[spuggy]

Originally Posted by mikedsilva

Stock headers with J Pipe.

Aftermarket headers would probably improve response/spool quite a lot...

Originally Posted by mikedsilva

EFI using 3.2 manifolds

Don't forget a non-return valve if you retained the IAC, else it'll be leaking boost through that...

If you don't have an IAC, you'll probably be fitting one eventually. I know I've concluded it's the only way to get the warmup behavior I would prefer..

Originally Posted by mikedsilva

Wastegate is Tial F46P with 0.5 Bar Spring

A 0.5 bar spring will be wide open at 0.5 bar - and in practice will crack off the seat long before the rated pressure, it's IMHO way too soft to hold a large wastegate closed.

When I ran the same wastegate with a 0.5 bar spring w/ boost control, it leaked boost like crazy - as demonstrated by a 0.8 bar spring making a night and day difference to spool. My BOV dumps boost between shifts now if I run RPMs up with almost no load at all.

Running a higher spring pressure not an option with a low-boost setup of course. And complicated by the fact that with a 3-port MAC, you can only rely on spring pressure to keep it closed.

However, if you use a 4-port MAC, you can utilize diverted boost to augment spring pressure to keep it closed until the desired setting is achieved.

I think that'd help a low-boost setup significantly. You need to make the most of what you can use.

Originally Posted by mikedsilva

Looking at Spuggy's map above, I think I might be quite conservative?

Heh. I was reading Juan's account of how much boost he runs recently, and thinking "I don't need 700+ WHP exactly - but maybe a 1.2 bar target is kind of wimpy..." Followed by "I should fit that GTX35R sometime..." LOL. It's just hard to get motivated to take the car apart when it already runs pretty darned sweet...

26 degrees on boost is factory timing for a RoW 930/60 - it'll hit that figure as soon as any boost at all gets done backing out all the mech advance imparted by the vacuum pot. I run knock control, and never saw knock under boost (touch wood). So that' seems to be in the ballpark of conservative.

I ran 35 degrees of timing off-boost single-plugged on CIS. Huge improvement in response/pickup over factory timing - especially low/mid-range..

For mid-range - and especially low-load cruise - you should be able to run plenty of timing. It should snarl along sounding kind of angry - and give you loads of response.

Pretty sure the factory were simply (a) conservative and (b) working around the limits of what they could do with a distributor and the advance curve.

Look at 3.2 or 964/993 (remember these are twin-plugged) ignition maps for the N/A portion - and remember those are factory maps.

But every motor is different, they don't all respond the same - so listen to what it's telling you.

A guy posted his ignition map, similar motor build/spec to mine on paper - apparently the result of a pro-dyno tune for maximum power, no knock and optimal CHTs. Much more conservative timings than mine, but I tried it anyway. For me, it was not an improvement in any way and it did not stay loaded long...

Originally Posted by mikedsilva

Also, I'm pretty sure his motor is twin plugged where mine is single...

Yeh, twin-plugged/COP 3.4 with 8:1 J&Es, thermal coatings from the piston crowns to the turbine flange...

Full-size plugs on the bottom because they pull more heat out of the combustion chamber than the smaller ones. Still running 3DPOs because they're insanely cold - plus I've yet to foul a single one, ever, even running pig rich with (spit) CIS in town in the dark ages... In fact, 6-10mpg stoplight-to-stoplight (exactly the same as the track) was a big motivator to go EFI. That and the typical "going lean over 5K" problem.