Has anyone compared the Promax and Blitz chips?

 

Yes.......
Ive had a Blitz in a 968 cabrio. + Currently have a Promax in my 968 Sport.. I cant say ive noticed much if any difference between either, apart from they both do a good job..
I dought you can get hold of a Blitz now, as Promax bought them out..Many moons ago..[Unless its a "used" chip your after.]...
I might have a Promax chip spare in a week or so... Interested...???

 

Ha, I just bought the Promax and found when going to fit it, it already had the Blitz. Swapped to the promax so i'll see...

 

Right, the Promax seems to have more mid range, top end seems about the same. I think the cold start map is slightly over ignitioned, but the normal-warm map seems spot on. I must have an old Blitz chip I guess.

 

Hi James,

The Blitz chips were the very earliest iterations (<2004). Later ProMAX chips (especially the 968) changed quite a bit. There are still 4 different versions (7100 & 7700 both ROW & USA).

Regards,
Andrew

 

Did you change the cold start map at all on the Promax chip?

 

Hi James,

Subtle changes were made through all maps, but mainly the partial and full load maps. Only 3 maps are present, idle, partial and WOT (Wide Open Throttle). The following is a generalised explanation of how Bosch Motronic works (as used in most 80's and early 90's Porsche models).

Basic ignition timing is stored in a two dimensional map and the engine load and speed signals determine the ignition timing. The main engine load sensor is the AFM (Air Fuel Meter) or MAF (Mass Air Flow) and engine speed is determined from the CAS (Crank Angle Sensor) signal.

Correction factors are then applied for starting, idle, deceleration and part and full-load operation. The main correction factor is engine temperature. Minor corrections to timing and AFR (Air Fuel Ratio) are made with reference to the ATS (Air Temperature Sensor) and TP (Throttle Position) signals. The basic AFR is also stored in a two dimensional map and the engine load and speed signals determines the basic injection pulse value. Motronic calculates the AFR from the AFM/MAF signal and the speed of the engine (CAS).

The AFR and the pulse duration are then corrected with reference to ATS, CTS, battery voltage and position of the TS. Other controlling factors are determined by operating conditions such as cold start and warm-up, idle condition, acceleration and deceleration.

Motronic accesses a different map for idle running conditions and this map is implemented whenever the engine speed is at idle. Idle speeds during all warm-up and normal hot running conditions are maintained by the ISCV (Idle Stabilisation Control Valve). However, Motronic does make small adjustments to the idle.

 

I installed a ProMax 7100 when I was in Colorado, and I really enjoyed the improvement at high altitude. My favorite drive was from Ridgway to Telluride. You get about 20 miles of good quality road, with altitudes ranging from 7000 to 9000, and the 968 was an absolute blast.

 

Mine came with a promax.

 

i purchased a promax 7700 chip, which i had for a a short while before i upgraded to an RS Barn Stage 2 chip after installing the header, and then eventually a custom map & dyno Tune. Promax makes an Awesome chip.

 

Do you really mean 2D or is it 3D with the third dimension being the ignition value?

That aside, what I thought was over ignitioned cold start map was my Head Gasket going pop

 

Hi James,

The idle and WOT maps are 2D; the partial load is effectively 3D when you factor in the AFM/MAF signal.

Regards,
Andrew

 

Moook, I'm interested in the chip!

 

Sorry Arash, but ive got another "project" that i might just use it in....

 

no worries