NA vs. Supercharger vs. Turbo

[RussRamz]

Now having driven both Normally Aspirated cars and Turbocharged cars, I am interested in those owning Supercharged Z4M's and your opinion of driving these cars on a road circuit. My 335d, while modestly powerful, has an annoying amount of turbo lag which I can imagine would be difficult to modulate when driven aggressively out of corners on a road circuit.

My main question is whether SC cars exhibit the same type of lag in the power development and whether or not those of you who own a SC Z4M have any regrets about leaving the NA engine behind.

Some days I am torn about whether I should go SC or build a race engine and leave it NA knowing I will lose some top end power.

[The__J__Factor]

Considering the s/c used on the M are centrifugal, power delivery is exactly like NA just much stronger.
It will be very linear as boost builds in relation to rpm, so the only difference between NA and S/C is that the S/C M should keep making power all the way to red line and not tapper off like stock does. Throttle response should be no different.

Turbos you think might be harder to drive but obviously once your racing you dont drop the revs enough to drop out of boost. So turbo lag isnt a problem. Plus you can get more boost/full boost sooner with a turbo so your mid range will be stronger compared to a centrifugal s/c set up.

People have their preferences and thats fine. My last car had a Rotrex s/c set up and i loved the power delivery - revving to 8500rpm it felt just like a crazy NA set up. My friend had the same car as me but went with a turbo set up. His you could defiantly feel the power swelling then explodes once full boost hit.

[O-cha]

Originally Posted by The__J__Factor

Turbos you think might be harder to drive but obviously once your racing you dont drop the revs enough to drop out of boost. So turbo lag isnt a problem. Plus you can get more boost/full boost sooner with a turbo so your mid range will be stronger compared to a centrifugal s/c set up.

I agree that turbo isn't a "problem" on track but to say there is no lag would be incorrect. There's several forms of "lag" one of which is the throttle response suffering.

[Vondelta]

Does anyone produce a turbo kit for a z4mc? I have looked but can't find one. Do you not also have to have your tune redone?

[The__J__Factor]

^ no turbo kits for the M, mainly because not many people can tune the ecu as needed.

[tofu4]

I'm sure you can use HPF's turbo kit for the E46 M3 but the intercooler piping will have to be customized to fit the E85/E86 chassie. If you dont want to deal with the intercooler pipes you can always go for a liquid to air aftercooler. HPF is using an AEM stand alone acting as piggyback, so almost any good local tuner can tune it.

[O-cha]

Originally Posted by tofu4

I'm sure you can use HPF's turbo kit for the E46 M3 but the intercooler piping will have to be customized to fit the E85/E86 chassie. If you dont want to deal with the intercooler pipes you can always go for a liquid to air aftercooler. HPF is using an AEM stand alone acting as piggyback, so almost any good local tuner can tune it.

You're completely wrong on both what HPF uses and its ability to be put on the z4M.

Trust me.

[tofu4]

So what do they use and why wont it fit?

[O-cha]

Originally Posted by tofu4

So what do they use and why wont it fit?

Proprietary AEM hardware. Completely different ecu and wiring harnesses between the cars, I noted a few possible clearance issues with the manifold vs tranny (wastegate pipes is very close to m3, z4 has protrusions there)

Fuel system would also have to be redone for higher stages as our FPR is in the tank.

[Z4-VILLA]

so can YOU make one work?

[ZM4000]

Yeah Can You Make One Work? :d

[Z4-VILLA]

o-cha make us a turbo.

[mfanatic325]

^ so pushy. But I like where this is going