet land the stock 07-12 blowers (2.0L Eaton M122’s) are commonly referred to as “Heatons” because highly modded GT500’s that are still running M122’s have high intake air temperature (IAT) problems. The high IAT problem in this situation is because of many factors. Yes, the M122 is not as efficient at compressing air as let’s say a Twin Screw blower (a Whipple for example). But the M122 is not a horrible blower by any means. When the GT500 crowd goes looking for more power out of their stock M122 they start by speeding it up…….a lot. On a stock GT500 the M122 spins at 15,625rpm which is right in its “sweet spot” and it doesn’t make a ton of heat. When the GT500 guys go for big power out of the M122 they first bump it up using a smaller upper pulley to 18,750rpm, which is not in its sweet spot anymore. And it really starts to make some heat. The next step is to add a 10% overdrive lower pulley which spins the blower at 19,875rpm. Now they’re making a lot of heat. The next step after that is to run a 15% overdrive lower pulley which spins the blower at 20,325rpm. Which makes a TON of heat. And all of those blower speeds are based on them not spinning the motor past 6,250rpm. If they raise the motors rev limit (most do) the blower spins even faster. There are guys out there spinning their stock M122 at 23,000rpm!!!! Some of these guys are spinning their M122’s 50% over their “sweet spot”. It’s no surprise that they don’t perform very well and produce a lot of heat. Complaining about a blower spinning nearly 50% faster than its sweet spot and making a ton of heat is like spinning your motor to 9,000rpm and complaining when parts come flying out of it.

A GT450 kit making 450rwhp spins the M122 at 13,000rpm. Yes, at 450rwhp we are spinning the M122 slower than what a stock GT500 does (2,625prm slower). That makes for a very “happy” blower with low IAT’s and very little parasitic loss.

The M122 is not a “junk” blower. There are no junk blowers out there (that we know of). The problem people run into is they try and use the wrong blower for their goals. Different blower designs, sizes, etc do different things better than others. But it mostly comes down to size (displacement). If you try and get more power out of a blower than it was designed for it will give you problems, it really is that simple. The M122 is VERY “happy” making 450rwhp. And it remains happy all the way up to about 575rwhp. Someone could spend more money and run a 2.3L TVS, 2.3L Whipple, 2.3L Edelbrock, 2.8L Kenne Bell, etc. and at 450rwhp won’t see any performance advantage over the M122. So who wins? The guy who spent less money and went with the M122? Of the guy who went with the other ones? We say the guy making the same 450hp with no sacrifices for less money…..wins.

There is a horsepower level where the M122 won’t be big enough and getting into something else is the smart move. But 95% of people never go for that kind of power. And for those that do at some point, they can put a 2.3L TVS on the GT450 manifold. No need to get a completely different kit.


“How much power can a GT450 kit make?”

This is a tricky question and quoting power numbers these days is very difficult because the industry and the public as a whole use “fuzzy math” when making claims. What does “How much power will it make?” really mean? Are we talking about a stone stock motor with stone stock exhaust? Are we talking about a built motor with ported heads, big cams, high compression pistons, monster exhaust and a huge throttle body and cold air intake? Or somewhere in between? Are we talking about 91 octane gas or 93? Are we talking about e85? As we’re sure you can tell there is going to be a huge difference in “what it makes” between stock and wild. And if you’re adding e85 to the mix it blows the whole estimate right out of the water.

That said here are some reasonable numbers that are based on the blowers running on stock 4.6L 3v motors (aside from forged rods/pistons so parts don’t fly out) running 93 octane gas, on the same dyno, on the same day. These numbers are based on the blowers spinning at 18,000rpm which is the effective safe limit. These numbers can move up or down depending on other variables.

Keep in mind none of these blowers will make this power out of the box. At an absolute minimum they would all need fuel injectors and fuel pump upgrades to see these numbers. Some will need more supporting mods than that. None of the kits are capable of running the maximum power the actual supercharger can make out of the box.

-The stock 2007-2012 GT500 2.0L M122 blower will make about 605-615rwhp.

-The stock 2013-2014 GT500 2.3L TVS blower will make about 665-675rwhp.

-The Whipple 2.3L will make about 625-645rwhp.

-The Roush 2.3L TVS will make about 625-645rwhp.

-The Edlebrock EForce 2.3L TVS will make about 580-590rwhp.

-The Kenne Bell 2.6L will make about 585-595rwhp.

-The Kenne Bell 2.8L will make about 675-685rwhp.

“But some dude on the internet is making 725hp out of his XYZ blower on his 3v. Those numbers aren’t right”!

The numbers listed above can go up or down based on conditions, fuel used, how safe they are tuned, how happy the dyno they were on is, other supporting modifications, etc. They are simply a representation of what you can expect out of the above blowers when they’re compared to each other under the same conditions.


“Can I run the GT450 kit with my cams, ported heads, headers, etc?”

