Educate me if you can!!!!!

[JBS99HT]

Can somebody please explain in simple terms what is the main difference between the Sean Roe supercharger and the others on the market.

- What is the biggest contributor to the price difference among them?
- Do you need to add Rockers and springs and why?
- Are there any "harmful" effects to the engine in the long run?

If it helps any, I have a 99 ACR with Belanger headers and exhaust.

 

[BigCarrot]

Sean Roe's is a roots blower, which sits atop the engine. The others are centrifugal, which sit in front of the engine. The rockers and springs just fortify your valvetrain, which allows you to rev the engine higher. They also give you a little more lift if the ratio is changed. Forced induction stresses the engine components, so yes it will have harmful effects. The amount of "harm" depends on how much boost you run. More boost=more power, but more wear. Just about any time you signifigantly increase the horsepower of an engine, you reduce the reliability. But it's SO much fun!

 

[JBS99HT]

Thanks BigCarrot,

Your explanation brings me to ask more questions. Is Sean's system producing less boost than the other competitors? and which of the two systems you explained above is more reliable or has less moving parts?

Thanks again and for the rest of you feel free to share your opinion and knowledge of the subject.

 

[BigCarrot]

6 in one hand half dozen in the other. The boost can be altered with a change of the pulley. Some people think the centrifugal setup is better because it transfers less heat to and from the engine since it's not actually attached. The roots type seems to be a bit more reliable. Sean's is also supposed to be a pretty easy install, which I like. That's probably going to be my choice.

 

[SUN RA KAT]

"Is Sean's system producing less boost than the other competitors?"

The Roe Supercharger System produces 5 psi so that the late model "Creampuff" Vipers with Hyper Cast Pistons will not self destruct. The hyper pistons are lighter than forged pistons and less weight means longer engine life.

The earlier Vipers had forged pistons that can take more of a boost without self destructing. Sean is working on an upgrade kit to boost his superchager system to the higher safe level that forged pistons can handle. Anything above 5 psi will require a bigger fuel pump. Air/fuel is very critical is a boosted engine - you do not want to run lean at full & even part boost.

Most other systems are for forged pistons only and the late model Vipers have to have new forged pistons put in.

Everything on the Roe Supercharger System is 1st class - I know from 1st hand experience. And just about everyone else has similar 1st class supercharger systems, too. But the Roe System can be installed where you live and you do not have to ship your Viper off to a tuner for however long it takes.

One of the things that sold me on the Roe System, other than Sean's reputation, is the horsepower and torque at lower RPMs - where I do almost all of my driving based on time at a given RPM - if you are peak RPM, then you are over the speed limit, so you let the RPMs drop back down to 1250-2500 to cruise in. That's where the design of the twin screw supercharger that Sean uses makes lots more power than the centrifugal systems. 6th gear with the stock 3.07 rear gear is very useable from 55 MPH on up - feels like 5th gear used to before the supercharger, and similarly, each gear feels like you are in the next lower gear.

" and which of the two systems you explained above is more reliable or has less moving parts?"

A single superchager will have less moving parts than a two superchagers set up, but I think any set up by a reputable tuner will be reliable. If you have more $, then you can buy more power. I'm not rich and the Roe Supercharger System with VEC2 was stretching my budget - I also added a lot of neccessary mods before even picked up my Viper so it would be ready for the Roe Supercharger. But, I am very happy with the Roe Superchager System and how it made my Viper so much easier to drive in everyday traffic. I still have a long way to go in getting to use the maximum power it has - I've only run it full throttle to 4,000 RPM in 4th gear (around 100 MPH) and it was accellerating like a rocket sled - I tried to smoothly go to full throttle in 3rd gear, but I'm over 100 MPH before the throttle is wide open - maybe I can do better once the weather gets better and the roads are cleaner.

 

[CitySnake]

Can somebody please explain in simple terms what is the main difference between the Sean Roe supercharger and the others on the market.

- What is the biggest contributor to the price difference among them?
- Do you need to add Rockers and springs and why?
- Are there any "harmful" effects to the engine in the long run?

If it helps any, I have a 99 ACR with Belanger headers and exhaust.

I think that you need to bear in mind the significant cost disparity between Sean's "bolt on" (roots) system and a Levin, et.al. (centrifugal) system. When it's all said and done you're looking at $10,000 v $30,000 (generally speaking) and to a slightly lesser extent the final HP (perhaps 650 RWHP v 800 RWHP). I would imagine that the price difference would be a determining factor for many. The "bolt on" system is also removable while the other is ostensibly not.

 

[MES]

A supercharged Viper with 5 psi twin screw will be faster than a 5 psi centrifugal EVEN if they make the same HP Why is this? Because the centrifugal ONLY makes its max boost at red line, below then the boost is proportional to the RPM (i.e. 3000 rpm = 1 psi, 4000 rpm = 3 psi, 6000 = 5 psi, for example) There are many high HP centrifugal Vipers but most only run 10's in the 1/4 There have been several Roe superchargers in the mid-high 10's even though they are 100's of HP lower than the centrifugal. This is not unique to Vipers the same thing happens to F-bodies, the centrifugal guys make good dyno numbers but get killed at the track by nitrous cars making the same peak HP.

Also the Roe supercharger is not a Roots but rather a twin screw, they look sort of the same but the twin screw is superior. The only down side (if you can call it that) with the Roe supercharger is the lack of an intercooler.

