Superchargers... And V-tec

I got 3 questions:

1) Does F/I go with V-tec well, I heard if I were to turbo my vtec engine, it would screw the v-tec over

2) A friend of mine wants to know if she can make her car a DOHC by swapping her current stock civic head for a b16 head.

3) Why is it that the most common supercharger is the "roots style" supercharger, when it can only give about %50 more power?

Bump^

I got 3 questions:

1) Does F/I go with V-tec well, I heard if I were to turbo my vtec engine, it would screw the v-tec over

2) A friend of mine wants to know if she can make her car a DOHC by swapping her current stock civic head for a b16 head.

3) Why is it that the most common supercharger is the "roots style" supercharger, when it can only give about %50 more power?


I heard both sides of the story about Vtec and FI. Some people say that it works terrible with it since when the hight lift cams are activated the valve overlap will cause presure to escape, other peole say that the hight lift valves are so mild that is not really an issue.

the second question is better suited for the honda acura section

the third question I'm really not sure since i know way less about superchargers than turbos.

Ok thanks, I will ask the first 2 questions in a Honda/Acura subforum

3) Why is it that the most common supercharger is the "roots style" supercharger, when it can only give about %50 more power?

I think that's probably because superchargers are more commonly used with muscle cars and such and back then they were the only kind, plus it's the coolest looking. with newer cars the more common type is centrifugal, and with new trucks its screw (they're pretty much the same as roots, they use the same mechanism to compress the air)

But with the newer centrifugals and newer twin-screw type, both which give more horsepower and no hood modifications, wouldn't it be better to choose 1 of the 2? Afterall, roots superchargers create more heat, and isn't efficient anyway, only thing good about it is that it's positive displacement.

yes centrifugal s/c's create more boost without taking as much from the engine but most people who use roots types are muscle car owners. these people like the look of the roots and they like using old technology from "back in the day." that's why they use them. most people nowadays use centrifugal because of the previously stated reasons.

Then how come I have found some roots type SC's for civics?!

How the VTEC affects the engine when going forced induction depends on the pressure ratio over the engine.

Roots are probably used because they are cheap, otherwise the car manufacturers don't use them that much. In dragracing they are in some classes the only supercharger allowed (top fuel, pro mod and so on).

Ok you can have a very fast and very reliable running car that is a turbo'd vtec.It's all about tuning.People that say turbo an vtec don't go are the people that have never owned or worked on one.If you tune the vehicle right, you will have no problems with it.You can always set your V-tec to a lower engagement and then have it cutoff while your turbo is giving you boost.I have worked on plenty of DOHC Vtec turbo cars..........work very well.

Also, people should think about it like this, Vtec is basically variable valve timing right, well the s14/s15 sr20det's are turbocharged from the factory and contain variable valve timing.

Like i said before, it's all about tuning it to run right.

Good tuning skills? I got none of that, all this stuff is too complicated for me, I am just an "amateur" tuner, I got some experience but nothing significant...

if you are unsure about tuning, then i would rec. you do not go F/I at all.No matter if it's super/turbo charged.If you don't kno wut u are doing, you will literaly blow up your motor from the inside out.I've seen pistons an rods shoot through the front of cars cuz they were tuned improperly.

Tuning??? what if i took it to a car shop would they be able to to it correctly for me so thats its reliable?? or is it like some car shops are better than others at tuning so????