Wormhole

Do you sell a non stealth version of the MAF kit, one that uses a cone filter, mounted around the headlight?

RK951

Is this something you are actually working on or are you just thinking out loud?

tommye

Andrew,
How about the throttle response of your MAF + DME/KLR chips ?
I don't mean turbo lag, but rather if you get boost with only partial throttle like with f.ex. the Vitesse chips ? With factory chips you need to completely floor it before you get any boost, this is not so pleasant.....

Cheers,
Tommy

Mike S

Have you checked out your air/fuel ratio? I'm just curious how close it was right out of the box.

cas951

Yes I have. It's been right on the money with my stock AFM.

black944 turbo

Very cool, sounds like a nice system. The a/fs are what I was wondering about.

promax_motorsport

Hi Rick,

This was me thinking out aloud, but we (ProMAX Motorsport) are currently looking at this if we can address the KLR pressure sensor limiation of 1.0 bar (should be possible). Controlling a DPW with the KLR should prove interesting too!

Regards,
Andrew
www.promaxmotorsport.com

promax_motorsport

Hi Tommy,

This is where this solution really scores. The throttle response is almost instant. Even partial throttle brings on the boost quickly as the cyling valve is switched by the KLR to function like a Boost Enhancer - the air signal is blocked from going to the wastegate until maximum boost approaches.

Throttle response and boost build up are further helped by the MAF not offering any restriction to the incoming air and the air metering being so accurate. Also at the top end, the boost does not fall away as with the standard car.

It's almost like driving with a DPW but with all the safety features of the factory electronic boost control.

Regards,
Andrew
www.promaxmotorsport.com

promax_motorsport

Hi,

AFR will be maintained when running closed loop at 14.7 / lamda 1 when running with the MAF kit. At WOT, the AFR is then determined by the software only (if running manual boost control). Hence, it is only important to set the boost level at WOT according to the WOT map on the DME chip being used.

If using the MAF kit with the optional MAF optimised KLR/DME combination - the fuel is always scaled to suit the boost. This is the ideal set-up for all those standard 1986 model cars with a K26/6. Very easy additional power and no risk of running lean at maximum boost when hard on the gas.

Regards,
Andrew
www.promaxmotorsport.com

promax_motorsport

Hi,

The MAF kit is designed to fit straight to the stock factory airbox. However, there is no reason why it can't work with a cone filter behind the headlight. At present we don't sell a kit in this format - however, if there was demand we would consider doing so. This would require a custom 'J' pipe and a filter that fits without interfering with the headlight stabiliser bracket.

Would anybody else be interested in this?

Regards,
Andrew
www.promaxmotorsport.com

promax_motorsport

Hi Danny,

This is quite true - however when you clamp the wastegate line (or remove the banjo bolt and block the hole on the back of the IC pipe), there is no force acting on the wastegate diaphragm at all. The boost will go very high, but the wastegate would eventually be forced open by exhaust gas - especially if the spring was weak.

The standard wastegate has a fairly modest spring, so only moderate air pressure is required to open it. This makes it easy to control. A really tired wastegate could be used with no control and just the air pressure opening it (as with earlier 911 Turbo models).

If the wastegate is then shimmed, or the spring rate increased - using the same KLR program - more boost will result.

The problem is, the KLR has a pressure sensing limit of 1.0 bar, anything higher will result in the overboost program being invoked. This is why going the manual boost control route with a DPW is so attractive - as it is easy.

However, by using the KLR you can then program for boost gain, start boost and maximum boost. The KLR can only control the switching of a solenoid valve (the CV), hence it does not actually control absolute boost - it will only influence boost from a minimum and maximum point (determined by the wastegate spring with full pressure on the diaphragm and the KLR maximum boost tolerance).

Once we have worked out a way of allowing the KLR to sense boost beyond 1.0 bar (14.7 psi), I think we can then have all the benefits of a Dual Port Wastegate - i.e. high boost, rapid spool up but without the disadvantages (i.e. flat boost curve only and no adjustment for gain and roll off).

Regards,
Andrew
www.promaxmotorsport.com

promax_motorsport

Hi Mark,

Can't remember if I answered this - so forgive me if I'm repeating myself.

The MAF optmised KLR/DME chips are different as the KLR has been programmed as well to allow up to 1,0 bar of boost using standard factory electronic boost control. It requires the wastegate to be shimmed so that high boost can be achieved within the parameters of the KLR program and overboost protect value (on the DME EPROM).

The chips you have and the ProMAX chips that we now produce still use the cycling valve - but the overboost protect and knock detect functionality are disabled (there is temperature sensing ignition retard). Instead, the DME is optimised for a specific boost level and turbocharger delivery. ProMAX Level 1 and 2 chips support 1.0 bar boost, 1.2 bar and 1.2 bar flat boost line to maximum RPM. For the AFR to be correct at WOT - the boost needs to be set until the AFR reaches about 12:1.

With the MAF DME/KLR chips, the fuel will scale according to boost as the full factory functionality of the DME and KLR computers is retained.

Regards,
Andrew
www.promaxmotorsport.com

Wormhole

Okay, what is the OD of the MAF inlet and outlet?
Thanks

promax_motorsport

Hi,

The MAF is 3" internally 76.8mm and 80mm externally.

Regards,
Andrew
www.promaxmotorsport.com

Transaxle

The MAF kit delivers the same values as the AFM. It is a AFM since it measures the flow in m3/h instead of kg/h. The kit is completly compatible with the stock AFM.

The benefits of the kit are better response to the throttle,faster spool up of the turbo and nearly no restrictions to the airflow. That leads to higher boost at high rpms with the small K26 turbos.

In a KLR/CV controlled system it is important that the programming of both systems (DME&KLR) match each other. The MAF kit works great with stock chips. It works also great with our DME/KLR chips. In both cases without any adjustments. That may be necessary in a system with a MBC.

The chips reaches the limit of the KLR. With the 1.0 bar sensor in the KLR it is not possible to control higher boost. That is the reason for the development of an update for the KLR with a 1.5 bar sensor.