Here is a http://www.kennebell.net/techinfo/techinfo-general.htm that explains some of the differences. Kenne Bell uses a twin screw which is the same basic blower as Roe uses.

 

[MaxedGTS]

A supercharged Viper with 5 psi twin screw will be faster than a 5 psi centrifugal EVEN if they make the same HP Why is this? Because the centrifugal ONLY makes its max boost at red line, below then the boost is proportional to the RPM (i.e. 3000 rpm = 1 psi, 4000 rpm = 3 psi, 6000 = 5 psi, for example) There are many high HP centrifugal Vipers but most only run 10's in the 1/4 There have been several Roe superchargers in the mid-high 10's even though they are 100's of HP lower than the centrifugal. This is not unique to Vipers the same thing happens to F-bodies, the centrifugal guys make good dyno numbers but get killed at the track by nitrous cars making the same peak HP.

Also the Roe supercharger is not a Roots but rather a twin screw, they look sort of the same but the twin screw is superior. The only down side (if you can call it that) with the Roe supercharger is the lack of an intercooler.

Here is a http://www.kennebell.net/techinfo/techinfo-general.htm that explains some of the differences. Kenne Bell uses a twin screw which is the same basic blower as Roe uses.

not true!
I see too many people guess at which is better roots or centrifugal and I've had the best of both worlds. I owned a Dodge Ram pace truck with a Kenny Bell roots blower and it almost ALWAYS detonated. Why? Because its nothing more than a cheap way of forced induction with boost pumps and gadgets making up for a poor excuse of a fuel system and computer. The roots sits center of the engine where the hottest air from the engine is and heat soaks into the blower and forces more HOT air into the engine. Thats why you hear everybody complaining about detonation. The roots has lots and tq down low and drops off where the centrifugal makes power. Thats when GEARING allows you to take advantage of a centrifugal blower. I hear to many people say the engine has to breath more so that's why they don't make enough power for the roots. Well try turning up the boost on a roots and see what you get, more hot air, more detonation.


just my 02
Max

 

[SUN RA KAT]

Max is partially correct on the intercooler thing, but at the low boost of the Roe Supercharger, it's not an issue. At higher boosts it would be an issue.

With the VEC2 I have absolutely no detonation. Kenne Bell Superchargers are notorious around the Dodge Ram/Dakota community for engine management & other problems, at least a few years ago. Maybe if they had a VEC2-type engine management system...

Also remember that that Roe Supercharger is a twin screw and not a Roots system, and has a lot of advantages over the inefficient Roots system.

How you intend to drive your Viper should determine which system is best for you, personal finances not an issue. Each system has advantages and disadvantages. I find in the real world that my Viper drives much more smoothly than before the Roe Supercharger and I am way above the speed limit long before I get to maximum power and I get to 100 MPH so fast at part throttle in 4th gear that it feels insane (full throttle is unreal insane ). 3rd gear going to 100 MPH happens so fast that I haven't been able to smoothly lower the snake pedal to the floor mat yet because I'm already at 100 MPH before the pedal is much over 2/3 there. My car will get slower when the air temperature gets up to summer temperatures, but it still will be insanely fast. I live in an area of our country where it would be almost impossible to go above 150 MPH without coming up on traffic or the long arm of the law...even 100 MPH is taking a chance. I can see going to more power than I have if you live in an area where you can actually use that power - if that's how you drive.

 

[JBS99HT]

Thanks everybody for the great info.

SUN RA KAT what mods did you have installed before adding the Supercharger?

 

[J DAWG]

JBS99HT

I have actually called DLM, Heffner, and Roe and spoke with them at length. Everyone here has some good points and there is a wealth of knowledge, but I know any of the tuners would certainly love to speak with you as well. So give them a call also.

With your car being a 99 you can go either way and actually(after speaking with the tuners) there really isn't to much of a price difference IMO. But it all depends on what you want to accomplish now and in the future.

DLM and Heffner are upgradeable systems with intercoolers where as Roe's is going to be good for approximately 5-8 lbs of boost without an intercooler.

 

[SUN RA KAT]

JBS99HT asks

"SUN RA KAT what mods did you have installed before adding the Supercharger?"

Belanger Headers
Random Tech Ultra High Flow Cats
Corsa 3" Cat Back
Roe Clutch Adjust
Roe Fan Timer
Roe Radiator Hoses
Roe 70 mm Air Box
Roe 70 mm Smooth Tubes
Roe 70 mm Throttle Bodies
Roe 180 Degree Thermostat
S&B Air Filters
Woodhouse Modified Shifter
MGW Shift Knob, and other Goodies
EBC Green Brake Pads
Lightweight Flywheel
North California Viper Club Floor Mats & Spare Tire Cover
Northwind 2" Seat Lowering Kits on both seats
Zaino
Roe VEC1 - replaced by the Roe VEC2, but will be installed in my Dodge Ram truck soon
Roe Smooth Tubes - replaced by Roe 70 mm Smooth Tubes
Magnacore 8.5 mm Spark Plug wires
Centerville Jazz Band Stuffed Bear wearing a Yellow shirt rides facing backwards under the back hatch on top of the N.California Viper Club spare tire cover. My daughter was the band's electric bassist for 4 years (she graduates in June). It is an over 190 member high school marching band & one of the best in the country.

I think this list is pretty complete, but there may be an item or two that I forgot to include. The 70 mm stuff, radiator hoses, and 180 degree thermostat weren't installed until the Roe Supercharger was installed.