golferjoe11

Whats a better superchrager for road racing, centri or twin-screw?

Nichepi

My opinion is a roots style unit such as Kenne bell or an eaton unit much like the 03-04 cobra setup. I've found that through most the track setups your always bumping through gears at sometimes low RPMS or look for quick stops and accelerations. Roots style units provide quicker boost at lower RPM's. thus more torque at like 1500RPMs, where Cent. style units give great horsepower but tend to provide full boost in the mid to upper rpm band.

RodeoFlyer

+ 1

Clif Brohn

It all depends on how long you're on the track. A roots or twin screw blower is great for low-down torque and quick boost, but after about ten to fifteen minutes of ***** out driving, the supercharger will be feeling the effects of severe heat soak into the super charger. Hot air will be getting pushed into the engine, performance will decrease, and your lap times will drop. This problem can be solved for teh right amount of $$$, so get the centri charger. You build boost just as fast, and not only, they are so much more effecient than the roots blowers. That would be the best route for a road track car.

PushinTheLimit

You are correct but wrong too. An Eaton is a roots style blower whereas a KB or Whipple is a twin screw. Pretty big difference. I honestly havent seen many road racing cobras with whipples or KB's... I tend to see more of them at the dragstrip. But those that have for example the whipple and road race, they normally donthave as much heat problems as with the Eaton for two reasons...

1. Twin screw is more efficient than a roots blower so it doesnt heat up as quickly
2. The whipple is set at a boost level in the range of 13-17. So its not spinning as fast as the Eaton would be at the same boost level, creating less heat.

I would say the Whipple 2.3L would be a good choice of blower for what your asking for.

David_K

the best supercharger is no supercharger. with a roots/screw style blower you make so much torque down low that exiting a corner full throttle becomes a hassle, impossible for 99% of the drivers. a centri supercharger creates a ramping torque/hp curve with would be acceptable for bigger tracks with long striaghts butyou run into the same problem you would with the roots style as far as exiting corners go. your best bet would be a pair of small turbos on low boost this will give you more of a N/A dyno graph being as how they would spool very fast as would hold constant boost throughout the RPM range.

RodeoFlyer

Allen superchargers makes a roots-style with a built in intercooler.

SinCityGT500

I agree 110% with goldeneagle_10 on this one. A twin screw setup like the Whipple is definately the way to go because it is so much more efficient. Heat is a track car's #1 enemy and the twin screw setup can produce the same numbers as an Eaton on less and much more efficient boost, which in the end, equates to less heat.

Centrifugial superchargers are not good at all IMO because they still have some lag as well as generating a lot of heat. Same goes for turbos which are the biggest heat monsters of them all. You also have to take into account power delivery. Having driven all of the types of forced induction on the track, naturally aspirated is definately the way to go, but if you must have forced induction, the next best thing is a twin screw blower, followed by a roots type, then coming in last is turbos which is ironic because my race car is a twin turbo Nissan 350Z. My turbos on the Z are tiny little Garrett 530bb turbos that are at full boost by 2200rpms. I never dip that low on the track so I have no complaints about coming in & out of boost, but I can tell you that they heat they generate is a huge problem and the power delivery of a turbo is inconcistent compared to a supercharger. Now to establish some credibility I have also raced with a Stillen supercharged 350Z which used an Eaton M62 blower and that was also a heat monster, but the power delivery was much more consitant and predictable.

Clif Brohn

Any super charger is gonna produce heat, but centri chargers are by far the most efficient. Theres no denying this. They are just as responsive as a roots/twin screw blower and dont suffer from the heat soak that comes from being bolted on top of a race oriented engine. Not only that, a LARGE intercooler can be used with a centri charger, chilling the semi hot air before it enters the intake manifolds. Theres no contest.

SinCityGT500

I have driven both a Vortech and a Procharger equipped Infiniti G35 and both had lag. Also, you can put a large intercooler on a roots type and a twin screw as well. I have also owned an Infiniti G35 equipped with an Eaton M62 blower and front mount intercooler...