You sure can. Positive displacement blowers don’t care much about what motor they are bolted to. Would a “blower” cam work better than a “naturally aspirated” cam? Yeah, just a touch. Nothing you could ever feel in the seat of you pants though. As far as things like ported heads, headers, exhaust, etc. they simply make the blowers job easier. So if you already have a bunch of bolt ons and you want to put a GT450 kit on it’s no problem at all. The only change you would want to make compared to someone without bolt ons is you may want to run a bigger upper pulley (slows the blower down) when running a stock shortblock. A bolt on motor will make 450rwhp easier than a stock one so you will want to run the blower a little slower to stay under that 450rwhp threshold. We can advise you on what pulley to run and you can change your pulley size when ordering at no charge.


“Can I put the big aftermarket GT500 blowers on the GT450 (Whipple, Kenne Bell, etc)?”

You can upgrade to a Eaton 2.3L TVS with the GT450. Most of the time people get them as take offs from 13-14’ GT500’s. The TVS can be run up to about 750rwhp on e85. If you’re looking for more blower than that you’re going “big time” anyway and should be looking at our 3V R-Spec kit. It was designed from the ground up to run huge blowers on the 4.6L 3v motors.

As far as the other big GT500 blowers go (2.8, 3.2, 3.6, 4.7L Kenne Bell’s and 2.9, 3.4, 4.0, 4.5L Whipples) the short answer is no. The big blowers will physically bolt up to the intake manifold but there will be a few issues getting it to work reliably.

First off is the drive belt situation. The 4.6L 3v motors have a 6 rib belt. All entry level blowers use that same 6 rib belt system. It’s adequate for most 3v applications but when things get turned up to “kill” the system needs to be converted to 8 rib. And even this will get you only so far. Stock GT500’s come with their own dedicated 10 rib belt for the blower and A/C compressor (they run a 6 rib belt for the other stuff). You need that 10 rib belt when playing with the big GT500 blowers. There is no easy way to convert the 4.6L 3v to a 10 rib belt to drive those big blowers. You could maybe possibly get away with running an 8 rib system on a big GT500 blower if you weren’t spinning it very hard, but it would be problematic, there would still be some fabrication necessary to make it all work and why put a big expensive GT500 blower on and not run it hard? That’s a colossal waste of money.

Second problem is that the blower offset front to rear is a little different on the GT450 so the huge blowers will have issues clearing the firewall.

Third issue is that a solution would have to be found for mounting the alternator. The GT450 location is not going to quite work with the huge blowers. Different brackets would need to be fabricated.

Long story short is that if you’re looking at going “big time” with a 3v (over 750rwhp) you want to be looking at a kit designed specifically for those goals. Our 3v R-Spec kit. There is a lot more to running huge blowers than “will it fit”. They need all sorts of supporting systems to work properly. Belt and intercooler systems to name the two most important .


“What other supporting modifications will I need?”

The short answer is none. You can bolt a GT450 kit on your car and run it as is with no problems. Plenty of people have done this.

We all have the mod bug though, so we will mod. Here is a list of the top desired supporting mods in order (according to us).

-Air/oil separator catch can. The 4.6L 3v already tends to suck oil through the PCV system into the intake manifold. It will do it more with a blower. It’s a good idea to run a air/oil separator on any blown application.

-Urethane engine mounts. We like Prothane.

-Clutch. If you’re going to drive hard and have big fat sticky tires you’re going to want to think about a clutch.

-Rear lower and upper control arms. You will have a lot more torque with a positive displacement blower, which means you will spin the tires more. S197’s already have a little wheel hop now and then. You will have more with the blower. Control arms help out a lot with this.

-Big fat rear tires.

Of course there are about a million and one things that would be nice to do. But these are the top of the list.


“Who can tune my GT450 kit?”

Any tuner that can tune a Mustang can tune a GT450 kit. Most tuners will find that the GT450 kits are easier to tune than some others because it uses stock Ford parts for all of the tuning related items (injectors, mass air sensor, intake air temp sensor, etc)

You can get your car tuned at your local dyno facility or you can have it remote tuned. The simple explanation of remote tuning is that you do driving tests for the tuner. You then email them your logs (the data your tuning device sees), they make changes, then email you back an updated tune. You repeat this process a few times until your car is tuned properly. Remote tuning works very well and 9 times out of 10 it is what we do ourselves. A great tuner for the 3v is Manuel Pazo from Tudyno. He is who we use for 3v tuning. He can be contacted at You can also find him on Facebook.


“Why doesn’t Department Of Boost supply tunes with their kits?”

To be perfectly honest the number one reason is it’s a PITA and tuning is not what we do. If we wanted to offer tunes there would be a infrastructure put in place to support that and we simply aren’t big enough to add a “department” for tuning.

