What to look for in used blower

[Jabooh]

So I am thinking about boosting the Boss. I am settled on a roots style (Roush, Ford Racing, VMP) blower.

Obviously it is a good bit cheaper used. What needs to be inspected, tested, on a used blower like this?

 

[Grant 302]

I'd look for bearing end-play, condition of the rotors & housing, and any service history. But most of all with used car parts, I'd consider the seller.

Good luck shopping. Weren't you thinking about going this route a while ago?

 

[Jabooh]

Yes I was. Just never got there. There is a used Roush in my area, complete kit, and he wants $4k.

With the 2015 models out I want a little more power. I was thinking of going N/A but to get to 500 is way more than $4k.

 

[blacksheep-1]

Boosting is one of the least expensive ways to create power, that being said a blower does build a lot of heat and so turbocharging is usually prefered for track cars. If you want an extremely nice, roots type blower, I would highly recommend a Kenne Bell, IMO they are the king of roots blowers. I've had experience with them and I currently have one with over 40K miles on it, no issues. They have also gone to great lengths to improve their customer service, which, in the past was a bit of an issue. Those blowers are designed to be torque monsters and power come son right off idle.
FWIW

 

[MordFustang]

I went with a Vortech/centrifugal on mine primarily because I didn't want the roots blower (which I've had before on 2003 GT), to bring me instant torque the moment I pull out of a corner. I went with a centri blower because the power is more gradual and I felt would be easier to handle without having a mass amount of torque. I'm sure you could get away with a roots/twin screw on a road course, but I wanted something a little easier to handle.

 

[blacksheep-1]

I went with a Vortech/centrifugal on mine primarily because I didn't want the roots blower (which I've had before on 2003 GT), to bring me instant torque the moment I pull out of a corner. I went with a centri blower because the power is more gradual and I felt would be easier to handle without having a mass amount of torque. I'm sure you could get away with a roots/twin screw on a road course, but I wanted something a little easier to handle.

That style of blower is not a bad compromise between a roots and a turbo, you can technically run more boost in one of those, but they aren't positive displacement so, basing something on pure boost is kind of sketchy, you can run a monster intercooler (actually an aftercooler) on one of those to get away from the heat, which you really can't in a roots, simply because there's no room under the blower (KB makes a water cooled blower BTW) so pick your poison, I like the roots because it kicks in right off idle for the street and I'm used to them, but there is more than one way to skin a cat.
I have seen a lot of Vortech used (used up?) out there so be careful there is a lot of junk floating around. It seems they (like a turbo) like to spin the bearings out of them a lot, I've seen a few so bad that they've ground up the vanes because of the end play. I would think that one that had a positive pressure oil feed would work the best, but I understand they've gotten away from them in the later models.

 

[LERCH]

I was thinking of supercharging my 3v a while back. I talked to Justin at VMP and found out he races (road coure) a 5.0 with one of his tvs blowers on it. Give him a call. He'll answer any of your questions.

LERCH

Sent from my LG-V410 using Tapatalk

 

[Fabman]

Kenne Bell is actually "Screw" type supercharger, rather than a "Roots" style. Both are positive displacement.
The difference lies in the style of rotor and method of compression.
Screw compressors run way way cooler than roots blowers and are the better choice for this application [SIZE=small]IMHO.[/SIZE]
I'm running a Kenne Bell 2.6 on my built 3 Valve and I am very happy with the results.
Although both styles have been used successfully, the cooler IAT's made the decision an easy one for me.

Roots:
[SIZE=small]










[/SIZE]Screw:
[SIZE=small]





[/SIZE][SIZE=small]Twin screw vs. roots:[/SIZE]
http://kennebell.net/KBWebsite/Common/pdfs/twinscrew-vs-roots-fromcatalog.pdf

 

[Fabman]

The late model Mustang Kenne Bells are all Water cooled.
They have an intercooler under the blower while some of the newer models have a water cooled housing as well as an intercooler.


The small water tanks that come with most street/strip blowers are marginal at best IMHO so a larger tank is advisable, especially for road course work.


I use a baffled trunk mounted tank for this very purpose and have some in stock if interested.
Drag racers love them because they can fill them with ice and lower IAT's even more.

 

[blacksheep-1]

Kenne Bell is actually "Screw" type supercharger, rather than a "Roots" style. Both are positive displacement.
The difference lies in the style of rotor and method of compression.
Screw compressors run way way cooler than roots blowers and are the better choice for this application [SIZE=small]IMHO.[/SIZE]
I'm running a Kenne Bell 2.6 on my built 3 Valve and I am very happy with the results.
Although both styles have been used successfully, the cooler IAT's made the decision an easy one for me.

Roots:
[SIZE=small]










[/SIZE]Screw:
[SIZE=small]





[/SIZE][SIZE=small]Twin screw vs. roots:[/SIZE]
http://kennebell.net/KBWebsite/Common/pdfs/twinscrew-vs-roots-fromcatalog.pdf

While I agree with that the design is a Lyshom (http://www.lysholm.us/) they have to be more closely matched to the engine application. With a normal blower you can , within it's capacity 4/71, 6/71, 8/71 you can simply overdrive or underdrive the blower. While this works to a lessor degree on the KB/Lyshom design, since the size of the blower inlets are smaller it has to be more closely sized. instead of just changing the pulley, you need to change the blower size since a specific size "stalls" at a specific volume of air. Don't get me wrong, I'm a big fan of KBs and their instant torque, but they have to be sized quite specifically.

 

[Fabman]

While I agree with that the design is a Lyshom (http://www.lysholm.us/) they have to be more closely matched to the engine application. With a normal blower you can , within it's capacity 4/71, 6/71, 8/71 you can simply overdrive or underdrive the blower. While this works to a lessor degree on the KB/Lyshom design, since the size of the blower inlets are smaller it has to be more closely sized. instead of just changing the pulley, you need to change the blower size since a specific size "stalls" at a specific volume of air. Don't get me wrong, I'm a big fan of KBs and their instant torque, but they have to be sized quite specifically.

I concur. At some point every PD blower will stall. With a KB 2.6 it's maxed at 19 psi.
The 2.8 will go over 25 psi and larger ones even more. When I was drag racing my blower would run out of air at 6500 rpm @ 20 psi. I made 700 rwhp and 676 rwtq AT 15psi. A 3.0 would give me another easy 100 hp.
However, 9 psi on the 2.6 gives me 650 rwhp and 7200 rpm which is plenty for an old 3 valve in a track day mustang. It's not hard to size them. I bought this blower for my stock motor and later built a motor that flowed more air than the little blower could supply. That's why they have 4 different sizes. A 2.6 is plenty for a track car and the smaller rotors are easier to turn so I have what's works for this application. I'd say 9 to 19 psi gives you plenty of room to work with with only a pulley change. It's versital, reliable, has low AIT's, makes a butt load of power and looks damn good doing it. I'll still take my KB over the alternatives.

 

[blacksheep-1]

Yep, my KB has over 40K miles on it