Supercharger "Lag"

[chr15w]

Now had my V6s for 4 months and still smiling. However on the rare occasion I can use sport mode and give her "the beans" there seems to be a momentry delay in power which I can only compare to turbo lag. When the power kicks in its awesome but I thought that a supercharger didnt suffer with this issue!

Is it only me whos noticed this?

[Aubrey]

Hi Chris,

I have read that there is still  lag with a supercharger although many say there is not

Copied it below so may not just be you possibly

Rgds

Julie.

If a turbo has lag, a supercharger doesn’t, right?
The thought is that people want to go with a supercharger because it doesn’t have any of the lag associated with having a turbo. However, this is actually not true. Superchargers still require to be at a certain rotational speed until they are able to produce maximum boost. Until you hit that max boost, there is still that dreaded lag.

We could keep talking about turbo lag and supercharger lag forever, and there are many cases where you can use a dual turbo/supercharger setup, or nitrous/turbo setup to reduce lag, but in the end, there is still that lag that you have to overcome. 

You will get more low end boost with a turbo. Superchargers require RPM to build boost (the higher the RPM, the faster a supercharger spins) so tend to build boost gradually.

 positive displacement supercharger so it builds boost at much lower RPMs than a centrifugal supercharger which is much more rpm dependent (max boost at redline). Roots blowers are much more efficient at lower RPMs than at higher ones.

But there is still going to be a momentary lag from when you tip into the throttle to when boost builds. Even though the supercharger will spin faster as soon as you get on the throttle, it will take a moment for it to move enough air.

The "lag" that you are feeling is from the supercharger bypass valve closing and the boost building. It is not from any rpm dependent variables. It's just the transition of the air pressure. The bypass valve allows air to bypass the rotors which prevents boost. If those cars you drove use a maf versus speed density, it will effect throttle response because the air measuring device is farther way from the intake valve

[chr15w]

Makes sense cheers

[F-type]

Put the gearbox in manual mode, select a suitable gear and give full throttle.

Is there still "lag" ?

If it is in automatic the gearbox first has to select the right gear (which requires time) and this can be translated as "lag"...

[Wrinkly]

Often a consideration when enhancing a performance/race engine. Do you need the almost instant power (from a turbo which is matched and programmed with the least lag possible) or do you need top end power/speed, (often chosen is a supercharger as will produce higher power once really at higher revs). 

 

[JOE-DOT-COM]

Hi

There should be no lag what so ever with a supercharger, its allways on boost because its mechanically connected, theres no spooling up as like a turbo

the supercharger is directly connected to the crank via a belt, so its allways creating boost proportianal to revs, the F-type uses a twin screw supercharger, which is perfect for the job and should create boost  all the time

if you have lag or its hesitant, there may be a issue, could be a split hose or air leak or even a slipping supercharger belt

cheers

Joe