Supercharger FAQ - MAF vs. MAFless discussion

[Eat this 2]

i have a similer problem but mine doesnt really matter what rpm im doing if i go from a higher throttle to a lower throttle its sometimes quite jerky makes it a real git to drive quick and smooth

[Nerih 0]

Perhaps the thoughts of another SC VR driver.

I drive mine daily.

Setup:

C2 8psi Kit with V1.

Dastek ECU from stealth.

i think my setup is far from perfect, it is NOWHERE near the advertised 280BHP, probably more like 240BHP! Anyways, its fine i enjoy it non the less.

Current driving issues:

Hates engine braking, if you let it overrun it will stall when you let it idle (ie if you come to traffic lights in 3rd and then put the clutch down)

This requires the non-DVLA approved approach to driving which involves coasting.....which is a pain. I can drive it without stalling at all now, its not particularly hard.

Also transitions from part throttle (20vac) to wide open (>0PSI) takes a delay, i have a feeling this is the recirc valve sticking. Any part throttle from greater than 20vac results in instant power.

Wide band tells me the engine is very rich on over run.

I currently have a MAF setup with no voltage clamp, but have the large C2 MAF housing.

TBH, if you can adjust your driving style slightly to eliminate the overun issue, its fine.

[407BHP VR 2]

To be honest i might stay with this setup for a while' date=' because the cost of remapping for an extra 10 horses is just not worth it at this time.[/quote']

Standalone ;-) LOL, only kidding mate. 270hp from 6psi is top dollar my man, you should be chuffed with that. My personal favourite of my 3 S/C setups was the 2.9 OBD2 8psi Vince MAF map and that made the numbers on the nail, 290hp with 260 torque....so with the same pulley, you'll hit that no worries, maybe a pinch more.

10 psi upwards gets awkward with the stock management and the MAF will definitely need to go IMO. I ran 12psi and it was barely any quicker than 8psi because the stock management just couldn't cope with it, and the heatsoak (no intercooling at the time) didn't help matters.....which is where the whole 4" MAF (or standalone) business comes in + inter or charge cooling. 8psi is the industry standard limit without cooling.....there after you need it. The temperature of the charger air will be about 70 degrees with a 12psi pulley and that really does need cooling down.

On another note' date=' does anyone with a charger setup with recirc valve experience a surge while driving just after lifting off the accelerator? Vince assured me it's a common symptom

[/quote']

Yes chap, been there, got the T shirt. You need to play around with the spring rates in the valve. Get yourself a spring tuning kit from Forgemotorsport. I recommend the blue spring.

Is the ten psi only on a charged vr or a turbo aswell ?

I was running 1.3bar on stock management with no probs !

[FishWick 21]

18 psi code for OBD1 and OBD2 has been around for ages and works OK with turbos.

Those issues were from a while ago when Vince was still working on the Vortech maps. He's getting there and almost perfected it.

I find that my view of "no problems" differs from other people's though.

[VR6Tuner 0]

So does anyone know how the ecu reads airflow on a MAFless setup?

Ecu uses load subsitute based on TPS.

[cadguy77 0]

Any update on setups?

To be brief my MAF setup has been fine for over a year of very minor maintenance.

[gkjnr 0]

did anybody solve the surging issue at part throttle? my zr2 system is the very same ,it,s very jerky at very light throttle openings and ok at full throttle, ive changed the maf and idle valve so far. i live in central scotland and i,m not sure who could map it, its running a zengineering chip at the moment and its obd1

[binliner 0]

are you using a dump valve?

[gkjnr 0]

the z engineering setup does not need a dump valve

[xyber 1]

fitting one may help i reacon, if you think about if when off throttle your charger is just throwing boost at the TB with no where to go, is there some built in feature on the charger to deal with this?

[gkjnr 0]

there must be ,it says on the fitting instructions that it was desigfned to run without one ,i would fit one if it would cure the problem

[PremiumVeeDub 0]

I have an OBD1 running the Z-Engineering charger, just reading this htread and thought it worth mentioning that if you have OBD1 you MUST run the MAF before the charger. Preferably in the middle of a 10ft pipe

Doing this in a Mk2 is.. tricky. Anyone done it?

[Ben Seabrook 4]

I have an OBD1 running the Z-Engineering charger' date=' just reading this htread and thought it worth mentioning that if you have OBD1 you MUST run the MAF before the charger. Preferably in the middle of a 10ft pipe

Doing this in a Mk2 is.. tricky. Anyone done it?

[/quote']

my car is obd1 but has an obd2 maf on it so it is situated after the charger !?!?!? maybe running it before might solve a couple of my issues

[PremiumVeeDub 0]

Distributor or coil pack OBD1?

If dizzy, you need the MAF part number ending 021 and it MUST go before the charger. Makes a world of difference to the idling and solves a lot of bucking/overfueling problems. Early MAFs just do not like turbulent air.

If you have something you can blank the gap with, just try moving it temporarily to where the air filter currently is and see if it runs better.

[Ben Seabrook 4]

coilpack obd1 mate - but having lots of probs with idling issues etc although most seem to be down to other issues !!

[fastmonkey 0]

I know this an old thread but I was wondering.......... I have bought a car with a Vortech charger and it has a stealth mafless map, however the maf was still connected. If it has a mafless map can you just remove the maf altogether ?

[FishWick 21]

You can indeed.

[Antihero1981 8]

and if it has a maf map can you run it mafless?

thinking about removing mine....asits before the charger but gets alot of abuse as its so close to road

[FishWick 21]

If the ECU is mapped to use MAF as the main engine load, then yep, the MAF must be connected. It will work with out it, of sorts, but won't drive very well and will stall lots.

The MAFless maps are ancient history now anyway. Vince solved that one long ago :-)

Yeah the MAF does take a beating down in the wing. Even in my Corrado with it's lovely splash guards and things, I still used to get through 3 or 4 MAFs a year. Always a short to B+ cause of water damage.

The VFEngineering kits were designed and tested in California. They're not really well suited to European cars with our frequent down pours!

[RoguePlank 0]

Right, I hate to ask a stupid question on a long-dead thread, but who the f- is this magical Vince character? Not once do you actually mention where he works in either of the pinned supercharger threads. I'm trying to find somewhere/someone that will fit a Rotrex on my Mk4 Golf V6 4Mo, and has preferably done it before. Is this Vince guy still in business somewhere?

[Reaperx 181]

Right, I hate to ask a stupid question on a long-dead thread, but who the f- is this magical Vince character? Not once do you actually mention where he works in either of the pinned supercharger threads. I'm trying to find somewhere/someone that will fit a Rotrex on my Mk4 Golf V6 4Mo, and has preferably done it before. Is this Vince guy still in business somewhere?

vince works for stealth I have never met or spoke to him but the guy knows his stuff.

[RoguePlank 0]

vince works for stealth I have never met or spoke to him but the guy knows his stuff.

 

THANKYOU

[dom.joy 87]

Give him a call on 01926 812259 is very helpful

[RoguePlank 0]

Give him a call on 01926 812259 is very helpful

 

I will do, but got to get the car through a 100k major service and MOT this month before I start chasing dat boost. Thanks guys

Edited November 4, 2015 by RoguePlank

[VR6Pete 1,455]

Wow this is a blast from the past!

 

MAF or no MAF that is the question