Result of Modifications to my '88 930

[73ess]

Looking through the old service records for my 88 930, I have discovered that the first owner had a shop install the following cams, in place of the originals in June of 1993, when the car had only 15,700 miles on it:

105 246 09 964 - C2/4 camshaft (right)
105 247 07 964 - C2/4 camshaft (left)

So I'm assuming these are stock 964 Turbo cams?

In addition to these cams being installed, the following was done at the same time:

CUSTOM MACHINE WORK
Performance valve job, including guides (tapered high flow) and surfacing heads. Convert heads for twin plug set up and port. Port match intake manifold and injector spacer blocks.

ENGINE VALVE OVERHAUL
Sublet heads for head surfacing, valve grinding, valve lapping and mating. Assemble fuel injection system, install new (93) fuel pressure regulator & set air flow box. Install TEC-1 Dual Plug Kit and wire as needed.

INSTALL Garretson Intercooler, K27-7006 turbocharger and GHL exhaust system.

So I'd like to know specifically what effect these modifications have over a stock 883.3 930? More HP? Or no HP change, just improved response and powerband moved higher up in the rpm range?

Oh, also, I'm really curious what effect these modifications have on smog emissions? Wouldn't the twin plug setup ensure a cleaner burn?

[RarlyL8]

Those are 964 cams, not 965.
K27-7006 is a top end turbo.
Twin plugs create better burn and move the detonation threshold up.
965 WUR has more inputs than '88 such as altitude compensation.
Intercooler will cool intake charge for free HP and allow use of higher boost.
Headers will aid in driveability and facilitate all other modifications.
This setup is very typical and should add 100HP on the top end. Boost probably is not all in until after 3000rpm. Affect on emissions has more to do with tuning than modifications.

[lucittm]

73,
I show that P/N 964-105-247-07 is the left cam and 964-105-246-09 is the right cam for a 3.6L NA 964. Those are desirable cams because of their longer duration, not sure about the lift specs. Turbo cams normally have a 930 part number. However, any cam can be a regrind, so you have to be careful. Most camgrinders will stamp their numbers on the cam, though.

I don't know how the cam would effect smog emissions unless there was some lobe overlap that caused some unburned fuel to exit into the exhaust system especially at idle. You have a catalytic converter? The twin plug heads and ignition may slightly improve the burn but I have never seen a before and after smog check to know for sure.

It sounds like you have a nice engine there.

Mark

[AFM744]

That's pretty much my build, and I passed CA smog fine.
Brian's right, those mods should be good for >100hp. I put down 354whp (probably 425 crank) last month with my stock K27/7200 on a very hot day.

[73ess]

Thanks for the info guys. Wow, I didn't think these mods would add that much HP. So 100HP above the stock 3.3 rating? So I guess I've got close to 400HP at the crank?

So which of the mods adds the most HP?

The engine feels very strong above 4500 rpm. I just took it on an 800 mile road trip, after changing all the W3DPO spark plugs. Pricey suckers! Well, actually, I changed 9 of the 12. I can't tell yet just how much stuff I've got to remove to get to the 3 plugs on the left intake manifold.