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spuggy spuggy is offline
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Join Date: Jul 2003
Location: Glorious Pac NW
Posts: 2,831
Originally Posted by billjam View Post
Keeping in mind that I'm not hunting big horsepower (= not wanting to spend mega bucks) but just wanting to improve low range performance, it looks like SC cams might be a better option
SC cams and more compression both help low/mid range. Raising compression will, limit the boost you can run or lower the safety margin for stock boost levels. An issue for very hot climates, track days or both...

The motor loves advance off-boost. 2-3 degrees will make a huge difference to drivability. If you're running stock ignition, make sure you're getting the advance the factory intended.

Twin-plug it whilst it's apart, you can add the rest later. When complete, you run more advance, because twin plugs provides faster/better combustion.

Some like the MSD CDI boxes because they fire the plugs multiple times below 3,000 RPM, and let you run bigger plug gaps for a hotter, fatter spark.

Fitting a 5-speed box will transform the car's off-boost performance. So will losing 500 pounds in weight...

I already have a K27 7200 turbo and larger intercooler ready to fit. (Its a B6 and yes, I have already gone through the pain of fitting it to my other car so I have all the fitting problems sorted! I am just swapping it between cars.)

Spuggy suggests "good headers, intercooler and a decent modern turbo". I'm not sure that the K27 7200 fits the bill but it's got to better than the standard issue.
As far as headers are concerned, I do have a set of new "Going Super Fast" headers available to me at a good price. We are getting off the topic of inlet spacers, but if there's any opinions about the merits (or otherwise) of these headers compared to Euro headers, I'd be interested to hear them.
K27/7200 is stock late fitment. Better than 3DLZ. Better still are the hybrid K27/S, K27/HF or K27/HFS, as these spool faster and push more air. Many threads here on the merits of these and many other turbos.

Factory headers will support up to 400 HP just fine, but most aftermarket headers allow the turbo to spool faster. Some older designs cause over-boosting (as much as .3 or .4 bar over settings) with higher-flowing turbos and the stock wastegate.

Many threads here on headers. Me, I don't quite understand why some are so keen on headers built down to a price (and from unidentifiable material) and potentially full of weld slag when wiping out a turbo with FOD would eat your cost savings in a heartbeat. GHLs are very nice, and so is the SSI alternative recently developed by board members here.

Despite flowing more air, the modern K27 variants apparently heat up the intake charge less. And thus to the intercooler. I've never seen flow, inlet/outlet temps or pressure drop figures posted for the B6 intercooler in any variant, either half- or full-bay. Hmmm..

Kokeln's figures are here:
'77 S with '78 930 power and a few other things.
Old 07-05-2008, 02:06 AM
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