Thom

I did the upgrade and I am satisfied (SciVision MAF). It has nicely improved throttle response and overall drivability.
I don't know about possible HP/TQ gains and quite frankly I don't care as my S2 was already fast enough for what I use it for (long distance cruising).

nize

there is nothing 'artificial' about this. even if you're using a different turbo, regardless how big, the boost will drop off with the stock wg, or with a manual boost controller.

as long as you're running mbc, you can not sustain steady boost with any turbocharger.

this really isn't a 'stock vs. aftermarket turbo' debate, it's an 'mbc vs. ebc' and 'single vs. dualport wg' debate. the only combination that will allow you to hold steady boost is dualport with ebc. the turbo doesn't really matter.

NeoRules

So will an 968 MAF work on 88 951?
Or is it back to "yes if you program a new chip and voltage converter"
Which leaves me to either want the Vitesse or some other "pre" engineered maf
JC

sawood12

There are quite a few guys in the UK with N/A cars that are using the SciVision MAF and all seem pleased as punch with them reporting much smoother and wider power bands, better pick up and response with smoother and more consistent idling.

fast951

The 968 MAF has a very unique curve, the voltage starts at 2.xV vs. 0V as the AFM or other MAFs. Also, why bother with the 968 MAF it does not flow enough (it maxes out early on, so it does not support the higher flow which the 951 is capable of).

TurboTommy

nize;

"even if you're using a different turbo, regardless how big, the boost will drop off with the stock wg, or with a manual boost controller."

Sorry, man, that statement is wrong.
The wastegate (especially the stock one) reacts to the overall efficiency of the system. If you have a big enough turbo, (especially the hot-housing), and keep the pressure drop, through the intake, to a minimum, you will be rewarded with a flat boost curve, efficiently, all the way to redline.
And this will be accompanied by the corresponding seat of your pants thrust into the upper RPM limits; not imaginary power because your boost gauge reads high.
And yes, one will need a MAF as part of the equation (part of the pressure drop reduction).

TurboTommy

I will amend this slightly, especially for those with larger than 2.5L displacement.
Because of the design of our boost control systems (boost signal coming off the charge pipe before the intake manifold), there is a natural boost drop off because the pressure drop increases slightly through the intake as the RPM rises. In this case an EBC will cure this, but should only be used if it's sure that the turbo can support the extra flow needed to make the higher boost in the RPMs.
Always use your common sense; if a turbo is only big enough to support "x" amount of power, manipulating the wastegate isn't going to make the turbo flow anymore (which is what your engine needs to see to make more power) Something's gotta give; (heat and back pressure)

nize

hah. nice save. i was going to ask for dyno graph proof of this magic mbc you have.