Additionally, we are not fans of supplied or “canned” tunes for blown cars. Even if we purchased a blower kit from another company we wouldn’t run the supplied tune. Supplied tunes are very, very safe. And that means they are down on power and run very soft. Supplied tunes need to be that way because every car is a little different. If they were to supply a dialed in tune it’s possible that someone will put it in a car with some other mods other than the blower and it will not be safe anymore. Canned tunes are pig rich and don’t have much timing. They run like crap.

You really, really want a custom tune for your car. The number one reason is so you can be 100% sure you are tuned safe. The number two reason is you want your car to make all the power it can make and run well. Tuning is incredibly easy in this day and age. There are dyno shops on every corner and if you don’t want to do that there are a couple of tuners that do remote tuning which is a great option.


“Are the GT450 kits 50 state emission legal?”

The short answer is no. It’s not because they couldn’t be made to be 50 state legal. It’s just that we don’t deal in large enough volume to be able to afford to get the kits certified. But…….

This is all in theory of course, we would never condone doing something illegal…….We aren’t in a state with emission testing so all of this is what we have head or been told. We don’t have any first hand knowledge.

There are a lot of people running GT450 kits in states with emission testing. What state you live in would determine how easy it is to get your car to pass the emission test. If your state simply tests the emissions at the tailpipe they are pretty easy to pass. Most good tuners can write you a tune to get past the sniff test. If your state has a visual inspection, it will be tougher. The good news is that the GT450 uses stock Ford parts so when you pop the hood your average person is going to think it’s stock even though they are looking at a supercharger.

You best bet when dealing with emission compliance is to get in touch with your local hot rod community and see what they’re doing. People get past emission every day in every state with aftermarket parts. The trick is figuring out what you need to do.


“Can I put a GT450 kit on my 2005-2010 Mustang with an automatic transmission?”

Yes. The only difference between a manual and auto trans supercharger kit is the tune. Your tuner will be the one who “makes it for an auto”.


“Why doesn’t my shop want to install a GT450 kit?”

Some shops won’t want to install your GT450 kit. Not all, but some.

Your shop doesn’t want to install your GT450 kit because of one simple reason, money. We are not saying that they’re wrong for basing it on money. Making money is what they’re supposed to be doing after all.

When your shop puts a blower on your car they are usually selling you that blower, which they make money on. They make money because they are set up with one or a few blower manufacturers (or distributors) and they get their kits at a lower price than you do. We have already priced our kits as low as they can go and that is the price we give our customers. We didn’t pad the price so we can afford to sell the kits to shops for less than we do our customers.

Most shops bill by the hour ($100/hr for example). And they pay their employees by the billed hour. If the shop charges you 12hrs to put a blower on and it takes them 14hrs they “lost money”. And the employee isn’t going to be too happy because they just got paid for 12hrs but it took them 14. If a shop sticks with one or two different blower kits and only installs those they can get really fast at them and make more money. They will still charge for 12hrs, but if they can do the job in 8hrs because they have done so many of them they are very happy. There is nothing wrong with this at all, it’s smart. But if they’re only installing a certain kit and doing it faster than 12hrs every time they are going to be less thrilled about tackling a different kit and maybe seeing their work time balloon to 12hrs+. It’s not that your shop doesn’t want to install a GT450 kit. They just don’t want to install a different kit then they’re used to.

Your shop makes money when they sell you the blower and they can make more money per hour if they get fast at a certain kit(s). That is why some shops won’t want to put your GT450 kit on. There is nothing at all wrong with this. They should be doing everything they can to maximize profit and stay in business.


“Can I put a blower on my high mileage car?”

Yes you can. But it depends on what shape the motor is in. And that mostly boils down to cylinder sealing. If you’re at all concerned about running a blower on a high mileage do a compression test. And if you’re really worried do a leakdown test. If the numbers are good you can put a blower on.


“How many GT450 kits are out in the world?”

We sold our first GT450 kit 1/7/12. There are over 250 GT450 kits out there in the world now. It has been completely tested and proven.


“How Do I Get The Stock Supercharger Pulley Swapped For The GT450 Pulley?”

If you purchase your supercharger (the actual head unit) from us in a Phase II or III kit it will come with the GT450 quick change pulley and hub already on it. If you purchase your own supercharger you can do one of two things:

-Remove your supercharger snout and send it to us to be swapped. The supercharger snout is very easy to remove/install. The only “hard” part is you want to catch the 6oz of fluid that comes out so you can re-use it. We will swap the GT450 components on to your snout and ship it back with your manifold kit free of charge.

-You can swap the pulleys out yourself but it’s not the easiest thing in the world. You will first need a pulley removal tool. They are about $150-160. That will be used to remove the stock one. Then our hub needs to be heated up to 350deg F and then “dropped” on the shaft with a “stop” attached to the face of it so the alignment is correct. We can walk you through this if you want to go this direction. For most people sending it in is the best option.
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