Those that are running 19+ psi boost; what are you doing for ignition?

 

Stand alone EMS.

 

20lbs on a TecGT.

 

16 psi on 93 octane.

Wideband reading 12.0 -11.8 on boost to redline

 

NGK plugs, Magnecore wires and MSD SS coil.

 

As far as parts go I have the MSD2 and a jacobs coil..NGK plugs etc..

AS far as timing goes.. it is at a max of 24 degrees over 22 psi. Referenced by a 3 bar map sensor wired into one of the extra inputs to the DME. It is very safe so far. I haven't been to the dyno lately to tune it all the way out. We could probably add some timing up top though.

As long as I don't see knock counts I'm happy, and the pressure overcomes timing IMO.

Funny though how these very conversations (thanks Duke) made me re-evaluate my timing technique. Coming from a blower background I was dead set on later spark lead for safety and Now I am seeing that with a turbo the peak is early and the lead can be sooner rather than later as the rpms go up..

anyway rambling...

 

40 on 87 octane



Oh wait, we are not talking about 6.4L diesels are we?

 

Is there an "acceptable" knock count?

 

not a 951, but in my old b5 s4, I was running 27psi and tapered to 23-24 to redline on 93oct

figure I'd share

 

does anyone have a graph showing the approximate boost buildup on a stock 951 with k26/6? i am interested in seeing how much boost there is at lower rpms and when the full ~11lbs comes on.

 

I shoot for 0 but I have had 3 per gear w/o any problems on short bursts.

You do have to pay attention to when they are happening though too. Most I have seen happen when you shift.

You really ned a passenger to pay attn. or use some sort of lighted warning. I also have my Zeitronix logging the output of the KLR signal. It may not be fast enough to catch all of them, but it will catch some, and if shooting for 0 it works OK for me.

 

See, I keep hearing this from all kinds of other people in other non Porsche forums. Plenty of people runnin 20-25psi on pump for years and no issues.

I have a bud locally that has a newer Mach 1 with sc kit and he runs stock compression (10:1) with 20psi on pump for a long time now and now issues........

 

apples to oranges.
Every engine is different. Some engines can run 30-40+ psi on pump or e85.
psi comparisons are pretty useless too if you aren't mentioning what turbo.

I could only manage 15psi on 93oct on my 1.9L ford escort with meth injection without ping.

 

My old 86 951 in Toronto ran 21lbs street using 93, with custom chip, 4" exhaust, shimmed WG. Other things were stock. No knock running fine.

Current 89 951 in HK runs 16lbs using 98, ProMax951 chip (can reach max 1.2bar), wideband, 3" exhaust, HKS EVC set at 16lbs, I love it!!!!!

 

Looking forward to the results with the new timing strategy